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 E053AC4707A for ; Thu, 14 Apr 2022 15:05:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1352048AbiDNPEB (ORCPT ); Thu, 14 Apr 2022 11:04:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346567AbiDNN5l (ORCPT ); Thu, 14 Apr 2022 09:57:41 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 18B3C83B38; Thu, 14 Apr 2022 06:47:07 -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 dfw.source.kernel.org (Postfix) with ESMTPS id A94D761DAB; Thu, 14 Apr 2022 13:47:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B53F0C385A1; Thu, 14 Apr 2022 13:47:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649944026; bh=59nRNgDgCe3ne56lbosghpRk61Xrl+tdqC0JaDJz/4I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cbUsXXsKjmU2O9X5UR7b8vGYgduLWchkSnkR1U97v5+4+yICGUQ5mfn9rcyaaIMpC GIVq0lnTYPnH5+oNIvh0G+GkFEEi9FizyD0lAVn/4KmtVdG4hmLFsCHRsyDSyBPVwD 1EK4ncDWpsTEXYhA1MClsQPrYhOS9SzuZEmNVL00= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Vitaly Kuznetsov , Paolo Bonzini Subject: [PATCH 5.4 367/475] KVM: x86: Forbid VMM to set SYNIC/STIMER MSRs when SynIC wasnt activated Date: Thu, 14 Apr 2022 15:12:32 +0200 Message-Id: <20220414110905.349401010@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110855.141582785@linuxfoundation.org> References: <20220414110855.141582785@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: Vitaly Kuznetsov commit b1e34d325397a33d97d845e312d7cf2a8b646b44 upstream. Setting non-zero values to SYNIC/STIMER MSRs activates certain features, this should not happen when KVM_CAP_HYPERV_SYNIC{,2} was not activated. Note, it would've been better to forbid writing anything to SYNIC/STIMER MSRs, including zeroes, however, at least QEMU tries clearing HV_X64_MSR_STIMER0_CONFIG without SynIC. HV_X64_MSR_EOM MSR is somewhat 'special' as writing zero there triggers an action, this also should not happen when SynIC wasn't activated. Signed-off-by: Vitaly Kuznetsov Message-Id: <20220325132140.25650-4-vkuznets@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Paolo Bonzini Signed-off-by: Greg Kroah-Hartman --- arch/x86/kvm/hyperv.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -205,7 +205,7 @@ static int synic_set_msr(struct kvm_vcpu struct kvm_vcpu *vcpu = synic_to_vcpu(synic); int ret; - if (!synic->active && !host) + if (!synic->active && (!host || data)) return 1; trace_kvm_hv_synic_set_msr(vcpu->vcpu_id, msr, data, host); @@ -251,6 +251,9 @@ static int synic_set_msr(struct kvm_vcpu case HV_X64_MSR_EOM: { int i; + if (!synic->active) + break; + for (i = 0; i < ARRAY_SIZE(synic->sint); i++) kvm_hv_notify_acked_sint(vcpu, i); break; @@ -514,6 +517,11 @@ static int stimer_set_config(struct kvm_ { union hv_stimer_config new_config = {.as_uint64 = config}, old_config = {.as_uint64 = stimer->config.as_uint64}; + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && (!host || config)) + return 1; trace_kvm_hv_stimer_set_config(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, config, host); @@ -533,6 +541,12 @@ static int stimer_set_config(struct kvm_ static int stimer_set_count(struct kvm_vcpu_hv_stimer *stimer, u64 count, bool host) { + struct kvm_vcpu *vcpu = stimer_to_vcpu(stimer); + struct kvm_vcpu_hv_synic *synic = vcpu_to_synic(vcpu); + + if (!synic->active && (!host || count)) + return 1; + trace_kvm_hv_stimer_set_count(stimer_to_vcpu(stimer)->vcpu_id, stimer->index, count, host);