arch/x86/include/asm/kvm_para.h

   1 #ifndef _ASM_X86_KVM_PARA_H
   2 #define _ASM_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 #define KVM_FEATURE_NOP_IO_DELAY        1
  15 #define KVM_FEATURE_MMU_OP              2
  16
  17 #define MSR_KVM_WALL_CLOCK  0x11
  18 #define MSR_KVM_SYSTEM_TIME 0x12
  19
  20 #define KVM_MAX_MMU_OP_BATCH           32
  21
  22 /* Operations for KVM_HC_MMU_OP */
  23 #define KVM_MMU_OP_WRITE_PTE            1
  24 #define KVM_MMU_OP_FLUSH_TLB            2
  25 #define KVM_MMU_OP_RELEASE_PT           3
  26
  27 /* Payload for KVM_HC_MMU_OP */
  28 struct kvm_mmu_op_header {
  29         __u32 op;
  30         __u32 pad;
  31 };
  32
  33 struct kvm_mmu_op_write_pte {
  34         struct kvm_mmu_op_header header;
  35         __u64 pte_phys;
  36         __u64 pte_val;
  37 };
  38
  39 struct kvm_mmu_op_flush_tlb {
  40         struct kvm_mmu_op_header header;
  41 };
  42
  43 struct kvm_mmu_op_release_pt {
  44         struct kvm_mmu_op_header header;
  45         __u64 pt_phys;
  46 };
  47
  48 #ifdef __KERNEL__
  49 #include <asm/processor.h>
  50
  51 extern void kvmclock_init(void);
  52
  53
  54 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  55  * trap that we will then rewrite to the appropriate instruction.
  56  */
  57 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
  58
  59 /* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
  60  * instruction.  The hypervisor may replace it with something else but only the
  61  * instructions are guaranteed to be supported.
  62  *
  63  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
  64  * The hypercall number should be placed in rax and the return value will be
  65  * placed in rax.  No other registers will be clobbered unless explicited
  66  * noted by the particular hypercall.
  67  */
  68
  69 static inline long kvm_hypercall0(unsigned int nr)
  70 {
  71         long ret;
  72         asm volatile(KVM_HYPERCALL
  73                      : "=a"(ret)
  74                      : "a"(nr)
  75                      : "memory");
  76         return ret;
  77 }
  78
  79 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
  80 {
  81         long ret;
  82         asm volatile(KVM_HYPERCALL
  83                      : "=a"(ret)
  84                      : "a"(nr), "b"(p1)
  85                      : "memory");
  86         return ret;
  87 }
  88
  89 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
  90                                   unsigned long p2)
  91 {
  92         long ret;
  93         asm volatile(KVM_HYPERCALL
  94                      : "=a"(ret)
  95                      : "a"(nr), "b"(p1), "c"(p2)
  96                      : "memory");
  97         return ret;
  98 }
  99
 100 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
 101                                   unsigned long p2, unsigned long p3)
 102 {
 103         long ret;
 104         asm volatile(KVM_HYPERCALL
 105                      : "=a"(ret)
 106                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
 107                      : "memory");
 108         return ret;
 109 }
 110
 111 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
 112                                   unsigned long p2, unsigned long p3,
 113                                   unsigned long p4)
 114 {
 115         long ret;
 116         asm volatile(KVM_HYPERCALL
 117                      : "=a"(ret)
 118                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
 119                      : "memory");
 120         return ret;
 121 }
 122
 123 static inline int kvm_para_available(void)
 124 {
 125         unsigned int eax, ebx, ecx, edx;
 126         char signature[13];
 127
 128         cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
 129         memcpy(signature + 0, &ebx, 4);
 130         memcpy(signature + 4, &ecx, 4);
 131         memcpy(signature + 8, &edx, 4);
 132         signature[12] = 0;
 133
 134         if (strcmp(signature, "KVMKVMKVM") == 0)
 135                 return 1;
 136
 137         return 0;
 138 }
 139
 140 static inline unsigned int kvm_arch_para_features(void)
 141 {
 142         return cpuid_eax(KVM_CPUID_FEATURES);
 143 }
 144
 145 #endif
 146
 147 #endif /* _ASM_X86_KVM_PARA_H */