diff options
author | Liran Alon <liran.alon@oracle.com> | 2019-03-25 21:09:17 +0200 |
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committer | Paolo Bonzini <pbonzini@redhat.com> | 2019-04-16 15:37:34 +0200 |
commit | e51bfdb68725dc052d16241ace40ea3140f938aa (patch) | |
tree | 3413e07454f91e271d62cc6a71af4fe9ffc6f577 /arch/x86/include/asm/kvm_emulate.h | |
parent | 672ff6cff80ca43bf3258410d2b887036969df5f (diff) |
KVM: nVMX: Expose RDPMC-exiting only when guest supports PMU
Issue was discovered when running kvm-unit-tests on KVM running as L1 on
top of Hyper-V.
When vmx_instruction_intercept unit-test attempts to run RDPMC to test
RDPMC-exiting, it is intercepted by L1 KVM which it's EXIT_REASON_RDPMC
handler raise #GP because vCPU exposed by Hyper-V doesn't support PMU.
Instead of unit-test expectation to be reflected with EXIT_REASON_RDPMC.
The reason vmx_instruction_intercept unit-test attempts to run RDPMC
even though Hyper-V doesn't support PMU is because L1 expose to L2
support for RDPMC-exiting. Which is reasonable to assume that is
supported only in case CPU supports PMU to being with.
Above issue can easily be simulated by modifying
vmx_instruction_intercept config in x86/unittests.cfg to run QEMU with
"-cpu host,+vmx,-pmu" and run unit-test.
To handle issue, change KVM to expose RDPMC-exiting only when guest
supports PMU.
Reported-by: Saar Amar <saaramar@microsoft.com>
Reviewed-by: Mihai Carabas <mihai.carabas@oracle.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_emulate.h')
0 files changed, 0 insertions, 0 deletions