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(unknown [2a02:6bf:8080:a4b::1:3c]) by mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net (smtpcorp/Yandex) with ESMTPSA id 6OWMXt1FjqM0-AOZ2PORW; Sun, 12 Oct 2025 02:24:18 +0300 Precedence: bulk X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=yandex-team.ru; s=default; t=1760225058; bh=lnmrNOdH9PiRJ6qfAMMgLMUKPbunmPfqaClpCsSkPRM=; h=Message-ID:Date:In-Reply-To:Cc:Subject:References:To:From; b=rBrkvocJrduEtCy2znmVy7Mkr7KS6qt04/5JeJoj+cx7CV1gHyuD25o1sMry2YWSX ZrCBDfPki6SdU/TRWc5X34CrX9wp930tTFTYD5y/Xpln9K1gfihbMcqXJ8oDIbpR4n zkOmegFyHP9QZrrxA7cSpwMz2MUxoohz1hOBYL/w= Authentication-Results: mail-nwsmtp-smtp-corp-main-83.vla.yp-c.yandex.net; dkim=pass header.i=@yandex-team.ru From: Vladimir Sementsov-Ogievskiy To: mst@redhat.com Cc: sgarzare@redhat.com, raphael@enfabrica.net, qemu-devel@nongnu.org, raphael.s.norwitz@gmail.com, vsementsov@yandex-team.ru, yc-core@yandex-team.ru, d-tatianin@yandex-team.ru Subject: [PATCH v2 11/23] vhost: make vhost_memory_unmap() null-safe Date: Sun, 12 Oct 2025 02:23:50 +0300 Message-ID: <20251011232404.561024-12-vsementsov@yandex-team.ru> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20251011232404.561024-1-vsementsov@yandex-team.ru> References: <20251011232404.561024-1-vsementsov@yandex-team.ru> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a02:6b8:c0e:500:1:45:d181:df01; envelope-from=vsementsov@yandex-team.ru; helo=forwardcorp1a.mail.yandex.net X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=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 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: qemu-devel-bounces+importer=patchew.org@nongnu.org X-ZohoMail-DKIM: pass (identity @yandex-team.ru) X-ZM-MESSAGEID: 1760225157398158500 Content-Type: text/plain; charset="utf-8" This helps to simplify failure paths of vhost_virtqueue_start() a lot. We also need to zero-out pointers on unmap, to not try to unmap invalid pointers. Signed-off-by: Vladimir Sementsov-Ogievskiy Reviewed-by: Raphael Norwitz --- hw/virtio/vhost.c | 41 +++++++++++++++++++++-------------------- 1 file changed, 21 insertions(+), 20 deletions(-) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index 8031c74e7b..6fec193d5f 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -472,14 +472,20 @@ static void *vhost_memory_map(struct vhost_dev *dev, = hwaddr addr, } } =20 -static void vhost_memory_unmap(struct vhost_dev *dev, void *buffer, +static void vhost_memory_unmap(struct vhost_dev *dev, void **buffer, hwaddr len, int is_write, hwaddr access_len) { + if (!*buffer) { + return; + } + if (!vhost_dev_has_iommu(dev)) { - address_space_unmap(dev->vdev->dma_as, buffer, len, is_write, + address_space_unmap(dev->vdev->dma_as, *buffer, len, is_write, access_len); } + + *buffer =3D NULL; } =20 static int vhost_verify_ring_part_mapping(void *ring_hva, @@ -1315,33 +1321,33 @@ int vhost_virtqueue_start(struct vhost_dev *dev, vq->desc =3D vhost_memory_map(dev, a, l, false); if (!vq->desc) { r =3D -ENOMEM; - goto fail_alloc_desc; + goto fail; } vq->avail_size =3D l =3D virtio_queue_get_avail_size(vdev, idx); vq->avail_phys =3D a =3D virtio_queue_get_avail_addr(vdev, idx); vq->avail =3D vhost_memory_map(dev, a, l, false); if (!vq->avail) { r =3D -ENOMEM; - goto fail_alloc_avail; + goto fail; } vq->used_size =3D l =3D virtio_queue_get_used_size(vdev, idx); vq->used_phys =3D a =3D virtio_queue_get_used_addr(vdev, idx); vq->used =3D vhost_memory_map(dev, a, l, true); if (!vq->used) { r =3D -ENOMEM; - goto fail_alloc_used; + goto fail; } =20 r =3D vhost_virtqueue_set_addr(dev, vq, vhost_vq_index, dev->log_enabl= ed); if (r < 0) { - goto fail_alloc; + goto fail; } =20 file.fd =3D event_notifier_get_fd(virtio_queue_get_host_notifier(vvq)); r =3D dev->vhost_ops->vhost_set_vring_kick(dev, &file); if (r) { VHOST_OPS_DEBUG(r, "vhost_set_vring_kick failed"); - goto fail_kick; + goto fail; } =20 /* Clear and discard previous events if any. */ @@ -1361,24 +1367,19 @@ int vhost_virtqueue_start(struct vhost_dev *dev, file.fd =3D -1; r =3D dev->vhost_ops->vhost_set_vring_call(dev, &file); if (r) { - goto fail_vector; + goto fail; } } =20 return 0; =20 -fail_vector: -fail_kick: -fail_alloc: - vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx= ), +fail: + vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, id= x), 0, 0); -fail_alloc_used: - vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, i= dx), + vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, = idx), 0, 0); -fail_alloc_avail: - vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx= ), + vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, id= x), 0, 0); -fail_alloc_desc: return r; } =20 @@ -1425,11 +1426,11 @@ static int do_vhost_virtqueue_stop(struct vhost_dev= *dev, vhost_vq_index); } =20 - vhost_memory_unmap(dev, vq->used, virtio_queue_get_used_size(vdev, idx= ), + vhost_memory_unmap(dev, &vq->used, virtio_queue_get_used_size(vdev, id= x), 1, virtio_queue_get_used_size(vdev, idx)); - vhost_memory_unmap(dev, vq->avail, virtio_queue_get_avail_size(vdev, i= dx), + vhost_memory_unmap(dev, &vq->avail, virtio_queue_get_avail_size(vdev, = idx), 0, virtio_queue_get_avail_size(vdev, idx)); - vhost_memory_unmap(dev, vq->desc, virtio_queue_get_desc_size(vdev, idx= ), + vhost_memory_unmap(dev, &vq->desc, virtio_queue_get_desc_size(vdev, id= x), 0, virtio_queue_get_desc_size(vdev, idx)); return r; } --=20 2.48.1