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[PATCH v4 11/22] hw/virtio: move vhd->started check into helper and add
From: |
Alex Bennée |
Subject: |
[PATCH v4 11/22] hw/virtio: move vhd->started check into helper and add FIXME |
Date: |
Tue, 2 Aug 2022 10:49:59 +0100 |
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 <alex.bennee@linaro.org>
---
include/hw/virtio/vhost.h | 12 ++++++++++++
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 +-
10 files changed, 33 insertions(+), 13 deletions(-)
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
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;
}
--
2.30.2
- [PATCH v4 11/22] hw/virtio: move vhd->started check into helper and add FIXME,
Alex Bennée <=