Hou Wenlong d2f7d49826 KVM: x86: Use different callback if msr access comes from the emulator
If msr access triggers an exit to userspace, the
complete_userspace_io callback would skip instruction by vendor
callback for kvm_skip_emulated_instruction(). However, when msr
access comes from the emulator, e.g. if kvm.force_emulation_prefix
is enabled and the guest uses rdmsr/wrmsr with kvm prefix,
VM_EXIT_INSTRUCTION_LEN in vmcs is invalid and
kvm_emulate_instruction() should be used to skip instruction
instead.

As Sean noted, unlike the previous case, there's no #UD if
unrestricted guest is disabled and the guest accesses an MSR in
Big RM. So the correct way to fix this is to attach a different
callback when the msr access comes from the emulator.

Suggested-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Hou Wenlong <houwenlong93@linux.alibaba.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <34208da8f51580a06e45afefac95afea0e3f96e3.1635842679.git.houwenlong93@linux.alibaba.com>
2021-12-08 04:25:16 -05:00
..
2021-11-10 11:22:03 -08:00
2021-11-08 09:15:45 -08:00
2021-11-20 10:35:54 -08:00
2021-11-10 11:22:03 -08:00
2021-11-10 11:22:03 -08:00
2021-11-14 11:37:49 -08:00
2021-11-01 20:05:19 -07:00