[{"id":3673043,"web_url":"http://patchwork.ozlabs.org/comment/3673043/","msgid":"<20260403053055-mutt-send-email-mst@kernel.org>","list_archive_url":null,"date":"2026-04-03T09:33:35","subject":"Re: [PATCH] hw/virtio/vhost: simplify ring mapping verification with\n loop","submitter":{"id":2235,"url":"http://patchwork.ozlabs.org/api/people/2235/","name":"Michael S. Tsirkin","email":"mst@redhat.com"},"content":"On Fri, Apr 03, 2026 at 05:16:21PM +0800, Bin Guo wrote:\n> Replace the three nearly-identical vhost_verify_ring_part_mapping() calls\n> with a simple loop over arrays. This eliminates code duplication while\n> maintaining identical behavior and error reporting.\n> \n> Signed-off-by: Bin Guo \n> ---\n> hw/virtio/vhost.c | 34 ++++++++++++----------------------\n> 1 file changed, 12 insertions(+), 22 deletions(-)\n> \n> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c\n> index b9dc4ed13b..7b5bfc86e6 100644\n> --- a/hw/virtio/vhost.c\n> +++ b/hw/virtio/vhost.c\n> @@ -525,31 +525,21 @@ static int vhost_verify_ring_mappings(struct vhost_dev *dev,\n> continue;\n> }\n> \n> - j = 0;\n> - r = vhost_verify_ring_part_mapping(\n> - vq->desc, vq->desc_phys, vq->desc_size,\n> - reg_hva, reg_gpa, reg_size);\n> - if (r) {\n> - break;\n> - }\n> -\n> - j++;\n> - r = vhost_verify_ring_part_mapping(\n> - vq->avail, vq->avail_phys, vq->avail_size,\n> - reg_hva, reg_gpa, reg_size);\n> - if (r) {\n> - break;\n> - }\n> -\n> - j++;\n> - r = vhost_verify_ring_part_mapping(\n> - vq->used, vq->used_phys, vq->used_size,\n> - reg_hva, reg_gpa, reg_size);\n> - if (r) {\n> - break;\n> + void *ring_addrs[] = {vq->desc, vq->avail, vq->used};\n> + uint64_t ring_phys[] = {vq->desc_phys, vq->avail_phys, vq->used_phys};\n> + uint64_t ring_sizes[] = {vq->desc_size, vq->avail_size, vq->used_size};\n> +\n> + for (j = 0; j < 3; j++) {\n> + r = vhost_verify_ring_part_mapping(\n> + ring_addrs[j], ring_phys[j], ring_sizes[j],\n> + reg_hva, reg_gpa, reg_size);\n> + if (r) {\n> + goto out;\n> + }\n> }\n> }\n> \n> +out:\n> if (r == -ENOMEM) {\n> error_report(\"Unable to map %s for ring %d\", part_name[j], i);\n\n\nI don't see the point, sorry. Maybe if it was a single array,\nand we used ARRAY_SIZE ... Even then, I am not sure.\n\nAs it is, we are replacing straight forward linear code with\ntricky arrays.\n\n> } else if (r == -EBUSY) {\n> -- \n> 2.50.1 (Apple Git-155)","headers":{"Return-Path":"","X-Original-To":"incoming@patchwork.ozlabs.org","Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (1024-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=mimecast20190719 header.b=hUjUN4Fk;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256\n header.s=google header.b=Y03V49QU;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org\n (client-ip=209.51.188.17; helo=lists.gnu.org;\n envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org;\n receiver=patchwork.ozlabs.org)"],"Received":["from lists.gnu.org (lists.gnu.org [209.51.188.17])\n\t(using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits))\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fnD8421y2z1yCt\n\tfor ; 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Tsirkin\" ","To":"Bin Guo ","Cc":"qemu-devel@nongnu.org, richard.henderson@linaro.org, philmd@linaro.org","Subject":"Re: [PATCH] hw/virtio/vhost: simplify ring mapping verification with\n loop","Message-ID":"<20260403053055-mutt-send-email-mst@kernel.org>","References":"<20260403091621.88914-1-guobin@linux.alibaba.com>","MIME-Version":"1.0","Content-Type":"text/plain; charset=us-ascii","Content-Disposition":"inline","In-Reply-To":"<20260403091621.88914-1-guobin@linux.alibaba.com>","Received-SPF":"pass client-ip=170.10.129.124; envelope-from=mst@redhat.com;\n helo=us-smtp-delivery-124.mimecast.com","X-Spam_score_int":"-25","X-Spam_score":"-2.6","X-Spam_bar":"--","X-Spam_report":"(-2.6 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.542,\n DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1,\n RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001,\n RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001,\n RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001,\n SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no","X-Spam_action":"no action","X-BeenThere":"qemu-devel@nongnu.org","X-Mailman-Version":"2.1.29","Precedence":"list","List-Id":"qemu development ","List-Unsubscribe":",\n ","List-Archive":"","List-Post":"","List-Help":"","List-Subscribe":",\n ","Errors-To":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org","Sender":"qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org"}}]