From patchwork Mon Feb 24 09:09:59 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Aneesh Kumar K.V" X-Patchwork-Id: 13987631 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 803D924BBE4 for ; Mon, 24 Feb 2025 09:10:14 +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=1740388214; cv=none; b=qaQOibX7C5NVo6oG3tTAU/ykAaiw4PMXIkRQ5umdaNjiJjZDvGrrOkK4uId/dPu1+g7RELPCT9mlDhrfR2JrUkUZDQqRHg6ij+B9j/RJmV0gekdwQv2+4VisUNSheb1RFHRUE/QMlowQQUtmy9FDSbJ36+y8Esn2gCmGESoEWTc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740388214; c=relaxed/simple; bh=d89GjCOAb8v1g8rv/GObFnQoi4giK3ojT0tAF8KaSkM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=gy14Cndi5MV6iFTHV0OuZ7eWQp9nq2sHlKxO2smOi20sekWzGp5xKI9QIh05XoL3ctOO39uTKpcGcfk73VM2bLa5gaFrztiQdFsftbx5mvs5LeStk/EBe4WED4k0KQj4s2On1IQMqrDhYX91zoNZgUoggr2dqa+mbmye3+wrex4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GD9/klwW; 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="GD9/klwW" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D2CDC4CEDD; Mon, 24 Feb 2025 09:10:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740388214; bh=d89GjCOAb8v1g8rv/GObFnQoi4giK3ojT0tAF8KaSkM=; h=From:To:Cc:Subject:Date:From; b=GD9/klwWJcjF7oPGb8bOec5XsGUAPU5bFsNXX1X/rRGqJZveSgIe6r6vLdbIbXfu8 N1hXaXmopqi7EhUw8T7NodmBcltwxkGJFzgNIb72rV67edLEyJY49zYf0anp0huEEh XVJji0CSx/nOdjGRDi6q/iCL5xk6AwYGHqWhFUdiA/JF+1y1i//U/35FAqjLEsA/B3 GujlEOHLA3ys8RVDqVRTobigzuBCHGJ/APbonXmoHP0TWy3U1ywsXqJP+lhwqS25Ml vE3b7Jqz6LnoWMHad1zBJrhPypEzFRWwWV2PTfsjkD0X9I66T11A2YvroOyMKi2i1y dSnbgecDp3V9w== From: "Aneesh Kumar K.V (Arm)" To: kvm@vger.kernel.org Cc: Suzuki K Poulose , Steven Price , Will Deacon , Julien Thierry , Alexandru Elisei , "Aneesh Kumar K.V (Arm)" Subject: [PATCH kvmtool v2 1/2] cpu: vmexit: Handle KVM_EXIT_UNKNOWN exit reason correctly Date: Mon, 24 Feb 2025 14:39:59 +0530 Message-ID: <20250224091000.3925918-1-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 The return value for kernel VM exit handlers is confusing and has led to errors in different kernel exit handlers. A return value of 0 indicates a return to the VMM, whereas a return value of 1 indicates resuming execution in the guest. Some handlers mistakenly return 0 to force a return to the guest. This worked in kvmtool because the exit_reason defaulted to 0 (KVM_EXIT_UNKNOWN), and kvmtool did not error out on an unknown exit reason. However, forcing a VMM exit with error on KVM_EXIT_UNKNOWN exit_reson would help catch these bugs early. Signed-off-by: Aneesh Kumar K.V (Arm) Reviewed-by: Alexandru Elisei --- kvm-cpu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kvm-cpu.c b/kvm-cpu.c index f66dcd07220c..7c62bfc56679 100644 --- a/kvm-cpu.c +++ b/kvm-cpu.c @@ -170,7 +170,7 @@ int kvm_cpu__start(struct kvm_cpu *cpu) switch (cpu->kvm_run->exit_reason) { case KVM_EXIT_UNKNOWN: - break; + goto panic_kvm; case KVM_EXIT_DEBUG: kvm_cpu__show_registers(cpu); kvm_cpu__show_code(cpu);