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authorSean Christopherson <sean.j.christopherson@intel.com>2019-12-20 20:45:09 -0800
committerBorislav Petkov <bp@suse.de>2020-01-13 19:19:32 +0100
commita4d0b2fdbcf75ef6654713c83c316ea3a661ddc3 (patch)
tree3fe066e0bc85f112fcbfd6bcb31026acc5e5c10d /arch/x86
parent21bd3467a58ea51ccc0b1d9bcb86dadf1640a002 (diff)
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KVM: VMX: Use VMX feature flag to query BIOS enabling
Replace KVM's manual checks on IA32_FEAT_CTL with a query on the boot CPU's MSR_IA32_FEAT_CTL and VMX feature flags. The MSR_IA32_FEAT_CTL indicates that IA32_FEAT_CTL has been configured and that dependent features are accurately reflected in cpufeatures, e.g. the VMX flag is now cleared during boot if VMX isn't fully enabled via IA32_FEAT_CTL, including the case where the MSR isn't supported. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Link: https://lkml.kernel.org/r/20191221044513.21680-16-sean.j.christopherson@intel.com
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/kvm/vmx/vmx.c27
1 files changed, 2 insertions, 25 deletions
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index a026334ffc58..06e0e5262704 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -2204,31 +2204,8 @@ static __init int cpu_has_kvm_support(void)
static __init int vmx_disabled_by_bios(void)
{
- u64 msr;
-
- rdmsrl(MSR_IA32_FEAT_CTL, msr);
-
- if (unlikely(!(msr & FEAT_CTL_LOCKED)))
- return 1;
-
- /* launched w/ TXT and VMX disabled */
- if (!(msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX) &&
- tboot_enabled())
- return 1;
- /* launched w/o TXT and VMX only enabled w/ TXT */
- if (!(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX) &&
- (msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX) &&
- !tboot_enabled()) {
- pr_warn("kvm: disable TXT in the BIOS or "
- "activate TXT before enabling KVM\n");
- return 1;
- }
- /* launched w/o TXT and VMX disabled */
- if (!(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX) &&
- !tboot_enabled())
- return 1;
-
- return 0;
+ return !boot_cpu_has(X86_FEATURE_MSR_IA32_FEAT_CTL) ||
+ !boot_cpu_has(X86_FEATURE_VMX);
}
static void kvm_cpu_vmxon(u64 addr)