| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Jake Oshins | 7356 | 61.21% | 2 | 2.99% |
| Dexuan Cui | 2305 | 19.18% | 26 | 38.81% |
| Long Li | 1028 | 8.55% | 5 | 7.46% |
| Jork Loeser | 684 | 5.69% | 4 | 5.97% |
| Haiyang Zhang | 229 | 1.91% | 3 | 4.48% |
| Stephen Hemminger | 205 | 1.71% | 5 | 7.46% |
| Maya Nakamura | 56 | 0.47% | 2 | 2.99% |
| Marc Zyngier | 40 | 0.33% | 1 | 1.49% |
| Vitaly Kuznetsov | 37 | 0.31% | 5 | 7.46% |
| Cathy Avery | 24 | 0.20% | 1 | 1.49% |
| Wei Yongjun | 12 | 0.10% | 2 | 2.99% |
| Elena Reshetova | 9 | 0.07% | 1 | 1.49% |
| Boqun Feng | 8 | 0.07% | 2 | 2.99% |
| K. Y. Srinivasan | 8 | 0.07% | 2 | 2.99% |
| Denis Efremov | 5 | 0.04% | 1 | 1.49% |
| Gustavo A. R. Silva | 4 | 0.03% | 1 | 1.49% |
| Nicolai Stange | 3 | 0.02% | 1 | 1.49% |
| Tobias Klauser | 2 | 0.02% | 1 | 1.49% |
| Björn Helgaas | 2 | 0.02% | 1 | 1.49% |
| Jia-Ju Bai | 1 | 0.01% | 1 | 1.49% |
| Total | 12018 | 67 |
// SPDX-License-Identifier: GPL-2.0 /* * Copyright (c) Microsoft Corporation. * * Author: * Jake Oshins <jakeo@microsoft.com> * * This driver acts as a paravirtual front-end for PCI Express root buses. * When a PCI Express function (either an entire device or an SR-IOV * Virtual Function) is being passed through to the VM, this driver exposes * a new bus to the guest VM. This is modeled as a root PCI bus because * no bridges are being exposed to the VM. In fact, with a "Generation 2" * VM within Hyper-V, there may seem to be no PCI bus at all in the VM * until a device as been exposed using this driver. * * Each root PCI bus has its own PCI domain, which is called "Segment" in * the PCI Firmware Specifications. Thus while each device passed through * to the VM using this front-end will appear at "device 0", the domain will * be unique. Typically, each bus will have one PCI function on it, though * this driver does support more than one. * * In order to map the interrupts from the device through to the guest VM, * this driver also implements an IRQ Domain, which handles interrupts (either * MSI or MSI-X) associated with the functions on the bus. As interrupts are * set up, torn down, or reaffined, this driver communicates with the * underlying hypervisor to adjust the mappings in the I/O MMU so that each * interrupt will be delivered to the correct virtual processor at the right * vector. This driver does not support level-triggered (line-based) * interrupts, and will report that the Interrupt Line register in the * function's configuration space is zero. * * The rest of this driver mostly maps PCI concepts onto underlying Hyper-V * facilities. For instance, the configuration space of a function exposed * by Hyper-V is mapped into a single page of memory space, and the * read and write handlers for config space must be aware of this mechanism. * Similarly, device setup and teardown involves messages sent to and from * the PCI back-end driver in Hyper-V. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/delay.h> #include <linux/semaphore.h> #include <linux/irqdomain.h> #include <asm/irqdomain.h> #include <asm/apic.h> #include <linux/irq.h> #include <linux/msi.h> #include <linux/hyperv.h> #include <linux/refcount.h> #include <asm/mshyperv.h> /* * Protocol versions. The low word is the minor version, the high word the * major version. */ #define PCI_MAKE_VERSION(major, minor) ((u32)(((major) << 16) | (minor))) #define PCI_MAJOR_VERSION(version) ((u32)(version) >> 16) #define PCI_MINOR_VERSION(version) ((u32)(version) & 0xff) enum pci_protocol_version_t { PCI_PROTOCOL_VERSION_1_1 = PCI_MAKE_VERSION(1, 1), /* Win10 */ PCI_PROTOCOL_VERSION_1_2 = PCI_MAKE_VERSION(1, 2), /* RS1 */ PCI_PROTOCOL_VERSION_1_3 = PCI_MAKE_VERSION(1, 3), /* Vibranium */ }; #define CPU_AFFINITY_ALL -1ULL /* * Supported protocol versions in the order of probing - highest go * first. */ static enum pci_protocol_version_t pci_protocol_versions[] = { PCI_PROTOCOL_VERSION_1_3, PCI_PROTOCOL_VERSION_1_2, PCI_PROTOCOL_VERSION_1_1, }; #define PCI_CONFIG_MMIO_LENGTH 0x2000 #define CFG_PAGE_OFFSET 0x1000 #define CFG_PAGE_SIZE (PCI_CONFIG_MMIO_LENGTH - CFG_PAGE_OFFSET) #define MAX_SUPPORTED_MSI_MESSAGES 0x400 #define STATUS_REVISION_MISMATCH 0xC0000059 /* space for 32bit serial number as string */ #define SLOT_NAME_SIZE 11 /* * Message Types */ enum pci_message_type { /* * Version 1.1 */ PCI_MESSAGE_BASE = 0x42490000, PCI_BUS_RELATIONS = PCI_MESSAGE_BASE + 0, PCI_QUERY_BUS_RELATIONS = PCI_MESSAGE_BASE + 1, PCI_POWER_STATE_CHANGE = PCI_MESSAGE_BASE + 4, PCI_QUERY_RESOURCE_REQUIREMENTS = PCI_MESSAGE_BASE + 5, PCI_QUERY_RESOURCE_RESOURCES = PCI_MESSAGE_BASE + 6, PCI_BUS_D0ENTRY = PCI_MESSAGE_BASE + 7, PCI_BUS_D0EXIT = PCI_MESSAGE_BASE + 8, PCI_READ_BLOCK = PCI_MESSAGE_BASE + 9, PCI_WRITE_BLOCK = PCI_MESSAGE_BASE + 0xA, PCI_EJECT = PCI_MESSAGE_BASE + 0xB, PCI_QUERY_STOP = PCI_MESSAGE_BASE + 0xC, PCI_REENABLE = PCI_MESSAGE_BASE + 0xD, PCI_QUERY_STOP_FAILED = PCI_MESSAGE_BASE + 0xE, PCI_EJECTION_COMPLETE = PCI_MESSAGE_BASE + 0xF, PCI_RESOURCES_ASSIGNED = PCI_MESSAGE_BASE + 0x10, PCI_RESOURCES_RELEASED = PCI_MESSAGE_BASE + 0x11, PCI_INVALIDATE_BLOCK = PCI_MESSAGE_BASE + 0x12, PCI_QUERY_PROTOCOL_VERSION = PCI_MESSAGE_BASE + 0x13, PCI_CREATE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x14, PCI_DELETE_INTERRUPT_MESSAGE = PCI_MESSAGE_BASE + 0x15, PCI_RESOURCES_ASSIGNED2 = PCI_MESSAGE_BASE + 0x16, PCI_CREATE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x17, PCI_DELETE_INTERRUPT_MESSAGE2 = PCI_MESSAGE_BASE + 0x18, /* unused */ PCI_BUS_RELATIONS2 = PCI_MESSAGE_BASE + 0x19, PCI_MESSAGE_MAXIMUM }; /* * Structures defining the virtual PCI Express protocol. */ union pci_version { struct { u16 minor_version; u16 major_version; } parts; u32 version; } __packed; /* * Function numbers are 8-bits wide on Express, as interpreted through ARI, * which is all this driver does. This representation is the one used in * Windows, which is what is expected when sending this back and forth with * the Hyper-V parent partition. */ union win_slot_encoding { struct { u32 dev:5; u32 func:3; u32 reserved:24; } bits; u32 slot; } __packed; /* * Pretty much as defined in the PCI Specifications. */ struct pci_function_description { u16 v_id; /* vendor ID */ u16 d_id; /* device ID */ u8 rev; u8 prog_intf; u8 subclass; u8 base_class; u32 subsystem_id; union win_slot_encoding win_slot; u32 ser; /* serial number */ } __packed; enum pci_device_description_flags { HV_PCI_DEVICE_FLAG_NONE = 0x0, HV_PCI_DEVICE_FLAG_NUMA_AFFINITY = 0x1, }; struct pci_function_description2 { u16 v_id; /* vendor ID */ u16 d_id; /* device ID */ u8 rev; u8 prog_intf; u8 subclass; u8 base_class; u32 subsystem_id; union win_slot_encoding win_slot; u32 ser; /* serial number */ u32 flags; u16 virtual_numa_node; u16 reserved; } __packed; /** * struct hv_msi_desc * @vector: IDT entry * @delivery_mode: As defined in Intel's Programmer's * Reference Manual, Volume 3, Chapter 8. * @vector_count: Number of contiguous entries in the * Interrupt Descriptor Table that are * occupied by this Message-Signaled * Interrupt. For "MSI", as first defined * in PCI 2.2, this can be between 1 and * 32. For "MSI-X," as first defined in PCI * 3.0, this must be 1, as each MSI-X table * entry would have its own descriptor. * @reserved: Empty space * @cpu_mask: All the target virtual processors. */ struct hv_msi_desc { u8 vector; u8 delivery_mode; u16 vector_count; u32 reserved; u64 cpu_mask; } __packed; /** * struct hv_msi_desc2 - 1.2 version of hv_msi_desc * @vector: IDT entry * @delivery_mode: As defined in Intel's Programmer's * Reference Manual, Volume 3, Chapter 8. * @vector_count: Number of contiguous entries in the * Interrupt Descriptor Table that are * occupied by this Message-Signaled * Interrupt. For "MSI", as first defined * in PCI 2.2, this can be between 1 and * 32. For "MSI-X," as first defined in PCI * 3.0, this must be 1, as each MSI-X table * entry would have its own descriptor. * @processor_count: number of bits enabled in array. * @processor_array: All the target virtual processors. */ struct hv_msi_desc2 { u8 vector; u8 delivery_mode; u16 vector_count; u16 processor_count; u16 processor_array[32]; } __packed; /** * struct tran_int_desc * @reserved: unused, padding * @vector_count: same as in hv_msi_desc * @data: This is the "data payload" value that is * written by the device when it generates * a message-signaled interrupt, either MSI * or MSI-X. * @address: This is the address to which the data * payload is written on interrupt * generation. */ struct tran_int_desc { u16 reserved; u16 vector_count; u32 data; u64 address; } __packed; /* * A generic message format for virtual PCI. * Specific message formats are defined later in the file. */ struct pci_message { u32 type; } __packed; struct pci_child_message { struct pci_message message_type; union win_slot_encoding wslot; } __packed; struct pci_incoming_message { struct vmpacket_descriptor hdr; struct pci_message message_type; } __packed; struct pci_response { struct vmpacket_descriptor hdr; s32 status; /* negative values are failures */ } __packed; struct pci_packet { void (*completion_func)(void *context, struct pci_response *resp, int resp_packet_size); void *compl_ctxt; struct pci_message message[]; }; /* * Specific message types supporting the PCI protocol. */ /* * Version negotiation message. Sent from the guest to the host. * The guest is free to try different versions until the host * accepts the version. * * pci_version: The protocol version requested. * is_last_attempt: If TRUE, this is the last version guest will request. * reservedz: Reserved field, set to zero. */ struct pci_version_request { struct pci_message message_type; u32 protocol_version; } __packed; /* * Bus D0 Entry. This is sent from the guest to the host when the virtual * bus (PCI Express port) is ready for action. */ struct pci_bus_d0_entry { struct pci_message message_type; u32 reserved; u64 mmio_base; } __packed; struct pci_bus_relations { struct pci_incoming_message incoming; u32 device_count; struct pci_function_description func[]; } __packed; struct pci_bus_relations2 { struct pci_incoming_message incoming; u32 device_count; struct pci_function_description2 func[]; } __packed; struct pci_q_res_req_response { struct vmpacket_descriptor hdr; s32 status; /* negative values are failures */ u32 probed_bar[PCI_STD_NUM_BARS]; } __packed; struct pci_set_power { struct pci_message message_type; union win_slot_encoding wslot; u32 power_state; /* In Windows terms */ u32 reserved; } __packed; struct pci_set_power_response { struct vmpacket_descriptor hdr; s32 status; /* negative values are failures */ union win_slot_encoding wslot; u32 resultant_state; /* In Windows terms */ u32 reserved; } __packed; struct pci_resources_assigned { struct pci_message message_type; union win_slot_encoding wslot; u8 memory_range[0x14][6]; /* not used here */ u32 msi_descriptors; u32 reserved[4]; } __packed; struct pci_resources_assigned2 { struct pci_message message_type; union win_slot_encoding wslot; u8 memory_range[0x14][6]; /* not used here */ u32 msi_descriptor_count; u8 reserved[70]; } __packed; struct pci_create_interrupt { struct pci_message message_type; union win_slot_encoding wslot; struct hv_msi_desc int_desc; } __packed; struct pci_create_int_response { struct pci_response response; u32 reserved; struct tran_int_desc int_desc; } __packed; struct pci_create_interrupt2 { struct pci_message message_type; union win_slot_encoding wslot; struct hv_msi_desc2 int_desc; } __packed; struct pci_delete_interrupt { struct pci_message message_type; union win_slot_encoding wslot; struct tran_int_desc int_desc; } __packed; /* * Note: the VM must pass a valid block id, wslot and bytes_requested. */ struct pci_read_block { struct pci_message message_type; u32 block_id; union win_slot_encoding wslot; u32 bytes_requested; } __packed; struct pci_read_block_response { struct vmpacket_descriptor hdr; u32 status; u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX]; } __packed; /* * Note: the VM must pass a valid block id, wslot and byte_count. */ struct pci_write_block { struct pci_message message_type; u32 block_id; union win_slot_encoding wslot; u32 byte_count; u8 bytes[HV_CONFIG_BLOCK_SIZE_MAX]; } __packed; struct pci_dev_inval_block { struct pci_incoming_message incoming; union win_slot_encoding wslot; u64 block_mask; } __packed; struct pci_dev_incoming { struct pci_incoming_message incoming; union win_slot_encoding wslot; } __packed; struct pci_eject_response { struct pci_message message_type; union win_slot_encoding wslot; u32 status; } __packed; static int pci_ring_size = (4 * PAGE_SIZE); /* * Driver specific state. */ enum hv_pcibus_state { hv_pcibus_init = 0, hv_pcibus_probed, hv_pcibus_installed, hv_pcibus_removing, hv_pcibus_removed, hv_pcibus_maximum }; struct hv_pcibus_device { struct pci_sysdata sysdata; /* Protocol version negotiated with the host */ enum pci_protocol_version_t protocol_version; enum hv_pcibus_state state; refcount_t remove_lock; struct hv_device *hdev; resource_size_t low_mmio_space; resource_size_t high_mmio_space; struct resource *mem_config; struct resource *low_mmio_res; struct resource *high_mmio_res; struct completion *survey_event; struct completion remove_event; struct pci_bus *pci_bus; spinlock_t config_lock; /* Avoid two threads writing index page */ spinlock_t device_list_lock; /* Protect lists below */ void __iomem *cfg_addr; struct list_head resources_for_children; struct list_head children; struct list_head dr_list; struct msi_domain_info msi_info; struct msi_controller msi_chip; struct irq_domain *irq_domain; spinlock_t retarget_msi_interrupt_lock; struct workqueue_struct *wq; /* hypercall arg, must not cross page boundary */ struct hv_retarget_device_interrupt retarget_msi_interrupt_params; /* * Don't put anything here: retarget_msi_interrupt_params must be last */ }; /* * Tracks "Device Relations" messages from the host, which must be both * processed in order and deferred so that they don't run in the context * of the incoming packet callback. */ struct hv_dr_work { struct work_struct wrk; struct hv_pcibus_device *bus; }; struct hv_pcidev_description { u16 v_id; /* vendor ID */ u16 d_id; /* device ID */ u8 rev; u8 prog_intf; u8 subclass; u8 base_class; u32 subsystem_id; union win_slot_encoding win_slot; u32 ser; /* serial number */ u32 flags; u16 virtual_numa_node; }; struct hv_dr_state { struct list_head list_entry; u32 device_count; struct hv_pcidev_description func[]; }; enum hv_pcichild_state { hv_pcichild_init = 0, hv_pcichild_requirements, hv_pcichild_resourced, hv_pcichild_ejecting, hv_pcichild_maximum }; struct hv_pci_dev { /* List protected by pci_rescan_remove_lock */ struct list_head list_entry; refcount_t refs; enum hv_pcichild_state state; struct pci_slot *pci_slot; struct hv_pcidev_description desc; bool reported_missing; struct hv_pcibus_device *hbus; struct work_struct wrk; void (*block_invalidate)(void *context, u64 block_mask); void *invalidate_context; /* * What would be observed if one wrote 0xFFFFFFFF to a BAR and then * read it back, for each of the BAR offsets within config space. */ u32 probed_bar[PCI_STD_NUM_BARS]; }; struct hv_pci_compl { struct completion host_event; s32 completion_status; }; static void hv_pci_onchannelcallback(void *context); /** * hv_pci_generic_compl() - Invoked for a completion packet * @context: Set up by the sender of the packet. * @resp: The response packet * @resp_packet_size: Size in bytes of the packet * * This function is used to trigger an event and report status * for any message for which the completion packet contains a * status and nothing else. */ static void hv_pci_generic_compl(void *context, struct pci_response *resp, int resp_packet_size) { struct hv_pci_compl *comp_pkt = context; if (resp_packet_size >= offsetofend(struct pci_response, status)) comp_pkt->completion_status = resp->status; else comp_pkt->completion_status = -1; complete(&comp_pkt->host_event); } static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, u32 wslot); static void get_pcichild(struct hv_pci_dev *hpdev) { refcount_inc(&hpdev->refs); } static void put_pcichild(struct hv_pci_dev *hpdev) { if (refcount_dec_and_test(&hpdev->refs)) kfree(hpdev); } static void get_hvpcibus(struct hv_pcibus_device *hv_pcibus); static void put_hvpcibus(struct hv_pcibus_device *hv_pcibus); /* * There is no good way to get notified from vmbus_onoffer_rescind(), * so let's use polling here, since this is not a hot path. */ static int wait_for_response(struct hv_device *hdev, struct completion *comp) { while (true) { if (hdev->channel->rescind) { dev_warn_once(&hdev->device, "The device is gone.\n"); return -ENODEV; } if (wait_for_completion_timeout(comp, HZ / 10)) break; } return 0; } /** * devfn_to_wslot() - Convert from Linux PCI slot to Windows * @devfn: The Linux representation of PCI slot * * Windows uses a slightly different representation of PCI slot. * * Return: The Windows representation */ static u32 devfn_to_wslot(int devfn) { union win_slot_encoding wslot; wslot.slot = 0; wslot.bits.dev = PCI_SLOT(devfn); wslot.bits.func = PCI_FUNC(devfn); return wslot.slot; } /** * wslot_to_devfn() - Convert from Windows PCI slot to Linux * @wslot: The Windows representation of PCI slot * * Windows uses a slightly different representation of PCI slot. * * Return: The Linux representation */ static int wslot_to_devfn(u32 wslot) { union win_slot_encoding slot_no; slot_no.slot = wslot; return PCI_DEVFN(slot_no.bits.dev, slot_no.bits.func); } /* * PCI Configuration Space for these root PCI buses is implemented as a pair * of pages in memory-mapped I/O space. Writing to the first page chooses * the PCI function being written or read. Once the first page has been * written to, the following page maps in the entire configuration space of * the function. */ /** * _hv_pcifront_read_config() - Internal PCI config read * @hpdev: The PCI driver's representation of the device * @where: Offset within config space * @size: Size of the transfer * @val: Pointer to the buffer receiving the data */ static void _hv_pcifront_read_config(struct hv_pci_dev *hpdev, int where, int size, u32 *val) { unsigned long flags; void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; /* * If the attempt is to read the IDs or the ROM BAR, simulate that. */ if (where + size <= PCI_COMMAND) { memcpy(val, ((u8 *)&hpdev->desc.v_id) + where, size); } else if (where >= PCI_CLASS_REVISION && where + size <= PCI_CACHE_LINE_SIZE) { memcpy(val, ((u8 *)&hpdev->desc.rev) + where - PCI_CLASS_REVISION, size); } else if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <= PCI_ROM_ADDRESS) { memcpy(val, (u8 *)&hpdev->desc.subsystem_id + where - PCI_SUBSYSTEM_VENDOR_ID, size); } else if (where >= PCI_ROM_ADDRESS && where + size <= PCI_CAPABILITY_LIST) { /* ROM BARs are unimplemented */ *val = 0; } else if (where >= PCI_INTERRUPT_LINE && where + size <= PCI_INTERRUPT_PIN) { /* * Interrupt Line and Interrupt PIN are hard-wired to zero * because this front-end only supports message-signaled * interrupts. */ *val = 0; } else if (where + size <= CFG_PAGE_SIZE) { spin_lock_irqsave(&hpdev->hbus->config_lock, flags); /* Choose the function to be read. (See comment above) */ writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); /* Make sure the function was chosen before we start reading. */ mb(); /* Read from that function's config space. */ switch (size) { case 1: *val = readb(addr); break; case 2: *val = readw(addr); break; default: *val = readl(addr); break; } /* * Make sure the read was done before we release the spinlock * allowing consecutive reads/writes. */ mb(); spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); } else { dev_err(&hpdev->hbus->hdev->device, "Attempt to read beyond a function's config space.\n"); } } static u16 hv_pcifront_get_vendor_id(struct hv_pci_dev *hpdev) { u16 ret; unsigned long flags; void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + PCI_VENDOR_ID; spin_lock_irqsave(&hpdev->hbus->config_lock, flags); /* Choose the function to be read. (See comment above) */ writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); /* Make sure the function was chosen before we start reading. */ mb(); /* Read from that function's config space. */ ret = readw(addr); /* * mb() is not required here, because the spin_unlock_irqrestore() * is a barrier. */ spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); return ret; } /** * _hv_pcifront_write_config() - Internal PCI config write * @hpdev: The PCI driver's representation of the device * @where: Offset within config space * @size: Size of the transfer * @val: The data being transferred */ static void _hv_pcifront_write_config(struct hv_pci_dev *hpdev, int where, int size, u32 val) { unsigned long flags; void __iomem *addr = hpdev->hbus->cfg_addr + CFG_PAGE_OFFSET + where; if (where >= PCI_SUBSYSTEM_VENDOR_ID && where + size <= PCI_CAPABILITY_LIST) { /* SSIDs and ROM BARs are read-only */ } else if (where >= PCI_COMMAND && where + size <= CFG_PAGE_SIZE) { spin_lock_irqsave(&hpdev->hbus->config_lock, flags); /* Choose the function to be written. (See comment above) */ writel(hpdev->desc.win_slot.slot, hpdev->hbus->cfg_addr); /* Make sure the function was chosen before we start writing. */ wmb(); /* Write to that function's config space. */ switch (size) { case 1: writeb(val, addr); break; case 2: writew(val, addr); break; default: writel(val, addr); break; } /* * Make sure the write was done before we release the spinlock * allowing consecutive reads/writes. */ mb(); spin_unlock_irqrestore(&hpdev->hbus->config_lock, flags); } else { dev_err(&hpdev->hbus->hdev->device, "Attempt to write beyond a function's config space.\n"); } } /** * hv_pcifront_read_config() - Read configuration space * @bus: PCI Bus structure * @devfn: Device/function * @where: Offset from base * @size: Byte/word/dword * @val: Value to be read * * Return: PCIBIOS_SUCCESSFUL on success * PCIBIOS_DEVICE_NOT_FOUND on failure */ static int hv_pcifront_read_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val) { struct hv_pcibus_device *hbus = container_of(bus->sysdata, struct hv_pcibus_device, sysdata); struct hv_pci_dev *hpdev; hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); if (!hpdev) return PCIBIOS_DEVICE_NOT_FOUND; _hv_pcifront_read_config(hpdev, where, size, val); put_pcichild(hpdev); return PCIBIOS_SUCCESSFUL; } /** * hv_pcifront_write_config() - Write configuration space * @bus: PCI Bus structure * @devfn: Device/function * @where: Offset from base * @size: Byte/word/dword * @val: Value to be written to device * * Return: PCIBIOS_SUCCESSFUL on success * PCIBIOS_DEVICE_NOT_FOUND on failure */ static int hv_pcifront_write_config(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val) { struct hv_pcibus_device *hbus = container_of(bus->sysdata, struct hv_pcibus_device, sysdata); struct hv_pci_dev *hpdev; hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(devfn)); if (!hpdev) return PCIBIOS_DEVICE_NOT_FOUND; _hv_pcifront_write_config(hpdev, where, size, val); put_pcichild(hpdev); return PCIBIOS_SUCCESSFUL; } /* PCIe operations */ static struct pci_ops hv_pcifront_ops = { .read = hv_pcifront_read_config, .write = hv_pcifront_write_config, }; /* * Paravirtual backchannel * * Hyper-V SR-IOV provides a backchannel mechanism in software for * communication between a VF driver and a PF driver. These * "configuration blocks" are similar in concept to PCI configuration space, * but instead of doing reads and writes in 32-bit chunks through a very slow * path, packets of up to 128 bytes can be sent or received asynchronously. * * Nearly every SR-IOV device contains just such a communications channel in * hardware, so using this one in software is usually optional. Using the * software channel, however, allows driver implementers to leverage software * tools that fuzz the communications channel looking for vulnerabilities. * * The usage model for these packets puts the responsibility for reading or * writing on the VF driver. The VF driver sends a read or a write packet, * indicating which "block" is being referred to by number. * * If the PF driver wishes to initiate communication, it can "invalidate" one or * more of the first 64 blocks. This invalidation is delivered via a callback * supplied by the VF driver by this driver. * * No protocol is implied, except that supplied by the PF and VF drivers. */ struct hv_read_config_compl { struct hv_pci_compl comp_pkt; void *buf; unsigned int len; unsigned int bytes_returned; }; /** * hv_pci_read_config_compl() - Invoked when a response packet * for a read config block operation arrives. * @context: Identifies the read config operation * @resp: The response packet itself * @resp_packet_size: Size in bytes of the response packet */ static void hv_pci_read_config_compl(void *context, struct pci_response *resp, int resp_packet_size) { struct hv_read_config_compl *comp = context; struct pci_read_block_response *read_resp = (struct pci_read_block_response *)resp; unsigned int data_len, hdr_len; hdr_len = offsetof(struct pci_read_block_response, bytes); if (resp_packet_size < hdr_len) { comp->comp_pkt.completion_status = -1; goto out; } data_len = resp_packet_size - hdr_len; if (data_len > 0 && read_resp->status == 0) { comp->bytes_returned = min(comp->len, data_len); memcpy(comp->buf, read_resp->bytes, comp->bytes_returned); } else { comp->bytes_returned = 0; } comp->comp_pkt.completion_status = read_resp->status; out: complete(&comp->comp_pkt.host_event); } /** * hv_read_config_block() - Sends a read config block request to * the back-end driver running in the Hyper-V parent partition. * @pdev: The PCI driver's representation for this device. * @buf: Buffer into which the config block will be copied. * @len: Size in bytes of buf. * @block_id: Identifies the config block which has been requested. * @bytes_returned: Size which came back from the back-end driver. * * Return: 0 on success, -errno on failure */ int hv_read_config_block(struct pci_dev *pdev, void *buf, unsigned int len, unsigned int block_id, unsigned int *bytes_returned) { struct hv_pcibus_device *hbus = container_of(pdev->bus->sysdata, struct hv_pcibus_device, sysdata); struct { struct pci_packet pkt; char buf[sizeof(struct pci_read_block)]; } pkt; struct hv_read_config_compl comp_pkt; struct pci_read_block *read_blk; int ret; if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX) return -EINVAL; init_completion(&comp_pkt.comp_pkt.host_event); comp_pkt.buf = buf; comp_pkt.len = len; memset(&pkt, 0, sizeof(pkt)); pkt.pkt.completion_func = hv_pci_read_config_compl; pkt.pkt.compl_ctxt = &comp_pkt; read_blk = (struct pci_read_block *)&pkt.pkt.message; read_blk->message_type.type = PCI_READ_BLOCK; read_blk->wslot.slot = devfn_to_wslot(pdev->devfn); read_blk->block_id = block_id; read_blk->bytes_requested = len; ret = vmbus_sendpacket(hbus->hdev->channel, read_blk, sizeof(*read_blk), (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) return ret; ret = wait_for_response(hbus->hdev, &comp_pkt.comp_pkt.host_event); if (ret) return ret; if (comp_pkt.comp_pkt.completion_status != 0 || comp_pkt.bytes_returned == 0) { dev_err(&hbus->hdev->device, "Read Config Block failed: 0x%x, bytes_returned=%d\n", comp_pkt.comp_pkt.completion_status, comp_pkt.bytes_returned); return -EIO; } *bytes_returned = comp_pkt.bytes_returned; return 0; } /** * hv_pci_write_config_compl() - Invoked when a response packet for a write * config block operation arrives. * @context: Identifies the write config operation * @resp: The response packet itself * @resp_packet_size: Size in bytes of the response packet */ static void hv_pci_write_config_compl(void *context, struct pci_response *resp, int resp_packet_size) { struct hv_pci_compl *comp_pkt = context; comp_pkt->completion_status = resp->status; complete(&comp_pkt->host_event); } /** * hv_write_config_block() - Sends a write config block request to the * back-end driver running in the Hyper-V parent partition. * @pdev: The PCI driver's representation for this device. * @buf: Buffer from which the config block will be copied. * @len: Size in bytes of buf. * @block_id: Identifies the config block which is being written. * * Return: 0 on success, -errno on failure */ int hv_write_config_block(struct pci_dev *pdev, void *buf, unsigned int len, unsigned int block_id) { struct hv_pcibus_device *hbus = container_of(pdev->bus->sysdata, struct hv_pcibus_device, sysdata); struct { struct pci_packet pkt; char buf[sizeof(struct pci_write_block)]; u32 reserved; } pkt; struct hv_pci_compl comp_pkt; struct pci_write_block *write_blk; u32 pkt_size; int ret; if (len == 0 || len > HV_CONFIG_BLOCK_SIZE_MAX) return -EINVAL; init_completion(&comp_pkt.host_event); memset(&pkt, 0, sizeof(pkt)); pkt.pkt.completion_func = hv_pci_write_config_compl; pkt.pkt.compl_ctxt = &comp_pkt; write_blk = (struct pci_write_block *)&pkt.pkt.message; write_blk->message_type.type = PCI_WRITE_BLOCK; write_blk->wslot.slot = devfn_to_wslot(pdev->devfn); write_blk->block_id = block_id; write_blk->byte_count = len; memcpy(write_blk->bytes, buf, len); pkt_size = offsetof(struct pci_write_block, bytes) + len; /* * This quirk is required on some hosts shipped around 2018, because * these hosts don't check the pkt_size correctly (new hosts have been * fixed since early 2019). The quirk is also safe on very old hosts * and new hosts, because, on them, what really matters is the length * specified in write_blk->byte_count. */ pkt_size += sizeof(pkt.reserved); ret = vmbus_sendpacket(hbus->hdev->channel, write_blk, pkt_size, (unsigned long)&pkt.pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) return ret; ret = wait_for_response(hbus->hdev, &comp_pkt.host_event); if (ret) return ret; if (comp_pkt.completion_status != 0) { dev_err(&hbus->hdev->device, "Write Config Block failed: 0x%x\n", comp_pkt.completion_status); return -EIO; } return 0; } /** * hv_register_block_invalidate() - Invoked when a config block invalidation * arrives from the back-end driver. * @pdev: The PCI driver's representation for this device. * @context: Identifies the device. * @block_invalidate: Identifies all of the blocks being invalidated. * * Return: 0 on success, -errno on failure */ int hv_register_block_invalidate(struct pci_dev *pdev, void *context, void (*block_invalidate)(void *context, u64 block_mask)) { struct hv_pcibus_device *hbus = container_of(pdev->bus->sysdata, struct hv_pcibus_device, sysdata); struct hv_pci_dev *hpdev; hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); if (!hpdev) return -ENODEV; hpdev->block_invalidate = block_invalidate; hpdev->invalidate_context = context; put_pcichild(hpdev); return 0; } /* Interrupt management hooks */ static void hv_int_desc_free(struct hv_pci_dev *hpdev, struct tran_int_desc *int_desc) { struct pci_delete_interrupt *int_pkt; struct { struct pci_packet pkt; u8 buffer[sizeof(struct pci_delete_interrupt)]; } ctxt; memset(&ctxt, 0, sizeof(ctxt)); int_pkt = (struct pci_delete_interrupt *)&ctxt.pkt.message; int_pkt->message_type.type = PCI_DELETE_INTERRUPT_MESSAGE; int_pkt->wslot.slot = hpdev->desc.win_slot.slot; int_pkt->int_desc = *int_desc; vmbus_sendpacket(hpdev->hbus->hdev->channel, int_pkt, sizeof(*int_pkt), (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0); kfree(int_desc); } /** * hv_msi_free() - Free the MSI. * @domain: The interrupt domain pointer * @info: Extra MSI-related context * @irq: Identifies the IRQ. * * The Hyper-V parent partition and hypervisor are tracking the * messages that are in use, keeping the interrupt redirection * table up to date. This callback sends a message that frees * the IRT entry and related tracking nonsense. */ static void hv_msi_free(struct irq_domain *domain, struct msi_domain_info *info, unsigned int irq) { struct hv_pcibus_device *hbus; struct hv_pci_dev *hpdev; struct pci_dev *pdev; struct tran_int_desc *int_desc; struct irq_data *irq_data = irq_domain_get_irq_data(domain, irq); struct msi_desc *msi = irq_data_get_msi_desc(irq_data); pdev = msi_desc_to_pci_dev(msi); hbus = info->data; int_desc = irq_data_get_irq_chip_data(irq_data); if (!int_desc) return; irq_data->chip_data = NULL; hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); if (!hpdev) { kfree(int_desc); return; } hv_int_desc_free(hpdev, int_desc); put_pcichild(hpdev); } static int hv_set_affinity(struct irq_data *data, const struct cpumask *dest, bool force) { struct irq_data *parent = data->parent_data; return parent->chip->irq_set_affinity(parent, dest, force); } static void hv_irq_mask(struct irq_data *data) { pci_msi_mask_irq(data); } /** * hv_irq_unmask() - "Unmask" the IRQ by setting its current * affinity. * @data: Describes the IRQ * * Build new a destination for the MSI and make a hypercall to * update the Interrupt Redirection Table. "Device Logical ID" * is built out of this PCI bus's instance GUID and the function * number of the device. */ static void hv_irq_unmask(struct irq_data *data) { struct msi_desc *msi_desc = irq_data_get_msi_desc(data); struct irq_cfg *cfg = irqd_cfg(data); struct hv_retarget_device_interrupt *params; struct hv_pcibus_device *hbus; struct cpumask *dest; cpumask_var_t tmp; struct pci_bus *pbus; struct pci_dev *pdev; unsigned long flags; u32 var_size = 0; int cpu, nr_bank; u64 res; dest = irq_data_get_effective_affinity_mask(data); pdev = msi_desc_to_pci_dev(msi_desc); pbus = pdev->bus; hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); spin_lock_irqsave(&hbus->retarget_msi_interrupt_lock, flags); params = &hbus->retarget_msi_interrupt_params; memset(params, 0, sizeof(*params)); params->partition_id = HV_PARTITION_ID_SELF; params->int_entry.source = 1; /* MSI(-X) */ hv_set_msi_entry_from_desc(¶ms->int_entry.msi_entry, msi_desc); params->device_id = (hbus->hdev->dev_instance.b[5] << 24) | (hbus->hdev->dev_instance.b[4] << 16) | (hbus->hdev->dev_instance.b[7] << 8) | (hbus->hdev->dev_instance.b[6] & 0xf8) | PCI_FUNC(pdev->devfn); params->int_target.vector = cfg->vector; /* * Honoring apic->irq_delivery_mode set to dest_Fixed by * setting the HV_DEVICE_INTERRUPT_TARGET_MULTICAST flag results in a * spurious interrupt storm. Not doing so does not seem to have a * negative effect (yet?). */ if (hbus->protocol_version >= PCI_PROTOCOL_VERSION_1_2) { /* * PCI_PROTOCOL_VERSION_1_2 supports the VP_SET version of the * HVCALL_RETARGET_INTERRUPT hypercall, which also coincides * with >64 VP support. * ms_hyperv.hints & HV_X64_EX_PROCESSOR_MASKS_RECOMMENDED * is not sufficient for this hypercall. */ params->int_target.flags |= HV_DEVICE_INTERRUPT_TARGET_PROCESSOR_SET; if (!alloc_cpumask_var(&tmp, GFP_ATOMIC)) { res = 1; goto exit_unlock; } cpumask_and(tmp, dest, cpu_online_mask); nr_bank = cpumask_to_vpset(¶ms->int_target.vp_set, tmp); free_cpumask_var(tmp); if (nr_bank <= 0) { res = 1; goto exit_unlock; } /* * var-sized hypercall, var-size starts after vp_mask (thus * vp_set.format does not count, but vp_set.valid_bank_mask * does). */ var_size = 1 + nr_bank; } else { for_each_cpu_and(cpu, dest, cpu_online_mask) { params->int_target.vp_mask |= (1ULL << hv_cpu_number_to_vp_number(cpu)); } } res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17), params, NULL); exit_unlock: spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags); if (res) { dev_err(&hbus->hdev->device, "%s() failed: %#llx", __func__, res); return; } pci_msi_unmask_irq(data); } struct compose_comp_ctxt { struct hv_pci_compl comp_pkt; struct tran_int_desc int_desc; }; static void hv_pci_compose_compl(void *context, struct pci_response *resp, int resp_packet_size) { struct compose_comp_ctxt *comp_pkt = context; struct pci_create_int_response *int_resp = (struct pci_create_int_response *)resp; comp_pkt->comp_pkt.completion_status = resp->status; comp_pkt->int_desc = int_resp->int_desc; complete(&comp_pkt->comp_pkt.host_event); } static u32 hv_compose_msi_req_v1( struct pci_create_interrupt *int_pkt, struct cpumask *affinity, u32 slot, u8 vector) { int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE; int_pkt->wslot.slot = slot; int_pkt->int_desc.vector = vector; int_pkt->int_desc.vector_count = 1; int_pkt->int_desc.delivery_mode = dest_Fixed; /* * Create MSI w/ dummy vCPU set, overwritten by subsequent retarget in * hv_irq_unmask(). */ int_pkt->int_desc.cpu_mask = CPU_AFFINITY_ALL; return sizeof(*int_pkt); } static u32 hv_compose_msi_req_v2( struct pci_create_interrupt2 *int_pkt, struct cpumask *affinity, u32 slot, u8 vector) { int cpu; int_pkt->message_type.type = PCI_CREATE_INTERRUPT_MESSAGE2; int_pkt->wslot.slot = slot; int_pkt->int_desc.vector = vector; int_pkt->int_desc.vector_count = 1; int_pkt->int_desc.delivery_mode = dest_Fixed; /* * Create MSI w/ dummy vCPU set targeting just one vCPU, overwritten * by subsequent retarget in hv_irq_unmask(). */ cpu = cpumask_first_and(affinity, cpu_online_mask); int_pkt->int_desc.processor_array[0] = hv_cpu_number_to_vp_number(cpu); int_pkt->int_desc.processor_count = 1; return sizeof(*int_pkt); } /** * hv_compose_msi_msg() - Supplies a valid MSI address/data * @data: Everything about this MSI * @msg: Buffer that is filled in by this function * * This function unpacks the IRQ looking for target CPU set, IDT * vector and mode and sends a message to the parent partition * asking for a mapping for that tuple in this partition. The * response supplies a data value and address to which that data * should be written to trigger that interrupt. */ static void hv_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) { struct irq_cfg *cfg = irqd_cfg(data); struct hv_pcibus_device *hbus; struct hv_pci_dev *hpdev; struct pci_bus *pbus; struct pci_dev *pdev; struct cpumask *dest; unsigned long flags; struct compose_comp_ctxt comp; struct tran_int_desc *int_desc; struct { struct pci_packet pci_pkt; union { struct pci_create_interrupt v1; struct pci_create_interrupt2 v2; } int_pkts; } __packed ctxt; u32 size; int ret; pdev = msi_desc_to_pci_dev(irq_data_get_msi_desc(data)); dest = irq_data_get_effective_affinity_mask(data); pbus = pdev->bus; hbus = container_of(pbus->sysdata, struct hv_pcibus_device, sysdata); hpdev = get_pcichild_wslot(hbus, devfn_to_wslot(pdev->devfn)); if (!hpdev) goto return_null_message; /* Free any previous message that might have already been composed. */ if (data->chip_data) { int_desc = data->chip_data; data->chip_data = NULL; hv_int_desc_free(hpdev, int_desc); } int_desc = kzalloc(sizeof(*int_desc), GFP_ATOMIC); if (!int_desc) goto drop_reference; memset(&ctxt, 0, sizeof(ctxt)); init_completion(&comp.comp_pkt.host_event); ctxt.pci_pkt.completion_func = hv_pci_compose_compl; ctxt.pci_pkt.compl_ctxt = ∁ switch (hbus->protocol_version) { case PCI_PROTOCOL_VERSION_1_1: size = hv_compose_msi_req_v1(&ctxt.int_pkts.v1, dest, hpdev->desc.win_slot.slot, cfg->vector); break; case PCI_PROTOCOL_VERSION_1_2: case PCI_PROTOCOL_VERSION_1_3: size = hv_compose_msi_req_v2(&ctxt.int_pkts.v2, dest, hpdev->desc.win_slot.slot, cfg->vector); break; default: /* As we only negotiate protocol versions known to this driver, * this path should never hit. However, this is it not a hot * path so we print a message to aid future updates. */ dev_err(&hbus->hdev->device, "Unexpected vPCI protocol, update driver."); goto free_int_desc; } ret = vmbus_sendpacket(hpdev->hbus->hdev->channel, &ctxt.int_pkts, size, (unsigned long)&ctxt.pci_pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) { dev_err(&hbus->hdev->device, "Sending request for interrupt failed: 0x%x", comp.comp_pkt.completion_status); goto free_int_desc; } /* * Since this function is called with IRQ locks held, can't * do normal wait for completion; instead poll. */ while (!try_wait_for_completion(&comp.comp_pkt.host_event)) { /* 0xFFFF means an invalid PCI VENDOR ID. */ if (hv_pcifront_get_vendor_id(hpdev) == 0xFFFF) { dev_err_once(&hbus->hdev->device, "the device has gone\n"); goto free_int_desc; } /* * When the higher level interrupt code calls us with * interrupt disabled, we must poll the channel by calling * the channel callback directly when channel->target_cpu is * the current CPU. When the higher level interrupt code * calls us with interrupt enabled, let's add the * local_irq_save()/restore() to avoid race: * hv_pci_onchannelcallback() can also run in tasklet. */ local_irq_save(flags); if (hbus->hdev->channel->target_cpu == smp_processor_id()) hv_pci_onchannelcallback(hbus); local_irq_restore(flags); if (hpdev->state == hv_pcichild_ejecting) { dev_err_once(&hbus->hdev->device, "the device is being ejected\n"); goto free_int_desc; } udelay(100); } if (comp.comp_pkt.completion_status < 0) { dev_err(&hbus->hdev->device, "Request for interrupt failed: 0x%x", comp.comp_pkt.completion_status); goto free_int_desc; } /* * Record the assignment so that this can be unwound later. Using * irq_set_chip_data() here would be appropriate, but the lock it takes * is already held. */ *int_desc = comp.int_desc; data->chip_data = int_desc; /* Pass up the result. */ msg->address_hi = comp.int_desc.address >> 32; msg->address_lo = comp.int_desc.address & 0xffffffff; msg->data = comp.int_desc.data; put_pcichild(hpdev); return; free_int_desc: kfree(int_desc); drop_reference: put_pcichild(hpdev); return_null_message: msg->address_hi = 0; msg->address_lo = 0; msg->data = 0; } /* HW Interrupt Chip Descriptor */ static struct irq_chip hv_msi_irq_chip = { .name = "Hyper-V PCIe MSI", .irq_compose_msi_msg = hv_compose_msi_msg, .irq_set_affinity = hv_set_affinity, .irq_ack = irq_chip_ack_parent, .irq_mask = hv_irq_mask, .irq_unmask = hv_irq_unmask, }; static irq_hw_number_t hv_msi_domain_ops_get_hwirq(struct msi_domain_info *info, msi_alloc_info_t *arg) { return arg->msi_hwirq; } static struct msi_domain_ops hv_msi_ops = { .get_hwirq = hv_msi_domain_ops_get_hwirq, .msi_prepare = pci_msi_prepare, .set_desc = pci_msi_set_desc, .msi_free = hv_msi_free, }; /** * hv_pcie_init_irq_domain() - Initialize IRQ domain * @hbus: The root PCI bus * * This function creates an IRQ domain which will be used for * interrupts from devices that have been passed through. These * devices only support MSI and MSI-X, not line-based interrupts * or simulations of line-based interrupts through PCIe's * fabric-layer messages. Because interrupts are remapped, we * can support multi-message MSI here. * * Return: '0' on success and error value on failure */ static int hv_pcie_init_irq_domain(struct hv_pcibus_device *hbus) { hbus->msi_info.chip = &hv_msi_irq_chip; hbus->msi_info.ops = &hv_msi_ops; hbus->msi_info.flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS | MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX); hbus->msi_info.handler = handle_edge_irq; hbus->msi_info.handler_name = "edge"; hbus->msi_info.data = hbus; hbus->irq_domain = pci_msi_create_irq_domain(hbus->sysdata.fwnode, &hbus->msi_info, x86_vector_domain); if (!hbus->irq_domain) { dev_err(&hbus->hdev->device, "Failed to build an MSI IRQ domain\n"); return -ENODEV; } return 0; } /** * get_bar_size() - Get the address space consumed by a BAR * @bar_val: Value that a BAR returned after -1 was written * to it. * * This function returns the size of the BAR, rounded up to 1 * page. It has to be rounded up because the hypervisor's page * table entry that maps the BAR into the VM can't specify an * offset within a page. The invariant is that the hypervisor * must place any BARs of smaller than page length at the * beginning of a page. * * Return: Size in bytes of the consumed MMIO space. */ static u64 get_bar_size(u64 bar_val) { return round_up((1 + ~(bar_val & PCI_BASE_ADDRESS_MEM_MASK)), PAGE_SIZE); } /** * survey_child_resources() - Total all MMIO requirements * @hbus: Root PCI bus, as understood by this driver */ static void survey_child_resources(struct hv_pcibus_device *hbus) { struct hv_pci_dev *hpdev; resource_size_t bar_size = 0; unsigned long flags; struct completion *event; u64 bar_val; int i; /* If nobody is waiting on the answer, don't compute it. */ event = xchg(&hbus->survey_event, NULL); if (!event) return; /* If the answer has already been computed, go with it. */ if (hbus->low_mmio_space || hbus->high_mmio_space) { complete(event); return; } spin_lock_irqsave(&hbus->device_list_lock, flags); /* * Due to an interesting quirk of the PCI spec, all memory regions * for a child device are a power of 2 in size and aligned in memory, * so it's sufficient to just add them up without tracking alignment. */ list_for_each_entry(hpdev, &hbus->children, list_entry) { for (i = 0; i < PCI_STD_NUM_BARS; i++) { if (hpdev->probed_bar[i] & PCI_BASE_ADDRESS_SPACE_IO) dev_err(&hbus->hdev->device, "There's an I/O BAR in this list!\n"); if (hpdev->probed_bar[i] != 0) { /* * A probed BAR has all the upper bits set that * can be changed. */ bar_val = hpdev->probed_bar[i]; if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64) bar_val |= ((u64)hpdev->probed_bar[++i] << 32); else bar_val |= 0xffffffff00000000ULL; bar_size = get_bar_size(bar_val); if (bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64) hbus->high_mmio_space += bar_size; else hbus->low_mmio_space += bar_size; } } } spin_unlock_irqrestore(&hbus->device_list_lock, flags); complete(event); } /** * prepopulate_bars() - Fill in BARs with defaults * @hbus: Root PCI bus, as understood by this driver * * The core PCI driver code seems much, much happier if the BARs * for a device have values upon first scan. So fill them in. * The algorithm below works down from large sizes to small, * attempting to pack the assignments optimally. The assumption, * enforced in other parts of the code, is that the beginning of * the memory-mapped I/O space will be aligned on the largest * BAR size. */ static void prepopulate_bars(struct hv_pcibus_device *hbus) { resource_size_t high_size = 0; resource_size_t low_size = 0; resource_size_t high_base = 0; resource_size_t low_base = 0; resource_size_t bar_size; struct hv_pci_dev *hpdev; unsigned long flags; u64 bar_val; u32 command; bool high; int i; if (hbus->low_mmio_space) { low_size = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space)); low_base = hbus->low_mmio_res->start; } if (hbus->high_mmio_space) { high_size = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space)); high_base = hbus->high_mmio_res->start; } spin_lock_irqsave(&hbus->device_list_lock, flags); /* * Clear the memory enable bit, in case it's already set. This occurs * in the suspend path of hibernation, where the device is suspended, * resumed and suspended again: see hibernation_snapshot() and * hibernation_platform_enter(). * * If the memory enable bit is already set, Hyper-V sliently ignores * the below BAR updates, and the related PCI device driver can not * work, because reading from the device register(s) always returns * 0xFFFFFFFF. */ list_for_each_entry(hpdev, &hbus->children, list_entry) { _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command); command &= ~PCI_COMMAND_MEMORY; _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command); } /* Pick addresses for the BARs. */ do { list_for_each_entry(hpdev, &hbus->children, list_entry) { for (i = 0; i < PCI_STD_NUM_BARS; i++) { bar_val = hpdev->probed_bar[i]; if (bar_val == 0) continue; high = bar_val & PCI_BASE_ADDRESS_MEM_TYPE_64; if (high) { bar_val |= ((u64)hpdev->probed_bar[i + 1] << 32); } else { bar_val |= 0xffffffffULL << 32; } bar_size = get_bar_size(bar_val); if (high) { if (high_size != bar_size) { i++; continue; } _hv_pcifront_write_config(hpdev, PCI_BASE_ADDRESS_0 + (4 * i), 4, (u32)(high_base & 0xffffff00)); i++; _hv_pcifront_write_config(hpdev, PCI_BASE_ADDRESS_0 + (4 * i), 4, (u32)(high_base >> 32)); high_base += bar_size; } else { if (low_size != bar_size) continue; _hv_pcifront_write_config(hpdev, PCI_BASE_ADDRESS_0 + (4 * i), 4, (u32)(low_base & 0xffffff00)); low_base += bar_size; } } if (high_size <= 1 && low_size <= 1) { /* Set the memory enable bit. */ _hv_pcifront_read_config(hpdev, PCI_COMMAND, 2, &command); command |= PCI_COMMAND_MEMORY; _hv_pcifront_write_config(hpdev, PCI_COMMAND, 2, command); break; } } high_size >>= 1; low_size >>= 1; } while (high_size || low_size); spin_unlock_irqrestore(&hbus->device_list_lock, flags); } /* * Assign entries in sysfs pci slot directory. * * Note that this function does not need to lock the children list * because it is called from pci_devices_present_work which * is serialized with hv_eject_device_work because they are on the * same ordered workqueue. Therefore hbus->children list will not change * even when pci_create_slot sleeps. */ static void hv_pci_assign_slots(struct hv_pcibus_device *hbus) { struct hv_pci_dev *hpdev; char name[SLOT_NAME_SIZE]; int slot_nr; list_for_each_entry(hpdev, &hbus->children, list_entry) { if (hpdev->pci_slot) continue; slot_nr = PCI_SLOT(wslot_to_devfn(hpdev->desc.win_slot.slot)); snprintf(name, SLOT_NAME_SIZE, "%u", hpdev->desc.ser); hpdev->pci_slot = pci_create_slot(hbus->pci_bus, slot_nr, name, NULL); if (IS_ERR(hpdev->pci_slot)) { pr_warn("pci_create slot %s failed\n", name); hpdev->pci_slot = NULL; } } } /* * Remove entries in sysfs pci slot directory. */ static void hv_pci_remove_slots(struct hv_pcibus_device *hbus) { struct hv_pci_dev *hpdev; list_for_each_entry(hpdev, &hbus->children, list_entry) { if (!hpdev->pci_slot) continue; pci_destroy_slot(hpdev->pci_slot); hpdev->pci_slot = NULL; } } /* * Set NUMA node for the devices on the bus */ static void hv_pci_assign_numa_node(struct hv_pcibus_device *hbus) { struct pci_dev *dev; struct pci_bus *bus = hbus->pci_bus; struct hv_pci_dev *hv_dev; list_for_each_entry(dev, &bus->devices, bus_list) { hv_dev = get_pcichild_wslot(hbus, devfn_to_wslot(dev->devfn)); if (!hv_dev) continue; if (hv_dev->desc.flags & HV_PCI_DEVICE_FLAG_NUMA_AFFINITY) set_dev_node(&dev->dev, hv_dev->desc.virtual_numa_node); put_pcichild(hv_dev); } } /** * create_root_hv_pci_bus() - Expose a new root PCI bus * @hbus: Root PCI bus, as understood by this driver * * Return: 0 on success, -errno on failure */ static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus) { /* Register the device */ hbus->pci_bus = pci_create_root_bus(&hbus->hdev->device, 0, /* bus number is always zero */ &hv_pcifront_ops, &hbus->sysdata, &hbus->resources_for_children); if (!hbus->pci_bus) return -ENODEV; hbus->pci_bus->msi = &hbus->msi_chip; hbus->pci_bus->msi->dev = &hbus->hdev->device; pci_lock_rescan_remove(); pci_scan_child_bus(hbus->pci_bus); hv_pci_assign_numa_node(hbus); pci_bus_assign_resources(hbus->pci_bus); hv_pci_assign_slots(hbus); pci_bus_add_devices(hbus->pci_bus); pci_unlock_rescan_remove(); hbus->state = hv_pcibus_installed; return 0; } struct q_res_req_compl { struct completion host_event; struct hv_pci_dev *hpdev; }; /** * q_resource_requirements() - Query Resource Requirements * @context: The completion context. * @resp: The response that came from the host. * @resp_packet_size: The size in bytes of resp. * * This function is invoked on completion of a Query Resource * Requirements packet. */ static void q_resource_requirements(void *context, struct pci_response *resp, int resp_packet_size) { struct q_res_req_compl *completion = context; struct pci_q_res_req_response *q_res_req = (struct pci_q_res_req_response *)resp; int i; if (resp->status < 0) { dev_err(&completion->hpdev->hbus->hdev->device, "query resource requirements failed: %x\n", resp->status); } else { for (i = 0; i < PCI_STD_NUM_BARS; i++) { completion->hpdev->probed_bar[i] = q_res_req->probed_bar[i]; } } complete(&completion->host_event); } /** * new_pcichild_device() - Create a new child device * @hbus: The internal struct tracking this root PCI bus. * @desc: The information supplied so far from the host * about the device. * * This function creates the tracking structure for a new child * device and kicks off the process of figuring out what it is. * * Return: Pointer to the new tracking struct */ static struct hv_pci_dev *new_pcichild_device(struct hv_pcibus_device *hbus, struct hv_pcidev_description *desc) { struct hv_pci_dev *hpdev; struct pci_child_message *res_req; struct q_res_req_compl comp_pkt; struct { struct pci_packet init_packet; u8 buffer[sizeof(struct pci_child_message)]; } pkt; unsigned long flags; int ret; hpdev = kzalloc(sizeof(*hpdev), GFP_KERNEL); if (!hpdev) return NULL; hpdev->hbus = hbus; memset(&pkt, 0, sizeof(pkt)); init_completion(&comp_pkt.host_event); comp_pkt.hpdev = hpdev; pkt.init_packet.compl_ctxt = &comp_pkt; pkt.init_packet.completion_func = q_resource_requirements; res_req = (struct pci_child_message *)&pkt.init_packet.message; res_req->message_type.type = PCI_QUERY_RESOURCE_REQUIREMENTS; res_req->wslot.slot = desc->win_slot.slot; ret = vmbus_sendpacket(hbus->hdev->channel, res_req, sizeof(struct pci_child_message), (unsigned long)&pkt.init_packet, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) goto error; if (wait_for_response(hbus->hdev, &comp_pkt.host_event)) goto error; hpdev->desc = *desc; refcount_set(&hpdev->refs, 1); get_pcichild(hpdev); spin_lock_irqsave(&hbus->device_list_lock, flags); list_add_tail(&hpdev->list_entry, &hbus->children); spin_unlock_irqrestore(&hbus->device_list_lock, flags); return hpdev; error: kfree(hpdev); return NULL; } /** * get_pcichild_wslot() - Find device from slot * @hbus: Root PCI bus, as understood by this driver * @wslot: Location on the bus * * This function looks up a PCI device and returns the internal * representation of it. It acquires a reference on it, so that * the device won't be deleted while somebody is using it. The * caller is responsible for calling put_pcichild() to release * this reference. * * Return: Internal representation of a PCI device */ static struct hv_pci_dev *get_pcichild_wslot(struct hv_pcibus_device *hbus, u32 wslot) { unsigned long flags; struct hv_pci_dev *iter, *hpdev = NULL; spin_lock_irqsave(&hbus->device_list_lock, flags); list_for_each_entry(iter, &hbus->children, list_entry) { if (iter->desc.win_slot.slot == wslot) { hpdev = iter; get_pcichild(hpdev); break; } } spin_unlock_irqrestore(&hbus->device_list_lock, flags); return hpdev; } /** * pci_devices_present_work() - Handle new list of child devices * @work: Work struct embedded in struct hv_dr_work * * "Bus Relations" is the Windows term for "children of this * bus." The terminology is preserved here for people trying to * debug the interaction between Hyper-V and Linux. This * function is called when the parent partition reports a list * of functions that should be observed under this PCI Express * port (bus). * * This function updates the list, and must tolerate being * called multiple times with the same information. The typical * number of child devices is one, with very atypical cases * involving three or four, so the algorithms used here can be * simple and inefficient. * * It must also treat the omission of a previously observed device as * notification that the device no longer exists. * * Note that this function is serialized with hv_eject_device_work(), * because both are pushed to the ordered workqueue hbus->wq. */ static void pci_devices_present_work(struct work_struct *work) { u32 child_no; bool found; struct hv_pcidev_description *new_desc; struct hv_pci_dev *hpdev; struct hv_pcibus_device *hbus; struct list_head removed; struct hv_dr_work *dr_wrk; struct hv_dr_state *dr = NULL; unsigned long flags; dr_wrk = container_of(work, struct hv_dr_work, wrk); hbus = dr_wrk->bus; kfree(dr_wrk); INIT_LIST_HEAD(&removed); /* Pull this off the queue and process it if it was the last one. */ spin_lock_irqsave(&hbus->device_list_lock, flags); while (!list_empty(&hbus->dr_list)) { dr = list_first_entry(&hbus->dr_list, struct hv_dr_state, list_entry); list_del(&dr->list_entry); /* Throw this away if the list still has stuff in it. */ if (!list_empty(&hbus->dr_list)) { kfree(dr); continue; } } spin_unlock_irqrestore(&hbus->device_list_lock, flags); if (!dr) { put_hvpcibus(hbus); return; } /* First, mark all existing children as reported missing. */ spin_lock_irqsave(&hbus->device_list_lock, flags); list_for_each_entry(hpdev, &hbus->children, list_entry) { hpdev->reported_missing = true; } spin_unlock_irqrestore(&hbus->device_list_lock, flags); /* Next, add back any reported devices. */ for (child_no = 0; child_no < dr->device_count; child_no++) { found = false; new_desc = &dr->func[child_no]; spin_lock_irqsave(&hbus->device_list_lock, flags); list_for_each_entry(hpdev, &hbus->children, list_entry) { if ((hpdev->desc.win_slot.slot == new_desc->win_slot.slot) && (hpdev->desc.v_id == new_desc->v_id) && (hpdev->desc.d_id == new_desc->d_id) && (hpdev->desc.ser == new_desc->ser)) { hpdev->reported_missing = false; found = true; } } spin_unlock_irqrestore(&hbus->device_list_lock, flags); if (!found) { hpdev = new_pcichild_device(hbus, new_desc); if (!hpdev) dev_err(&hbus->hdev->device, "couldn't record a child device.\n"); } } /* Move missing children to a list on the stack. */ spin_lock_irqsave(&hbus->device_list_lock, flags); do { found = false; list_for_each_entry(hpdev, &hbus->children, list_entry) { if (hpdev->reported_missing) { found = true; put_pcichild(hpdev); list_move_tail(&hpdev->list_entry, &removed); break; } } } while (found); spin_unlock_irqrestore(&hbus->device_list_lock, flags); /* Delete everything that should no longer exist. */ while (!list_empty(&removed)) { hpdev = list_first_entry(&removed, struct hv_pci_dev, list_entry); list_del(&hpdev->list_entry); if (hpdev->pci_slot) pci_destroy_slot(hpdev->pci_slot); put_pcichild(hpdev); } switch (hbus->state) { case hv_pcibus_installed: /* * Tell the core to rescan bus * because there may have been changes. */ pci_lock_rescan_remove(); pci_scan_child_bus(hbus->pci_bus); hv_pci_assign_numa_node(hbus); hv_pci_assign_slots(hbus); pci_unlock_rescan_remove(); break; case hv_pcibus_init: case hv_pcibus_probed: survey_child_resources(hbus); break; default: break; } put_hvpcibus(hbus); kfree(dr); } /** * hv_pci_start_relations_work() - Queue work to start device discovery * @hbus: Root PCI bus, as understood by this driver * @dr: The list of children returned from host * * Return: 0 on success, -errno on failure */ static int hv_pci_start_relations_work(struct hv_pcibus_device *hbus, struct hv_dr_state *dr) { struct hv_dr_work *dr_wrk; unsigned long flags; bool pending_dr; if (hbus->state == hv_pcibus_removing) { dev_info(&hbus->hdev->device, "PCI VMBus BUS_RELATIONS: ignored\n"); return -ENOENT; } dr_wrk = kzalloc(sizeof(*dr_wrk), GFP_NOWAIT); if (!dr_wrk) return -ENOMEM; INIT_WORK(&dr_wrk->wrk, pci_devices_present_work); dr_wrk->bus = hbus; spin_lock_irqsave(&hbus->device_list_lock, flags); /* * If pending_dr is true, we have already queued a work, * which will see the new dr. Otherwise, we need to * queue a new work. */ pending_dr = !list_empty(&hbus->dr_list); list_add_tail(&dr->list_entry, &hbus->dr_list); spin_unlock_irqrestore(&hbus->device_list_lock, flags); if (pending_dr) { kfree(dr_wrk); } else { get_hvpcibus(hbus); queue_work(hbus->wq, &dr_wrk->wrk); } return 0; } /** * hv_pci_devices_present() - Handle list of new children * @hbus: Root PCI bus, as understood by this driver * @relations: Packet from host listing children * * Process a new list of devices on the bus. The list of devices is * discovered by VSP and sent to us via VSP message PCI_BUS_RELATIONS, * whenever a new list of devices for this bus appears. */ static void hv_pci_devices_present(struct hv_pcibus_device *hbus, struct pci_bus_relations *relations) { struct hv_dr_state *dr; int i; dr = kzalloc(offsetof(struct hv_dr_state, func) + (sizeof(struct hv_pcidev_description) * (relations->device_count)), GFP_NOWAIT); if (!dr) return; dr->device_count = relations->device_count; for (i = 0; i < dr->device_count; i++) { dr->func[i].v_id = relations->func[i].v_id; dr->func[i].d_id = relations->func[i].d_id; dr->func[i].rev = relations->func[i].rev; dr->func[i].prog_intf = relations->func[i].prog_intf; dr->func[i].subclass = relations->func[i].subclass; dr->func[i].base_class = relations->func[i].base_class; dr->func[i].subsystem_id = relations->func[i].subsystem_id; dr->func[i].win_slot = relations->func[i].win_slot; dr->func[i].ser = relations->func[i].ser; } if (hv_pci_start_relations_work(hbus, dr)) kfree(dr); } /** * hv_pci_devices_present2() - Handle list of new children * @hbus: Root PCI bus, as understood by this driver * @relations: Packet from host listing children * * This function is the v2 version of hv_pci_devices_present() */ static void hv_pci_devices_present2(struct hv_pcibus_device *hbus, struct pci_bus_relations2 *relations) { struct hv_dr_state *dr; int i; dr = kzalloc(offsetof(struct hv_dr_state, func) + (sizeof(struct hv_pcidev_description) * (relations->device_count)), GFP_NOWAIT); if (!dr) return; dr->device_count = relations->device_count; for (i = 0; i < dr->device_count; i++) { dr->func[i].v_id = relations->func[i].v_id; dr->func[i].d_id = relations->func[i].d_id; dr->func[i].rev = relations->func[i].rev; dr->func[i].prog_intf = relations->func[i].prog_intf; dr->func[i].subclass = relations->func[i].subclass; dr->func[i].base_class = relations->func[i].base_class; dr->func[i].subsystem_id = relations->func[i].subsystem_id; dr->func[i].win_slot = relations->func[i].win_slot; dr->func[i].ser = relations->func[i].ser; dr->func[i].flags = relations->func[i].flags; dr->func[i].virtual_numa_node = relations->func[i].virtual_numa_node; } if (hv_pci_start_relations_work(hbus, dr)) kfree(dr); } /** * hv_eject_device_work() - Asynchronously handles ejection * @work: Work struct embedded in internal device struct * * This function handles ejecting a device. Windows will * attempt to gracefully eject a device, waiting 60 seconds to * hear back from the guest OS that this completed successfully. * If this timer expires, the device will be forcibly removed. */ static void hv_eject_device_work(struct work_struct *work) { struct pci_eject_response *ejct_pkt; struct hv_pcibus_device *hbus; struct hv_pci_dev *hpdev; struct pci_dev *pdev; unsigned long flags; int wslot; struct { struct pci_packet pkt; u8 buffer[sizeof(struct pci_eject_response)]; } ctxt; hpdev = container_of(work, struct hv_pci_dev, wrk); hbus = hpdev->hbus; WARN_ON(hpdev->state != hv_pcichild_ejecting); /* * Ejection can come before or after the PCI bus has been set up, so * attempt to find it and tear down the bus state, if it exists. This * must be done without constructs like pci_domain_nr(hbus->pci_bus) * because hbus->pci_bus may not exist yet. */ wslot = wslot_to_devfn(hpdev->desc.win_slot.slot); pdev = pci_get_domain_bus_and_slot(hbus->sysdata.domain, 0, wslot); if (pdev) { pci_lock_rescan_remove(); pci_stop_and_remove_bus_device(pdev); pci_dev_put(pdev); pci_unlock_rescan_remove(); } spin_lock_irqsave(&hbus->device_list_lock, flags); list_del(&hpdev->list_entry); spin_unlock_irqrestore(&hbus->device_list_lock, flags); if (hpdev->pci_slot) pci_destroy_slot(hpdev->pci_slot); memset(&ctxt, 0, sizeof(ctxt)); ejct_pkt = (struct pci_eject_response *)&ctxt.pkt.message; ejct_pkt->message_type.type = PCI_EJECTION_COMPLETE; ejct_pkt->wslot.slot = hpdev->desc.win_slot.slot; vmbus_sendpacket(hbus->hdev->channel, ejct_pkt, sizeof(*ejct_pkt), (unsigned long)&ctxt.pkt, VM_PKT_DATA_INBAND, 0); /* For the get_pcichild() in hv_pci_eject_device() */ put_pcichild(hpdev); /* For the two refs got in new_pcichild_device() */ put_pcichild(hpdev); put_pcichild(hpdev); /* hpdev has been freed. Do not use it any more. */ put_hvpcibus(hbus); } /** * hv_pci_eject_device() - Handles device ejection * @hpdev: Internal device tracking struct * * This function is invoked when an ejection packet arrives. It * just schedules work so that we don't re-enter the packet * delivery code handling the ejection. */ static void hv_pci_eject_device(struct hv_pci_dev *hpdev) { struct hv_pcibus_device *hbus = hpdev->hbus; struct hv_device *hdev = hbus->hdev; if (hbus->state == hv_pcibus_removing) { dev_info(&hdev->device, "PCI VMBus EJECT: ignored\n"); return; } hpdev->state = hv_pcichild_ejecting; get_pcichild(hpdev); INIT_WORK(&hpdev->wrk, hv_eject_device_work); get_hvpcibus(hbus); queue_work(hbus->wq, &hpdev->wrk); } /** * hv_pci_onchannelcallback() - Handles incoming packets * @context: Internal bus tracking struct * * This function is invoked whenever the host sends a packet to * this channel (which is private to this root PCI bus). */ static void hv_pci_onchannelcallback(void *context) { const int packet_size = 0x100; int ret; struct hv_pcibus_device *hbus = context; u32 bytes_recvd; u64 req_id; struct vmpacket_descriptor *desc; unsigned char *buffer; int bufferlen = packet_size; struct pci_packet *comp_packet; struct pci_response *response; struct pci_incoming_message *new_message; struct pci_bus_relations *bus_rel; struct pci_bus_relations2 *bus_rel2; struct pci_dev_inval_block *inval; struct pci_dev_incoming *dev_message; struct hv_pci_dev *hpdev; buffer = kmalloc(bufferlen, GFP_ATOMIC); if (!buffer) return; while (1) { ret = vmbus_recvpacket_raw(hbus->hdev->channel, buffer, bufferlen, &bytes_recvd, &req_id); if (ret == -ENOBUFS) { kfree(buffer); /* Handle large packet */ bufferlen = bytes_recvd; buffer = kmalloc(bytes_recvd, GFP_ATOMIC); if (!buffer) return; continue; } /* Zero length indicates there are no more packets. */ if (ret || !bytes_recvd) break; /* * All incoming packets must be at least as large as a * response. */ if (bytes_recvd <= sizeof(struct pci_response)) continue; desc = (struct vmpacket_descriptor *)buffer; switch (desc->type) { case VM_PKT_COMP: /* * The host is trusted, and thus it's safe to interpret * this transaction ID as a pointer. */ comp_packet = (struct pci_packet *)req_id; response = (struct pci_response *)buffer; comp_packet->completion_func(comp_packet->compl_ctxt, response, bytes_recvd); break; case VM_PKT_DATA_INBAND: new_message = (struct pci_incoming_message *)buffer; switch (new_message->message_type.type) { case PCI_BUS_RELATIONS: bus_rel = (struct pci_bus_relations *)buffer; if (bytes_recvd < offsetof(struct pci_bus_relations, func) + (sizeof(struct pci_function_description) * (bus_rel->device_count))) { dev_err(&hbus->hdev->device, "bus relations too small\n"); break; } hv_pci_devices_present(hbus, bus_rel); break; case PCI_BUS_RELATIONS2: bus_rel2 = (struct pci_bus_relations2 *)buffer; if (bytes_recvd < offsetof(struct pci_bus_relations2, func) + (sizeof(struct pci_function_description2) * (bus_rel2->device_count))) { dev_err(&hbus->hdev->device, "bus relations v2 too small\n"); break; } hv_pci_devices_present2(hbus, bus_rel2); break; case PCI_EJECT: dev_message = (struct pci_dev_incoming *)buffer; hpdev = get_pcichild_wslot(hbus, dev_message->wslot.slot); if (hpdev) { hv_pci_eject_device(hpdev); put_pcichild(hpdev); } break; case PCI_INVALIDATE_BLOCK: inval = (struct pci_dev_inval_block *)buffer; hpdev = get_pcichild_wslot(hbus, inval->wslot.slot); if (hpdev) { if (hpdev->block_invalidate) { hpdev->block_invalidate( hpdev->invalidate_context, inval->block_mask); } put_pcichild(hpdev); } break; default: dev_warn(&hbus->hdev->device, "Unimplemented protocol message %x\n", new_message->message_type.type); break; } break; default: dev_err(&hbus->hdev->device, "unhandled packet type %d, tid %llx len %d\n", desc->type, req_id, bytes_recvd); break; } } kfree(buffer); } /** * hv_pci_protocol_negotiation() - Set up protocol * @hdev: VMBus's tracking struct for this root PCI bus * * This driver is intended to support running on Windows 10 * (server) and later versions. It will not run on earlier * versions, as they assume that many of the operations which * Linux needs accomplished with a spinlock held were done via * asynchronous messaging via VMBus. Windows 10 increases the * surface area of PCI emulation so that these actions can take * place by suspending a virtual processor for their duration. * * This function negotiates the channel protocol version, * failing if the host doesn't support the necessary protocol * level. */ static int hv_pci_protocol_negotiation(struct hv_device *hdev, enum pci_protocol_version_t version[], int num_version) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct pci_version_request *version_req; struct hv_pci_compl comp_pkt; struct pci_packet *pkt; int ret; int i; /* * Initiate the handshake with the host and negotiate * a version that the host can support. We start with the * highest version number and go down if the host cannot * support it. */ pkt = kzalloc(sizeof(*pkt) + sizeof(*version_req), GFP_KERNEL); if (!pkt) return -ENOMEM; init_completion(&comp_pkt.host_event); pkt->completion_func = hv_pci_generic_compl; pkt->compl_ctxt = &comp_pkt; version_req = (struct pci_version_request *)&pkt->message; version_req->message_type.type = PCI_QUERY_PROTOCOL_VERSION; for (i = 0; i < num_version; i++) { version_req->protocol_version = version[i]; ret = vmbus_sendpacket(hdev->channel, version_req, sizeof(struct pci_version_request), (unsigned long)pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (!ret) ret = wait_for_response(hdev, &comp_pkt.host_event); if (ret) { dev_err(&hdev->device, "PCI Pass-through VSP failed to request version: %d", ret); goto exit; } if (comp_pkt.completion_status >= 0) { hbus->protocol_version = version[i]; dev_info(&hdev->device, "PCI VMBus probing: Using version %#x\n", hbus->protocol_version); goto exit; } if (comp_pkt.completion_status != STATUS_REVISION_MISMATCH) { dev_err(&hdev->device, "PCI Pass-through VSP failed version request: %#x", comp_pkt.completion_status); ret = -EPROTO; goto exit; } reinit_completion(&comp_pkt.host_event); } dev_err(&hdev->device, "PCI pass-through VSP failed to find supported version"); ret = -EPROTO; exit: kfree(pkt); return ret; } /** * hv_pci_free_bridge_windows() - Release memory regions for the * bus * @hbus: Root PCI bus, as understood by this driver */ static void hv_pci_free_bridge_windows(struct hv_pcibus_device *hbus) { /* * Set the resources back to the way they looked when they * were allocated by setting IORESOURCE_BUSY again. */ if (hbus->low_mmio_space && hbus->low_mmio_res) { hbus->low_mmio_res->flags |= IORESOURCE_BUSY; vmbus_free_mmio(hbus->low_mmio_res->start, resource_size(hbus->low_mmio_res)); } if (hbus->high_mmio_space && hbus->high_mmio_res) { hbus->high_mmio_res->flags |= IORESOURCE_BUSY; vmbus_free_mmio(hbus->high_mmio_res->start, resource_size(hbus->high_mmio_res)); } } /** * hv_pci_allocate_bridge_windows() - Allocate memory regions * for the bus * @hbus: Root PCI bus, as understood by this driver * * This function calls vmbus_allocate_mmio(), which is itself a * bit of a compromise. Ideally, we might change the pnp layer * in the kernel such that it comprehends either PCI devices * which are "grandchildren of ACPI," with some intermediate bus * node (in this case, VMBus) or change it such that it * understands VMBus. The pnp layer, however, has been declared * deprecated, and not subject to change. * * The workaround, implemented here, is to ask VMBus to allocate * MMIO space for this bus. VMBus itself knows which ranges are * appropriate by looking at its own ACPI objects. Then, after * these ranges are claimed, they're modified to look like they * would have looked if the ACPI and pnp code had allocated * bridge windows. These descriptors have to exist in this form * in order to satisfy the code which will get invoked when the * endpoint PCI function driver calls request_mem_region() or * request_mem_region_exclusive(). * * Return: 0 on success, -errno on failure */ static int hv_pci_allocate_bridge_windows(struct hv_pcibus_device *hbus) { resource_size_t align; int ret; if (hbus->low_mmio_space) { align = 1ULL << (63 - __builtin_clzll(hbus->low_mmio_space)); ret = vmbus_allocate_mmio(&hbus->low_mmio_res, hbus->hdev, 0, (u64)(u32)0xffffffff, hbus->low_mmio_space, align, false); if (ret) { dev_err(&hbus->hdev->device, "Need %#llx of low MMIO space. Consider reconfiguring the VM.\n", hbus->low_mmio_space); return ret; } /* Modify this resource to become a bridge window. */ hbus->low_mmio_res->flags |= IORESOURCE_WINDOW; hbus->low_mmio_res->flags &= ~IORESOURCE_BUSY; pci_add_resource(&hbus->resources_for_children, hbus->low_mmio_res); } if (hbus->high_mmio_space) { align = 1ULL << (63 - __builtin_clzll(hbus->high_mmio_space)); ret = vmbus_allocate_mmio(&hbus->high_mmio_res, hbus->hdev, 0x100000000, -1, hbus->high_mmio_space, align, false); if (ret) { dev_err(&hbus->hdev->device, "Need %#llx of high MMIO space. Consider reconfiguring the VM.\n", hbus->high_mmio_space); goto release_low_mmio; } /* Modify this resource to become a bridge window. */ hbus->high_mmio_res->flags |= IORESOURCE_WINDOW; hbus->high_mmio_res->flags &= ~IORESOURCE_BUSY; pci_add_resource(&hbus->resources_for_children, hbus->high_mmio_res); } return 0; release_low_mmio: if (hbus->low_mmio_res) { vmbus_free_mmio(hbus->low_mmio_res->start, resource_size(hbus->low_mmio_res)); } return ret; } /** * hv_allocate_config_window() - Find MMIO space for PCI Config * @hbus: Root PCI bus, as understood by this driver * * This function claims memory-mapped I/O space for accessing * configuration space for the functions on this bus. * * Return: 0 on success, -errno on failure */ static int hv_allocate_config_window(struct hv_pcibus_device *hbus) { int ret; /* * Set up a region of MMIO space to use for accessing configuration * space. */ ret = vmbus_allocate_mmio(&hbus->mem_config, hbus->hdev, 0, -1, PCI_CONFIG_MMIO_LENGTH, 0x1000, false); if (ret) return ret; /* * vmbus_allocate_mmio() gets used for allocating both device endpoint * resource claims (those which cannot be overlapped) and the ranges * which are valid for the children of this bus, which are intended * to be overlapped by those children. Set the flag on this claim * meaning that this region can't be overlapped. */ hbus->mem_config->flags |= IORESOURCE_BUSY; return 0; } static void hv_free_config_window(struct hv_pcibus_device *hbus) { vmbus_free_mmio(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH); } /** * hv_pci_enter_d0() - Bring the "bus" into the D0 power state * @hdev: VMBus's tracking struct for this root PCI bus * * Return: 0 on success, -errno on failure */ static int hv_pci_enter_d0(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct pci_bus_d0_entry *d0_entry; struct hv_pci_compl comp_pkt; struct pci_packet *pkt; int ret; /* * Tell the host that the bus is ready to use, and moved into the * powered-on state. This includes telling the host which region * of memory-mapped I/O space has been chosen for configuration space * access. */ pkt = kzalloc(sizeof(*pkt) + sizeof(*d0_entry), GFP_KERNEL); if (!pkt) return -ENOMEM; init_completion(&comp_pkt.host_event); pkt->completion_func = hv_pci_generic_compl; pkt->compl_ctxt = &comp_pkt; d0_entry = (struct pci_bus_d0_entry *)&pkt->message; d0_entry->message_type.type = PCI_BUS_D0ENTRY; d0_entry->mmio_base = hbus->mem_config->start; ret = vmbus_sendpacket(hdev->channel, d0_entry, sizeof(*d0_entry), (unsigned long)pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (!ret) ret = wait_for_response(hdev, &comp_pkt.host_event); if (ret) goto exit; if (comp_pkt.completion_status < 0) { dev_err(&hdev->device, "PCI Pass-through VSP failed D0 Entry with status %x\n", comp_pkt.completion_status); ret = -EPROTO; goto exit; } ret = 0; exit: kfree(pkt); return ret; } /** * hv_pci_query_relations() - Ask host to send list of child * devices * @hdev: VMBus's tracking struct for this root PCI bus * * Return: 0 on success, -errno on failure */ static int hv_pci_query_relations(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct pci_message message; struct completion comp; int ret; /* Ask the host to send along the list of child devices */ init_completion(&comp); if (cmpxchg(&hbus->survey_event, NULL, &comp)) return -ENOTEMPTY; memset(&message, 0, sizeof(message)); message.type = PCI_QUERY_BUS_RELATIONS; ret = vmbus_sendpacket(hdev->channel, &message, sizeof(message), 0, VM_PKT_DATA_INBAND, 0); if (!ret) ret = wait_for_response(hdev, &comp); return ret; } /** * hv_send_resources_allocated() - Report local resource choices * @hdev: VMBus's tracking struct for this root PCI bus * * The host OS is expecting to be sent a request as a message * which contains all the resources that the device will use. * The response contains those same resources, "translated" * which is to say, the values which should be used by the * hardware, when it delivers an interrupt. (MMIO resources are * used in local terms.) This is nice for Windows, and lines up * with the FDO/PDO split, which doesn't exist in Linux. Linux * is deeply expecting to scan an emulated PCI configuration * space. So this message is sent here only to drive the state * machine on the host forward. * * Return: 0 on success, -errno on failure */ static int hv_send_resources_allocated(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct pci_resources_assigned *res_assigned; struct pci_resources_assigned2 *res_assigned2; struct hv_pci_compl comp_pkt; struct hv_pci_dev *hpdev; struct pci_packet *pkt; size_t size_res; u32 wslot; int ret; size_res = (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) ? sizeof(*res_assigned) : sizeof(*res_assigned2); pkt = kmalloc(sizeof(*pkt) + size_res, GFP_KERNEL); if (!pkt) return -ENOMEM; ret = 0; for (wslot = 0; wslot < 256; wslot++) { hpdev = get_pcichild_wslot(hbus, wslot); if (!hpdev) continue; memset(pkt, 0, sizeof(*pkt) + size_res); init_completion(&comp_pkt.host_event); pkt->completion_func = hv_pci_generic_compl; pkt->compl_ctxt = &comp_pkt; if (hbus->protocol_version < PCI_PROTOCOL_VERSION_1_2) { res_assigned = (struct pci_resources_assigned *)&pkt->message; res_assigned->message_type.type = PCI_RESOURCES_ASSIGNED; res_assigned->wslot.slot = hpdev->desc.win_slot.slot; } else { res_assigned2 = (struct pci_resources_assigned2 *)&pkt->message; res_assigned2->message_type.type = PCI_RESOURCES_ASSIGNED2; res_assigned2->wslot.slot = hpdev->desc.win_slot.slot; } put_pcichild(hpdev); ret = vmbus_sendpacket(hdev->channel, &pkt->message, size_res, (unsigned long)pkt, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (!ret) ret = wait_for_response(hdev, &comp_pkt.host_event); if (ret) break; if (comp_pkt.completion_status < 0) { ret = -EPROTO; dev_err(&hdev->device, "resource allocated returned 0x%x", comp_pkt.completion_status); break; } } kfree(pkt); return ret; } /** * hv_send_resources_released() - Report local resources * released * @hdev: VMBus's tracking struct for this root PCI bus * * Return: 0 on success, -errno on failure */ static int hv_send_resources_released(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct pci_child_message pkt; struct hv_pci_dev *hpdev; u32 wslot; int ret; for (wslot = 0; wslot < 256; wslot++) { hpdev = get_pcichild_wslot(hbus, wslot); if (!hpdev) continue; memset(&pkt, 0, sizeof(pkt)); pkt.message_type.type = PCI_RESOURCES_RELEASED; pkt.wslot.slot = hpdev->desc.win_slot.slot; put_pcichild(hpdev); ret = vmbus_sendpacket(hdev->channel, &pkt, sizeof(pkt), 0, VM_PKT_DATA_INBAND, 0); if (ret) return ret; } return 0; } static void get_hvpcibus(struct hv_pcibus_device *hbus) { refcount_inc(&hbus->remove_lock); } static void put_hvpcibus(struct hv_pcibus_device *hbus) { if (refcount_dec_and_test(&hbus->remove_lock)) complete(&hbus->remove_event); } #define HVPCI_DOM_MAP_SIZE (64 * 1024) static DECLARE_BITMAP(hvpci_dom_map, HVPCI_DOM_MAP_SIZE); /* * PCI domain number 0 is used by emulated devices on Gen1 VMs, so define 0 * as invalid for passthrough PCI devices of this driver. */ #define HVPCI_DOM_INVALID 0 /** * hv_get_dom_num() - Get a valid PCI domain number * Check if the PCI domain number is in use, and return another number if * it is in use. * * @dom: Requested domain number * * return: domain number on success, HVPCI_DOM_INVALID on failure */ static u16 hv_get_dom_num(u16 dom) { unsigned int i; if (test_and_set_bit(dom, hvpci_dom_map) == 0) return dom; for_each_clear_bit(i, hvpci_dom_map, HVPCI_DOM_MAP_SIZE) { if (test_and_set_bit(i, hvpci_dom_map) == 0) return i; } return HVPCI_DOM_INVALID; } /** * hv_put_dom_num() - Mark the PCI domain number as free * @dom: Domain number to be freed */ static void hv_put_dom_num(u16 dom) { clear_bit(dom, hvpci_dom_map); } /** * hv_pci_probe() - New VMBus channel probe, for a root PCI bus * @hdev: VMBus's tracking struct for this root PCI bus * @dev_id: Identifies the device itself * * Return: 0 on success, -errno on failure */ static int hv_pci_probe(struct hv_device *hdev, const struct hv_vmbus_device_id *dev_id) { struct hv_pcibus_device *hbus; u16 dom_req, dom; char *name; int ret; /* * hv_pcibus_device contains the hypercall arguments for retargeting in * hv_irq_unmask(). Those must not cross a page boundary. */ BUILD_BUG_ON(sizeof(*hbus) > HV_HYP_PAGE_SIZE); /* * With the recent 59bb47985c1d ("mm, sl[aou]b: guarantee natural * alignment for kmalloc(power-of-two)"), kzalloc() is able to allocate * a 4KB buffer that is guaranteed to be 4KB-aligned. Here the size and * alignment of hbus is important because hbus's field * retarget_msi_interrupt_params must not cross a 4KB page boundary. * * Here we prefer kzalloc to get_zeroed_page(), because a buffer * allocated by the latter is not tracked and scanned by kmemleak, and * hence kmemleak reports the pointer contained in the hbus buffer * (i.e. the hpdev struct, which is created in new_pcichild_device() and * is tracked by hbus->children) as memory leak (false positive). * * If the kernel doesn't have 59bb47985c1d, get_zeroed_page() *must* be * used to allocate the hbus buffer and we can avoid the kmemleak false * positive by using kmemleak_alloc() and kmemleak_free() to ask * kmemleak to track and scan the hbus buffer. */ hbus = kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL); if (!hbus) return -ENOMEM; hbus->state = hv_pcibus_init; /* * The PCI bus "domain" is what is called "segment" in ACPI and other * specs. Pull it from the instance ID, to get something usually * unique. In rare cases of collision, we will find out another number * not in use. * * Note that, since this code only runs in a Hyper-V VM, Hyper-V * together with this guest driver can guarantee that (1) The only * domain used by Gen1 VMs for something that looks like a physical * PCI bus (which is actually emulated by the hypervisor) is domain 0. * (2) There will be no overlap between domains (after fixing possible * collisions) in the same VM. */ dom_req = hdev->dev_instance.b[5] << 8 | hdev->dev_instance.b[4]; dom = hv_get_dom_num(dom_req); if (dom == HVPCI_DOM_INVALID) { dev_err(&hdev->device, "Unable to use dom# 0x%hx or other numbers", dom_req); ret = -EINVAL; goto free_bus; } if (dom != dom_req) dev_info(&hdev->device, "PCI dom# 0x%hx has collision, using 0x%hx", dom_req, dom); hbus->sysdata.domain = dom; hbus->hdev = hdev; refcount_set(&hbus->remove_lock, 1); INIT_LIST_HEAD(&hbus->children); INIT_LIST_HEAD(&hbus->dr_list); INIT_LIST_HEAD(&hbus->resources_for_children); spin_lock_init(&hbus->config_lock); spin_lock_init(&hbus->device_list_lock); spin_lock_init(&hbus->retarget_msi_interrupt_lock); init_completion(&hbus->remove_event); hbus->wq = alloc_ordered_workqueue("hv_pci_%x", 0, hbus->sysdata.domain); if (!hbus->wq) { ret = -ENOMEM; goto free_dom; } ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0, hv_pci_onchannelcallback, hbus); if (ret) goto destroy_wq; hv_set_drvdata(hdev, hbus); ret = hv_pci_protocol_negotiation(hdev, pci_protocol_versions, ARRAY_SIZE(pci_protocol_versions)); if (ret) goto close; ret = hv_allocate_config_window(hbus); if (ret) goto close; hbus->cfg_addr = ioremap(hbus->mem_config->start, PCI_CONFIG_MMIO_LENGTH); if (!hbus->cfg_addr) { dev_err(&hdev->device, "Unable to map a virtual address for config space\n"); ret = -ENOMEM; goto free_config; } name = kasprintf(GFP_KERNEL, "%pUL", &hdev->dev_instance); if (!name) { ret = -ENOMEM; goto unmap; } hbus->sysdata.fwnode = irq_domain_alloc_named_fwnode(name); kfree(name); if (!hbus->sysdata.fwnode) { ret = -ENOMEM; goto unmap; } ret = hv_pcie_init_irq_domain(hbus); if (ret) goto free_fwnode; ret = hv_pci_query_relations(hdev); if (ret) goto free_irq_domain; ret = hv_pci_enter_d0(hdev); if (ret) goto free_irq_domain; ret = hv_pci_allocate_bridge_windows(hbus); if (ret) goto free_irq_domain; ret = hv_send_resources_allocated(hdev); if (ret) goto free_windows; prepopulate_bars(hbus); hbus->state = hv_pcibus_probed; ret = create_root_hv_pci_bus(hbus); if (ret) goto free_windows; return 0; free_windows: hv_pci_free_bridge_windows(hbus); free_irq_domain: irq_domain_remove(hbus->irq_domain); free_fwnode: irq_domain_free_fwnode(hbus->sysdata.fwnode); unmap: iounmap(hbus->cfg_addr); free_config: hv_free_config_window(hbus); close: vmbus_close(hdev->channel); destroy_wq: destroy_workqueue(hbus->wq); free_dom: hv_put_dom_num(hbus->sysdata.domain); free_bus: kfree(hbus); return ret; } static int hv_pci_bus_exit(struct hv_device *hdev, bool hibernating) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); struct { struct pci_packet teardown_packet; u8 buffer[sizeof(struct pci_message)]; } pkt; struct hv_dr_state *dr; struct hv_pci_compl comp_pkt; int ret; /* * After the host sends the RESCIND_CHANNEL message, it doesn't * access the per-channel ringbuffer any longer. */ if (hdev->channel->rescind) return 0; if (!hibernating) { /* Delete any children which might still exist. */ dr = kzalloc(sizeof(*dr), GFP_KERNEL); if (dr && hv_pci_start_relations_work(hbus, dr)) kfree(dr); } ret = hv_send_resources_released(hdev); if (ret) { dev_err(&hdev->device, "Couldn't send resources released packet(s)\n"); return ret; } memset(&pkt.teardown_packet, 0, sizeof(pkt.teardown_packet)); init_completion(&comp_pkt.host_event); pkt.teardown_packet.completion_func = hv_pci_generic_compl; pkt.teardown_packet.compl_ctxt = &comp_pkt; pkt.teardown_packet.message[0].type = PCI_BUS_D0EXIT; ret = vmbus_sendpacket(hdev->channel, &pkt.teardown_packet.message, sizeof(struct pci_message), (unsigned long)&pkt.teardown_packet, VM_PKT_DATA_INBAND, VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED); if (ret) return ret; if (wait_for_completion_timeout(&comp_pkt.host_event, 10 * HZ) == 0) return -ETIMEDOUT; return 0; } /** * hv_pci_remove() - Remove routine for this VMBus channel * @hdev: VMBus's tracking struct for this root PCI bus * * Return: 0 on success, -errno on failure */ static int hv_pci_remove(struct hv_device *hdev) { struct hv_pcibus_device *hbus; int ret; hbus = hv_get_drvdata(hdev); if (hbus->state == hv_pcibus_installed) { /* Remove the bus from PCI's point of view. */ pci_lock_rescan_remove(); pci_stop_root_bus(hbus->pci_bus); hv_pci_remove_slots(hbus); pci_remove_root_bus(hbus->pci_bus); pci_unlock_rescan_remove(); hbus->state = hv_pcibus_removed; } ret = hv_pci_bus_exit(hdev, false); vmbus_close(hdev->channel); iounmap(hbus->cfg_addr); hv_free_config_window(hbus); pci_free_resource_list(&hbus->resources_for_children); hv_pci_free_bridge_windows(hbus); irq_domain_remove(hbus->irq_domain); irq_domain_free_fwnode(hbus->sysdata.fwnode); put_hvpcibus(hbus); wait_for_completion(&hbus->remove_event); destroy_workqueue(hbus->wq); hv_put_dom_num(hbus->sysdata.domain); kfree(hbus); return ret; } static int hv_pci_suspend(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); enum hv_pcibus_state old_state; int ret; /* * hv_pci_suspend() must make sure there are no pending work items * before calling vmbus_close(), since it runs in a process context * as a callback in dpm_suspend(). When it starts to run, the channel * callback hv_pci_onchannelcallback(), which runs in a tasklet * context, can be still running concurrently and scheduling new work * items onto hbus->wq in hv_pci_devices_present() and * hv_pci_eject_device(), and the work item handlers can access the * vmbus channel, which can be being closed by hv_pci_suspend(), e.g. * the work item handler pci_devices_present_work() -> * new_pcichild_device() writes to the vmbus channel. * * To eliminate the race, hv_pci_suspend() disables the channel * callback tasklet, sets hbus->state to hv_pcibus_removing, and * re-enables the tasklet. This way, when hv_pci_suspend() proceeds, * it knows that no new work item can be scheduled, and then it flushes * hbus->wq and safely closes the vmbus channel. */ tasklet_disable(&hdev->channel->callback_event); /* Change the hbus state to prevent new work items. */ old_state = hbus->state; if (hbus->state == hv_pcibus_installed) hbus->state = hv_pcibus_removing; tasklet_enable(&hdev->channel->callback_event); if (old_state != hv_pcibus_installed) return -EINVAL; flush_workqueue(hbus->wq); ret = hv_pci_bus_exit(hdev, true); if (ret) return ret; vmbus_close(hdev->channel); return 0; } static int hv_pci_resume(struct hv_device *hdev) { struct hv_pcibus_device *hbus = hv_get_drvdata(hdev); enum pci_protocol_version_t version[1]; int ret; hbus->state = hv_pcibus_init; ret = vmbus_open(hdev->channel, pci_ring_size, pci_ring_size, NULL, 0, hv_pci_onchannelcallback, hbus); if (ret) return ret; /* Only use the version that was in use before hibernation. */ version[0] = hbus->protocol_version; ret = hv_pci_protocol_negotiation(hdev, version, 1); if (ret) goto out; ret = hv_pci_query_relations(hdev); if (ret) goto out; ret = hv_pci_enter_d0(hdev); if (ret) goto out; ret = hv_send_resources_allocated(hdev); if (ret) goto out; prepopulate_bars(hbus); hbus->state = hv_pcibus_installed; return 0; out: vmbus_close(hdev->channel); return ret; } static const struct hv_vmbus_device_id hv_pci_id_table[] = { /* PCI Pass-through Class ID */ /* 44C4F61D-4444-4400-9D52-802E27EDE19F */ { HV_PCIE_GUID, }, { }, }; MODULE_DEVICE_TABLE(vmbus, hv_pci_id_table); static struct hv_driver hv_pci_drv = { .name = "hv_pci", .id_table = hv_pci_id_table, .probe = hv_pci_probe, .remove = hv_pci_remove, .suspend = hv_pci_suspend, .resume = hv_pci_resume, }; static void __exit exit_hv_pci_drv(void) { vmbus_driver_unregister(&hv_pci_drv); hvpci_block_ops.read_block = NULL; hvpci_block_ops.write_block = NULL; hvpci_block_ops.reg_blk_invalidate = NULL; } static int __init init_hv_pci_drv(void) { /* Set the invalid domain number's bit, so it will not be used */ set_bit(HVPCI_DOM_INVALID, hvpci_dom_map); /* Initialize PCI block r/w interface */ hvpci_block_ops.read_block = hv_read_config_block; hvpci_block_ops.write_block = hv_write_config_block; hvpci_block_ops.reg_blk_invalidate = hv_register_block_invalidate; return vmbus_driver_register(&hv_pci_drv); } module_init(init_hv_pci_drv); module_exit(exit_hv_pci_drv); MODULE_DESCRIPTION("Hyper-V PCI"); MODULE_LICENSE("GPL v2");
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