diff options
| author | Sean Christopherson <sean.j.christopherson@intel.com> | 2020-06-08 10:41:34 -0700 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2020-06-15 14:18:37 +0200 |
| commit | 5d5103595e9e53048bb7e70ee2673c897ab38300 (patch) | |
| tree | 733c865296305bee65d1f418f2a4816ead780237 /arch/x86/include | |
| parent | 8e742aa79780b13cd300a42198c1a4cea9c89905 (diff) | |
| download | linux-5d5103595e9e53048bb7e70ee2673c897ab38300.tar.bz2 | |
x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup
Reinitialize IA32_FEAT_CTL on the BSP during wakeup to handle the case
where firmware doesn't initialize or save/restore across S3. This fixes
a bug where IA32_FEAT_CTL is left uninitialized and results in VMXON
taking a #GP due to VMX not being fully enabled, i.e. breaks KVM.
Use init_ia32_feat_ctl() to "restore" IA32_FEAT_CTL as it already deals
with the case where the MSR is locked, and because APs already redo
init_ia32_feat_ctl() during suspend by virtue of the SMP boot flow being
used to reinitialize APs upon wakeup. Do the call in the early wakeup
flow to avoid dependencies in the syscore_ops chain, e.g. simply adding
a resume hook is not guaranteed to work, as KVM does VMXON in its own
resume hook, kvm_resume(), when KVM has active guests.
Fixes: 21bd3467a58e ("KVM: VMX: Drop initialization of IA32_FEAT_CTL MSR")
Reported-by: Brad Campbell <lists2009@fnarfbargle.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Liam Merwick <liam.merwick@oracle.com>
Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Tested-by: Brad Campbell <lists2009@fnarfbargle.com>
Cc: stable@vger.kernel.org # v5.6
Link: https://lkml.kernel.org/r/20200608174134.11157-1-sean.j.christopherson@intel.com
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/cpu.h | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/include/asm/cpu.h b/arch/x86/include/asm/cpu.h index dd17c2da1af5..da78ccbd493b 100644 --- a/arch/x86/include/asm/cpu.h +++ b/arch/x86/include/asm/cpu.h @@ -58,4 +58,9 @@ static inline bool handle_guest_split_lock(unsigned long ip) return false; } #endif +#ifdef CONFIG_IA32_FEAT_CTL +void init_ia32_feat_ctl(struct cpuinfo_x86 *c); +#else +static inline void init_ia32_feat_ctl(struct cpuinfo_x86 *c) {} +#endif #endif /* _ASM_X86_CPU_H */ |