From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831323; b=pjSoufc7p5191C7MYxZ6BTxi7Li9khvFzrKQzdoIpLhYTzxLD/V1+r05WQc9dmIwmN7c l0lpWjTRhfbbQPIGfo0nl+GGGtPl+4wWLobPiSZ7vQ/X8s09z4/Wke56UIeRby+28uUaR eAjN72eJviqYmqR/9H7YExeAcD+T6LyGUyfs0vlAIvi/NCO15841N/IXQiCIgW/J/PX6h GwCuTyYBx52HkudL4ICHDNOCA+sMEFa3ICULZ/KuMZ28xqEbEtHk+mJ21LEcxqtA0evV6 KifzZ+tb0R0txRxNvTwVT6TsfYL7kseYPtrANOQ8zVlIci9aP4nw+go3ecV7dzSuW7g== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831323; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=KmImZm8QkcfAeOSmdJG2oh8gr/A6In/nKEMNjV0R4PM=; b=qQtUZQhSfiaUQcPfMgVnl+mjH9F9ysDAlJylCfk9r85tPL4wNrmNgUXVvNQLVzklybdn 6v00ug8t8dqwW2Fq71H+LTFJG48GYtdrAXmf11CKfYcIgAm1XFFz00dMDaNzcmc7n6YBA 3wPZ75+5gbfnEuJ+cdfo61PRHdx4ZfftDORwOdH9Y5oKQHcmpYLNr0bgV3rX/7GY8HwMk tO11HSRuIzdMPJy2Dfb6gy/rL/UmIjgprMYCpn7NYwLwjHuf0RN4Z3TSsQD/dqfNu/CQ0 fV7Kp0XxfJtzLvda126wCpzV5AhVp0d0gp8vHgzZ4DOh9nXJRYO/hzFXPtXZtsMtmcg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=uhpaovAe; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CB107606A33A; Wed, 4 Nov 2026 22:28:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=uhpaovAe Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C06F1F00919; Wed, 4 Nov 2026 22:28:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831322; bh=KmImZm8QkcfAeOSmdJG2oh8gr/A6In/nKEMNjV0R4PM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=uhpaovAeJqRPGSwdG8XMcW0RfqHIzUBx5brr/vETBZE00qgJcvg1AIe0xXx11Bij6 TH3dvh46fOb/BQ/mRQSSBUWaBD0Yj0fferBsPkmcc3NZffLNFXCHALLQvGj/uLRUif 4wuNxQq/tFM1teK4LABmqgIdosP0V+kM+neIkQFo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jinwoo Lee , Stefan Teodorescu , Sean Christopherson , Sasha Levin Subject: [PATCH 6.18 0595/1005] KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths Date: Wed, 4 Nov 2026 16:05:28 -0500 Message-ID: <20261104211100.527687952@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sean Christopherson [ Upstream commit c1214f293d77c6e425a379f90d09bdb4815993a8 ] Fill kvm_run with "internal error, emulation" in the common error handling paths for getting nested state pages, as requiring each check to manually fill kvm_run is error prone and requires a non-trivial amount of copy+paste. Specifically, both SVM and VMX fail to fill kvm_run if load_pdptrs() fails, and SVM fails to fill kvm_run if kvm_hv_verify_vp_assist() fails. If those flows fail, the *best* case scenario is that KVM will exit to userspace with KVM_EXIT_UNKNOWN. The worst case scenario is that KVM exits with a stale exit_reason and confuses userspace. Note, SVM never exits to userspace if something goes sideways when dealing with vmcb12 assets while emulating VMRUN, i.e. lack of SVM-specific code is not a bug. Fixes: 0f85722341b0 ("KVM: nVMX: delay loading of PDPTRs to KVM_REQ_GET_NESTED_STATE_PAGES") Fixes: 232f75d3b4b5 ("KVM: nSVM: call nested_svm_load_cr3 on nested state load") Fixes: 3f4a812edf5c ("KVM: nSVM: hyper-v: Enable L2 TLB flush") Cc: stable@vger.kernel.org Reported-by: Jinwoo Lee Closes: https://lore.kernel.org/all/20260813043932.3214460-1-rkskek9254@gmail.com Reported-by: Stefan Teodorescu Link: https://patch.msgid.link/20260921211608.1030158-3-seanjc@google.com Signed-off-by: Sean Christopherson [ sashal: Kept this tree's vmx->nested.nested_run_pending in the vmentry_failed: context line, since the field has not yet moved to vcpu->arch. ] Signed-off-by: Sasha Levin --- arch/x86/kvm/svm/nested.c | 7 +------ arch/x86/kvm/vmx/nested.c | 15 +++++---------- arch/x86/kvm/x86.c | 3 +++ 3 files changed, 9 insertions(+), 16 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 892b6fd48a0d7..ec984fa88dbce 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1949,13 +1949,8 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) if (CC(!load_pdptrs(vcpu, vcpu->arch.cr3))) return false; - if (!nested_svm_merge_msrpm(vcpu)) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = - KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + if (!nested_svm_merge_msrpm(vcpu)) return false; - } if (kvm_hv_verify_vp_assist(vcpu)) return false; diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c index be2ab71cd9eab..6dd21c2938d99 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3499,10 +3499,6 @@ static bool nested_get_vmcs12_pages(struct kvm_vcpu *vcpu) } else { pr_debug_ratelimited("%s: no backing for APIC-access address in vmcs12\n", __func__); - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = - KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; return false; } } @@ -3573,11 +3569,6 @@ static bool vmx_get_nested_state_pages(struct kvm_vcpu *vcpu) if (!nested_get_evmcs_page(vcpu)) { pr_debug_ratelimited("%s: enlightened vmptrld failed\n", __func__); - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = - KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; - return false; } #endif @@ -3965,8 +3956,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmentry_failed: vmx->nested.nested_run_pending = 0; - if (status == NVMX_VMENTRY_KVM_INTERNAL_ERROR) + if (status == NVMX_VMENTRY_KVM_INTERNAL_ERROR) { + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; return 0; + } if (status == NVMX_VMENTRY_VMEXIT) return 1; WARN_ON_ONCE(status != NVMX_VMENTRY_VMFAIL); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 9493af5fa8275..64e24e75a17c5 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10715,6 +10715,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) { if (unlikely(!kvm_nested_call(get_nested_state_pages)(vcpu))) { + vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; + vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_EMULATION; + vcpu->run->internal.ndata = 0; kvm_make_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu); r = 0; goto out; -- 2.53.0