arch/x86/include/asm/kvm_para.h

   1 #ifndef _ASM_X86_KVM_PARA_H
   2 #define _ASM_X86_KVM_PARA_H
   3
   4 #include <linux/types.h>
   5
   6 /* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx.  It
   7  * should be used to determine that a VM is running under KVM.
   8  */
   9 #define KVM_CPUID_SIGNATURE     0x40000000
  10
  11 /* This CPUID returns a feature bitmap in eax.  Before enabling a particular
  12  * paravirtualization, the appropriate feature bit should be checked.
  13  */
  14 #define KVM_CPUID_FEATURES      0x40000001
  15 #define KVM_FEATURE_CLOCKSOURCE         0
  16 #define KVM_FEATURE_NOP_IO_DELAY        1
  17 #define KVM_FEATURE_MMU_OP              2
  18
  19 #define MSR_KVM_WALL_CLOCK  0x11
  20 #define MSR_KVM_SYSTEM_TIME 0x12
  21
  22 #define KVM_MAX_MMU_OP_BATCH           32
  23
  24 /* Operations for KVM_HC_MMU_OP */
  25 #define KVM_MMU_OP_WRITE_PTE            1
  26 #define KVM_MMU_OP_FLUSH_TLB            2
  27 #define KVM_MMU_OP_RELEASE_PT           3
  28
  29 /* Payload for KVM_HC_MMU_OP */
  30 struct kvm_mmu_op_header {
  31         __u32 op;
  32         __u32 pad;
  33 };
  34
  35 struct kvm_mmu_op_write_pte {
  36         struct kvm_mmu_op_header header;
  37         __u64 pte_phys;
  38         __u64 pte_val;
  39 };
  40
  41 struct kvm_mmu_op_flush_tlb {
  42         struct kvm_mmu_op_header header;
  43 };
  44
  45 struct kvm_mmu_op_release_pt {
  46         struct kvm_mmu_op_header header;
  47         __u64 pt_phys;
  48 };
  49
  50 #ifdef __KERNEL__
  51 #include <asm/processor.h>
  52
  53 extern void kvmclock_init(void);
  54
  55
  56 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  57  * trap that we will then rewrite to the appropriate instruction.
  58  */
  59 #define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
  60
  61 /* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
  62  * instruction.  The hypervisor may replace it with something else but only the
  63  * instructions are guaranteed to be supported.
  64  *
  65  * Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
  66  * The hypercall number should be placed in rax and the return value will be
  67  * placed in rax.  No other registers will be clobbered unless explicited
  68  * noted by the particular hypercall.
  69  */
  70
  71 static inline long kvm_hypercall0(unsigned int nr)
  72 {
  73         long ret;
  74         asm volatile(KVM_HYPERCALL
  75                      : "=a"(ret)
  76                      : "a"(nr)
  77                      : "memory");
  78         return ret;
  79 }
  80
  81 static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
  82 {
  83         long ret;
  84         asm volatile(KVM_HYPERCALL
  85                      : "=a"(ret)
  86                      : "a"(nr), "b"(p1)
  87                      : "memory");
  88         return ret;
  89 }
  90
  91 static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
  92                                   unsigned long p2)
  93 {
  94         long ret;
  95         asm volatile(KVM_HYPERCALL
  96                      : "=a"(ret)
  97                      : "a"(nr), "b"(p1), "c"(p2)
  98                      : "memory");
  99         return ret;
 100 }
 101
 102 static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
 103                                   unsigned long p2, unsigned long p3)
 104 {
 105         long ret;
 106         asm volatile(KVM_HYPERCALL
 107                      : "=a"(ret)
 108                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3)
 109                      : "memory");
 110         return ret;
 111 }
 112
 113 static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
 114                                   unsigned long p2, unsigned long p3,
 115                                   unsigned long p4)
 116 {
 117         long ret;
 118         asm volatile(KVM_HYPERCALL
 119                      : "=a"(ret)
 120                      : "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4)
 121                      : "memory");
 122         return ret;
 123 }
 124
 125 static inline int kvm_para_available(void)
 126 {
 127         unsigned int eax, ebx, ecx, edx;
 128         char signature[13];
 129
 130         cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
 131         memcpy(signature + 0, &ebx, 4);
 132         memcpy(signature + 4, &ecx, 4);
 133         memcpy(signature + 8, &edx, 4);
 134         signature[12] = 0;
 135
 136         if (strcmp(signature, "KVMKVMKVM") == 0)
 137                 return 1;
 138
 139         return 0;
 140 }
 141
 142 static inline unsigned int kvm_arch_para_features(void)
 143 {
 144         return cpuid_eax(KVM_CPUID_FEATURES);
 145 }
 146
 147 #endif
 148
 149 #endif /* _ASM_X86_KVM_PARA_H */