include/asm-x86/kvm_para.h

   1 #ifndef __X86_KVM_PARA_H
   2 #define __X86_KVM_PARA_H
   3
   4 /* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx.  It
   5  * should be used to determine that a VM is running under KVM.
   6  */
   7 #define KVM_CPUID_SIGNATURE     0x40000000
   8
   9 /* This CPUID returns a feature bitmap in eax.  Before enabling a particular
  10  * paravirtualization, the appropriate feature bit should be checked.
  11  */
  12 #define KVM_CPUID_FEATURES      0x40000001
  13 #define KVM_FEATURE_CLOCKSOURCE 0
  14
  15 #define MSR_KVM_WALL_CLOCK  0x11
  16 #define MSR_KVM_SYSTEM_TIME 0x12
  17
  18 #ifdef __KERNEL__
  19 #include <asm/processor.h>
  20
  21 /* xen binary-compatible interface. See xen headers for details */
  22 struct kvm_vcpu_time_info {
  23         uint32_t version;
  24         uint32_t pad0;
  25         uint64_t tsc_timestamp;
  26         uint64_t system_time;
  27         uint32_t tsc_to_system_mul;
  28         int8_t   tsc_shift;
  29         int8_t   pad[3];
  30 } __attribute__((__packed__)); /* 32 bytes */
  31
  32 struct kvm_wall_clock {
  33         uint32_t wc_version;
  34         uint32_t wc_sec;
  35         uint32_t wc_nsec;
  36 } __attribute__((__packed__));
  37
  38
  39 extern void kvmclock_init(void);
  40
  41
  42 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  43  * trap that we will then rewrite to the appropriate instruction.
  44  */
  45 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
  46
  47 /* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
  48  * instruction.  The hypervisor may replace it with something else but only the
  49  * instructions are guaranteed to be supported.
  50  *
  51  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
  52  * The hypercall number should be placed in rax and the return value will be
  53  * placed in rax.  No other registers will be clobbered unless explicited
  54  * noted by the particular hypercall.
  55  */
  56
  57 static inline long kvm_hypercall0(unsigned int nr)
  58 {
  59         long ret;
  60         asm volatile(KVM_HYPERCALL
  61                      : "=a"(ret)
  62                      : "a"(nr));
  63         return ret;
  64 }
  65
  66 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
  67 {
  68         long ret;
  69         asm volatile(KVM_HYPERCALL
  70                      : "=a"(ret)
  71                      : "a"(nr), "b"(p1));
  72         return ret;
  73 }
  74
  75 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
  76                                   unsigned long p2)
  77 {
  78         long ret;
  79         asm volatile(KVM_HYPERCALL
  80                      : "=a"(ret)
  81                      : "a"(nr), "b"(p1), "c"(p2));
  82         return ret;
  83 }
  84
  85 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
  86                                   unsigned long p2, unsigned long p3)
  87 {
  88         long ret;
  89         asm volatile(KVM_HYPERCALL
  90                      : "=a"(ret)
  91                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3));
  92         return ret;
  93 }
  94
  95 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
  96                                   unsigned long p2, unsigned long p3,
  97                                   unsigned long p4)
  98 {
  99         long ret;
 100         asm volatile(KVM_HYPERCALL
 101                      : "=a"(ret)
 102                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4));
 103         return ret;
 104 }
 105
 106 static inline int kvm_para_available(void)
 107 {
 108         unsigned int eax, ebx, ecx, edx;
 109         char signature[13];
 110
 111         cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
 112         memcpy(signature + 0, &ebx, 4);
 113         memcpy(signature + 4, &ecx, 4);
 114         memcpy(signature + 8, &edx, 4);
 115         signature[12] = 0;
 116
 117         if (strcmp(signature, "KVMKVMKVM") == 0)
 118                 return 1;
 119
 120         return 0;
 121 }
 122
 123 static inline unsigned int kvm_arch_para_features(void)
 124 {
 125         return cpuid_eax(KVM_CPUID_FEATURES);
 126 }
 127
 128 #endif
 129
 130 #endif