tree 4c224df721c46248d93081e45a4d1dd94aa03cb6
parent 51b87946279cf6e9248ceacf0f27833b6ebeef5e
author Mingwei Zhang <mizhang@google.com> 1713396546 +0000
committer Sean Christopherson <seanjc@google.com> 1717620089 -0700

x86: msr: testing MSR_IA32_FLUSH_CMD reserved bits only in KVM emulation

Avoid testing reserved bits of MSR_IA32_FLUSH_CMD in hardware. Since KVM
passes through the MSR at runtime, testing reserved bits directly on the HW
does not generate #GP in some older CPU models like skylake.

Ideally, it could be fixed by enumerating all such CPU models. The value
added is would be low. So just focus on testing bits when the KVM force
emulation is enabled. This is in a new helper test_wrmsr_fep_fault().

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Mingwei Zhang <mizhang@google.com>
Link: https://lore.kernel.org/r/20240417232906.3057638-3-mizhang@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>