KVM: nested VMX: disable perf cpuid reporting

Initilization of L2 guest with -cpu host, on L1 guest with -cpu host
triggers:

(qemu) KVM: entry failed, hardware error 0x7
...
nested_vmx_run: VMCS MSR_{LOAD,STORE} unsupported

Nested VMX MSR load/store support is not sufficient to
allow perf for L2 guest.

Until properly fixed, trap CPUID and disable function 0xA.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Marcelo Tosatti 2014-09-18 18:24:57 -03:00 committed by Paolo Bonzini
parent a2b9e6c1a3
commit bc6134942d
2 changed files with 8 additions and 0 deletions

View file

@ -774,6 +774,12 @@ void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
if (!best)
best = check_cpuid_limit(vcpu, function, index);
/*
* Perfmon not yet supported for L2 guest.
*/
if (is_guest_mode(vcpu) && function == 0xa)
best = NULL;
if (best) {
*eax = best->eax;
*ebx = best->ebx;

View file

@ -6986,6 +6986,8 @@ static bool nested_vmx_exit_handled(struct kvm_vcpu *vcpu)
case EXIT_REASON_TASK_SWITCH:
return 1;
case EXIT_REASON_CPUID:
if (kvm_register_read(vcpu, VCPU_REGS_RAX) == 0xa)
return 0;
return 1;
case EXIT_REASON_HLT:
return nested_cpu_has(vmcs12, CPU_BASED_HLT_EXITING);