[PATCH 0/2] KVM: VMX: Add Force Emulation Prefix for "emulate the next instruction"
From: Wanpeng Li
Date: Mon Mar 26 2018 - 22:13:12 EST
This patchset introduces a Force Emulation Prefix (ud2a; .ascii "kvm")
for "emulate the next instruction", the codes will be executed by emulator
instead of processor, for testing purposes.
A testcase here:
#include <stdio.h>
#include <string.h>
#define HYPERVISOR_INFO 0x40000000
#define CPUID(idx, eax, ebx, ecx, edx)\
asm volatile (\
"ud2a; .ascii \"kvm\"; 1: cpuid" \
:"=b" (*ebx), "=a" (*eax),"=c" (*ecx), "=d" (*edx)\
:"0"(idx) );
void main()
{
unsigned int eax,ebx,ecx,edx;
char string[13];
CPUID(HYPERVISOR_INFO, &eax, &ebx, &ecx, &edx);
*(unsigned int *)(string+0) = ebx;
*(unsigned int *)(string+4) = ecx;
*(unsigned int *)(string+8) = edx;
string[12] = 0;
if (strncmp(string, "KVMKVMKVM\0\0\0",12) == 0)
printf("kvm guest\n");
else
printf("bare hardware\n");
}
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Wanpeng Li (2):
KVM: VMX: Introduce handle_ud()
KVM: VMX: Add Force Emulation Prefix for "emulate the next instruction"
arch/x86/kvm/vmx.c | 38 ++++++++++++++++++++++++++++++--------
1 file changed, 30 insertions(+), 8 deletions(-)
--
2.7.4