diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2019-12-20 20:45:02 -0800 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-01-13 17:53:57 +0100 |
| commit | ef4d3bf19855641fc8a1f621eaf06e2a2bb872bb (patch) | |
| tree | 59a71b6e73ea5ee9a9b07728687a5fb1af3a39a6 | |
| parent | 7d37953ba81121c8725f99356f7ee9762d4c3ed9 (diff) | |
| download | linux-ef4d3bf19855641fc8a1f621eaf06e2a2bb872bb.tar.bz2 | |
x86/cpu: Clear VMX feature flag if VMX is not fully enabled
Now that IA32_FEAT_CTL is always configured and locked for CPUs that are
known to support VMX[*], clear the VMX capability flag if the MSR is
unsupported or BIOS disabled VMX, i.e. locked IA32_FEAT_CTL and didn't
set the appropriate VMX enable bit.
[*] Because init_ia32_feat_ctl() is called from vendors ->c_init(), it's
still possible for IA32_FEAT_CTL to be left unlocked when VMX is
supported by the CPU. This is not fatal, and will be addressed in a
future patch.
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20191221044513.21680-9-sean.j.christopherson@intel.com
| -rw-r--r-- | arch/x86/kernel/cpu/feat_ctl.c | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/arch/x86/kernel/cpu/feat_ctl.c b/arch/x86/kernel/cpu/feat_ctl.c index c4f8f767853b..a46c9e46f937 100644 --- a/arch/x86/kernel/cpu/feat_ctl.c +++ b/arch/x86/kernel/cpu/feat_ctl.c @@ -5,15 +5,21 @@ #include <asm/msr-index.h> #include <asm/processor.h> +#undef pr_fmt +#define pr_fmt(fmt) "x86/cpu: " fmt + void init_ia32_feat_ctl(struct cpuinfo_x86 *c) { + bool tboot = tboot_enabled(); u64 msr; - if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) + if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) { + clear_cpu_cap(c, X86_FEATURE_VMX); return; + } if (msr & FEAT_CTL_LOCKED) - return; + goto update_caps; /* * Ignore whatever value BIOS left in the MSR to avoid enabling random @@ -29,9 +35,20 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c) if (cpu_has(c, X86_FEATURE_VMX) && IS_ENABLED(CONFIG_KVM_INTEL)) { msr |= FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX; - if (tboot_enabled()) + if (tboot) msr |= FEAT_CTL_VMX_ENABLED_INSIDE_SMX; } wrmsrl(MSR_IA32_FEAT_CTL, msr); + +update_caps: + if (!cpu_has(c, X86_FEATURE_VMX)) + return; + + if ( (tboot && !(msr & FEAT_CTL_VMX_ENABLED_INSIDE_SMX)) || + (!tboot && !(msr & FEAT_CTL_VMX_ENABLED_OUTSIDE_SMX))) { + pr_err_once("VMX (%s TXT) disabled by BIOS\n", + tboot ? "inside" : "outside"); + clear_cpu_cap(c, X86_FEATURE_VMX); + } } |