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 2D94726C3AE for ; Mon, 28 Apr 2025 11:57:57 +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=1745841477; cv=none; b=B6sbKKOQ5KGsJD1jg3iqrH7zyNid1NA12q2wRbhJx4MrrqnQAD17eZVWCCjp1wsR8jQDgDX77fcFByD2DKfA9/39d9/zGdNh+/WCnJL+2n1zXlLyZZOrroiRJD2+JTfK1EWknGo5RYD1b7s42STr1eEzOHTIhsyq22F7085M6VU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745841477; c=relaxed/simple; bh=RfZin90kUqqU1HpghidM+AHb1+8BQ8idqiaMyyS/Tw8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fGULJPzX4JW1Y/R/Td3rgZCBOlIdcNhGZORfwTfgWaRDXGy/cQD8CurynoghGaSIs1xjsRLgIzrowCo0e2hz7iw64GlbrTkeUzIGs8yoSjhwt84XXv4wS2VoSJ+tZUva8xBTn/WHRtDVYdao8LtkFGCs9OQ2++x7XMpJPyOwXDE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Y9u52b4X; 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="Y9u52b4X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 911E4C4CEED; Mon, 28 Apr 2025 11:57:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1745841477; bh=RfZin90kUqqU1HpghidM+AHb1+8BQ8idqiaMyyS/Tw8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Y9u52b4XBa0H/OGbViMHHh5sNGukBr86AyFltRP7Z0ZDz3g+u5ElFQ6SE3CZ5WNP9 NuDfbmDQrIJpUiccEOYiaQ98dLB78CRkK7Tz4XsNXeuM/+4zy1u1JAxefNvct3bc3Z yVSEnuv30SGJZ8SMeEwSz6SF0QxPbbVVhngB87yaoGM1cNQ0ikLLWSu//dWIwgUSOB C6ELTz/U4BynmqMqtrc/3DvzKsSGtoSiSvTn9OUU/6Ckw0eBgrY8MiATCVpq41dbz2 ux+igCPQBlH8FaN6lEOLClSRu2xJ8DNxpdrG7SrIpoPCf2esCQZANh6DI+pOw8ydRB rL9uB3vabMksw== From: "Aneesh Kumar K.V (Arm)" To: kvm@vger.kernel.org Cc: Suzuki K Poulose , Steven Price , Will Deacon , Julien Thierry , "Aneesh Kumar K.V (Arm)" , Alexandru Elisei Subject: [PATCH kvmtool v3 1/3] cpu: vmexit: Handle KVM_EXIT_MEMORY_FAULT in KVM_RUN ioctl return Date: Mon, 28 Apr 2025 17:27:43 +0530 Message-ID: <20250428115745.70832-2-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250428115745.70832-1-aneesh.kumar@kernel.org> References: <20250428115745.70832-1-aneesh.kumar@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 Linux kernel documentation states: "Note! KVM_EXIT_MEMORY_FAULT is unique among all KVM exit reasons in that it accompanies a return code of '-1', not '0'! errno will always be set to EFAULT or EHWPOISON when KVM exits with KVM_EXIT_MEMORY_FAULT, userspace should assume kvm_run.exit_reason is stale/undefined for all other error numbers." " Update KVM_RUN ioctl error handling to correctly handle KVM_EXIT_MEMORY_FAULT. This enables the memory fault exit handlers in the kernel to return -EFAULT as the return value. VMM support is still required to handle these memory fault exits, but that is not included in this change Reviewed-by: Alexandru Elisei Signed-off-by: Aneesh Kumar K.V (Arm) --- kvm-cpu.c | 15 +++++++++++++-- kvm.c | 1 + 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/kvm-cpu.c b/kvm-cpu.c index 7362f2e99261..40041a22b3fe 100644 --- a/kvm-cpu.c +++ b/kvm-cpu.c @@ -43,8 +43,19 @@ void kvm_cpu__run(struct kvm_cpu *vcpu) return; err = ioctl(vcpu->vcpu_fd, KVM_RUN, 0); - if (err < 0 && (errno != EINTR && errno != EAGAIN)) - die_perror("KVM_RUN failed"); + if (err < 0) { + switch (errno) { + case EINTR: + case EAGAIN: + return; + case EFAULT: + if (vcpu->kvm_run->exit_reason == KVM_EXIT_MEMORY_FAULT) + return; + /* fallthrough */ + default: + die_perror("KVM_RUN failed"); + } + } } static void kvm_cpu_signal_handler(int signum) diff --git a/kvm.c b/kvm.c index 07089cf1b332..b6375a114d11 100644 --- a/kvm.c +++ b/kvm.c @@ -55,6 +55,7 @@ const char *kvm_exit_reasons[] = { #ifdef CONFIG_PPC64 DEFINE_KVM_EXIT_REASON(KVM_EXIT_PAPR_HCALL), #endif + DEFINE_KVM_EXIT_REASON(KVM_EXIT_MEMORY_FAULT), }; static int pause_event; -- 2.43.0