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 <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Liam Merwick <[email protected]>
Reviewed-by: Maxim Levitsky <[email protected]>
Tested-by: Brad Campbell <[email protected]>
Cc: [email protected] # v5.6
Link: https://lkml.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions