Fix KVM IA32_RTIT_CTL MSR validation logic so that if RTIT_CTL_TRACEEN bit is cleared, then other bits are allowed to change also. For example, writing 0 to IA32_RTIT_CTL in order to stop tracing, is valid.
Fixes: bf8c55d8dc09 ("KVM: x86: Implement Intel PT MSRs read/write emulation") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter adrian.hunter@intel.com --- arch/x86/kvm/vmx/vmx.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 1a4438358c5e..eaf4965ac6df 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -1635,7 +1635,8 @@ static int vmx_rtit_ctl_check(struct kvm_vcpu *vcpu, u64 data) * result in a #GP unless the same write also clears TraceEn. */ if ((vmx->pt_desc.guest.ctl & RTIT_CTL_TRACEEN) && - ((vmx->pt_desc.guest.ctl ^ data) & ~RTIT_CTL_TRACEEN)) + (data & RTIT_CTL_TRACEEN) && + data != vmx->pt_desc.guest.ctl) return 1;
/*