On 03/11/2015 12:40, Wanpeng Li wrote: > Reference SDM Volume 1 3.4.3: > > Following initialization of the processor (either by asserting the > RESET pin or the INIT pin), the state of the EFLAGS register is > 00000002H. > > However, the eflags fixed bit is not set and other bits are also not > cleared during the init/reset in kvm. > > This patch reset eflags register to 00000002H following initialization > of the processor. > > Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx> > --- > v1 -> v2: > * use vmcs_writel > > arch/x86/kvm/vmx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c > index b680c2e..1a95ef7 100644 > --- a/arch/x86/kvm/vmx.c > +++ b/arch/x86/kvm/vmx.c > @@ -4935,6 +4935,7 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) > vmx_set_efer(vcpu, 0); > vmx_fpu_activate(vcpu); > update_exception_bitmap(vcpu); > + vmcs_writel(GUEST_RFLAGS, X86_EFLAGS_FIXED); > > vpid_sync_context(vmx->vpid); > } > No, this is doing exactly the same thing that is already done elsewhere in vmx_vcpu_reset (which Nadav pointed out to you). So it's not just a pointless addition with no effect at all; it's wrong, because it introduces duplication. Please answer this question: is there a bug or not? If yes, then using kvm_set_rflags as in v1 is the right thing. However, you have to remove the _existing_ vmcs_writel call in vmx_vcpu_reset. Also, if there is a bug you have to explain it in the commit message and provide a testcase. By the way, I am still waiting for the VPID test cases. If no, then this is a cleanup, we can still do the change but you have to explain this in the commit message. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
