From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 132C428690; Fri, 13 Mar 2026 00:10:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773360645; cv=none; b=R+DO+D4r3LTGO0n8ezuKhAqAs2HOSZD8dKe8iTdKdMiDXM8c6jq45EMYmScyhuajTAQUY6XBXBdnGyiuWaoNCytQFwM8XraXuDPlSXKbaL7SfBIjFlnwu2yEmNm1fSkhZxAxVeqM/NGzl4hagTvTsuYvGoj/7RP/wnVPSd4bj7w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773360645; c=relaxed/simple; bh=iT7ytVgEpQbRU1hUnmwIaSYlLLEpefPIQyU87UhnxmU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Dyo4FlMO+o+VrjxTkGwIPka6Mtq68YST/R5p2oeNhl+cCNu7qWgElsasrvVlO9hSrOF9pLJSJnmoXGcf6jMfYyREgIFnfEikIqHNmXvpwHYYdnuAgx12JP2ytlj6r0mvwVQ4a68ni5dRP3a+xt1yAdUPXlBo+HITNHkMEmhFbgE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=a7wMqaZ3; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="a7wMqaZ3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9DC57C2BC86; Fri, 13 Mar 2026 00:10:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773360644; bh=iT7ytVgEpQbRU1hUnmwIaSYlLLEpefPIQyU87UhnxmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=a7wMqaZ3KBW4J+jLyepP82QkOAlxwoDXhQZ4MRXmrQoZh1OcRRc3Mq15EEeIsSyP2 wrKJTHVtql0lWlTUADU+fU6WpJiKBI8kEDXgr5CDIb89A3laZwDVJrjo4/9A/T8NZF 4wcfvh5tgfIUIkk6VZm2RcmKzbV5L3gH3Gqlb04zqGw9GBBPW35zsgDftuFHo4euQ9 pCjfamJcQMMytNISEO84OCwASbt/XahgBLkwUnjPGDA/yJ0fyz+cJ97jUUKQc20jME f4I+0o3jjxrPLX2KwPsFKDdtxFxQ0gIzANiyYVfTGniVrUG9HO0H1XTRcIbg05iyru u+vbJwinCr7XQ== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , Jim Mattson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v3 5/7] KVM: nSVM: Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails Date: Fri, 13 Mar 2026 00:10:22 +0000 Message-ID: <20260313001024.136619-6-yosry@kernel.org> X-Mailer: git-send-email 2.53.0.851.ga537e3e6e9-goog In-Reply-To: <20260313001024.136619-1-yosry@kernel.org> References: <20260313001024.136619-1-yosry@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit KVM currently injects a #GP if mapping vmcb12 fails when emulating VMRUN/VMLOAD/VMSAVE. This is not architectural behavior, as #GP should only be injected if the physical address is not supported or not aligned. Instead, handle it as an emulation failure, similar to how nVMX handles failures to read/write guest memory in several emulation paths. When virtual VMLOAD/VMSAVE is enabled, if vmcb12's GPA is not mapped in the NPTs a VMEXIT(#NPF) will be generated, and KVM will install an MMIO SPTE and emulate the instruction if there is no corresponding memslot. x86_emulate_insn() will return EMULATION_FAILED as VMLOAD/VMSAVE are not handled as part of the twobyte_insn cases. Even though this will also result in an emulation failure, it will only result in a straight return to userspace if KVM_CAP_EXIT_ON_EMULATION_FAILURE is set. Otherwise, it would inject #UD and only exit to userspace if not in guest mode. So the behavior is slightly different if virtual VMLOAD/VMSAVE is enabled. Fixes: 3d6368ef580a ("KVM: SVM: Add VMRUN handler") Reported-by: Jim Mattson Signed-off-by: Yosry Ahmed --- arch/x86/kvm/svm/nested.c | 6 ++---- arch/x86/kvm/svm/svm.c | 6 ++---- 2 files changed, 4 insertions(+), 8 deletions(-) diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 016bf88ec2def..8320c98b704ce 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1122,10 +1122,8 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu) ret = nested_svm_copy_vmcb12_to_cache(vcpu, vmcb12_gpa); if (ret) { - if (ret == -EFAULT) { - kvm_inject_gp(vcpu, 0); - return 1; - } + if (ret == -EFAULT) + return kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL); /* Advance RIP past VMRUN as part of the nested #VMEXIT. */ return kvm_skip_emulated_instruction(vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 3b1516ea45d4f..a0dacbeaa3c5a 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2196,10 +2196,8 @@ static int vmload_vmsave_interception(struct kvm_vcpu *vcpu, bool vmload) return 1; } - if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->vmcb->save.rax), &map)) { - kvm_inject_gp(vcpu, 0); - return 1; - } + if (kvm_vcpu_map(vcpu, gpa_to_gfn(svm->vmcb->save.rax), &map)) + return kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL); vmcb12 = map.hva; -- 2.53.0.851.ga537e3e6e9-goog