Messages in this thread | | | From | Wanpeng Li <> | Subject | [PATCH 0/2] KVM: VMX: Add Force Emulation Prefix for "emulate the next instruction" | Date | Mon, 26 Mar 2018 19:12:13 -0700 |
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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@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com>
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
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