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=1794061420; b=sr8oWuZvQXPla88/vdbDUtGTNy+v36CB7JkJw5xLDkou+De2JZXoK53mDOLX1jRHiLoL ePaRo/AhkQmQbw7wGcHDjxqVhDGVXCDbzrueDj4NivSdLSFgMODraWJQGLZMucLRrumil NXpju4CY3xBorMaHabOJ3dpeJ1OrKnnC4fRDMOQ2Oeaos3fmkf+YqkirTFFsnt+HEpqrg Os1rdc4HUmmB4iuxsbqInH03ZQg9QyU3GWndxohOxdY+7unPsNUhG+Yqro6ZbPTMq359q Ai2tGRcJihaGBiwgaKti6/dHy1w9BfZ1hMe+f7jsHqFyjoYsx49OzC6pwI95dwnUiog== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794061420; 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=274D2ipJ0AKWod+Fv22HtE+wkWzmreiMAlafDi5GFOU=; b=0RNeeHR6st2BkM8tGU5NCWMxPdWL52iMAvkJE/9HTOvGWxwQx/bWu+rwF3tLHIAY3x29 eI+oBjB732jQAjE4BdaiRnxvEiEBtqURPIItsHsxXgJ2vay7BDK1CU8vUpxVyYUjnEzFd PFaargELpeU/8do41j9+G3JZIuDeu04beoaGgsRiQAMcVCZ0sdpg7kgqQxCv5hf8efnaZ +K6IsMMzBJHLasNupdZLjVWR4t0oUkXpHWjdcadHs0hOzHDnRYKCEx4+U22FnBwh04232 cKrLCsQyx1MKo+5utoKvJtHMqVPdxgSxIg97KFGDNJsgXm3TF/dqQRInO/kuvqfKjJA== 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=FPkEkUSG; 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 E8571606A32F; Sat, 7 Nov 2026 14:23:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=FPkEkUSG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 966D31F0089F; Sat, 7 Nov 2026 14:23:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794061419; bh=274D2ipJ0AKWod+Fv22HtE+wkWzmreiMAlafDi5GFOU=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FPkEkUSGuIJeBGk6qsmzERoBQknZj6CvMSjQOrZ5wyp7/oP0CLqKaJ2Ag+tN1GNOL /M0cw5lk6rqITosnhYEkcGIQZ23yAX8n3JLTTEQKKLEL2fdBU/RLybC2rVEyVUyOBk Mz52mA50uqZW2L6OQfU6TKjv2FmqPVUQQA1hh6Kk= 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 6.12 0531/1536] KVM: x86: Fill kvm_run exit fields in common get_nested_state_pages() error paths Date: Sat, 7 Nov 2026 08:42:27 -0500 Message-ID: <20261107135012.527164180@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-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: Adapted to local code by keeping nested_svm_vmrun_msrpm(svm), vmx->nested.nested_run_pending, and the open-coded nested_ops->get_nested_state_pages(vcpu) call instead of kvm_nested_call(). ] 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 4aee865718fe3..c1ecaf1578052 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1834,13 +1834,8 @@ static bool svm_get_nested_state_pages(struct kvm_vcpu *vcpu) if (CC(!load_pdptrs(vcpu, vcpu->arch.cr3))) return false; - if (!nested_svm_vmrun_msrpm(svm)) { - vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR; - vcpu->run->internal.suberror = - KVM_INTERNAL_ERROR_EMULATION; - vcpu->run->internal.ndata = 0; + if (!nested_svm_vmrun_msrpm(svm)) 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 a107b2a6d1152..016acc678fc03 100644 --- a/arch/x86/kvm/vmx/nested.c +++ b/arch/x86/kvm/vmx/nested.c @@ -3361,10 +3361,6 @@ 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; } } @@ -3435,11 +3431,6 @@ 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 @@ -3844,8 +3835,12 @@ 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 0e7fac0012605..4c6cae3a0f3f6 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10300,6 +10300,9 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) if (kvm_check_request(KVM_REQ_GET_NESTED_STATE_PAGES, vcpu)) { if (unlikely(!kvm_x86_ops.nested_ops->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