Commit 1eaafe91a0df ("kvm: x86: IA32_ARCH_CAPABILITIES is always
supported") unconditionally allowed host userspace to expose
ARCH_CAPABILITIES to the guest "Since the IA32_ARCH_CAPABILITIES MSR is
emulated in kvm". Unfortunately, that assertion is only partially true.
KVM only emulates the SKIP_VMENTRY_L1DFLUSH capability, everything else
enumerated in MSR_IA32_ARCH_CAPABILITIES relies on hardware support.
And on AMD, the MSR is not emulated at all. Fix the bugs to avoid
inducing faults and bad behavior in the guest due to advertising support
that doesn't exist.
Sean Christopherson (2):
KVM: x86: enforce MSR_IA32_ARCH_CAPABILITIES value set by userspace
KVM: x86: Emulate MSR_IA32_ARCH_CAPABILITIES on AMD hosts
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/vmx/vmx.c | 13 -------------
arch/x86/kvm/vmx/vmx.h | 1 -
arch/x86/kvm/x86.c | 13 +++++++++++++
4 files changed, 14 insertions(+), 14 deletions(-)
--
2.21.0
