[PATCH v2 04/26] KVM: x86 emulator: emulate cpuid

Avi Kivity
2012-06-27T15:19:44Z

Opcode 0F A2.

Used by Linux during the mode change trampoline while in a state that is
not virtualizable on vmx without unrestricted_guest, so we need to emulate
it is emulate_invalid_guest_state=1.

Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/emulate.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index ba1f8ec..db95a55 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3142,6 +3142,20 @@ static int em_bsr(struct x86_emulate_ctxt *ctxt)
return X86EMUL_CONTINUE;
}

+static int em_cpuid(struct x86_emulate_ctxt *ctxt)
+{
+ u32 eax, ebx, ecx, edx;
+
+ eax = ctxt->regs[VCPU_REGS_RAX];
+ ecx = ctxt->regs[VCPU_REGS_RCX];
+ ctxt->ops->get_cpuid(ctxt, &eax, &ebx, &ecx, &edx);
+ ctxt->regs[VCPU_REGS_RAX] = eax;
+ ctxt->regs[VCPU_REGS_RBX] = ebx;
+ ctxt->regs[VCPU_REGS_RCX] = ecx;
+ ctxt->regs[VCPU_REGS_RDX] = edx;
+ return X86EMUL_CONTINUE;
+}
+
static bool valid_cr(int nr)
{
switch (nr) {
@@ -3634,7 +3648,7 @@ static int check_perm_out(struct x86_emulate_ctxt *ctxt)
X16(D(ByteOp | DstMem | SrcNone | ModRM| Mov)),
/* 0xA0 - 0xA7 */
I(Stack | Src2FS, em_push_sreg), I(Stack | Src2FS, em_pop_sreg),
- DI(ImplicitOps, cpuid), I(DstMem | SrcReg | ModRM | BitOp, em_bt),
+ II(ImplicitOps, em_cpuid, cpuid), I(DstMem | SrcReg | ModRM | BitOp, em_bt),
D(DstMem | SrcReg | Src2ImmByte | ModRM),
D(DstMem | SrcReg | Src2CL | ModRM), N, N,
/* 0xA8 - 0xAF */
--
1.7.11