This is a note to let you know that I've just added the patch titled KVM: x86: emulating RDPID failure shall return #UD rather than #GP to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-x86-emulating-rdpid-failure-shall-return-ud-rath.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 996aa0aa489ece7527c301eafcf9e67dcd96e675 Author: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> Date: Fri Aug 28 10:23:42 2020 +0800 KVM: x86: emulating RDPID failure shall return #UD rather than #GP [ Upstream commit a9e2e0ae686094571378c72d8146b5a1a92d0652 ] Per Intel's SDM, RDPID takes a #UD if it is unsupported, which is more or less what KVM is emulating when MSR_TSC_AUX is not available. In fact, there are no scenarios in which RDPID is supposed to #GP. Fixes: fb6d4d340e ("KVM: x86: emulate RDPID") Signed-off-by: Robert Hoo <robert.hu@xxxxxxxxxxxxxxx> Message-Id: <1598581422-76264-1-git-send-email-robert.hu@xxxxxxxxxxxxxxx> Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c index da3cd734dee10..d455221d958fc 100644 --- a/arch/x86/kvm/emulate.c +++ b/arch/x86/kvm/emulate.c @@ -3536,7 +3536,7 @@ static int em_rdpid(struct x86_emulate_ctxt *ctxt) u64 tsc_aux = 0; if (ctxt->ops->get_msr(ctxt, MSR_TSC_AUX, &tsc_aux)) - return emulate_gp(ctxt, 0); + return emulate_ud(ctxt); ctxt->dst.val = tsc_aux; return X86EMUL_CONTINUE; }