From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B1366C43217 for ; Mon, 31 Jan 2022 11:12:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1359757AbiAaLME (ORCPT ); Mon, 31 Jan 2022 06:12:04 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:56576 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376311AbiAaLIM (ORCPT ); Mon, 31 Jan 2022 06:08:12 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E261AB82A65; Mon, 31 Jan 2022 11:08:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F213C340E8; Mon, 31 Jan 2022 11:08:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1643627289; bh=PIWXcB5Fa/gVjYfYWMPLSNXd548BK4/WctdiAE7AqA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2gp044S5RVDHtN5A+m2qzU3SZfhJbIjor347c3D3PxQIJTn+sw64g593OZ4LA3+vj So7GqqIfI1+mC4SBX/70L9SDtCanrlEsNcMrwmQ6gwZhpET2Hr5V5V3q7HxsElT/li reFfjtApczWtFu3SiP4G+uavtb5kQnVCHp18kKro= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tom Lendacky , Brijesh Singh , Sean Christopherson , Liam Merwick , Paolo Bonzini Subject: [PATCH 5.15 036/171] KVM: SVM: Dont intercept #GP for SEV guests Date: Mon, 31 Jan 2022 11:55:01 +0100 Message-Id: <20220131105231.241048477@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220131105229.959216821@linuxfoundation.org> References: <20220131105229.959216821@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sean Christopherson commit 0b0be065b7563ac708aaa9f69dd4941c80b3446d upstream. Never intercept #GP for SEV guests as reading SEV guest private memory will return cyphertext, i.e. emulating on #GP can't work as intended. Cc: stable@vger.kernel.org Cc: Tom Lendacky Cc: Brijesh Singh Signed-off-by: Sean Christopherson Reviewed-by: Liam Merwick Message-Id: <20220120010719.711476-4-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/svm/svm.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -303,7 +303,11 @@ int svm_set_efer(struct kvm_vcpu *vcpu, return ret; } - if (svm_gp_erratum_intercept) + /* + * Never intercept #GP for SEV guests, KVM can't + * decrypt guest memory to workaround the erratum. + */ + if (svm_gp_erratum_intercept && !sev_guest(vcpu->kvm)) set_exception_intercept(svm, GP_VECTOR); } } @@ -1176,9 +1180,10 @@ static void init_vmcb(struct kvm_vcpu *v * Guest access to VMware backdoor ports could legitimately * trigger #GP because of TSS I/O permission bitmap. * We intercept those #GP and allow access to them anyway - * as VMware does. + * as VMware does. Don't intercept #GP for SEV guests as KVM can't + * decrypt guest memory to decode the faulting instruction. */ - if (enable_vmware_backdoor) + if (enable_vmware_backdoor && !sev_guest(vcpu->kvm)) set_exception_intercept(svm, GP_VECTOR); svm_set_intercept(svm, INTERCEPT_INTR);