[PATCH] KVM/x86: pmu: Fix #GP condition check for RDPMC emulation

Like Xu
2020-07-08T07:45:48Z

In guest protected mode, if the current privilege level
is not 0 and the PCE flag in the CR4 register is cleared,
we will inject a #GP for RDPMC usage.

Signed-off-by: Like Xu <like.xu@linux.intel.com>
---
arch/x86/kvm/pmu.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c
index b86346903f2e..d080d475c808 100644
--- a/arch/x86/kvm/pmu.c
+++ b/arch/x86/kvm/pmu.c
@@ -372,6 +372,11 @@ int kvm_pmu_rdpmc(struct kvm_vcpu *vcpu, unsigned idx, u64 *data)
if (!pmc)
return 1;

+ if ((kvm_x86_ops.get_cpl(vcpu) != 0) &&
+ !(kvm_read_cr4(vcpu) & X86_CR4_PCE) &&
+ (kvm_read_cr4(vcpu) & X86_CR0_PE))
+ return 1;
+
*data = pmc_read_counter(pmc) & mask;
return 0;
}
--
2.21.3