From nobody Mon Sep 29 21:09:37 2025 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 DC1BDC25B0D for ; Tue, 16 Aug 2022 04:54:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233398AbiHPEyE (ORCPT ); Tue, 16 Aug 2022 00:54:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43792 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233653AbiHPEvb (ORCPT ); Tue, 16 Aug 2022 00:51:31 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 610D619F4BC; Mon, 15 Aug 2022 13:48:45 -0700 (PDT) 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 BD7FEB8113E; Mon, 15 Aug 2022 20:48:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06A0EC433C1; Mon, 15 Aug 2022 20:48:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1660596522; bh=dKpsUjoQlrAZnpBF4F5UQj6kOe4rpK9ydyr0Zx2ZhH8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xsW6wLjmW30STG5vqXQ/JqVllgYvIjwAqaQICSN3ihNI5+OYLg3zpMmN4606vF9wk P4FLtWGAI35C50N1gEIELDqm89ZhDPBd+XpUxw42hNK4Y80T8pDstRRwpPP8i6vIe6 BfvPds98H1YcaZZdmDVLzW6f3eGKc5S7q3wkotqk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sean Christopherson , Paolo Bonzini , Sasha Levin Subject: [PATCH 5.19 1106/1157] Revert "KVM: x86/pmu: Accept 0 for absent PMU MSRs when host-initiated if !enable_pmu" Date: Mon, 15 Aug 2022 20:07:42 +0200 Message-Id: <20220815180524.516213846@linuxfoundation.org> X-Mailer: git-send-email 2.37.2 In-Reply-To: <20220815180439.416659447@linuxfoundation.org> References: <20220815180439.416659447@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Sean Christopherson [ Upstream commit 5d4283df5a0fc8299fba9443c33d219939eccc2d ] Eating reads and writes to all "PMU" MSRs when there is no PMU is wildly broken as it results in allowing accesses to _any_ MSR on Intel CPUs as intel_is_valid_msr() returns true for all host_initiated accesses. A revert of commit d1c88a402056 ("KVM: x86: always allow host-initiated writes to PMU MSRs") will soon follow. This reverts commit 8e6a58e28b34e8d247e772159b8fa8f6bae39192. Signed-off-by: Sean Christopherson Message-Id: <20220611005755.753273-4-seanjc@google.com> Signed-off-by: Paolo Bonzini Signed-off-by: Sasha Levin --- arch/x86/kvm/pmu.c | 8 -------- arch/x86/kvm/svm/pmu.c | 11 +---------- 2 files changed, 1 insertion(+), 18 deletions(-) diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c index 2334ddfbbab2..3f868fed9114 100644 --- a/arch/x86/kvm/pmu.c +++ b/arch/x86/kvm/pmu.c @@ -433,19 +433,11 @@ static void kvm_pmu_mark_pmc_in_use(struct kvm_vcpu *= vcpu, u32 msr) =20 int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { - if (msr_info->host_initiated && !vcpu->kvm->arch.enable_pmu) { - msr_info->data =3D 0; - return 0; - } - return static_call(kvm_x86_pmu_get_msr)(vcpu, msr_info); } =20 int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) { - if (msr_info->host_initiated && !vcpu->kvm->arch.enable_pmu) - return !!msr_info->data; - kvm_pmu_mark_pmc_in_use(vcpu, msr_info->index); return static_call(kvm_x86_pmu_set_msr)(vcpu, msr_info); } diff --git a/arch/x86/kvm/svm/pmu.c b/arch/x86/kvm/svm/pmu.c index d93ecb25fe17..136039fc6d01 100644 --- a/arch/x86/kvm/svm/pmu.c +++ b/arch/x86/kvm/svm/pmu.c @@ -232,16 +232,7 @@ static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm= _vcpu *vcpu, static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) { /* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough. */ - if (!host_initiated) - return false; - - switch (msr) { - case MSR_K7_EVNTSEL0 ... MSR_K7_PERFCTR3: - case MSR_F15H_PERF_CTL0 ... MSR_F15H_PERF_CTR5: - return true; - default: - return false; - } + return false; } =20 static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr) --=20 2.35.1