From patchwork Mon Feb 24 09:10:00 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: 13987632 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 3BD86243364 for ; Mon, 24 Feb 2025 09:10:18 +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=1740388218; cv=none; b=ggAAoJ7nAgaWUNAeR7OOrf4StR7nTI0e86qQPrrRK6YQXbVhdB4jaw84vI/Vfn77EmMyRzrLB0FJYtZvQzyhlyOPwjI+0B2W3y+G3bB/CazQXOUVSCblbr0Mhtfq0DRakKd7OAOhIJaO0zfb3b7ce+sfB3L4ImnTSAsQ5rSaKMs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740388218; c=relaxed/simple; bh=25WXkM/8rWEaoR8LFVp2KbNEahjJte6M9YZgoly96/k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=QZKlJ2i6m0zuJpxqvy54LIsV2TeEV0skY1ef9zmOjE5QkprsYanWwcr2DG9rbSLDNnASA64/3vZwXlfbELibyn7zh/vOyQWRGeJSMse7Rfc1DbS3CYGj5NZ6oiH+Rw68JdCE1VF6wGt9RHEnoMBnRFyWH+OTyWy9VBO/2+a2WOg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qpzZXn8L; 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="qpzZXn8L" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26196C4CED6; Mon, 24 Feb 2025 09:10:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1740388218; bh=25WXkM/8rWEaoR8LFVp2KbNEahjJte6M9YZgoly96/k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=qpzZXn8L1aQBqOsvb+yp/83lYCIJyb70RwcmdBiwXcxpdAg52ilg5B7wSCx8SEoZb qLqxnFHjdNqS+yz2YD0r4EoNboQCFNK4SpMumjVmpQzli70bmSz8/prZV6Duebd4or O3R3cClzegFyUcE9e6MEGS/PYRhHMJQ0QVjAQ8EgynerK4ambFJ+OP63pQFuRWPvyV UbVk5I9YxrWA9HXB2hu+Fnzw9+ZwCa29OJZ0ZymsDz4tmr7ZtMBdVLwMr75TL2jbhM 93JM0+3UmG8OHrGn7eM+TFk8CVGcNTYHuJYhS3KfVY0Yo3Yoxgq2/SA88IyVy+sxVg 4LqgCzIwgTBWg== 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 2/2] cpu: vmexit: Handle KVM_EXIT_MEMORY_FAULT in KVM_RUN ioctl return Date: Mon, 24 Feb 2025 14:40:00 +0530 Message-ID: <20250224091000.3925918-2-aneesh.kumar@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20250224091000.3925918-1-aneesh.kumar@kernel.org> References: <20250224091000.3925918-1-aneesh.kumar@kernel.org> Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 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 Signed-off-by: Aneesh Kumar K.V (Arm) Reviewed-by: Alexandru Elisei --- 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 7c62bfc56679..c0b10b1534ab 100644 --- a/kvm-cpu.c +++ b/kvm-cpu.c @@ -41,8 +41,19 @@ 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; + /* faullthrough */ + default: + die_perror("KVM_RUN failed"); + } + } } static void kvm_cpu_signal_handler(int signum) diff --git a/kvm.c b/kvm.c index 42b881217df6..172d951bfe4e 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;