#ifndef __X86_KVM_PARA_H
#define __X86_KVM_PARA_H
/* This CPUID returns the signature 'KVMKVMKVM' in ebx, ecx, and edx. It
* should be used to determine that a VM is running under KVM.
*/
#define KVM_CPUID_SIGNATURE 0x40000000
/* This CPUID returns a feature bitmap in eax. Before enabling a particular
* paravirtualization, the appropriate feature bit should be checked.
*/
#define KVM_CPUID_FEATURES 0x40000001
#ifdef __KERNEL__
#include <asm/processor.h>
/* This instruction is vmcall. On non-VT architectures, it will generate a
* trap that we will then rewrite to the appropriate instruction.
*/
#define KVM_HYPERCALL ".byte 0x0f,0x01,0xc1"
/* For KVM hypercalls, a three-byte sequence of either the vmrun or the vmmrun
* instruction. The hypervisor may replace it with something else but only the
* instructions are guaranteed to be supported.
*
* Up to four arguments may be passed in rbx, rcx, rdx, and rsi respectively.
* The hypercall number should be placed in rax and the return value will be
* placed in rax. No other registers will be clobbered unless explicited
* noted by the particular hypercall.
*/
static inline long kvm_hypercall0(unsigned int nr)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr));
return ret;
}
static inline long kvm_hypercall1(unsigned int nr, unsigned long p1)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1));
return ret;
}
static inline long kvm_hypercall2(unsigned int nr, unsigned long p1,
unsigned long p2)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2));
return ret;
}
static inline long kvm_hypercall3(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3));
return ret;
}
static inline long kvm_hypercall4(unsigned int nr, unsigned long p1,
unsigned long p2, unsigned long p3,
unsigned long p4)
{
long ret;
asm volatile(KVM_HYPERCALL
: "=a"(ret)
: "a"(nr), "b"(p1), "c"(p2), "d"(p3), "S"(p4));
return ret;
}
static inline int kvm_para_available(void)
{
unsigned int eax, ebx, ecx, edx;
char signature[13];
cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx);
memcpy(signature + 0, &ebx, 4);
memcpy(signature + 4, &ecx, 4);
memcpy(signature + 8, &edx, 4);
signature[12] = 0;
if (strcmp(signature, "KVMKVMKVM") == 0)
return 1;
return 0;
}
static inline unsigned int kvm_arch_para_features(void)
{
return cpuid_eax(KVM_CPUID_FEATURES);
}
#endif
#endif
