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bh=4+WAH92SNYw1I0R63EWnB7Xfs3BvI/uefRj3o3pNaD4=; b=HebC2I2RIRSnxw1p6c0NJenk4de/+VQEO4GhZi1rbpx45h20xSeHIuPyIlMwoY1rQbKhOq tdAcWWT5J/A6oz1hkjjCQONV9M5wFntk2roeda7PAKG89Jc3+frKUuz60513GOWEhScmzm 2AVtHDPhNBRQpGV//NTd0NAIGGSSIoI= X-MC-Unique: 6S4Dbln-OWaN1Tqzn83lHQ-1 From: Stefan Hajnoczi To: qemu-devel@nongnu.org Subject: [PATCH 2/5] vhost: involve device backends in feature negotiation Date: Fri, 22 May 2020 18:17:23 +0100 Message-Id: <20200522171726.648279-3-stefanha@redhat.com> In-Reply-To: <20200522171726.648279-1-stefanha@redhat.com> References: <20200522171726.648279-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com 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=205.139.110.120; envelope-from=stefanha@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/05/22 10:36:44 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -3 X-Spam_score: -0.4 X-Spam_bar: / X-Spam_report: (-0.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, MIME_BASE64_TEXT=1.741, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , Laurent Vivier , Thomas Huth , Eduardo Habkost , qemu-block@nongnu.org, "Michael S. Tsirkin" , jasowang@redhat.com, cohuck@redhat.com, Stefan Hajnoczi , "Dr. David Alan Gilbert" , Raphael Norwitz , "Gonglei \(Arei\)" , Gerd Hoffmann , Paolo Bonzini , =?UTF-8?q?Marc-Andr=C3=A9=20Lureau?= , Fam Zheng , Max Reitz Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Content-Type: text/plain; charset="utf-8" Many vhost devices in QEMU currently do not involve the device backend in feature negotiation. This seems fine at first glance for device types without their own feature bits (virtio-net has many but other device types have none). This overlooks the fact that QEMU's virtqueue implementation and the device backend's implementation may support different features. QEMU must not report features to the guest that the the device backend doesn't support. For example, QEMU supports VIRTIO 1.1 packed virtqueues while many existing vhost device backends do not. When the user sets packed=3Don the device backend breaks. This should have been handled gracefully by feature negotiation instead. Introduce vhost_get_default_features() and update all vhost devices in QEMU to involve the device backend in feature negotiation. This patch fixes the following error: $ x86_64-softmmu/qemu-system-x86_64 \ -drive if=3Dvirtio,file=3Dtest.img,format=3Draw \ -chardev socket,path=3D/tmp/vhost-user-blk.sock,id=3Dchar0 \ -device vhost-user-blk-pci,chardev=3Dchar0,packed=3Don \ -object memory-backend-memfd,size=3D1G,share=3Don,id=3Dram0 \ -M accel=3Dkvm,memory-backend=3Dram0 qemu-system-x86_64: Failed to set msg fds. qemu-system-x86_64: vhost VQ 0 ring restore failed: -1: Success (0) The vhost-user-blk backend failed as follows: $ ./vhost-user-blk --socket-path=3D/tmp/vhost-user-blk.sock -b test2.img vu_panic: virtio: zero sized buffers are not allowed virtio-blk request missing headers Signed-off-by: Stefan Hajnoczi --- include/hw/virtio/vhost.h | 1 + include/hw/virtio/virtio-gpu.h | 2 ++ include/sysemu/cryptodev-vhost.h | 11 +++++++++++ backends/cryptodev-vhost.c | 19 +++++++++++++++++++ hw/display/vhost-user-gpu.c | 17 +++++++++++++++++ hw/display/virtio-gpu-base.c | 2 +- hw/input/vhost-user-input.c | 9 +++++++++ hw/virtio/vhost-user-fs.c | 5 +++-- hw/virtio/vhost-vsock.c | 5 +++-- hw/virtio/vhost.c | 22 ++++++++++++++++++++++ hw/virtio/virtio-crypto.c | 3 ++- 11 files changed, 90 insertions(+), 6 deletions(-) diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index 085450c6f8..d2e54dd4a8 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -112,6 +112,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtI= ODevice *vdev, int n, bool mask); uint64_t vhost_get_features(struct vhost_dev *hdev, const int *feature_bit= s, uint64_t features); +uint64_t vhost_get_default_features(struct vhost_dev *hdev, uint64_t featu= res); void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, uint64_t features); bool vhost_has_free_slot(void); diff --git a/include/hw/virtio/virtio-gpu.h b/include/hw/virtio/virtio-gpu.h index 6dd57f2025..41d270d80e 100644 --- a/include/hw/virtio/virtio-gpu.h +++ b/include/hw/virtio/virtio-gpu.h @@ -192,6 +192,8 @@ bool virtio_gpu_base_device_realize(DeviceState *qdev, void virtio_gpu_base_reset(VirtIOGPUBase *g); void virtio_gpu_base_fill_display_info(VirtIOGPUBase *g, struct virtio_gpu_resp_display_info *dpy_info); +uint64_t virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t feature= s, + Error **errp); =20 /* virtio-gpu.c */ void virtio_gpu_ctrl_response(VirtIOGPU *g, diff --git a/include/sysemu/cryptodev-vhost.h b/include/sysemu/cryptodev-vh= ost.h index f42824fbde..e629446bfb 100644 --- a/include/sysemu/cryptodev-vhost.h +++ b/include/sysemu/cryptodev-vhost.h @@ -122,6 +122,17 @@ int cryptodev_vhost_start(VirtIODevice *dev, int total= _queues); */ void cryptodev_vhost_stop(VirtIODevice *dev, int total_queues); =20 +/** + * cryptodev_vhost_get_features: + * @dev: the virtio crypto object + * @requested_features: the features being offered + * + * Returns: the requested features bits that are supported by the vhost de= vice, + * or the original request feature bits if vhost is disabled + * + */ +uint64_t cryptodev_vhost_get_features(VirtIODevice *dev, uint64_t features= ); + /** * cryptodev_vhost_virtqueue_mask: * @dev: the virtio crypto object diff --git a/backends/cryptodev-vhost.c b/backends/cryptodev-vhost.c index 8337c9a495..5f5a4fda7b 100644 --- a/backends/cryptodev-vhost.c +++ b/backends/cryptodev-vhost.c @@ -266,6 +266,20 @@ void cryptodev_vhost_stop(VirtIODevice *dev, int total= _queues) assert(r >=3D 0); } =20 +uint64_t cryptodev_vhost_get_features(VirtIODevice *dev, uint64_t features) +{ + VirtIOCrypto *vcrypto =3D VIRTIO_CRYPTO(dev); + CryptoDevBackend *b =3D vcrypto->cryptodev; + CryptoDevBackendClient *cc =3D b->conf.peers.ccs[0]; + CryptoDevBackendVhost *vhost_crypto =3D cryptodev_get_vhost(cc, b, 0); + + if (!vhost_crypto) { + return features; /* vhost disabled */ + } + + return vhost_get_default_features(&vhost_crypto->dev, features); +} + void cryptodev_vhost_virtqueue_mask(VirtIODevice *dev, int queue, int idx, bool mask) @@ -333,6 +347,11 @@ void cryptodev_vhost_stop(VirtIODevice *dev, int total= _queues) { } =20 +uint64_t cryptodev_vhost_get_features(VirtIODevice *dev, uint64_t features) +{ + return features; +} + void cryptodev_vhost_virtqueue_mask(VirtIODevice *dev, int queue, int idx, bool mask) diff --git a/hw/display/vhost-user-gpu.c b/hw/display/vhost-user-gpu.c index 4cdaee1bde..e483df2a9e 100644 --- a/hw/display/vhost-user-gpu.c +++ b/hw/display/vhost-user-gpu.c @@ -466,6 +466,22 @@ vhost_user_gpu_set_config(VirtIODevice *vdev, } } =20 +static uint64_t +vhost_user_gpu_get_features(VirtIODevice *vdev, uint64_t features, + Error **errp) +{ + VhostUserGPU *g =3D VHOST_USER_GPU(vdev); + Error *local_err =3D NULL; + + features =3D virtio_gpu_base_get_features(vdev, features, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return 0; + } + + return vhost_get_default_features(&g->vhost->dev, features); +} + static void vhost_user_gpu_set_status(VirtIODevice *vdev, uint8_t val) { @@ -582,6 +598,7 @@ vhost_user_gpu_class_init(ObjectClass *klass, void *dat= a) =20 vdc->realize =3D vhost_user_gpu_device_realize; vdc->reset =3D vhost_user_gpu_reset; + vdc->get_features =3D vhost_user_gpu_get_features; vdc->set_status =3D vhost_user_gpu_set_status; vdc->guest_notifier_mask =3D vhost_user_gpu_guest_notifier_mask; vdc->guest_notifier_pending =3D vhost_user_gpu_guest_notifier_pending; diff --git a/hw/display/virtio-gpu-base.c b/hw/display/virtio-gpu-base.c index c159351be3..05d1ff2db2 100644 --- a/hw/display/virtio-gpu-base.c +++ b/hw/display/virtio-gpu-base.c @@ -176,7 +176,7 @@ virtio_gpu_base_device_realize(DeviceState *qdev, return true; } =20 -static uint64_t +uint64_t virtio_gpu_base_get_features(VirtIODevice *vdev, uint64_t features, Error **errp) { diff --git a/hw/input/vhost-user-input.c b/hw/input/vhost-user-input.c index 63984a8ba7..1371fb32cc 100644 --- a/hw/input/vhost-user-input.c +++ b/hw/input/vhost-user-input.c @@ -45,6 +45,14 @@ static void vhost_input_change_active(VirtIOInput *vinpu= t) } } =20 +static uint64_t vhost_input_get_features(VirtIODevice *vdev, uint64_t feat= ures, + Error **errp) +{ + VHostUserInput *vhi =3D VHOST_USER_INPUT(vdev); + + return vhost_get_default_features(&vhi->vhost->dev, features); +} + static void vhost_input_get_config(VirtIODevice *vdev, uint8_t *config_dat= a) { VirtIOInput *vinput =3D VIRTIO_INPUT(vdev); @@ -89,6 +97,7 @@ static void vhost_input_class_init(ObjectClass *klass, vo= id *data) DeviceClass *dc =3D DEVICE_CLASS(klass); =20 dc->vmsd =3D &vmstate_vhost_input; + vdc->get_features =3D vhost_input_get_features; vdc->get_config =3D vhost_input_get_config; vdc->set_config =3D vhost_input_set_config; vic->realize =3D vhost_input_realize; diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c index 1bc5d03a00..56015ca3d4 100644 --- a/hw/virtio/vhost-user-fs.c +++ b/hw/virtio/vhost-user-fs.c @@ -130,8 +130,9 @@ static uint64_t vuf_get_features(VirtIODevice *vdev, uint64_t requested_features, Error **errp) { - /* No feature bits used yet */ - return requested_features; + VHostUserFS *fs =3D VHOST_USER_FS(vdev); + + return vhost_get_default_features(&fs->vhost_dev, requested_features); } =20 static void vuf_handle_output(VirtIODevice *vdev, VirtQueue *vq) diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c index 4a228f5168..7276587be6 100644 --- a/hw/virtio/vhost-vsock.c +++ b/hw/virtio/vhost-vsock.c @@ -180,8 +180,9 @@ static uint64_t vhost_vsock_get_features(VirtIODevice *= vdev, uint64_t requested_features, Error **errp) { - /* No feature bits used yet */ - return requested_features; + VHostVSock *vsock =3D VHOST_VSOCK(vdev); + + return vhost_get_default_features(&vsock->vhost_dev, requested_feature= s); } =20 static void vhost_vsock_handle_output(VirtIODevice *vdev, VirtQueue *vq) diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c index aff98a0ede..f8a144dcd0 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -48,6 +48,23 @@ static unsigned int used_memslots; static QLIST_HEAD(, vhost_dev) vhost_devices =3D QLIST_HEAD_INITIALIZER(vhost_devices); =20 +/* + * Feature bits that device backends must explicitly report. Feature bits = not + * listed here maybe set by QEMU without checking with the device backend. + * Ideally all feature bits would be listed here but existing vhost device + * implementations do not explicitly report bits like VIRTIO_F_VERSION_1, = so we + * can only assume they are supported. + * + * New feature bits added to the VIRTIO spec should usually be included he= re + * so that existing vhost device backends that do not support them yet con= tinue + * to work. + */ +static const int vhost_default_feature_bits[] =3D { + VIRTIO_F_IOMMU_PLATFORM, + VIRTIO_F_RING_PACKED, + VHOST_INVALID_FEATURE_BIT +}; + bool vhost_has_free_slot(void) { unsigned int slots_limit =3D ~0U; @@ -1468,6 +1485,11 @@ uint64_t vhost_get_features(struct vhost_dev *hdev, = const int *feature_bits, return features; } =20 +uint64_t vhost_get_default_features(struct vhost_dev *hdev, uint64_t featu= res) +{ + return vhost_get_features(hdev, vhost_default_feature_bits, features); +} + void vhost_ack_features(struct vhost_dev *hdev, const int *feature_bits, uint64_t features) { diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c index bd9165c565..ef711b56f4 100644 --- a/hw/virtio/virtio-crypto.c +++ b/hw/virtio/virtio-crypto.c @@ -739,7 +739,8 @@ static uint64_t virtio_crypto_get_features(VirtIODevice= *vdev, uint64_t features, Error **errp) { - return features; + /* Just returns features when vhost is disabled */ + return cryptodev_vhost_get_features(vdev, features); } =20 static void virtio_crypto_reset(VirtIODevice *vdev) --=20 2.25.3