From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 02855514751 for ; Tue, 29 Sep 2026 11:38:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790681932; cv=none; b=CVqmNlEmjnsmwc/L/wrb2v42pf/UgXFvILYXatb7EDuOujkw0zDr4CFGLlQRND2l8hsUSriGgcwUB9TBpQqeW0ndUV8Cw7JVHYE9I5TjTuJzGvjLxRTgQF3GKPI0+YKXovdikym1QVvJ7hxk9YqndFW0ZWoqUbEgqdI3mLe0298= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790681932; c=relaxed/simple; bh=s1PX7brVYRmQNt6wCK+WfPLUz2oaR+2gcBKYk8EsaFg=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=N6UPWrzUmttdO1S3V7ZKz7t3rSrWgA2av13Ldl9xwxtGUl/JZtypFlKiGlJpVDxr6wjYoRneO/Hy8YL5/h4SdAiqY/+ulCUZKAGPC0gn156388ZauNqLculN17Brif4lLMMbg0jxYKpv2QlR5w1/fayU/KjHGapyCrM2aU/k7Eo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Bjfj9F4w; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Bjfj9F4w" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B4C31F000FF; Tue, 29 Sep 2026 11:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790681930; bh=H9v+DDOvA1cAWtbc1ppib+n8ZpecAOvR1yqkzi7Vjls=; h=Subject:To:Cc:From:Date; b=Bjfj9F4w/2VfCCzNPFeW69ENtvcGeBvjVHFVWrT3c1i0ToVCw1rxvlU/aXDOtYnYR lwnNyNgQ1c0qPk8KFO1ctxgNT9if6DFNem/exlwUclPE/R6QCH0JbB5or5LMIpwC90 fighQhbMZUgMuScRSn/oV3PxN8G8ENUSJBWFWwSY= Subject: FAILED: patch "[PATCH] KVM: x86: Fill kvm_run exit fields in common" failed to apply to 6.18-stable tree To: seanjc@google.com,fane@google.com,rkskek9254@gmail.com Cc: From: Date: Tue, 29 Sep 2026 13:38:38 +0200 Message-ID: <2026092938-celibate-sarcastic-e56f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.18-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.18.y git checkout FETCH_HEAD git cherry-pick -x c1214f293d77c6e425a379f90d09bdb4815993a8 # git commit -s git send-email --to '' --in-reply-to '2026092938-celibate-sarcastic-e56f@gregkh' --subject-prefix 'PATCH 6.18.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From c1214f293d77c6e425a379f90d09bdb4815993a8 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Mon, 21 Sep 2026 14:16:08 -0700 Subject: [PATCH] KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths 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 diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 73f37b050d0a..f9090b601efa 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -2125,13 +2125,8 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) 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 151873407abd..40c1a5f6fa8a 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3465,10 +3465,6 @@ 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; } } @@ -3539,11 +3535,6 @@ 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 @@ -3915,8 +3906,12 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch) vmentry_failed: vcpu->arch.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 4ec17aaff413..aad065d035fb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8072,6 +8072,9 @@ 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;