From df67696e97d3edd0cb1683bf2eb3b3236bd9a5ed Mon Sep 17 00:00:00 2001 From: Liu Jinsong Date: Mon, 19 Aug 2013 09:33:30 +0800 Subject: [PATCH] kvm: x86: fix setting IA32_FEATURE_CONTROL with nested VMX disabled This patch is to fix the bug https://bugs.launchpad.net/qemu-kvm/+bug/1207623 IA32_FEATURE_CONTROL is pointless if not expose VMX or SMX bits to cpuid.1.ecx of vcpu. Current qemu-kvm will error return when kvm_put_msrs or kvm_get_msrs. Signed-off-by: Liu Jinsong Signed-off-by: Paolo Bonzini --- target-i386/kvm.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/target-i386/kvm.c b/target-i386/kvm.c index 513ae5279a..7bb8455109 100644 --- a/target-i386/kvm.c +++ b/target-i386/kvm.c @@ -65,6 +65,7 @@ static bool has_msr_star; static bool has_msr_hsave_pa; static bool has_msr_tsc_adjust; static bool has_msr_tsc_deadline; +static bool has_msr_feature_control; static bool has_msr_async_pf_en; static bool has_msr_pv_eoi_en; static bool has_msr_misc_enable; @@ -666,6 +667,12 @@ int kvm_arch_init_vcpu(CPUState *cs) qemu_add_vm_change_state_handler(cpu_update_state, env); + c = cpuid_find_entry(&cpuid_data.cpuid, 1, 0); + if (c) { + has_msr_feature_control = !!(c->ecx & CPUID_EXT_VMX) || + !!(c->ecx & CPUID_EXT_SMX); + } + cpuid_data.cpuid.padding = 0; r = kvm_vcpu_ioctl(cs, KVM_SET_CPUID2, &cpuid_data); if (r) { @@ -1169,7 +1176,10 @@ static int kvm_put_msrs(X86CPU *cpu, int level) if (hyperv_vapic_recommended()) { kvm_msr_entry_set(&msrs[n++], HV_X64_MSR_APIC_ASSIST_PAGE, 0); } - kvm_msr_entry_set(&msrs[n++], MSR_IA32_FEATURE_CONTROL, env->msr_ia32_feature_control); + if (has_msr_feature_control) { + kvm_msr_entry_set(&msrs[n++], MSR_IA32_FEATURE_CONTROL, + env->msr_ia32_feature_control); + } } if (env->mcg_cap) { int i; @@ -1394,7 +1404,9 @@ static int kvm_get_msrs(X86CPU *cpu) if (has_msr_misc_enable) { msrs[n++].index = MSR_IA32_MISC_ENABLE; } - msrs[n++].index = MSR_IA32_FEATURE_CONTROL; + if (has_msr_feature_control) { + msrs[n++].index = MSR_IA32_FEATURE_CONTROL; + } if (!env->tsc_valid) { msrs[n++].index = MSR_IA32_TSC; @@ -1509,6 +1521,7 @@ static int kvm_get_msrs(X86CPU *cpu) break; case MSR_IA32_FEATURE_CONTROL: env->msr_ia32_feature_control = msrs[i].data; + break; default: if (msrs[i].index >= MSR_MC0_CTL && msrs[i].index < MSR_MC0_CTL + (env->mcg_cap & 0xff) * 4) {