From b8f3e6a18de6ad5cb668c5430b4933f1e40783cf Mon Sep 17 00:00:00 2001 From: =?utf8?q?Alex=20Benn=C3=A9e?= Date: Tue, 2 Aug 2022 10:49:59 +0100 Subject: [PATCH] hw/virtio: move vhd->started check into helper and add FIXME MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The `started` field is manipulated internally within the vhost code except for one place, vhost-user-blk via f5b22d06fb (vhost: recheck dev state in the vhost_migration_log routine). Mark that as a FIXME because it introduces a potential race. I think the referenced fix should be tracking its state locally. Signed-off-by: Alex Bennée Message-Id: <20220802095010.3330793-12-alex.bennee@linaro.org> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Raphael Norwitz --- hw/block/vhost-user-blk.c | 10 ++++++++-- hw/scsi/vhost-scsi.c | 4 ++-- hw/scsi/vhost-user-scsi.c | 2 +- hw/virtio/vhost-user-fs.c | 3 ++- hw/virtio/vhost-user-i2c.c | 4 ++-- hw/virtio/vhost-user-rng.c | 4 ++-- hw/virtio/vhost-user-vsock.c | 2 +- hw/virtio/vhost-vsock-common.c | 3 ++- hw/virtio/vhost-vsock.c | 2 +- include/hw/virtio/vhost.h | 12 ++++++++++++ 10 files changed, 33 insertions(+), 13 deletions(-) diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c index 9117222456..2bba42478d 100644 --- a/hw/block/vhost-user-blk.c +++ b/hw/block/vhost-user-blk.c @@ -229,7 +229,7 @@ static void vhost_user_blk_set_status(VirtIODevice *vdev, uint8_t status) return; } - if (s->dev.started == should_start) { + if (vhost_dev_is_started(&s->dev) == should_start) { return; } @@ -286,7 +286,7 @@ static void vhost_user_blk_handle_output(VirtIODevice *vdev, VirtQueue *vq) return; } - if (s->dev.started) { + if (vhost_dev_is_started(&s->dev)) { return; } @@ -415,6 +415,12 @@ static void vhost_user_blk_event(void *opaque, QEMUChrEvent event) * the vhost migration code. If disconnect was caught there is an * option for the general vhost code to get the dev state without * knowing its type (in this case vhost-user). + * + * FIXME: this is sketchy to be reaching into vhost_dev + * now because we are forcing something that implies we + * have executed vhost_dev_stop() but that won't happen + * until vhost_user_blk_stop() gets called from the bh. + * Really this state check should be tracked locally. */ s->dev.started = false; } diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c index 3059068175..bdf337a7a2 100644 --- a/hw/scsi/vhost-scsi.c +++ b/hw/scsi/vhost-scsi.c @@ -120,7 +120,7 @@ static void vhost_scsi_set_status(VirtIODevice *vdev, uint8_t val) start = false; } - if (vsc->dev.started == start) { + if (vhost_dev_is_started(&vsc->dev) == start) { return; } @@ -147,7 +147,7 @@ static int vhost_scsi_pre_save(void *opaque) /* At this point, backend must be stopped, otherwise * it might keep writing to memory. */ - assert(!vsc->dev.started); + assert(!vhost_dev_is_started(&vsc->dev)); return 0; } diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c index 1b2f7eed98..bc37317d55 100644 --- a/hw/scsi/vhost-user-scsi.c +++ b/hw/scsi/vhost-user-scsi.c @@ -49,7 +49,7 @@ static void vhost_user_scsi_set_status(VirtIODevice *vdev, uint8_t status) VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s); bool start = (status & VIRTIO_CONFIG_S_DRIVER_OK) && vdev->vm_running; - if (vsc->dev.started == start) { + if (vhost_dev_is_started(&vsc->dev) == start) { return; } diff --git a/hw/virtio/vhost-user-fs.c b/hw/virtio/vhost-user-fs.c index d2bebba785..ad0f91c607 100644 --- a/hw/virtio/vhost-user-fs.c +++ b/hw/virtio/vhost-user-fs.c @@ -20,6 +20,7 @@ #include "hw/virtio/virtio-bus.h" #include "hw/virtio/virtio-access.h" #include "qemu/error-report.h" +#include "hw/virtio/vhost.h" #include "hw/virtio/vhost-user-fs.h" #include "monitor/monitor.h" #include "sysemu/sysemu.h" @@ -124,7 +125,7 @@ static void vuf_set_status(VirtIODevice *vdev, uint8_t status) VHostUserFS *fs = VHOST_USER_FS(vdev); bool should_start = virtio_device_started(vdev, status); - if (fs->vhost_dev.started == should_start) { + if (vhost_dev_is_started(&fs->vhost_dev) == should_start) { return; } diff --git a/hw/virtio/vhost-user-i2c.c b/hw/virtio/vhost-user-i2c.c index b930cf6d5e..bc58b6c0d1 100644 --- a/hw/virtio/vhost-user-i2c.c +++ b/hw/virtio/vhost-user-i2c.c @@ -95,7 +95,7 @@ static void vu_i2c_set_status(VirtIODevice *vdev, uint8_t status) VHostUserI2C *i2c = VHOST_USER_I2C(vdev); bool should_start = virtio_device_started(vdev, status); - if (i2c->vhost_dev.started == should_start) { + if (vhost_dev_is_started(&i2c->vhost_dev) == should_start) { return; } @@ -174,7 +174,7 @@ static void vu_i2c_disconnect(DeviceState *dev) } i2c->connected = false; - if (i2c->vhost_dev.started) { + if (vhost_dev_is_started(&i2c->vhost_dev)) { vu_i2c_stop(vdev); } } diff --git a/hw/virtio/vhost-user-rng.c b/hw/virtio/vhost-user-rng.c index a9c1c4bc79..bc1f36c5ac 100644 --- a/hw/virtio/vhost-user-rng.c +++ b/hw/virtio/vhost-user-rng.c @@ -92,7 +92,7 @@ static void vu_rng_set_status(VirtIODevice *vdev, uint8_t status) VHostUserRNG *rng = VHOST_USER_RNG(vdev); bool should_start = virtio_device_started(vdev, status); - if (rng->vhost_dev.started == should_start) { + if (vhost_dev_is_started(&rng->vhost_dev) == should_start) { return; } @@ -160,7 +160,7 @@ static void vu_rng_disconnect(DeviceState *dev) rng->connected = false; - if (rng->vhost_dev.started) { + if (vhost_dev_is_started(&rng->vhost_dev)) { vu_rng_stop(vdev); } } diff --git a/hw/virtio/vhost-user-vsock.c b/hw/virtio/vhost-user-vsock.c index 22c1616ebd..7b67e29d83 100644 --- a/hw/virtio/vhost-user-vsock.c +++ b/hw/virtio/vhost-user-vsock.c @@ -57,7 +57,7 @@ static void vuv_set_status(VirtIODevice *vdev, uint8_t status) VHostVSockCommon *vvc = VHOST_VSOCK_COMMON(vdev); bool should_start = virtio_device_started(vdev, status); - if (vvc->vhost_dev.started == should_start) { + if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) { return; } diff --git a/hw/virtio/vhost-vsock-common.c b/hw/virtio/vhost-vsock-common.c index 7394818e00..29b9ab4f72 100644 --- a/hw/virtio/vhost-vsock-common.c +++ b/hw/virtio/vhost-vsock-common.c @@ -14,6 +14,7 @@ #include "hw/virtio/virtio-access.h" #include "qemu/error-report.h" #include "hw/qdev-properties.h" +#include "hw/virtio/vhost.h" #include "hw/virtio/vhost-vsock.h" #include "qemu/iov.h" #include "monitor/monitor.h" @@ -199,7 +200,7 @@ int vhost_vsock_common_pre_save(void *opaque) * At this point, backend must be stopped, otherwise * it might keep writing to memory. */ - assert(!vvc->vhost_dev.started); + assert(!vhost_dev_is_started(&vvc->vhost_dev)); return 0; } diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c index 8031c164a5..7dc3c73931 100644 --- a/hw/virtio/vhost-vsock.c +++ b/hw/virtio/vhost-vsock.c @@ -73,7 +73,7 @@ static void vhost_vsock_set_status(VirtIODevice *vdev, uint8_t status) bool should_start = virtio_device_started(vdev, status); int ret; - if (vvc->vhost_dev.started == should_start) { + if (vhost_dev_is_started(&vvc->vhost_dev) == should_start) { return; } diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h index 586c5457e2..61b957e927 100644 --- a/include/hw/virtio/vhost.h +++ b/include/hw/virtio/vhost.h @@ -94,6 +94,7 @@ struct vhost_dev { uint64_t protocol_features; uint64_t max_queues; uint64_t backend_cap; + /* @started: is the vhost device started? */ bool started; bool log_enabled; uint64_t log_size; @@ -165,6 +166,17 @@ int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); */ void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev); +/** + * vhost_dev_is_started() - report status of vhost device + * @hdev: common vhost_dev structure + * + * Return the started status of the vhost device + */ +static inline bool vhost_dev_is_started(struct vhost_dev *hdev) +{ + return hdev->started; +} + /** * vhost_dev_start() - start the vhost device * @hdev: common vhost_dev structure -- 2.39.2