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[Qemu-devel] [PULL 61/65] virtio-rng: stop virtqueue while the CPU is st
From: |
Juan Quintela |
Subject: |
[Qemu-devel] [PULL 61/65] virtio-rng: stop virtqueue while the CPU is stopped |
Date: |
Fri, 21 Apr 2017 13:56:42 +0200 |
From: Laurent Vivier <address@hidden>
If we modify the virtio-rng virqueue while the
vmstate is already migrated we can have some
inconsistencies between the virtqueue state and
the memory content.
To avoid this, stop the virtqueue while the CPU
is stopped.
Signed-off-by: Laurent Vivier <address@hidden>
Reviewed-by: Amit Shah <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
Reviewed-by: Juan Quintela <address@hidden>
Signed-off-by: Juan Quintela <address@hidden>
---
hw/virtio/trace-events | 3 +++
hw/virtio/virtio-rng.c | 29 +++++++++++++++++++++++------
include/hw/virtio/virtio-rng.h | 2 ++
3 files changed, 28 insertions(+), 6 deletions(-)
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 6926eed..1f7a7c1 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -11,8 +11,11 @@ virtio_set_status(void *vdev, uint8_t val) "vdev %p val %u"
# hw/virtio/virtio-rng.c
virtio_rng_guest_not_ready(void *rng) "rng %p: guest not ready"
+virtio_rng_cpu_is_stopped(void *rng, int size) "rng %p: cpu is stopped,
dropping %d bytes"
+virtio_rng_popped(void *rng) "rng %p: elem popped"
virtio_rng_pushed(void *rng, size_t len) "rng %p: %zd bytes pushed"
virtio_rng_request(void *rng, size_t size, unsigned quota) "rng %p: %zd bytes
requested, %u bytes quota left"
+virtio_rng_vm_state_change(void *rng, int running, int state) "rng %p: state
change to running %d state %d"
# hw/virtio/virtio-balloon.c
#
diff --git a/hw/virtio/virtio-rng.c b/hw/virtio/virtio-rng.c
index 9639f4e..a6ee501 100644
--- a/hw/virtio/virtio-rng.c
+++ b/hw/virtio/virtio-rng.c
@@ -53,6 +53,15 @@ static void chr_read(void *opaque, const void *buf, size_t
size)
return;
}
+ /* we can't modify the virtqueue until
+ * our state is fully synced
+ */
+
+ if (!runstate_check(RUN_STATE_RUNNING)) {
+ trace_virtio_rng_cpu_is_stopped(vrng, size);
+ return;
+ }
+
vrng->quota_remaining -= size;
offset = 0;
@@ -61,6 +70,7 @@ static void chr_read(void *opaque, const void *buf, size_t
size)
if (!elem) {
break;
}
+ trace_virtio_rng_popped(vrng);
len = iov_from_buf(elem->in_sg, elem->in_num,
0, buf + offset, size - offset);
offset += len;
@@ -120,17 +130,21 @@ static uint64_t get_features(VirtIODevice *vdev, uint64_t
f, Error **errp)
return f;
}
-static int virtio_rng_post_load(void *opaque, int version_id)
+static void virtio_rng_vm_state_change(void *opaque, int running,
+ RunState state)
{
VirtIORNG *vrng = opaque;
+ trace_virtio_rng_vm_state_change(vrng, running, state);
+
/* We may have an element ready but couldn't process it due to a quota
- * limit. Make sure to try again after live migration when the quota may
- * have been reset.
+ * limit or because CPU was stopped. Make sure to try again when the
+ * CPU restart.
*/
- virtio_rng_process(vrng);
- return 0;
+ if (running && is_guest_ready(vrng)) {
+ virtio_rng_process(vrng);
+ }
}
static void check_rate_limit(void *opaque)
@@ -198,6 +212,9 @@ static void virtio_rng_device_realize(DeviceState *dev,
Error **errp)
vrng->rate_limit_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
check_rate_limit, vrng);
vrng->activate_timer = true;
+
+ vrng->vmstate =
qemu_add_vm_change_state_handler(virtio_rng_vm_state_change,
+ vrng);
}
static void virtio_rng_device_unrealize(DeviceState *dev, Error **errp)
@@ -205,6 +222,7 @@ static void virtio_rng_device_unrealize(DeviceState *dev,
Error **errp)
VirtIODevice *vdev = VIRTIO_DEVICE(dev);
VirtIORNG *vrng = VIRTIO_RNG(dev);
+ qemu_del_vm_change_state_handler(vrng->vmstate);
timer_del(vrng->rate_limit_timer);
timer_free(vrng->rate_limit_timer);
virtio_cleanup(vdev);
@@ -218,7 +236,6 @@ static const VMStateDescription vmstate_virtio_rng = {
VMSTATE_VIRTIO_DEVICE,
VMSTATE_END_OF_LIST()
},
- .post_load = virtio_rng_post_load,
};
static Property virtio_rng_properties[] = {
diff --git a/include/hw/virtio/virtio-rng.h b/include/hw/virtio/virtio-rng.h
index 2d40abd..922dce7 100644
--- a/include/hw/virtio/virtio-rng.h
+++ b/include/hw/virtio/virtio-rng.h
@@ -45,6 +45,8 @@ typedef struct VirtIORNG {
QEMUTimer *rate_limit_timer;
int64_t quota_remaining;
bool activate_timer;
+
+ VMChangeStateEntry *vmstate;
} VirtIORNG;
#endif
--
2.9.3
- [Qemu-devel] [PULL 52/65] ram: rename last_ram_offset() last_ram_pages(), (continued)
- [Qemu-devel] [PULL 52/65] ram: rename last_ram_offset() last_ram_pages(), Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 54/65] migration: Remove MigrationState parameter from migration_is_idle(), Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 51/65] ram: Use ramblock and page offset instead of absolute offset, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 53/65] ram: Use RAMBitmap type for coherence, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 55/65] qdev: qdev_hotplug is really a bool, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 56/65] qdev: Export qdev_hot_removed, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 59/65] ram: Remove migration_bitmap_extend(), Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 58/65] migration: Disable hotplug/unplug during migration, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 57/65] qdev: Move qdev_unplug() to qdev-monitor.c, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 60/65] migration: don't close a file descriptor while it can be in use, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 61/65] virtio-rng: stop virtqueue while the CPU is stopped,
Juan Quintela <=
- [Qemu-devel] [PULL 62/65] migration: set current_active_state once, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 65/65] hmp: info migrate_parameters format tunes, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 64/65] hmp: info migrate_capability format tunes, Juan Quintela, 2017/04/21
- [Qemu-devel] [PULL 63/65] migration: rename max_size to threshold_size, Juan Quintela, 2017/04/21
- Re: [Qemu-devel] [PULL 00/65] Migration pull request, Peter Maydell, 2017/04/21