Paolo Bonzini d77c1ab54c KVM: x86: avoid incorrect writes to host MSR_IA32_SPEC_CTRL
[ Upstream commit 6441fa6178f5456d1d4b512c08798888f99db185 ]

If the guest is configured to have SPEC_CTRL but the host does not
(which is a nonsensical configuration but these are not explicitly
forbidden) then a host-initiated MSR write can write vmx->spec_ctrl
(respectively svm->spec_ctrl) and trigger a #GP when KVM tries to
restore the host value of the MSR.  Add a more comprehensive check
for valid bits of SPEC_CTRL, covering host CPUID flags and,
since we are at it and it is more correct that way, guest CPUID
flags too.

For AMD, remove the unnecessary is_guest_mode check around setting
the MSR interception bitmap, so that the code looks the same as
for Intel.

Cc: Jim Mattson <jmattson@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-01-06 14:48:36 +01:00
..
2020-05-10 10:31:31 +02:00
2020-11-05 11:43:33 +01:00
2019-09-27 13:02:19 -07:00
2020-12-30 11:51:39 +01:00