linux/arch/x86/power
Sean Christopherson 5d5103595e 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: 21bd3467a5 ("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
2020-06-15 14:18:37 +02:00
..
cpu.c x86/cpu: Reinitialize IA32_FEAT_CTL MSR on BSP during wakeup 2020-06-15 14:18:37 +02:00
hibernate_32.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hibernate_64.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hibernate_asm_32.S x86/asm/32: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 12:03:43 +02:00
hibernate_asm_64.S x86/asm: Change all ENTRY+ENDPROC to SYM_FUNC_* 2019-10-18 11:58:33 +02:00
hibernate.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
Makefile x86, hibernate: Extract the common code of 64/32 bit system 2018-10-03 11:56:33 +02:00