i386: do kvm_put_msr_feature_control() first thing when vCPU is reset

kvm_put_sregs2() fails to reset 'locked' CR4/CR0 bits upon vCPU reset when
it is in VMX root operation. Do kvm_put_msr_feature_control() before
kvm_put_sregs2() to (possibly) kick vCPU out of VMX root operation. It also
seems logical to do kvm_put_msr_feature_control() before
kvm_put_nested_state() and not after it, especially when 'real' nested
state is set.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220818150113.479917-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vitaly Kuznetsov 2022-08-18 17:01:13 +02:00 committed by Paolo Bonzini
parent 3cafdb6750
commit 45ed68a1a3
1 changed files with 12 additions and 5 deletions

View File

@ -4529,6 +4529,18 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
assert(cpu_is_stopped(cpu) || qemu_cpu_is_self(cpu));
/*
* Put MSR_IA32_FEATURE_CONTROL first, this ensures the VM gets out of VMX
* root operation upon vCPU reset. kvm_put_msr_feature_control() should also
* preceed kvm_put_nested_state() when 'real' nested state is set.
*/
if (level >= KVM_PUT_RESET_STATE) {
ret = kvm_put_msr_feature_control(x86_cpu);
if (ret < 0) {
return ret;
}
}
/* must be before kvm_put_nested_state so that EFER.SVME is set */
ret = has_sregs2 ? kvm_put_sregs2(x86_cpu) : kvm_put_sregs(x86_cpu);
if (ret < 0) {
@ -4540,11 +4552,6 @@ int kvm_arch_put_registers(CPUState *cpu, int level)
if (ret < 0) {
return ret;
}
ret = kvm_put_msr_feature_control(x86_cpu);
if (ret < 0) {
return ret;
}
}
if (level == KVM_PUT_FULL_STATE) {