From patchwork Fri Jun 22 09:51:00 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Borislav Petkov X-Patchwork-Id: 10481601 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AE4E460383 for ; Fri, 22 Jun 2018 09:51:31 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8DB9928815 for ; Fri, 22 Jun 2018 09:51:31 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8279428E01; Fri, 22 Jun 2018 09:51:31 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 323FC28815 for ; Fri, 22 Jun 2018 09:51:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754292AbeFVJvT (ORCPT ); Fri, 22 Jun 2018 05:51:19 -0400 Received: from mail.skyhub.de ([5.9.137.197]:41146 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752688AbeFVJvR (ORCPT ); Fri, 22 Jun 2018 05:51:17 -0400 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id dX9XiefXvbaB; Fri, 22 Jun 2018 11:51:16 +0200 (CEST) Received: from zn.tnic (p200300EC2BCF3400329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2bcf:3400:329c:23ff:fea6:a903]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 2382D1EC0236; Fri, 22 Jun 2018 11:51:16 +0200 (CEST) From: Borislav Petkov To: KVM Cc: Joerg Roedel , Tom Lendacky , Tony Luck , Yazen Ghannam , LKML Subject: [PATCH 2/3] x86/kvm: Implement MSR_HWCR support Date: Fri, 22 Jun 2018 11:51:00 +0200 Message-Id: <20180622095101.32587-3-bp@alien8.de> X-Mailer: git-send-email 2.17.0.582.gccdcbd54c In-Reply-To: <20180622095101.32587-1-bp@alien8.de> References: <20180622095101.32587-1-bp@alien8.de> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Borislav Petkov The hardware configuration register has some useful bits which can be used by guests. Implement McStatusWrEn which can be used by guests when injecting MCEs with the in-kernel mce-inject module. For that, we need to set bit 18 - McStatusWrEn - first, before writing the MCi_STATUS registers (otherwise we #GP). Add the required machinery to do so. Signed-off-by: Borislav Petkov --- arch/x86/kvm/svm.c | 12 +++++++++--- arch/x86/kvm/x86.c | 34 +++++++++++++++++++++++++++++++--- 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index 72e60daf3ab8..623be0034f7d 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -251,6 +251,9 @@ struct vcpu_svm { /* which host CPU was used for running this vcpu */ unsigned int last_cpu; + + /* MSRC001_0015 Hardware Configuration */ + u64 msr_hwcr; }; /* @@ -4154,7 +4157,7 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) msr_info->data = svm->msr_decfg; break; case MSR_K7_HWCR: - msr_info->data = 0; + msr_info->data = svm->msr_hwcr; break; default: return kvm_get_msr_common(vcpu, msr_info); @@ -4364,8 +4367,11 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) data &= ~(u64)0x40; /* ignore flush filter disable */ data &= ~(u64)0x100; /* ignore ignne emulation enable */ data &= ~(u64)0x8; /* ignore TLB cache disable */ - data &= ~(u64)0x40000; /* ignore Mc status write enable */ - if (data != 0) { + + /* Handle McStatusWrEn */ + if (data == BIT_ULL(18)) { + svm->msr_hwcr = data; + } else if (data != 0) { vcpu_unimpl(vcpu, "unimplemented HWCR wrmsr: 0x%llx\n", data); return 1; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 3bf721c22124..80452b0f0e8c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -2146,6 +2146,30 @@ static void kvmclock_sync_fn(struct work_struct *work) KVMCLOCK_SYNC_PERIOD); } +/* + * On AMD, HWCR[McStatusWrEn] controls whether setting MCi_STATUS results in #GP. + */ +static bool __set_mci_status(struct kvm_vcpu *vcpu, struct msr_data *msr_info) +{ + if (guest_cpuid_is_amd(vcpu)) { + struct msr_data tmp; + + tmp.index = MSR_K7_HWCR; + + if (kvm_x86_ops->get_msr(vcpu, &tmp)) + return false; + + /* McStatusWrEn enabled? */ + if (tmp.data & BIT_ULL(18)) + return true; + } + + if (!msr_info->host_initiated && msr_info->data != 0) + return false; + + return true; +} + static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { u64 mcg_cap = vcpu->arch.mcg_cap; @@ -2176,9 +2200,13 @@ static int set_msr_mce(struct kvm_vcpu *vcpu, struct msr_data *msr_info) if ((offset & 0x3) == 0 && data != 0 && (data | (1 << 10)) != ~(u64)0) return -1; - if (!msr_info->host_initiated && - (offset & 0x3) == 1 && data != 0) - return -1; + + /* MCi_STATUS */ + if ((offset & 0x3) == 1) { + if (!__set_mci_status(vcpu, msr_info)) + return -1; + } + vcpu->arch.mce_banks[offset] = data; break; }