cregit-Linux how code gets into the kernel

Release 4.13 arch/x86/include/asm/mshyperv.h

#ifndef _ASM_X86_MSHYPER_H

#define _ASM_X86_MSHYPER_H

#include <linux/types.h>
#include <linux/atomic.h>
#include <asm/hyperv.h>

/*
 * The below CPUID leaves are present if VersionAndFeatures.HypervisorPresent
 * is set by CPUID(HVCPUID_VERSION_FEATURES).
 */

enum hv_cpuid_function {
	
HVCPUID_VERSION_FEATURES		= 0x00000001,
	
HVCPUID_VENDOR_MAXFUNCTION		= 0x40000000,
	
HVCPUID_INTERFACE			= 0x40000001,

	/*
         * The remaining functions depend on the value of
         * HVCPUID_INTERFACE
         */
	
HVCPUID_VERSION				= 0x40000002,
	
HVCPUID_FEATURES			= 0x40000003,
	
HVCPUID_ENLIGHTENMENT_INFO		= 0x40000004,
	
HVCPUID_IMPLEMENTATION_LIMITS		= 0x40000005,
};


struct ms_hyperv_info {
	
u32 features;
	
u32 misc_features;
	
u32 hints;
};

extern struct ms_hyperv_info ms_hyperv;

/*
 * Declare the MSR used to setup pages used to communicate with the hypervisor.
 */

union hv_x64_msr_hypercall_contents {
	
u64 as_uint64;
	struct {
		
u64 enable:1;
		
u64 reserved:11;
		
u64 guest_physical_address:52;
	};
};

/*
 * TSC page layout.
 */


struct ms_hyperv_tsc_page {
	
volatile u32 tsc_sequence;
	
u32 reserved1;
	
volatile u64 tsc_scale;
	
volatile s64 tsc_offset;
	
u64 reserved2[509];
};

/*
 * The guest OS needs to register the guest ID with the hypervisor.
 * The guest ID is a 64 bit entity and the structure of this ID is
 * specified in the Hyper-V specification:
 *
 * msdn.microsoft.com/en-us/library/windows/hardware/ff542653%28v=vs.85%29.aspx
 *
 * While the current guideline does not specify how Linux guest ID(s)
 * need to be generated, our plan is to publish the guidelines for
 * Linux and other guest operating systems that currently are hosted
 * on Hyper-V. The implementation here conforms to this yet
 * unpublished guidelines.
 *
 *
 * Bit(s)
 * 63 - Indicates if the OS is Open Source or not; 1 is Open Source
 * 62:56 - Os Type; Linux is 0x100
 * 55:48 - Distro specific identification
 * 47:16 - Linux kernel version number
 * 15:0  - Distro specific identification
 *
 *
 */


#define HV_LINUX_VENDOR_ID              0x8100

/*
 * Generate the guest ID based on the guideline described above.
 */


static inline __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version, __u64 d_info2) { __u64 guest_id = 0; guest_id = (((__u64)HV_LINUX_VENDOR_ID) << 48); guest_id |= (d_info1 << 48); guest_id |= (kernel_version << 16); guest_id |= d_info2; return guest_id; }

Contributors

PersonTokensPropCommitsCommitProp
K. Y. Srinivasan57100.00%2100.00%
Total57100.00%2100.00%

/* Free the message slot and signal end-of-message if required */
static inline void vmbus_signal_eom(struct hv_message *msg, u32 old_msg_type) { /* * On crash we're reading some other CPU's message page and we need * to be careful: this other CPU may already had cleared the header * and the host may already had delivered some other message there. * In case we blindly write msg->header.message_type we're going * to lose it. We can still lose a message of the same type but * we count on the fact that there can only be one * CHANNELMSG_UNLOAD_RESPONSE and we don't care about other messages * on crash. */ if (cmpxchg(&msg->header.message_type, old_msg_type, HVMSG_NONE) != old_msg_type) return; /* * Make sure the write to MessageType (ie set to * HVMSG_NONE) happens before we read the * MessagePending and EOMing. Otherwise, the EOMing * will not deliver any more messages since there is * no empty slot */ mb(); if (msg->header.message_flags.msg_pending) { /* * This will cause message queue rescan to * possibly deliver another msg from the * hypervisor */ wrmsrl(HV_X64_MSR_EOM, 0); } }

Contributors

PersonTokensPropCommitsCommitProp
K. Y. Srinivasan59100.00%1100.00%
Total59100.00%1100.00%

#define hv_init_timer(timer, tick) wrmsrl(timer, tick) #define hv_init_timer_config(config, val) wrmsrl(config, val) #define hv_get_simp(val) rdmsrl(HV_X64_MSR_SIMP, val) #define hv_set_simp(val) wrmsrl(HV_X64_MSR_SIMP, val) #define hv_get_siefp(val) rdmsrl(HV_X64_MSR_SIEFP, val) #define hv_set_siefp(val) wrmsrl(HV_X64_MSR_SIEFP, val) #define hv_get_synic_state(val) rdmsrl(HV_X64_MSR_SCONTROL, val) #define hv_set_synic_state(val) wrmsrl(HV_X64_MSR_SCONTROL, val) #define hv_get_vp_index(index) rdmsrl(HV_X64_MSR_VP_INDEX, index) #define hv_get_synint_state(int_num, val) rdmsrl(int_num, val) #define hv_set_synint_state(int_num, val) wrmsrl(int_num, val) void hyperv_callback_vector(void); #ifdef CONFIG_TRACING #define trace_hyperv_callback_vector hyperv_callback_vector #endif void hyperv_vector_handler(struct pt_regs *regs); void hv_setup_vmbus_irq(void (*handler)(void)); void hv_remove_vmbus_irq(void); void hv_setup_kexec_handler(void (*handler)(void)); void hv_remove_kexec_handler(void); void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs)); void hv_remove_crash_handler(void); #if IS_ENABLED(CONFIG_HYPERV) extern struct clocksource *hyperv_cs; void hyperv_init(void); void hyperv_report_panic(struct pt_regs *regs); bool hv_is_hypercall_page_setup(void); void hyperv_cleanup(void); #endif #ifdef CONFIG_HYPERV_TSCPAGE struct ms_hyperv_tsc_page *hv_get_tsc_page(void);
static inline u64 hv_read_tsc_page(const struct ms_hyperv_tsc_page *tsc_pg) { u64 scale, offset, cur_tsc; u32 sequence; /* * The protocol for reading Hyper-V TSC page is specified in Hypervisor * Top-Level Functional Specification ver. 3.0 and above. To get the * reference time we must do the following: * - READ ReferenceTscSequence * A special '0' value indicates the time source is unreliable and we * need to use something else. The currently published specification * versions (up to 4.0b) contain a mistake and wrongly claim '-1' * instead of '0' as the special value, see commit c35b82ef0294. * - ReferenceTime = * ((RDTSC() * ReferenceTscScale) >> 64) + ReferenceTscOffset * - READ ReferenceTscSequence again. In case its value has changed * since our first reading we need to discard ReferenceTime and repeat * the whole sequence as the hypervisor was updating the page in * between. */ do { sequence = READ_ONCE(tsc_pg->tsc_sequence); if (!sequence) return U64_MAX; /* * Make sure we read sequence before we read other values from * TSC page. */ smp_rmb(); scale = READ_ONCE(tsc_pg->tsc_scale); offset = READ_ONCE(tsc_pg->tsc_offset); cur_tsc = rdtsc_ordered(); /* * Make sure we read sequence after we read all other values * from TSC page. */ smp_rmb(); } while (READ_ONCE(tsc_pg->tsc_sequence) != sequence); return mul_u64_u64_shr(cur_tsc, scale, 64) + offset; }

Contributors

PersonTokensPropCommitsCommitProp
Vitaly Kuznetsov99100.00%1100.00%
Total99100.00%1100.00%

#else
static inline struct ms_hyperv_tsc_page *hv_get_tsc_page(void) { return NULL; }

Contributors

PersonTokensPropCommitsCommitProp
Vitaly Kuznetsov14100.00%1100.00%
Total14100.00%1100.00%

#endif #endif

Overall Contributors

PersonTokensPropCommitsCommitProp
K. Y. Srinivasan35159.90%1758.62%
Vitaly Kuznetsov18331.23%620.69%
H. Peter Anvin233.92%13.45%
Thomas Gleixner172.90%310.34%
Seiji Aguchi91.54%13.45%
Denis V. Lunev30.51%13.45%
Total586100.00%29100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
Created with cregit.