From nobody Tue Apr 7 05:42:07 2026 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 B6B3F3EF0A9; Mon, 16 Mar 2026 20:27:45 +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=1773692865; cv=none; b=qvy7tKN+WzuSLCbq0GBTcYPpR1a+jVAjuqufd3IHSMFcIbAtdNlT2x03HAN8gew7LcvjsQI6tQDRKTpeJ+no03Je55ZBdiHmjTZ+qqj8wa0AWGsT3PgQuGORQi6hVdz5f85mj69q/padCGWYrB+m0sNXtLs4Zp2eeNfbFPlHCDk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773692865; c=relaxed/simple; bh=6INPicvGAwF0HOdZHKimaIrincjL/kzHV/eR4X4flmQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=h44yapEGzFFgrjkW+8oBSfuFBtN06qxuCV21ZwfsT6cQNKY2qIGd6kahd4DqMqccjb4Y6WE+zn9AxVGjFTVujYU9lRz6jMj024BNtp5/yXOBVs43ZwDWqxWEghKiPLugmtyzF4ncj8+5+RhC/A4pjKMRrsCAskMTNLI00flgFWs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=D3SB0UVL; 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="D3SB0UVL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5637DC19424; Mon, 16 Mar 2026 20:27:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773692865; bh=6INPicvGAwF0HOdZHKimaIrincjL/kzHV/eR4X4flmQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=D3SB0UVLuxlCvnjoiSo2cp759SuEqc9NQ+BIkBL08bIEftt+Xl6LGX9brvgTj17QZ 7ZBgnyzYtlaLMwmtuMf9U6N1i/OnyjP4w+fL0huniVfVkWK/Ec2gmR0waDt9SWeYFB x6bPPUsjCTkOAJIjF5r2GcNWrIHfU3Cg/qzrByYF6LIGaJSR+sSAf/F+HlC7qF4kNw D0yKCJdPbUCZdIuYiVAnGFNS5efZfZUJsoX2DKrSC62xytdC6gRt0CL/DquwJuF7BO ulstZh9MWteYwXfhIcEvR7bDUs7rZAeERhMSx3yxUfRYeX+aEYLdvNK7ooHer5DW+T D7i63Urx740LQ== From: Yosry Ahmed To: Sean Christopherson Cc: Paolo Bonzini , Jim Mattson , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Yosry Ahmed Subject: [PATCH v4 7/9] KVM: nSVM: Fail emulation of VMRUN/VMLOAD/VMSAVE if mapping vmcb12 fails Date: Mon, 16 Mar 2026 20:27:30 +0000 Message-ID: <20260316202732.3164936-8-yosry@kernel.org> X-Mailer: git-send-email 2.53.0.851.ga537e3e6e9-goog In-Reply-To: <20260316202732.3164936-1-yosry@kernel.org> References: <20260316202732.3164936-1-yosry@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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 75943a607777c..73c0df0a81f0e 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -1121,10 +1121,8 @@ int nested_svm_vmrun(struct kvm_vcpu *vcpu) =20 ret =3D nested_svm_copy_vmcb12_to_cache(vcpu, vmcb12_gpa); if (ret) { - if (ret =3D=3D -EFAULT) { - kvm_inject_gp(vcpu, 0); - return 1; - } + if (ret =3D=3D -EFAULT) + return kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL); =20 /* 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 9f6f60fc8c133..1843627fa4cac 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2201,10 +2201,8 @@ static int vmload_vmsave_interception(struct kvm_vcp= u *vcpu, bool vmload) return 1; } =20 - if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map)) { - kvm_inject_gp(vcpu, 0); - return 1; - } + if (kvm_vcpu_map(vcpu, gpa_to_gfn(vmcb12_gpa), &map)) + return kvm_handle_memory_failure(vcpu, X86EMUL_IO_NEEDED, NULL); =20 vmcb12 =3D map.hva; =20 --=20 2.53.0.851.ga537e3e6e9-goog