KVM: x86: Fix handling of APIC LVT updates when userspace changes MCG_CAP

Add a helper to update KVM's in-kernel local APIC in response to MCG_CAP
being changed by userspace to fix multiple bugs.  First and foremost,
KVM needs to check that there's an in-kernel APIC prior to dereferencing
vcpu->arch.apic.  Beyond that, any "new" LVT entries need to be masked,
and the APIC version register needs to be updated as it reports out the
number of LVT entries.

Fixes: 4b903561ec49 ("KVM: x86: Add Corrected Machine Check Interrupt (CMCI) emulation to lapic.")
Reported-by: [email protected]
Cc: Siddh Raman Pant <[email protected]>
Cc: Jue Wang <[email protected]>
Signed-off-by: Sean Christopherson <[email protected]>

0 files changed, 0 insertions, 0 deletions