| Message ID | 20240205172659.476970-2-stefanha@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | virtio-blk: iothread-vq-mapping cleanups | expand |
On Mon, 05 Feb 2024 19:26, Stefan Hajnoczi <stefanha@redhat.com> wrote: >Hanna Czenczek <hreitz@redhat.com> noticed that the safety of >`vq_aio_context[vq->value] = ctx;` with user-defined vq->value inputs is >not obvious. > >The code is structured in validate() + apply() steps so input validation >is there, but it happens way earlier and there is nothing that >guarantees apply() can only be called with validated inputs. > >This patch moves the validate() call inside the apply() function so >validation is guaranteed. I also added the bounds checking assertion >that Hanna suggested. > >Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> >--- > hw/block/virtio-blk.c | 192 +++++++++++++++++++++++------------------- > 1 file changed, 107 insertions(+), 85 deletions(-) > >diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c >index 227d83569f..e8b37fd5f4 100644 >--- a/hw/block/virtio-blk.c >+++ b/hw/block/virtio-blk.c >@@ -1485,6 +1485,72 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, > return 0; > } > >+static void virtio_resize_cb(void *opaque) >+{ >+ VirtIODevice *vdev = opaque; >+ >+ assert(qemu_get_current_aio_context() == qemu_get_aio_context()); >+ virtio_notify_config(vdev); >+} >+ >+static void virtio_blk_resize(void *opaque) >+{ >+ VirtIODevice *vdev = VIRTIO_DEVICE(opaque); >+ >+ /* >+ * virtio_notify_config() needs to acquire the BQL, >+ * so it can't be called from an iothread. Instead, schedule >+ * it to be run in the main context BH. >+ */ >+ aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); >+} >+ >+static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) >+{ >+ VirtIODevice *vdev = VIRTIO_DEVICE(s); >+ >+ for (uint16_t i = 0; i < s->conf.num_queues; i++) { >+ VirtQueue *vq = virtio_get_queue(vdev, i); >+ virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); >+ } >+} >+ >+static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) >+{ >+ VirtIODevice *vdev = VIRTIO_DEVICE(s); >+ >+ for (uint16_t i = 0; i < s->conf.num_queues; i++) { >+ VirtQueue *vq = virtio_get_queue(vdev, i); >+ virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); >+ } >+} >+ >+/* Suspend virtqueue ioeventfd processing during drain */ >+static void virtio_blk_drained_begin(void *opaque) >+{ >+ VirtIOBlock *s = opaque; >+ >+ if (s->ioeventfd_started) { >+ virtio_blk_ioeventfd_detach(s); >+ } >+} >+ >+/* Resume virtqueue ioeventfd processing after drain */ >+static void virtio_blk_drained_end(void *opaque) >+{ >+ VirtIOBlock *s = opaque; >+ >+ if (s->ioeventfd_started) { >+ virtio_blk_ioeventfd_attach(s); >+ } >+} >+ >+static const BlockDevOps virtio_block_ops = { >+ .resize_cb = virtio_blk_resize, >+ .drained_begin = virtio_blk_drained_begin, >+ .drained_end = virtio_blk_drained_end, >+}; >+ > static bool > validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, > uint16_t num_queues, Error **errp) >@@ -1547,81 +1613,33 @@ validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, > return true; > } > >-static void virtio_resize_cb(void *opaque) >-{ >- VirtIODevice *vdev = opaque; >- >- assert(qemu_get_current_aio_context() == qemu_get_aio_context()); >- virtio_notify_config(vdev); >-} >- >-static void virtio_blk_resize(void *opaque) >-{ >- VirtIODevice *vdev = VIRTIO_DEVICE(opaque); >- >- /* >- * virtio_notify_config() needs to acquire the BQL, >- * so it can't be called from an iothread. Instead, schedule >- * it to be run in the main context BH. >- */ >- aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); >-} >- >-static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) >-{ >- VirtIODevice *vdev = VIRTIO_DEVICE(s); >- >- for (uint16_t i = 0; i < s->conf.num_queues; i++) { >- VirtQueue *vq = virtio_get_queue(vdev, i); >- virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); >- } >-} >- >-static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) >-{ >- VirtIODevice *vdev = VIRTIO_DEVICE(s); >- >- for (uint16_t i = 0; i < s->conf.num_queues; i++) { >- VirtQueue *vq = virtio_get_queue(vdev, i); >- virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); >- } >-} >- >-/* Suspend virtqueue ioeventfd processing during drain */ >-static void virtio_blk_drained_begin(void *opaque) >-{ >- VirtIOBlock *s = opaque; >- >- if (s->ioeventfd_started) { >- virtio_blk_ioeventfd_detach(s); >- } >-} >- >-/* Resume virtqueue ioeventfd processing after drain */ >-static void virtio_blk_drained_end(void *opaque) >-{ >- VirtIOBlock *s = opaque; >- >- if (s->ioeventfd_started) { >- virtio_blk_ioeventfd_attach(s); >- } >-} >- >-static const BlockDevOps virtio_block_ops = { >- .resize_cb = virtio_blk_resize, >- .drained_begin = virtio_blk_drained_begin, >- .drained_end = virtio_blk_drained_end, >-}; >- >-/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */ >-static void >-apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, >- AioContext **vq_aio_context, uint16_t num_queues) >+/** >+ * apply_iothread_vq_mapping: >+ * @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads. >+ * @vq_aio_context: The array of AioContext pointers to fill in. >+ * @num_queues: The length of @vq_aio_context. >+ * @errp: If an error occurs, a pointer to the area to store the error. >+ * >+ * Fill in the AioContext for each virtqueue in the @vq_aio_context array given >+ * the iothread-vq-mapping parameter in @iothread_vq_mapping_list. >+ * >+ * Returns: %true on success, %false on failure. >+ **/ >+static bool apply_iothread_vq_mapping( >+ IOThreadVirtQueueMappingList *iothread_vq_mapping_list, >+ AioContext **vq_aio_context, >+ uint16_t num_queues, >+ Error **errp) > { > IOThreadVirtQueueMappingList *node; > size_t num_iothreads = 0; > size_t cur_iothread = 0; > >+ if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list, >+ num_queues, errp)) { >+ return false; >+ } >+ > for (node = iothread_vq_mapping_list; node; node = node->next) { > num_iothreads++; > } >@@ -1638,6 +1656,7 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > /* Explicit vq:IOThread assignment */ > for (vq = node->value->vqs; vq; vq = vq->next) { >+ assert(vq->value < num_queues); > vq_aio_context[vq->value] = ctx; > } > } else { >@@ -1650,6 +1669,8 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > cur_iothread++; > } >+ >+ return true; > } > > /* Context: BQL held */ >@@ -1660,6 +1681,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) > BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > >+ if (conf->iothread && conf->iothread_vq_mapping_list) { >+ if (conf->iothread) { >+ error_setg(errp, "iothread and iothread-vq-mapping properties " >+ "cannot be set at the same time"); >+ return false; >+ } >+ } >+ > if (conf->iothread || conf->iothread_vq_mapping_list) { > if (!k->set_guest_notifiers || !k->ioeventfd_assign) { > error_setg(errp, >@@ -1685,8 +1714,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) > s->vq_aio_context = g_new(AioContext *, conf->num_queues); > > if (conf->iothread_vq_mapping_list) { >- apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context, >- conf->num_queues); >+ if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list, >+ s->vq_aio_context, >+ conf->num_queues, >+ errp)) { >+ g_free(s->vq_aio_context); >+ s->vq_aio_context = NULL; >+ return false; >+ } > } else if (conf->iothread) { > AioContext *ctx = iothread_get_aio_context(conf->iothread); > for (unsigned i = 0; i < conf->num_queues; i++) { >@@ -1996,19 +2031,6 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) > return; > } > >- if (conf->iothread_vq_mapping_list) { >- if (conf->iothread) { >- error_setg(errp, "iothread and iothread-vq-mapping properties " >- "cannot be set at the same time"); >- return; >- } >- >- if (!validate_iothread_vq_mapping_list(conf->iothread_vq_mapping_list, >- conf->num_queues, errp)) { >- return; >- } >- } >- > s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, > s->host_features); > virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size); >-- >2.43.0 > > virtio_block_ops and methods are moved around without changes in the diff, is that on purpose? If no the patch and history would be less noisy. Regardless: Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
On 05.02.24 18:26, Stefan Hajnoczi wrote: > Hanna Czenczek <hreitz@redhat.com> noticed that the safety of > `vq_aio_context[vq->value] = ctx;` with user-defined vq->value inputs is > not obvious. > > The code is structured in validate() + apply() steps so input validation > is there, but it happens way earlier and there is nothing that > guarantees apply() can only be called with validated inputs. > > This patch moves the validate() call inside the apply() function so > validation is guaranteed. I also added the bounds checking assertion > that Hanna suggested. > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > --- > hw/block/virtio-blk.c | 192 +++++++++++++++++++++++------------------- > 1 file changed, 107 insertions(+), 85 deletions(-) > > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c > index 227d83569f..e8b37fd5f4 100644 > --- a/hw/block/virtio-blk.c > +++ b/hw/block/virtio-blk.c [...] > @@ -1660,6 +1681,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) > BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > > + if (conf->iothread && conf->iothread_vq_mapping_list) { > + if (conf->iothread) { This inner condition should probably be dropped. With that done: Reviewed-by: Hanna Czenczek <hreitz@redhat.com> > + error_setg(errp, "iothread and iothread-vq-mapping properties " > + "cannot be set at the same time"); > + return false; > + } > + } > + > if (conf->iothread || conf->iothread_vq_mapping_list) { > if (!k->set_guest_notifiers || !k->ioeventfd_assign) { > error_setg(errp,
On Tue, Feb 06, 2024 at 09:29:29AM +0200, Manos Pitsidianakis wrote: > On Mon, 05 Feb 2024 19:26, Stefan Hajnoczi <stefanha@redhat.com> wrote: > > Hanna Czenczek <hreitz@redhat.com> noticed that the safety of > > `vq_aio_context[vq->value] = ctx;` with user-defined vq->value inputs is > > not obvious. > > > > The code is structured in validate() + apply() steps so input validation > > is there, but it happens way earlier and there is nothing that > > guarantees apply() can only be called with validated inputs. > > > > This patch moves the validate() call inside the apply() function so > > validation is guaranteed. I also added the bounds checking assertion > > that Hanna suggested. > > > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > > --- > > hw/block/virtio-blk.c | 192 +++++++++++++++++++++++------------------- > > 1 file changed, 107 insertions(+), 85 deletions(-) > > > > diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c > > index 227d83569f..e8b37fd5f4 100644 > > --- a/hw/block/virtio-blk.c > > +++ b/hw/block/virtio-blk.c > > @@ -1485,6 +1485,72 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, > > return 0; > > } > > > > +static void virtio_resize_cb(void *opaque) > > +{ > > + VirtIODevice *vdev = opaque; > > + > > + assert(qemu_get_current_aio_context() == qemu_get_aio_context()); > > + virtio_notify_config(vdev); > > +} > > + > > +static void virtio_blk_resize(void *opaque) > > +{ > > + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); > > + > > + /* > > + * virtio_notify_config() needs to acquire the BQL, > > + * so it can't be called from an iothread. Instead, schedule > > + * it to be run in the main context BH. > > + */ > > + aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); > > +} > > + > > +static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) > > +{ > > + VirtIODevice *vdev = VIRTIO_DEVICE(s); > > + > > + for (uint16_t i = 0; i < s->conf.num_queues; i++) { > > + VirtQueue *vq = virtio_get_queue(vdev, i); > > + virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); > > + } > > +} > > + > > +static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) > > +{ > > + VirtIODevice *vdev = VIRTIO_DEVICE(s); > > + > > + for (uint16_t i = 0; i < s->conf.num_queues; i++) { > > + VirtQueue *vq = virtio_get_queue(vdev, i); > > + virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); > > + } > > +} > > + > > +/* Suspend virtqueue ioeventfd processing during drain */ > > +static void virtio_blk_drained_begin(void *opaque) > > +{ > > + VirtIOBlock *s = opaque; > > + > > + if (s->ioeventfd_started) { > > + virtio_blk_ioeventfd_detach(s); > > + } > > +} > > + > > +/* Resume virtqueue ioeventfd processing after drain */ > > +static void virtio_blk_drained_end(void *opaque) > > +{ > > + VirtIOBlock *s = opaque; > > + > > + if (s->ioeventfd_started) { > > + virtio_blk_ioeventfd_attach(s); > > + } > > +} > > + > > +static const BlockDevOps virtio_block_ops = { > > + .resize_cb = virtio_blk_resize, > > + .drained_begin = virtio_blk_drained_begin, > > + .drained_end = virtio_blk_drained_end, > > +}; > > + > > static bool > > validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, > > uint16_t num_queues, Error **errp) > > @@ -1547,81 +1613,33 @@ validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, > > return true; > > } > > > > -static void virtio_resize_cb(void *opaque) > > -{ > > - VirtIODevice *vdev = opaque; > > - > > - assert(qemu_get_current_aio_context() == qemu_get_aio_context()); > > - virtio_notify_config(vdev); > > -} > > - > > -static void virtio_blk_resize(void *opaque) > > -{ > > - VirtIODevice *vdev = VIRTIO_DEVICE(opaque); > > - > > - /* > > - * virtio_notify_config() needs to acquire the BQL, > > - * so it can't be called from an iothread. Instead, schedule > > - * it to be run in the main context BH. > > - */ > > - aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); > > -} > > - > > -static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) > > -{ > > - VirtIODevice *vdev = VIRTIO_DEVICE(s); > > - > > - for (uint16_t i = 0; i < s->conf.num_queues; i++) { > > - VirtQueue *vq = virtio_get_queue(vdev, i); > > - virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); > > - } > > -} > > - > > -static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) > > -{ > > - VirtIODevice *vdev = VIRTIO_DEVICE(s); > > - > > - for (uint16_t i = 0; i < s->conf.num_queues; i++) { > > - VirtQueue *vq = virtio_get_queue(vdev, i); > > - virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); > > - } > > -} > > - > > -/* Suspend virtqueue ioeventfd processing during drain */ > > -static void virtio_blk_drained_begin(void *opaque) > > -{ > > - VirtIOBlock *s = opaque; > > - > > - if (s->ioeventfd_started) { > > - virtio_blk_ioeventfd_detach(s); > > - } > > -} > > - > > -/* Resume virtqueue ioeventfd processing after drain */ > > -static void virtio_blk_drained_end(void *opaque) > > -{ > > - VirtIOBlock *s = opaque; > > - > > - if (s->ioeventfd_started) { > > - virtio_blk_ioeventfd_attach(s); > > - } > > -} > > - > > -static const BlockDevOps virtio_block_ops = { > > - .resize_cb = virtio_blk_resize, > > - .drained_begin = virtio_blk_drained_begin, > > - .drained_end = virtio_blk_drained_end, > > -}; > > - > > -/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */ > > -static void > > -apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > - AioContext **vq_aio_context, uint16_t num_queues) > > +/** > > + * apply_iothread_vq_mapping: > > + * @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads. > > + * @vq_aio_context: The array of AioContext pointers to fill in. > > + * @num_queues: The length of @vq_aio_context. > > + * @errp: If an error occurs, a pointer to the area to store the error. > > + * > > + * Fill in the AioContext for each virtqueue in the @vq_aio_context array given > > + * the iothread-vq-mapping parameter in @iothread_vq_mapping_list. > > + * > > + * Returns: %true on success, %false on failure. > > + **/ > > +static bool apply_iothread_vq_mapping( > > + IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > + AioContext **vq_aio_context, > > + uint16_t num_queues, > > + Error **errp) > > { > > IOThreadVirtQueueMappingList *node; > > size_t num_iothreads = 0; > > size_t cur_iothread = 0; > > > > + if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list, > > + num_queues, errp)) { > > + return false; > > + } > > + > > for (node = iothread_vq_mapping_list; node; node = node->next) { > > num_iothreads++; > > } > > @@ -1638,6 +1656,7 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > > > /* Explicit vq:IOThread assignment */ > > for (vq = node->value->vqs; vq; vq = vq->next) { > > + assert(vq->value < num_queues); > > vq_aio_context[vq->value] = ctx; > > } > > } else { > > @@ -1650,6 +1669,8 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, > > > > cur_iothread++; > > } > > + > > + return true; > > } > > > > /* Context: BQL held */ > > @@ -1660,6 +1681,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) > > BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); > > VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); > > > > + if (conf->iothread && conf->iothread_vq_mapping_list) { > > + if (conf->iothread) { > > + error_setg(errp, "iothread and iothread-vq-mapping properties " > > + "cannot be set at the same time"); > > + return false; > > + } > > + } > > + > > if (conf->iothread || conf->iothread_vq_mapping_list) { > > if (!k->set_guest_notifiers || !k->ioeventfd_assign) { > > error_setg(errp, > > @@ -1685,8 +1714,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) > > s->vq_aio_context = g_new(AioContext *, conf->num_queues); > > > > if (conf->iothread_vq_mapping_list) { > > - apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context, > > - conf->num_queues); > > + if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list, > > + s->vq_aio_context, > > + conf->num_queues, > > + errp)) { > > + g_free(s->vq_aio_context); > > + s->vq_aio_context = NULL; > > + return false; > > + } > > } else if (conf->iothread) { > > AioContext *ctx = iothread_get_aio_context(conf->iothread); > > for (unsigned i = 0; i < conf->num_queues; i++) { > > @@ -1996,19 +2031,6 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) > > return; > > } > > > > - if (conf->iothread_vq_mapping_list) { > > - if (conf->iothread) { > > - error_setg(errp, "iothread and iothread-vq-mapping properties " > > - "cannot be set at the same time"); > > - return; > > - } > > - > > - if (!validate_iothread_vq_mapping_list(conf->iothread_vq_mapping_list, > > - conf->num_queues, errp)) { > > - return; > > - } > > - } > > - > > s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, > > s->host_features); > > virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size); > > -- > > 2.43.0 > > > > > > > virtio_block_ops and methods are moved around without changes in the diff, > is that on purpose? If no the patch and history would be less noisy. Yes, it's because I moved the validate() function immediately before the apply() function. Previously they were far apart. I guess git's diff algorithm optimized for the shortest patch rather than the most readable patch. > Regardless: > > Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org> >
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c index 227d83569f..e8b37fd5f4 100644 --- a/hw/block/virtio-blk.c +++ b/hw/block/virtio-blk.c @@ -1485,6 +1485,72 @@ static int virtio_blk_load_device(VirtIODevice *vdev, QEMUFile *f, return 0; } +static void virtio_resize_cb(void *opaque) +{ + VirtIODevice *vdev = opaque; + + assert(qemu_get_current_aio_context() == qemu_get_aio_context()); + virtio_notify_config(vdev); +} + +static void virtio_blk_resize(void *opaque) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(opaque); + + /* + * virtio_notify_config() needs to acquire the BQL, + * so it can't be called from an iothread. Instead, schedule + * it to be run in the main context BH. + */ + aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); +} + +static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); + } +} + +static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) +{ + VirtIODevice *vdev = VIRTIO_DEVICE(s); + + for (uint16_t i = 0; i < s->conf.num_queues; i++) { + VirtQueue *vq = virtio_get_queue(vdev, i); + virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); + } +} + +/* Suspend virtqueue ioeventfd processing during drain */ +static void virtio_blk_drained_begin(void *opaque) +{ + VirtIOBlock *s = opaque; + + if (s->ioeventfd_started) { + virtio_blk_ioeventfd_detach(s); + } +} + +/* Resume virtqueue ioeventfd processing after drain */ +static void virtio_blk_drained_end(void *opaque) +{ + VirtIOBlock *s = opaque; + + if (s->ioeventfd_started) { + virtio_blk_ioeventfd_attach(s); + } +} + +static const BlockDevOps virtio_block_ops = { + .resize_cb = virtio_blk_resize, + .drained_begin = virtio_blk_drained_begin, + .drained_end = virtio_blk_drained_end, +}; + static bool validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, uint16_t num_queues, Error **errp) @@ -1547,81 +1613,33 @@ validate_iothread_vq_mapping_list(IOThreadVirtQueueMappingList *list, return true; } -static void virtio_resize_cb(void *opaque) -{ - VirtIODevice *vdev = opaque; - - assert(qemu_get_current_aio_context() == qemu_get_aio_context()); - virtio_notify_config(vdev); -} - -static void virtio_blk_resize(void *opaque) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(opaque); - - /* - * virtio_notify_config() needs to acquire the BQL, - * so it can't be called from an iothread. Instead, schedule - * it to be run in the main context BH. - */ - aio_bh_schedule_oneshot(qemu_get_aio_context(), virtio_resize_cb, vdev); -} - -static void virtio_blk_ioeventfd_detach(VirtIOBlock *s) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(s); - - for (uint16_t i = 0; i < s->conf.num_queues; i++) { - VirtQueue *vq = virtio_get_queue(vdev, i); - virtio_queue_aio_detach_host_notifier(vq, s->vq_aio_context[i]); - } -} - -static void virtio_blk_ioeventfd_attach(VirtIOBlock *s) -{ - VirtIODevice *vdev = VIRTIO_DEVICE(s); - - for (uint16_t i = 0; i < s->conf.num_queues; i++) { - VirtQueue *vq = virtio_get_queue(vdev, i); - virtio_queue_aio_attach_host_notifier(vq, s->vq_aio_context[i]); - } -} - -/* Suspend virtqueue ioeventfd processing during drain */ -static void virtio_blk_drained_begin(void *opaque) -{ - VirtIOBlock *s = opaque; - - if (s->ioeventfd_started) { - virtio_blk_ioeventfd_detach(s); - } -} - -/* Resume virtqueue ioeventfd processing after drain */ -static void virtio_blk_drained_end(void *opaque) -{ - VirtIOBlock *s = opaque; - - if (s->ioeventfd_started) { - virtio_blk_ioeventfd_attach(s); - } -} - -static const BlockDevOps virtio_block_ops = { - .resize_cb = virtio_blk_resize, - .drained_begin = virtio_blk_drained_begin, - .drained_end = virtio_blk_drained_end, -}; - -/* Generate vq:AioContext mappings from a validated iothread-vq-mapping list */ -static void -apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, - AioContext **vq_aio_context, uint16_t num_queues) +/** + * apply_iothread_vq_mapping: + * @iothread_vq_mapping_list: The mapping of virtqueues to IOThreads. + * @vq_aio_context: The array of AioContext pointers to fill in. + * @num_queues: The length of @vq_aio_context. + * @errp: If an error occurs, a pointer to the area to store the error. + * + * Fill in the AioContext for each virtqueue in the @vq_aio_context array given + * the iothread-vq-mapping parameter in @iothread_vq_mapping_list. + * + * Returns: %true on success, %false on failure. + **/ +static bool apply_iothread_vq_mapping( + IOThreadVirtQueueMappingList *iothread_vq_mapping_list, + AioContext **vq_aio_context, + uint16_t num_queues, + Error **errp) { IOThreadVirtQueueMappingList *node; size_t num_iothreads = 0; size_t cur_iothread = 0; + if (!validate_iothread_vq_mapping_list(iothread_vq_mapping_list, + num_queues, errp)) { + return false; + } + for (node = iothread_vq_mapping_list; node; node = node->next) { num_iothreads++; } @@ -1638,6 +1656,7 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, /* Explicit vq:IOThread assignment */ for (vq = node->value->vqs; vq; vq = vq->next) { + assert(vq->value < num_queues); vq_aio_context[vq->value] = ctx; } } else { @@ -1650,6 +1669,8 @@ apply_vq_mapping(IOThreadVirtQueueMappingList *iothread_vq_mapping_list, cur_iothread++; } + + return true; } /* Context: BQL held */ @@ -1660,6 +1681,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(vdev))); VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(qbus); + if (conf->iothread && conf->iothread_vq_mapping_list) { + if (conf->iothread) { + error_setg(errp, "iothread and iothread-vq-mapping properties " + "cannot be set at the same time"); + return false; + } + } + if (conf->iothread || conf->iothread_vq_mapping_list) { if (!k->set_guest_notifiers || !k->ioeventfd_assign) { error_setg(errp, @@ -1685,8 +1714,14 @@ static bool virtio_blk_vq_aio_context_init(VirtIOBlock *s, Error **errp) s->vq_aio_context = g_new(AioContext *, conf->num_queues); if (conf->iothread_vq_mapping_list) { - apply_vq_mapping(conf->iothread_vq_mapping_list, s->vq_aio_context, - conf->num_queues); + if (!apply_iothread_vq_mapping(conf->iothread_vq_mapping_list, + s->vq_aio_context, + conf->num_queues, + errp)) { + g_free(s->vq_aio_context); + s->vq_aio_context = NULL; + return false; + } } else if (conf->iothread) { AioContext *ctx = iothread_get_aio_context(conf->iothread); for (unsigned i = 0; i < conf->num_queues; i++) { @@ -1996,19 +2031,6 @@ static void virtio_blk_device_realize(DeviceState *dev, Error **errp) return; } - if (conf->iothread_vq_mapping_list) { - if (conf->iothread) { - error_setg(errp, "iothread and iothread-vq-mapping properties " - "cannot be set at the same time"); - return; - } - - if (!validate_iothread_vq_mapping_list(conf->iothread_vq_mapping_list, - conf->num_queues, errp)) { - return; - } - } - s->config_size = virtio_get_config_size(&virtio_blk_cfg_size_params, s->host_features); virtio_init(vdev, VIRTIO_ID_BLOCK, s->config_size);
Hanna Czenczek <hreitz@redhat.com> noticed that the safety of `vq_aio_context[vq->value] = ctx;` with user-defined vq->value inputs is not obvious. The code is structured in validate() + apply() steps so input validation is there, but it happens way earlier and there is nothing that guarantees apply() can only be called with validated inputs. This patch moves the validate() call inside the apply() function so validation is guaranteed. I also added the bounds checking assertion that Hanna suggested. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> --- hw/block/virtio-blk.c | 192 +++++++++++++++++++++++------------------- 1 file changed, 107 insertions(+), 85 deletions(-)