cregit-Linux how code gets into the kernel

Release 4.12 include/linux/hyperv.h

Directory: include/linux
/*
 *
 * Copyright (c) 2011, Microsoft Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
 * Place - Suite 330, Boston, MA 02111-1307 USA.
 *
 * Authors:
 *   Haiyang Zhang <haiyangz@microsoft.com>
 *   Hank Janssen  <hjanssen@microsoft.com>
 *   K. Y. Srinivasan <kys@microsoft.com>
 *
 */

#ifndef _HYPERV_H

#define _HYPERV_H

#include <uapi/linux/hyperv.h>
#include <uapi/asm/hyperv.h>

#include <linux/types.h>
#include <linux/scatterlist.h>
#include <linux/list.h>
#include <linux/timer.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
#include <linux/interrupt.h>


#define MAX_PAGE_BUFFER_COUNT				32

#define MAX_MULTIPAGE_BUFFER_COUNT			32 
/* 128K */

#pragma pack(push, 1)

/* Single-page buffer */

struct hv_page_buffer {
	
u32 len;
	
u32 offset;
	
u64 pfn;
};

/* Multiple-page buffer */

struct hv_multipage_buffer {
	/* Length and Offset determines the # of pfns in the array */
	
u32 len;
	
u32 offset;
	
u64 pfn_array[MAX_MULTIPAGE_BUFFER_COUNT];
};

/*
 * Multiple-page buffer array; the pfn array is variable size:
 * The number of entries in the PFN array is determined by
 * "len" and "offset".
 */

struct hv_mpb_array {
	/* Length and Offset determines the # of pfns in the array */
	
u32 len;
	
u32 offset;
	
u64 pfn_array[];
};

/* 0x18 includes the proprietary packet header */

#define MAX_PAGE_BUFFER_PACKET		(0x18 +                 \
                                        (sizeof(struct hv_page_buffer) * \
                                         MAX_PAGE_BUFFER_COUNT))

#define MAX_MULTIPAGE_BUFFER_PACKET	(0x18 +                 \
                                         sizeof(struct hv_multipage_buffer))


#pragma pack(pop)


struct hv_ring_buffer {
	/* Offset in bytes from the start of ring data below */
	
u32 write_index;

	/* Offset in bytes from the start of ring data below */
	
u32 read_index;

	
u32 interrupt_mask;

	/*
         * Win8 uses some of the reserved bits to implement
         * interrupt driven flow management. On the send side
         * we can request that the receiver interrupt the sender
         * when the ring transitions from being full to being able
         * to handle a message of size "pending_send_sz".
         *
         * Add necessary state for this enhancement.
         */
	
u32 pending_send_sz;

	
u32 reserved1[12];

	union {
		struct {
			
u32 feat_pending_send_sz:1;
		};
		
u32 value;
	
} feature_bits;

	/* Pad it to PAGE_SIZE so that data starts on page boundary */
	
u8	reserved2[4028];

	/*
         * Ring data starts here + RingDataStartOffset
         * !!! DO NOT place any fields below this !!!
         */
	
u8 buffer[0];

} __packed;


struct hv_ring_buffer_info {
	
struct hv_ring_buffer *ring_buffer;
	
u32 ring_size;			/* Include the shared header */
	
spinlock_t ring_lock;

	
u32 ring_datasize;		/* < ring_size */
	
u32 ring_data_startoffset;
	
u32 priv_write_index;
	
u32 priv_read_index;
	
u32 cached_read_index;
};

/*
 *
 * hv_get_ringbuffer_availbytes()
 *
 * Get number of bytes available to read and to write to
 * for the specified ring buffer
 */

static inline void hv_get_ringbuffer_availbytes(const struct hv_ring_buffer_info *rbi, u32 *read, u32 *write) { u32 read_loc, write_loc, dsize; /* Capture the read/write indices before they changed */ read_loc = rbi->ring_buffer->read_index; write_loc = rbi->ring_buffer->write_index; dsize = rbi->ring_datasize; *write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : read_loc - write_loc; *read = dsize - *write; }

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static inline u32 hv_get_bytes_to_read(const struct hv_ring_buffer_info *rbi) { u32 read_loc, write_loc, dsize, read; dsize = rbi->ring_datasize; read_loc = rbi->ring_buffer->read_index; write_loc = READ_ONCE(rbi->ring_buffer->write_index); read = write_loc >= read_loc ? (write_loc - read_loc) : (dsize - read_loc) + write_loc; return read; }

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static inline u32 hv_get_bytes_to_write(const struct hv_ring_buffer_info *rbi) { u32 read_loc, write_loc, dsize, write; dsize = rbi->ring_datasize; read_loc = READ_ONCE(rbi->ring_buffer->read_index); write_loc = rbi->ring_buffer->write_index; write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : read_loc - write_loc; return write; }

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static inline u32 hv_get_cached_bytes_to_write( const struct hv_ring_buffer_info *rbi) { u32 read_loc, write_loc, dsize, write; dsize = rbi->ring_datasize; read_loc = rbi->cached_read_index; write_loc = rbi->ring_buffer->write_index; write = write_loc >= read_loc ? dsize - (write_loc - read_loc) : read_loc - write_loc; return write; }

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/* * VMBUS version is 32 bit entity broken up into * two 16 bit quantities: major_number. minor_number. * * 0 . 13 (Windows Server 2008) * 1 . 1 (Windows 7) * 2 . 4 (Windows 8) * 3 . 0 (Windows 8 R2) * 4 . 0 (Windows 10) */ #define VERSION_WS2008 ((0 << 16) | (13)) #define VERSION_WIN7 ((1 << 16) | (1)) #define VERSION_WIN8 ((2 << 16) | (4)) #define VERSION_WIN8_1 ((3 << 16) | (0)) #define VERSION_WIN10 ((4 << 16) | (0)) #define VERSION_INVAL -1 #define VERSION_CURRENT VERSION_WIN10 /* Make maximum size of pipe payload of 16K */ #define MAX_PIPE_DATA_PAYLOAD (sizeof(u8) * 16384) /* Define PipeMode values. */ #define VMBUS_PIPE_TYPE_BYTE 0x00000000 #define VMBUS_PIPE_TYPE_MESSAGE 0x00000004 /* The size of the user defined data buffer for non-pipe offers. */ #define MAX_USER_DEFINED_BYTES 120 /* The size of the user defined data buffer for pipe offers. */ #define MAX_PIPE_USER_DEFINED_BYTES 116 /* * At the center of the Channel Management library is the Channel Offer. This * struct contains the fundamental information about an offer. */ struct vmbus_channel_offer { uuid_le if_type; uuid_le if_instance; /* * These two fields are not currently used. */ u64 reserved1; u64 reserved2; u16 chn_flags; u16 mmio_megabytes; /* in bytes * 1024 * 1024 */ union { /* Non-pipes: The user has MAX_USER_DEFINED_BYTES bytes. */ struct { unsigned char user_def[MAX_USER_DEFINED_BYTES]; } std; /* * Pipes: * The following sructure is an integrated pipe protocol, which * is implemented on top of standard user-defined data. Pipe * clients have MAX_PIPE_USER_DEFINED_BYTES left for their own * use. */ struct { u32 pipe_mode; unsigned char user_def[MAX_PIPE_USER_DEFINED_BYTES]; } pipe; } u; /* * The sub_channel_index is defined in win8. */ u16 sub_channel_index; u16 reserved3; } __packed; /* Server Flags */ #define VMBUS_CHANNEL_ENUMERATE_DEVICE_INTERFACE 1 #define VMBUS_CHANNEL_SERVER_SUPPORTS_TRANSFER_PAGES 2 #define VMBUS_CHANNEL_SERVER_SUPPORTS_GPADLS 4 #define VMBUS_CHANNEL_NAMED_PIPE_MODE 0x10 #define VMBUS_CHANNEL_LOOPBACK_OFFER 0x100 #define VMBUS_CHANNEL_PARENT_OFFER 0x200 #define VMBUS_CHANNEL_REQUEST_MONITORED_NOTIFICATION 0x400 #define VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER 0x2000 struct vmpacket_descriptor { u16 type; u16 offset8; u16 len8; u16 flags; u64 trans_id; } __packed; struct vmpacket_header { u32 prev_pkt_start_offset; struct vmpacket_descriptor descriptor; } __packed; struct vmtransfer_page_range { u32 byte_count; u32 byte_offset; } __packed; struct vmtransfer_page_packet_header { struct vmpacket_descriptor d; u16 xfer_pageset_id; u8 sender_owns_set; u8 reserved; u32 range_cnt; struct vmtransfer_page_range ranges[1]; } __packed; struct vmgpadl_packet_header { struct vmpacket_descriptor d; u32 gpadl; u32 reserved; } __packed; struct vmadd_remove_transfer_page_set { struct vmpacket_descriptor d; u32 gpadl; u16 xfer_pageset_id; u16 reserved; } __packed; /* * This structure defines a range in guest physical space that can be made to * look virtually contiguous. */ struct gpa_range { u32 byte_count; u32 byte_offset; u64 pfn_array[0]; }; /* * This is the format for an Establish Gpadl packet, which contains a handle by * which this GPADL will be known and a set of GPA ranges associated with it. * This can be converted to a MDL by the guest OS. If there are multiple GPA * ranges, then the resulting MDL will be "chained," representing multiple VA * ranges. */ struct vmestablish_gpadl { struct vmpacket_descriptor d; u32 gpadl; u32 range_cnt; struct gpa_range range[1]; } __packed; /* * This is the format for a Teardown Gpadl packet, which indicates that the * GPADL handle in the Establish Gpadl packet will never be referenced again. */ struct vmteardown_gpadl { struct vmpacket_descriptor d; u32 gpadl; u32 reserved; /* for alignment to a 8-byte boundary */ } __packed; /* * This is the format for a GPA-Direct packet, which contains a set of GPA * ranges, in addition to commands and/or data. */ struct vmdata_gpa_direct { struct vmpacket_descriptor d; u32 reserved; u32 range_cnt; struct gpa_range range[1]; } __packed; /* This is the format for a Additional Data Packet. */ struct vmadditional_data { struct vmpacket_descriptor d; u64 total_bytes; u32 offset; u32 byte_cnt; unsigned char data[1]; } __packed; union vmpacket_largest_possible_header { struct vmpacket_descriptor simple_hdr; struct vmtransfer_page_packet_header xfer_page_hdr; struct vmgpadl_packet_header gpadl_hdr; struct vmadd_remove_transfer_page_set add_rm_xfer_page_hdr; struct vmestablish_gpadl establish_gpadl_hdr; struct vmteardown_gpadl teardown_gpadl_hdr; struct vmdata_gpa_direct data_gpa_direct_hdr; }; #define VMPACKET_DATA_START_ADDRESS(__packet) \ (void *)(((unsigned char *)__packet) + \ ((struct vmpacket_descriptor)__packet)->offset8 * 8) #define VMPACKET_DATA_LENGTH(__packet) \ ((((struct vmpacket_descriptor)__packet)->len8 - \ ((struct vmpacket_descriptor)__packet)->offset8) * 8) #define VMPACKET_TRANSFER_MODE(__packet) \ (((struct IMPACT)__packet)->type) enum vmbus_packet_type { VM_PKT_INVALID = 0x0, VM_PKT_SYNCH = 0x1, VM_PKT_ADD_XFER_PAGESET = 0x2, VM_PKT_RM_XFER_PAGESET = 0x3, VM_PKT_ESTABLISH_GPADL = 0x4, VM_PKT_TEARDOWN_GPADL = 0x5, VM_PKT_DATA_INBAND = 0x6, VM_PKT_DATA_USING_XFER_PAGES = 0x7, VM_PKT_DATA_USING_GPADL = 0x8, VM_PKT_DATA_USING_GPA_DIRECT = 0x9, VM_PKT_CANCEL_REQUEST = 0xa, VM_PKT_COMP = 0xb, VM_PKT_DATA_USING_ADDITIONAL_PKT = 0xc, VM_PKT_ADDITIONAL_DATA = 0xd }; #define VMBUS_DATA_PACKET_FLAG_COMPLETION_REQUESTED 1 /* Version 1 messages */ enum vmbus_channel_message_type { CHANNELMSG_INVALID = 0, CHANNELMSG_OFFERCHANNEL = 1, CHANNELMSG_RESCIND_CHANNELOFFER = 2, CHANNELMSG_REQUESTOFFERS = 3, CHANNELMSG_ALLOFFERS_DELIVERED = 4, CHANNELMSG_OPENCHANNEL = 5, CHANNELMSG_OPENCHANNEL_RESULT = 6, CHANNELMSG_CLOSECHANNEL = 7, CHANNELMSG_GPADL_HEADER = 8, CHANNELMSG_GPADL_BODY = 9, CHANNELMSG_GPADL_CREATED = 10, CHANNELMSG_GPADL_TEARDOWN = 11, CHANNELMSG_GPADL_TORNDOWN = 12, CHANNELMSG_RELID_RELEASED = 13, CHANNELMSG_INITIATE_CONTACT = 14, CHANNELMSG_VERSION_RESPONSE = 15, CHANNELMSG_UNLOAD = 16, CHANNELMSG_UNLOAD_RESPONSE = 17, CHANNELMSG_18 = 18, CHANNELMSG_19 = 19, CHANNELMSG_20 = 20, CHANNELMSG_TL_CONNECT_REQUEST = 21, CHANNELMSG_COUNT }; struct vmbus_channel_message_header { enum vmbus_channel_message_type msgtype; u32 padding; } __packed; /* Query VMBus Version parameters */ struct vmbus_channel_query_vmbus_version { struct vmbus_channel_message_header header; u32 version; } __packed; /* VMBus Version Supported parameters */ struct vmbus_channel_version_supported { struct vmbus_channel_message_header header; u8 version_supported; } __packed; /* Offer Channel parameters */ struct vmbus_channel_offer_channel { struct vmbus_channel_message_header header; struct vmbus_channel_offer offer; u32 child_relid; u8 monitorid; /* * win7 and beyond splits this field into a bit field. */ u8 monitor_allocated:1; u8 reserved:7; /* * These are new fields added in win7 and later. * Do not access these fields without checking the * negotiated protocol. * * If "is_dedicated_interrupt" is set, we must not set the * associated bit in the channel bitmap while sending the * interrupt to the host. * * connection_id is to be used in signaling the host. */ u16 is_dedicated_interrupt:1; u16 reserved1:15; u32 connection_id; } __packed; /* Rescind Offer parameters */ struct vmbus_channel_rescind_offer { struct vmbus_channel_message_header header; u32 child_relid; } __packed;
static inline u32 hv_ringbuffer_pending_size(const struct hv_ring_buffer_info *rbi) { return rbi->ring_buffer->pending_send_sz; }

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/* * Request Offer -- no parameters, SynIC message contains the partition ID * Set Snoop -- no parameters, SynIC message contains the partition ID * Clear Snoop -- no parameters, SynIC message contains the partition ID * All Offers Delivered -- no parameters, SynIC message contains the partition * ID * Flush Client -- no parameters, SynIC message contains the partition ID */ /* Open Channel parameters */ struct vmbus_channel_open_channel { struct vmbus_channel_message_header header; /* Identifies the specific VMBus channel that is being opened. */ u32 child_relid; /* ID making a particular open request at a channel offer unique. */ u32 openid; /* GPADL for the channel's ring buffer. */ u32 ringbuffer_gpadlhandle; /* * Starting with win8, this field will be used to specify * the target virtual processor on which to deliver the interrupt for * the host to guest communication. * Prior to win8, incoming channel interrupts would only * be delivered on cpu 0. Setting this value to 0 would * preserve the earlier behavior. */ u32 target_vp; /* * The upstream ring buffer begins at offset zero in the memory * described by RingBufferGpadlHandle. The downstream ring buffer * follows it at this offset (in pages). */ u32 downstream_ringbuffer_pageoffset; /* User-specific data to be passed along to the server endpoint. */ unsigned char userdata[MAX_USER_DEFINED_BYTES]; } __packed; /* Open Channel Result parameters */ struct vmbus_channel_open_result { struct vmbus_channel_message_header header; u32 child_relid; u32 openid; u32 status; } __packed; /* Close channel parameters; */ struct vmbus_channel_close_channel { struct vmbus_channel_message_header header; u32 child_relid; } __packed; /* Channel Message GPADL */ #define GPADL_TYPE_RING_BUFFER 1 #define GPADL_TYPE_SERVER_SAVE_AREA 2 #define GPADL_TYPE_TRANSACTION 8 /* * The number of PFNs in a GPADL message is defined by the number of * pages that would be spanned by ByteCount and ByteOffset. If the * implied number of PFNs won't fit in this packet, there will be a * follow-up packet that contains more. */ struct vmbus_channel_gpadl_header { struct vmbus_channel_message_header header; u32 child_relid; u32 gpadl; u16 range_buflen; u16 rangecount; struct gpa_range range[0]; } __packed; /* This is the followup packet that contains more PFNs. */ struct vmbus_channel_gpadl_body { struct vmbus_channel_message_header header; u32 msgnumber; u32 gpadl; u64 pfn[0]; } __packed; struct vmbus_channel_gpadl_created { struct vmbus_channel_message_header header; u32 child_relid; u32 gpadl; u32 creation_status; } __packed; struct vmbus_channel_gpadl_teardown { struct vmbus_channel_message_header header; u32 child_relid; u32 gpadl; } __packed; struct vmbus_channel_gpadl_torndown { struct vmbus_channel_message_header header; u32 gpadl; } __packed; struct vmbus_channel_relid_released { struct vmbus_channel_message_header header; u32 child_relid; } __packed; struct vmbus_channel_initiate_contact { struct vmbus_channel_message_header header; u32 vmbus_version_requested; u32 target_vcpu; /* The VCPU the host should respond to */ u64 interrupt_page; u64 monitor_page1; u64 monitor_page2; } __packed; /* Hyper-V socket: guest's connect()-ing to host */ struct vmbus_channel_tl_connect_request { struct vmbus_channel_message_header header; uuid_le guest_endpoint_id; uuid_le host_service_id; } __packed; struct vmbus_channel_version_response { struct vmbus_channel_message_header header; u8 version_supported; } __packed; enum vmbus_channel_state { CHANNEL_OFFER_STATE, CHANNEL_OPENING_STATE, CHANNEL_OPEN_STATE, CHANNEL_OPENED_STATE, }; /* * Represents each channel msg on the vmbus connection This is a * variable-size data structure depending on the msg type itself */ struct vmbus_channel_msginfo { /* Bookkeeping stuff */ struct list_head msglistentry; /* So far, this is only used to handle gpadl body message */ struct list_head submsglist; /* Synchronize the request/response if needed */ struct completion waitevent; struct vmbus_channel *waiting_channel; union { struct vmbus_channel_version_supported version_supported; struct vmbus_channel_open_result open_result; struct vmbus_channel_gpadl_torndown gpadl_torndown; struct vmbus_channel_gpadl_created gpadl_created; struct vmbus_channel_version_response version_response; } response; u32 msgsize; /* * The channel message that goes out on the "wire". * It will contain at minimum the VMBUS_CHANNEL_MESSAGE_HEADER header */ unsigned char msg[0]; }; struct vmbus_close_msg { struct vmbus_channel_msginfo info; struct vmbus_channel_close_channel msg; }; /* Define connection identifier type. */ union hv_connection_id { u32 asu32; struct { u32 id:24; u32 reserved:8; } u; }; /* Definition of the hv_signal_event hypercall input structure. */ struct hv_input_signal_event { union hv_connection_id connectionid; u16 flag_number; u16 rsvdz; }; struct hv_input_signal_event_buffer { u64 align8; struct hv_input_signal_event event; }; enum hv_numa_policy { HV_BALANCED = 0, HV_LOCALIZED, }; enum vmbus_device_type { HV_IDE = 0, HV_SCSI, HV_FC, HV_NIC, HV_ND, HV_PCIE, HV_FB, HV_KBD, HV_MOUSE, HV_KVP, HV_TS, HV_HB, HV_SHUTDOWN, HV_FCOPY, HV_BACKUP, HV_DM, HV_UNKNOWN, }; struct vmbus_device { u16 dev_type; uuid_le guid; bool perf_device; }; struct vmbus_channel { struct list_head listentry; struct hv_device *device_obj; enum vmbus_channel_state state; struct vmbus_channel_offer_channel offermsg; /* * These are based on the OfferMsg.MonitorId. * Save it here for easy access. */ u8 monitor_grp; u8 monitor_bit; bool rescind; /* got rescind msg */ u32 ringbuffer_gpadlhandle; /* Allocated memory for ring buffer */ void *ringbuffer_pages; u32 ringbuffer_pagecount; struct hv_ring_buffer_info outbound; /* send to parent */ struct hv_ring_buffer_info inbound; /* receive from parent */ spinlock_t inbound_lock; struct vmbus_close_msg close_msg; /* Channel callback's invoked in softirq context */ struct tasklet_struct callback_event; void (*onchannel_callback)(void *context); void *channel_callback_context; /* * A channel can be marked for one of three modes of reading: * BATCHED - callback called from taslket and should read * channel until empty. Interrupts from the host * are masked while read is in process (default). * DIRECT - callback called from tasklet (softirq). * ISR - callback called in interrupt context and must * invoke its own deferred processing. * Host interrupts are disabled and must be re-enabled * when ring is empty. */ enum hv_callback_mode { HV_CALL_BATCHED, HV_CALL_DIRECT, HV_CALL_ISR } callback_mode; bool is_dedicated_interrupt; struct hv_input_signal_event_buffer sig_buf; struct hv_input_signal_event *sig_event; /* * Starting with win8, this field will be used to specify * the target virtual processor on which to deliver the interrupt for * the host to guest communication. * Prior to win8, incoming channel interrupts would only * be delivered on cpu 0. Setting this value to 0 would * preserve the earlier behavior. */ u32 target_vp; /* The corresponding CPUID in the guest */ u32 target_cpu; /* * State to manage the CPU affiliation of channels. */ struct cpumask alloced_cpus_in_node; int numa_node; /* * Support for sub-channels. For high performance devices, * it will be useful to have multiple sub-channels to support * a scalable communication infrastructure with the host. * The support for sub-channels is implemented as an extention * to the current infrastructure. * The initial offer is considered the primary channel and this * offer message will indicate if the host supports sub-channels. * The guest is free to ask for sub-channels to be offerred and can * open these sub-channels as a normal "primary" channel. However, * all sub-channels will have the same type and instance guids as the * primary channel. Requests sent on a given channel will result in a * response on the same channel. */ /* * Sub-channel creation callback. This callback will be called in * process context when a sub-channel offer is received from the host. * The guest can open the sub-channel in the context of this callback. */ void (*sc_creation_callback)(struct vmbus_channel *new_sc); /* * Channel rescind callback. Some channels (the hvsock ones), need to * register a callback which is invoked in vmbus_onoffer_rescind(). */ void (*chn_rescind_callback)(struct vmbus_channel *channel); /* * The spinlock to protect the structure. It is being used to protect * test-and-set access to various attributes of the structure as well * as all sc_list operations. */ spinlock_t lock; /* * All Sub-channels of a primary channel are linked here. */ struct list_head sc_list; /* * Current number of sub-channels. */ int num_sc; /* * Number of a sub-channel (position within sc_list) which is supposed * to be used as the next outgoing channel. */ int next_oc; /* * The primary channel this sub-channel belongs to. * This will be NULL for the primary channel. */ struct vmbus_channel *primary_channel; /* * Support per-channel state for use by vmbus drivers. */ void *per_channel_state; /* * To support per-cpu lookup mapping of relid to channel, * link up channels based on their CPU affinity. */ struct list_head percpu_list; /* * Defer freeing channel until after all cpu's have * gone through grace period. */ struct rcu_head rcu; /* * For performance critical channels (storage, networking * etc,), Hyper-V has a mechanism to enhance the throughput * at the expense of latency: * When the host is to be signaled, we just set a bit in a shared page * and this bit will be inspected by the hypervisor within a certain * window and if the bit is set, the host will be signaled. The window * of time is the monitor latency - currently around 100 usecs. This * mechanism improves throughput by: * * A) Making the host more efficient - each time it wakes up, * potentially it will process morev number of packets. The * monitor latency allows a batch to build up. * B) By deferring the hypercall to signal, we will also minimize * the interrupts. * * Clearly, these optimizations improve throughput at the expense of * latency. Furthermore, since the channel is shared for both * control and data messages, control messages currently suffer * unnecessary latency adversley impacting performance and boot * time. To fix this issue, permit tagging the channel as being * in "low latency" mode. In this mode, we will bypass the monitor * mechanism. */ bool low_latency; /* * NUMA distribution policy: * We support teo policies: * 1) Balanced: Here all performance critical channels are * distributed evenly amongst all the NUMA nodes. * This policy will be the default policy. * 2) Localized: All channels of a given instance of a * performance critical service will be assigned CPUs * within a selected NUMA node. */ enum hv_numa_policy affinity_policy; };
static inline bool is_hvsock_channel(const struct vmbus_channel *c) { return !!(c->offermsg.offer.chn_flags & VMBUS_CHANNEL_TLNPI_PROVIDER_OFFER); }

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static inline void set_channel_affinity_state(struct vmbus_channel *c, enum hv_numa_policy policy) { c->affinity_policy = policy; }

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static inline void set_channel_read_mode(struct vmbus_channel *c, enum hv_callback_mode mode) { c->callback_mode = mode; }

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static inline void set_per_channel_state(struct vmbus_channel *c, void *s) { c->per_channel_state = s; }

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static inline void *get_per_channel_state(struct vmbus_channel *c) { return c->per_channel_state; }

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static inline void set_channel_pending_send_size(struct vmbus_channel *c, u32 size) { c->outbound.ring_buffer->pending_send_sz = size; }

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static inline void set_low_latency_mode(struct vmbus_channel *c) { c->low_latency = true; }

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static inline void clear_low_latency_mode(struct vmbus_channel *c) { c->low_latency = false; }

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K. Y. Srinivasan18100.00%1100.00%
Total18100.00%1100.00%

void vmbus_onmessage(void *context); int vmbus_request_offers(void); /* * APIs for managing sub-channels. */ void vmbus_set_sc_create_callback(struct vmbus_channel *primary_channel, void (*sc_cr_cb)(struct vmbus_channel *new_sc)); void vmbus_set_chn_rescind_callback(struct vmbus_channel *channel, void (*chn_rescind_cb)(struct vmbus_channel *)); /* * Retrieve the (sub) channel on which to send an outgoing request. * When a primary channel has multiple sub-channels, we choose a * channel whose VCPU binding is closest to the VCPU on which * this call is being made. */ struct vmbus_channel *vmbus_get_outgoing_channel(struct vmbus_channel *primary); /* * Check if sub-channels have already been offerred. This API will be useful * when the driver is unloaded after establishing sub-channels. In this case, * when the driver is re-loaded, the driver would have to check if the * subchannels have already been established before attempting to request * the creation of sub-channels. * This function returns TRUE to indicate that subchannels have already been * created. * This function should be invoked after setting the callback function for * sub-channel creation. */ bool vmbus_are_subchannels_present(struct vmbus_channel *primary); /* The format must be the same as struct vmdata_gpa_direct */ struct vmbus_channel_packet_page_buffer { u16 type; u16 dataoffset8; u16 length8; u16 flags; u64 transactionid; u32 reserved; u32 rangecount; struct hv_page_buffer range[MAX_PAGE_BUFFER_COUNT]; } __packed; /* The format must be the same as struct vmdata_gpa_direct */ struct vmbus_channel_packet_multipage_buffer { u16 type; u16 dataoffset8; u16 length8; u16 flags; u64 transactionid; u32 reserved; u32 rangecount; /* Always 1 in this case */ struct hv_multipage_buffer range; } __packed; /* The format must be the same as struct vmdata_gpa_direct */ struct vmbus_packet_mpb_array { u16 type; u16 dataoffset8; u16 length8; u16 flags; u64 transactionid; u32 reserved; u32 rangecount; /* Always 1 in this case */ struct hv_mpb_array range; } __packed; extern int vmbus_open(struct vmbus_channel *channel, u32 send_ringbuffersize, u32 recv_ringbuffersize, void *userdata, u32 userdatalen, void (*onchannel_callback)(void *context), void *context); extern void vmbus_close(struct vmbus_channel *channel); extern int vmbus_sendpacket(struct vmbus_channel *channel, void *buffer, u32 bufferLen, u64 requestid, enum vmbus_packet_type type, u32 flags); extern int vmbus_sendpacket_ctl(struct vmbus_channel *channel, void *buffer, u32 bufferLen, u64 requestid, enum vmbus_packet_type type, u32 flags); extern int vmbus_sendpacket_pagebuffer(struct vmbus_channel *channel, struct hv_page_buffer pagebuffers[], u32 pagecount, void *buffer, u32 bufferlen, u64 requestid); extern int vmbus_sendpacket_pagebuffer_ctl(struct vmbus_channel *