* Re: [PATCH RESEND v3] vdpa: reset the backend device in the end of vhost_net_stop()
2022-03-31 9:25 ` [PATCH RESEND " qiudayu
@ 2022-03-31 10:19 ` Michael Qiu
[not found] ` <6245804d.1c69fb81.3c35c.d7efSMTPIN_ADDED_BROKEN@mx.google.com>
` (2 subsequent siblings)
3 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-03-31 10:19 UTC (permalink / raw)
To: jasowang
Cc: lulu, mst@redhat.com, qemu-devel, eperezma, Si-Wei Liu,
lingshan.zhu
Hi, Jason
Does it work this time?
On 2022/3/31 17:25, qiudayu@archeros.com wrote:
> From: Michael Qiu <qiudayu@archeros.com>
>
> Currently, when VM poweroff, it will trigger vdpa
> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
> queue pair and one control queue, triggered 3 times), this
> leads to below issue:
>
> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>
> This because in vhost_net_stop(), it will stop all vhost device bind to
> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
> , then stop the queue: vhost_virtqueue_stop().
>
> In vhost_dev_stop(), it resets the device, which clear some flags
> in low level driver, and in next loop(stop other vhost backends),
> qemu try to stop the queue corresponding to the vhost backend,
> the driver finds that the VQ is invalied, this is the root cause.
>
> To solve the issue, vdpa should set vring unready, and
> remove reset ops in device stop: vhost_dev_start(hdev, false).
>
> and implement a new function vhost_dev_reset, only reset backend
> device after all vhost(per-queue) stoped.
>
> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> ---
> v3 --> v2:
> Call vhost_dev_reset() at the end of vhost_net_stop().
>
> Since the vDPA device need re-add the status bit
> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
> simply, add them inside vhost_vdpa_reset_device, and
> the only way calling vhost_vdpa_reset_device is in
> vhost_net_stop(), so it keeps the same behavior as before.
>
> v2 --> v1:
> Implement a new function vhost_dev_reset,
> reset the backend kernel device at last.
> ---
> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
> hw/virtio/vhost-vdpa.c | 15 +++++++++------
> hw/virtio/vhost.c | 15 ++++++++++++++-
> include/hw/virtio/vhost.h | 1 +
> 4 files changed, 45 insertions(+), 10 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 30379d2..422c9bf 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> int total_notifiers = data_queue_pairs * 2 + cvq;
> VirtIONet *n = VIRTIO_NET(dev);
> int nvhosts = data_queue_pairs + cvq;
> - struct vhost_net *net;
> + struct vhost_net *net = NULL;
> int r, e, i, index_end = data_queue_pairs * 2;
> NetClientState *peer;
>
> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> err_start:
> while (--i >= 0) {
> peer = qemu_get_peer(ncs , i);
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> + vhost_dev_reset(&net->dev);
> + }
> +
> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> if (e < 0) {
> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> VirtIONet *n = VIRTIO_NET(dev);
> NetClientState *peer;
> + struct vhost_net *net = NULL;
> int total_notifiers = data_queue_pairs * 2 + cvq;
> int nvhosts = data_queue_pairs + cvq;
> int i, r;
> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> } else {
> peer = qemu_get_peer(ncs, n->max_queue_pairs);
> }
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> + }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> + vhost_dev_reset(&net->dev);
> }
>
> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index c5ed7a3..3ef0199 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>
> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
> trace_vhost_vdpa_reset_device(dev, status);
> +
> + /* Add back this status, so that the device could work next time*/
> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> + VIRTIO_CONFIG_S_DRIVER);
> +
> return ret;
> }
>
> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
> return idx;
> }
>
> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
> {
> int i;
> trace_vhost_vdpa_set_vring_ready(dev);
> for (i = 0; i < dev->nvqs; ++i) {
> struct vhost_vring_state state = {
> .index = dev->vq_index + i,
> - .num = 1,
> + .num = ready,
> };
> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
> }
> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> if (unlikely(!ok)) {
> return -1;
> }
> - vhost_vdpa_set_vring_ready(dev);
> + vhost_vdpa_set_vring_ready(dev, 1);
> } else {
> + vhost_vdpa_set_vring_ready(dev, 0);
> ok = vhost_vdpa_svqs_stop(dev);
> if (unlikely(!ok)) {
> return -1;
> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> memory_listener_register(&v->listener, &address_space_memory);
> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> } else {
> - vhost_vdpa_reset_device(dev);
> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> - VIRTIO_CONFIG_S_DRIVER);
> memory_listener_unregister(&v->listener);
>
> return 0;
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index b643f42..7e0cdb6 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1820,7 +1820,6 @@ fail_features:
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> {
> int i;
> -
> /* should only be called after backend is connected */
> assert(hdev->vhost_ops);
>
> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>
> return -ENOSYS;
> }
> +
> +int vhost_dev_reset(struct vhost_dev *hdev)
> +{
> + int ret = 0;
> +
> + /* should only be called after backend is connected */
> + assert(hdev->vhost_ops);
> +
> + if (hdev->vhost_ops->vhost_reset_device) {
> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> + }
> +
> + return ret;
> +}
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 58a73e7..b8b7c20 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> void vhost_dev_cleanup(struct vhost_dev *hdev);
> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> +int vhost_dev_reset(struct vhost_dev *hdev);
> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>
^ permalink raw reply [flat|nested] 47+ messages in thread[parent not found: <6245804d.1c69fb81.3c35c.d7efSMTPIN_ADDED_BROKEN@mx.google.com>]
* Re: [PATCH RESEND v3] vdpa: reset the backend device in the end of vhost_net_stop()
[not found] ` <6245804d.1c69fb81.3c35c.d7efSMTPIN_ADDED_BROKEN@mx.google.com>
@ 2022-03-31 20:32 ` Michael S. Tsirkin
0 siblings, 0 replies; 47+ messages in thread
From: Michael S. Tsirkin @ 2022-03-31 20:32 UTC (permalink / raw)
To: Michael Qiu
Cc: lulu, jasowang, qemu-devel, eperezma, Si-Wei Liu, lingshan.zhu
On Thu, Mar 31, 2022 at 06:19:37PM +0800, Michael Qiu wrote:
> Hi, Jason
>
> Does it work this time?
Nope. Just use git-send-email.
--
MST
^ permalink raw reply [flat|nested] 47+ messages in thread
* Re: [PATCH RESEND v3] vdpa: reset the backend device in the end of vhost_net_stop()
2022-03-31 9:25 ` [PATCH RESEND " qiudayu
2022-03-31 10:19 ` Michael Qiu
[not found] ` <6245804d.1c69fb81.3c35c.d7efSMTPIN_ADDED_BROKEN@mx.google.com>
@ 2022-04-01 1:12 ` Si-Wei Liu
2022-04-01 1:45 ` Michael Qiu
2022-04-01 1:31 ` [PATCH v4] " Michael Qiu
3 siblings, 1 reply; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-01 1:12 UTC (permalink / raw)
To: qiudayu, jasowang, mst; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 3/31/2022 2:25 AM, qiudayu@archeros.com wrote:
> From: Michael Qiu <qiudayu@archeros.com>
>
> Currently, when VM poweroff, it will trigger vdpa
> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
> queue pair and one control queue, triggered 3 times), this
> leads to below issue:
>
> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>
> This because in vhost_net_stop(), it will stop all vhost device bind to
> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
> , then stop the queue: vhost_virtqueue_stop().
>
> In vhost_dev_stop(), it resets the device, which clear some flags
> in low level driver, and in next loop(stop other vhost backends),
> qemu try to stop the queue corresponding to the vhost backend,
> the driver finds that the VQ is invalied, this is the root cause.
>
> To solve the issue, vdpa should set vring unready, and
> remove reset ops in device stop: vhost_dev_start(hdev, false).
>
> and implement a new function vhost_dev_reset, only reset backend
> device after all vhost(per-queue) stoped.
>
> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
> ---
> v3 --> v2:
> Call vhost_dev_reset() at the end of vhost_net_stop().
>
> Since the vDPA device need re-add the status bit
> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
> simply, add them inside vhost_vdpa_reset_device, and
> the only way calling vhost_vdpa_reset_device is in
> vhost_net_stop(), so it keeps the same behavior as before.
>
> v2 --> v1:
> Implement a new function vhost_dev_reset,
> reset the backend kernel device at last.
> ---
> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
> hw/virtio/vhost-vdpa.c | 15 +++++++++------
> hw/virtio/vhost.c | 15 ++++++++++++++-
> include/hw/virtio/vhost.h | 1 +
> 4 files changed, 45 insertions(+), 10 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 30379d2..422c9bf 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> int total_notifiers = data_queue_pairs * 2 + cvq;
> VirtIONet *n = VIRTIO_NET(dev);
> int nvhosts = data_queue_pairs + cvq;
> - struct vhost_net *net;
> + struct vhost_net *net = NULL;
> int r, e, i, index_end = data_queue_pairs * 2;
> NetClientState *peer;
>
> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> err_start:
> while (--i >= 0) {
> peer = qemu_get_peer(ncs , i);
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
I would reset the device anyway regardless the first vhost_dev. Some
ioctl calls may have well changed device state in vhost_dev_start() that
has no way to get back than reset.
> + vhost_dev_reset(&net->dev);
I would move this to the end as it's more sensible to reset the device
after guest notifier is disabled.
> + }
> +
> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> if (e < 0) {
> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> VirtIONet *n = VIRTIO_NET(dev);
> NetClientState *peer;
> + struct vhost_net *net = NULL;
> int total_notifiers = data_queue_pairs * 2 + cvq;
> int nvhosts = data_queue_pairs + cvq;
> int i, r;
> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> } else {
> peer = qemu_get_peer(ncs, n->max_queue_pairs);
> }
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> + }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
Yikes, I think it needs some code refactoring here without having to
check VHOST_BACKEND_TYPE_VDPA explicitly. Historically the
.vhost_reset_device() op was misnamed: it was initially meant for
RESET_OWNER but never got used. Could you add a new .vhost_reset_owner()
op to VhostOps (via another patch) and rename properly, e.g. from
vhost_kernel_reset_device() to vhost_kernel_reset_owner()? For
vhost_user_reset_device(), you can safely factor out the
VHOST_USER_RESET_OWNER case to a new vhost_user_reset_owner() function,
and only reset the device in vhost_user_reset_device() depending on the
VHOST_USER_PROTOCOL_F_RESET_DEVICE protocol feature.
With this change, vhost_reset_device will be effectively a no-op on
vhost_kernel (NULL) and vhost_user (only applicable to vhost-user-scsi
backend which supports VHOST_USER_PROTOCOL_F_RESET_DEVICE).
> + vhost_dev_reset(&net->dev);
I would move this to the end as it's more sensible to reset the device
after guest notifier is disabled.
> }
>
> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index c5ed7a3..3ef0199 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>
> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
> trace_vhost_vdpa_reset_device(dev, status);
> +
> + /* Add back this status, so that the device could work next time*/
> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> + VIRTIO_CONFIG_S_DRIVER);
> +
Hmmm, this might not be the ideal place, but I'm fine to leave it as-is.
It would need some more future work in code refactoring for e.g. live
migration and error recovery.
Thanks,
-Siwei
> return ret;
> }
>
> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
> return idx;
> }
>
> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
> {
> int i;
> trace_vhost_vdpa_set_vring_ready(dev);
> for (i = 0; i < dev->nvqs; ++i) {
> struct vhost_vring_state state = {
> .index = dev->vq_index + i,
> - .num = 1,
> + .num = ready,
> };
> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
> }
> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> if (unlikely(!ok)) {
> return -1;
> }
> - vhost_vdpa_set_vring_ready(dev);
> + vhost_vdpa_set_vring_ready(dev, 1);
> } else {
> + vhost_vdpa_set_vring_ready(dev, 0);
> ok = vhost_vdpa_svqs_stop(dev);
> if (unlikely(!ok)) {
> return -1;
> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> memory_listener_register(&v->listener, &address_space_memory);
> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> } else {
> - vhost_vdpa_reset_device(dev);
> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> - VIRTIO_CONFIG_S_DRIVER);
> memory_listener_unregister(&v->listener);
>
> return 0;
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index b643f42..7e0cdb6 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1820,7 +1820,6 @@ fail_features:
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> {
> int i;
> -
> /* should only be called after backend is connected */
> assert(hdev->vhost_ops);
>
> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>
> return -ENOSYS;
> }
> +
> +int vhost_dev_reset(struct vhost_dev *hdev)
> +{
> + int ret = 0;
> +
> + /* should only be called after backend is connected */
> + assert(hdev->vhost_ops);
> +
> + if (hdev->vhost_ops->vhost_reset_device) {
> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> + }
> +
> + return ret;
> +}
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 58a73e7..b8b7c20 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> void vhost_dev_cleanup(struct vhost_dev *hdev);
> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> +int vhost_dev_reset(struct vhost_dev *hdev);
> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH RESEND v3] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 1:12 ` Si-Wei Liu
@ 2022-04-01 1:45 ` Michael Qiu
0 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 1:45 UTC (permalink / raw)
To: Si-Wei Liu, jasowang, mst; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 2022/4/1 9:12, Si-Wei Liu worte:
>
>
> On 3/31/2022 2:25 AM, qiudayu@archeros.com wrote:
>> From: Michael Qiu <qiudayu@archeros.com>
>>
>> Currently, when VM poweroff, it will trigger vdpa
>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>> queue pair and one control queue, triggered 3 times), this
>> leads to below issue:
>>
>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>
>> This because in vhost_net_stop(), it will stop all vhost device bind to
>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the
>> device
>> , then stop the queue: vhost_virtqueue_stop().
>>
>> In vhost_dev_stop(), it resets the device, which clear some flags
>> in low level driver, and in next loop(stop other vhost backends),
>> qemu try to stop the queue corresponding to the vhost backend,
>> the driver finds that the VQ is invalied, this is the root cause.
>>
>> To solve the issue, vdpa should set vring unready, and
>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>
>> and implement a new function vhost_dev_reset, only reset backend
>> device after all vhost(per-queue) stoped.
>>
>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>> Acked-by: Jason Wang <jasowang@redhat.com>
>> ---
>> v3 --> v2:
>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>
>> Since the vDPA device need re-add the status bit
>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>> simply, add them inside vhost_vdpa_reset_device, and
>> the only way calling vhost_vdpa_reset_device is in
>> vhost_net_stop(), so it keeps the same behavior as before.
>>
>> v2 --> v1:
>> Implement a new function vhost_dev_reset,
>> reset the backend kernel device at last.
>> ---
>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>> hw/virtio/vhost.c | 15 ++++++++++++++-
>> include/hw/virtio/vhost.h | 1 +
>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>> index 30379d2..422c9bf 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev,
>> NetClientState *ncs,
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> VirtIONet *n = VIRTIO_NET(dev);
>> int nvhosts = data_queue_pairs + cvq;
>> - struct vhost_net *net;
>> + struct vhost_net *net = NULL;
>> int r, e, i, index_end = data_queue_pairs * 2;
>> NetClientState *peer;
>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev,
>> NetClientState *ncs,
>> err_start:
>> while (--i >= 0) {
>> peer = qemu_get_peer(ncs , i);
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type ==
>> VHOST_BACKEND_TYPE_VDPA) {
> I would reset the device anyway regardless the first vhost_dev. Some
> ioctl calls may have well changed device state in vhost_dev_start() that
> has no way to get back than reset.
>
Here I just use the first vhost_dev as nothing is different in each
vhost_dev, reset just set 0 to the vhost-vdpa socket FD. In all
vhost_dev, FD is the same.
>> + vhost_dev_reset(&net->dev);
> I would move this to the end as it's more sensible to reset the device
> after guest notifier is disabled.
I will move it in next patch
>> + }
>> +
>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> if (e < 0) {
>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n",
>> e);
>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev,
>> NetClientState *ncs,
>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>> VirtIONet *n = VIRTIO_NET(dev);
>> NetClientState *peer;
>> + struct vhost_net *net = NULL;
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> int nvhosts = data_queue_pairs + cvq;
>> int i, r;
>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev,
>> NetClientState *ncs,
>> } else {
>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>> }
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> + }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type ==
>> VHOST_BACKEND_TYPE_VDPA) {
> Yikes, I think it needs some code refactoring here without having to
> check VHOST_BACKEND_TYPE_VDPA explicitly. Historically the
> .vhost_reset_device() op was misnamed: it was initially meant for
> RESET_OWNER but never got used. Could you add a new .vhost_reset_owner()
> op to VhostOps (via another patch) and rename properly, e.g. from
> vhost_kernel_reset_device() to vhost_kernel_reset_owner()? For
> vhost_user_reset_device(), you can safely factor out the
> VHOST_USER_RESET_OWNER case to a new vhost_user_reset_owner() function,
> and only reset the device in vhost_user_reset_device() depending on the
> VHOST_USER_PROTOCOL_F_RESET_DEVICE protocol feature.
>
> With this change, vhost_reset_device will be effectively a no-op on
> vhost_kernel (NULL) and vhost_user (only applicable to vhost-user-scsi
> backend which supports VHOST_USER_PROTOCOL_F_RESET_DEVICE).
OK, I will make a patch to do that.
>> + vhost_dev_reset(&net->dev);
> I would move this to the end as it's more sensible to reset the device
> after guest notifier is disabled.
>
>> }
>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>> index c5ed7a3..3ef0199 100644
>> --- a/hw/virtio/vhost-vdpa.c
>> +++ b/hw/virtio/vhost-vdpa.c
>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct
>> vhost_dev *dev)
>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>> trace_vhost_vdpa_reset_device(dev, status);
>> +
>> + /* Add back this status, so that the device could work next time*/
>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> + VIRTIO_CONFIG_S_DRIVER);
>> +
> Hmmm, this might not be the ideal place, but I'm fine to leave it as-is.
> It would need some more future work in code refactoring for e.g. live
> migration and error recovery.
>
> Thanks,
> -Siwei
>
>> return ret;
>> }
>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct
>> vhost_dev *dev, int idx)
>> return idx;
>> }
>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned
>> int ready)
>> {
>> int i;
>> trace_vhost_vdpa_set_vring_ready(dev);
>> for (i = 0; i < dev->nvqs; ++i) {
>> struct vhost_vring_state state = {
>> .index = dev->vq_index + i,
>> - .num = 1,
>> + .num = ready,
>> };
>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>> }
>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev
>> *dev, bool started)
>> if (unlikely(!ok)) {
>> return -1;
>> }
>> - vhost_vdpa_set_vring_ready(dev);
>> + vhost_vdpa_set_vring_ready(dev, 1);
>> } else {
>> + vhost_vdpa_set_vring_ready(dev, 0);
>> ok = vhost_vdpa_svqs_stop(dev);
>> if (unlikely(!ok)) {
>> return -1;
>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev
>> *dev, bool started)
>> memory_listener_register(&v->listener, &address_space_memory);
>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>> } else {
>> - vhost_vdpa_reset_device(dev);
>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> - VIRTIO_CONFIG_S_DRIVER);
>> memory_listener_unregister(&v->listener);
>> return 0;
>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>> index b643f42..7e0cdb6 100644
>> --- a/hw/virtio/vhost.c
>> +++ b/hw/virtio/vhost.c
>> @@ -1820,7 +1820,6 @@ fail_features:
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>> {
>> int i;
>> -
>> /* should only be called after backend is connected */
>> assert(hdev->vhost_ops);
>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>> return -ENOSYS;
>> }
>> +
>> +int vhost_dev_reset(struct vhost_dev *hdev)
>> +{
>> + int ret = 0;
>> +
>> + /* should only be called after backend is connected */
>> + assert(hdev->vhost_ops);
>> +
>> + if (hdev->vhost_ops->vhost_reset_device) {
>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>> + }
>> +
>> + return ret;
>> +}
>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>> index 58a73e7..b8b7c20 100644
>> --- a/include/hw/virtio/vhost.h
>> +++ b/include/hw/virtio/vhost.h
>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void
>> *opaque,
>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>> +int vhost_dev_reset(struct vhost_dev *hdev);
>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice
>> *vdev);
>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev,
>> VirtIODevice *vdev);
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread
* [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-03-31 9:25 ` [PATCH RESEND " qiudayu
` (2 preceding siblings ...)
2022-04-01 1:12 ` Si-Wei Liu
@ 2022-04-01 1:31 ` Michael Qiu
2022-04-01 2:53 ` Jason Wang
2022-04-01 11:06 ` [PATCH 0/3] Refactor vhost device reset Michael Qiu
3 siblings, 2 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 1:31 UTC (permalink / raw)
To: jasowang, mst, si-wei.liu
Cc: Michael Qiu, eperezma, lingshan.zhu, qemu-devel, lulu
Currently, when VM poweroff, it will trigger vdpa
device(such as mlx bluefield2 VF) reset many times(with 1 datapath
queue pair and one control queue, triggered 3 times), this
leads to below issue:
vhost VQ 2 ring restore failed: -22: Invalid argument (22)
This because in vhost_net_stop(), it will stop all vhost device bind to
this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
, then stop the queue: vhost_virtqueue_stop().
In vhost_dev_stop(), it resets the device, which clear some flags
in low level driver, and in next loop(stop other vhost backends),
qemu try to stop the queue corresponding to the vhost backend,
the driver finds that the VQ is invalied, this is the root cause.
To solve the issue, vdpa should set vring unready, and
remove reset ops in device stop: vhost_dev_start(hdev, false).
and implement a new function vhost_dev_reset, only reset backend
device after all vhost(per-queue) stoped.
Signed-off-by: Michael Qiu<qiudayu@archeros.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
v4 --> v3
Nothing changed, becasue of issue with mimecast,
when the From: tag is different from the sender,
the some mail client will take the patch as an
attachment, RESEND v3 does not work, So resend
the patch as v4
v3 --> v2:
Call vhost_dev_reset() at the end of vhost_net_stop().
Since the vDPA device need re-add the status bit
VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
simply, add them inside vhost_vdpa_reset_device, and
the only way calling vhost_vdpa_reset_device is in
vhost_net_stop(), so it keeps the same behavior as before.
v2 --> v1:
Implement a new function vhost_dev_reset,
reset the backend kernel device at last.
---
hw/net/vhost_net.c | 24 +++++++++++++++++++++---
hw/virtio/vhost-vdpa.c | 15 +++++++++------
hw/virtio/vhost.c | 15 ++++++++++++++-
include/hw/virtio/vhost.h | 1 +
4 files changed, 45 insertions(+), 10 deletions(-)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 30379d2..422c9bf 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
int total_notifiers = data_queue_pairs * 2 + cvq;
VirtIONet *n = VIRTIO_NET(dev);
int nvhosts = data_queue_pairs + cvq;
- struct vhost_net *net;
+ struct vhost_net *net = NULL;
int r, e, i, index_end = data_queue_pairs * 2;
NetClientState *peer;
@@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
err_start:
while (--i >= 0) {
peer = qemu_get_peer(ncs , i);
- vhost_net_stop_one(get_vhost_net(peer), dev);
+
+ net = get_vhost_net(peer);
+
+ vhost_net_stop_one(net, dev);
}
+
+ /* We only reset backend vdpa device */
+ if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
+ vhost_dev_reset(&net->dev);
+ }
+
e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
if (e < 0) {
fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
@@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
VirtIONet *n = VIRTIO_NET(dev);
NetClientState *peer;
+ struct vhost_net *net = NULL;
int total_notifiers = data_queue_pairs * 2 + cvq;
int nvhosts = data_queue_pairs + cvq;
int i, r;
@@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
} else {
peer = qemu_get_peer(ncs, n->max_queue_pairs);
}
- vhost_net_stop_one(get_vhost_net(peer), dev);
+
+ net = get_vhost_net(peer);
+
+ vhost_net_stop_one(net, dev);
+ }
+
+ /* We only reset backend vdpa device */
+ if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
+ vhost_dev_reset(&net->dev);
}
r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index c5ed7a3..3ef0199 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
trace_vhost_vdpa_reset_device(dev, status);
+
+ /* Add back this status, so that the device could work next time*/
+ vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+ VIRTIO_CONFIG_S_DRIVER);
+
return ret;
}
@@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
return idx;
}
-static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
+static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
{
int i;
trace_vhost_vdpa_set_vring_ready(dev);
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_vring_state state = {
.index = dev->vq_index + i,
- .num = 1,
+ .num = ready,
};
vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
}
@@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
if (unlikely(!ok)) {
return -1;
}
- vhost_vdpa_set_vring_ready(dev);
+ vhost_vdpa_set_vring_ready(dev, 1);
} else {
+ vhost_vdpa_set_vring_ready(dev, 0);
ok = vhost_vdpa_svqs_stop(dev);
if (unlikely(!ok)) {
return -1;
@@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
memory_listener_register(&v->listener, &address_space_memory);
return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
} else {
- vhost_vdpa_reset_device(dev);
- vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
- VIRTIO_CONFIG_S_DRIVER);
memory_listener_unregister(&v->listener);
return 0;
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b643f42..7e0cdb6 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1820,7 +1820,6 @@ fail_features:
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
{
int i;
-
/* should only be called after backend is connected */
assert(hdev->vhost_ops);
@@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
return -ENOSYS;
}
+
+int vhost_dev_reset(struct vhost_dev *hdev)
+{
+ int ret = 0;
+
+ /* should only be called after backend is connected */
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_reset_device) {
+ ret = hdev->vhost_ops->vhost_reset_device(hdev);
+ }
+
+ return ret;
+}
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 58a73e7..b8b7c20 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
void vhost_dev_cleanup(struct vhost_dev *hdev);
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
+int vhost_dev_reset(struct vhost_dev *hdev);
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 1:31 ` [PATCH v4] " Michael Qiu
@ 2022-04-01 2:53 ` Jason Wang
2022-04-01 3:20 ` Michael Qiu
` (2 more replies)
2022-04-01 11:06 ` [PATCH 0/3] Refactor vhost device reset Michael Qiu
1 sibling, 3 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-01 2:53 UTC (permalink / raw)
To: Michael Qiu; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Si-Wei Liu, Zhu Lingshan
On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>
> Currently, when VM poweroff, it will trigger vdpa
> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
> queue pair and one control queue, triggered 3 times), this
> leads to below issue:
>
> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>
> This because in vhost_net_stop(), it will stop all vhost device bind to
> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
> , then stop the queue: vhost_virtqueue_stop().
>
> In vhost_dev_stop(), it resets the device, which clear some flags
> in low level driver, and in next loop(stop other vhost backends),
> qemu try to stop the queue corresponding to the vhost backend,
> the driver finds that the VQ is invalied, this is the root cause.
>
> To solve the issue, vdpa should set vring unready, and
> remove reset ops in device stop: vhost_dev_start(hdev, false).
>
> and implement a new function vhost_dev_reset, only reset backend
> device after all vhost(per-queue) stoped.
Typo.
>
> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
> Acked-by: Jason Wang <jasowang@redhat.com>
Rethink this patch, consider there're devices that don't support
set_vq_ready(). I wonder if we need
1) uAPI to tell the user space whether or not it supports set_vq_ready()
2) userspace will call SET_VRING_ENABLE() when the device supports
otherwise it will use RESET.
And for safety, I suggest tagging this as 7.1.
> ---
> v4 --> v3
> Nothing changed, becasue of issue with mimecast,
> when the From: tag is different from the sender,
> the some mail client will take the patch as an
> attachment, RESEND v3 does not work, So resend
> the patch as v4
>
> v3 --> v2:
> Call vhost_dev_reset() at the end of vhost_net_stop().
>
> Since the vDPA device need re-add the status bit
> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
> simply, add them inside vhost_vdpa_reset_device, and
> the only way calling vhost_vdpa_reset_device is in
> vhost_net_stop(), so it keeps the same behavior as before.
>
> v2 --> v1:
> Implement a new function vhost_dev_reset,
> reset the backend kernel device at last.
> ---
> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
> hw/virtio/vhost-vdpa.c | 15 +++++++++------
> hw/virtio/vhost.c | 15 ++++++++++++++-
> include/hw/virtio/vhost.h | 1 +
> 4 files changed, 45 insertions(+), 10 deletions(-)
>
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 30379d2..422c9bf 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> int total_notifiers = data_queue_pairs * 2 + cvq;
> VirtIONet *n = VIRTIO_NET(dev);
> int nvhosts = data_queue_pairs + cvq;
> - struct vhost_net *net;
> + struct vhost_net *net = NULL;
> int r, e, i, index_end = data_queue_pairs * 2;
> NetClientState *peer;
>
> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> err_start:
> while (--i >= 0) {
> peer = qemu_get_peer(ncs , i);
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> + vhost_dev_reset(&net->dev);
> + }
> +
> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> if (e < 0) {
> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> VirtIONet *n = VIRTIO_NET(dev);
> NetClientState *peer;
> + struct vhost_net *net = NULL;
> int total_notifiers = data_queue_pairs * 2 + cvq;
> int nvhosts = data_queue_pairs + cvq;
> int i, r;
> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> } else {
> peer = qemu_get_peer(ncs, n->max_queue_pairs);
> }
> - vhost_net_stop_one(get_vhost_net(peer), dev);
> +
> + net = get_vhost_net(peer);
> +
> + vhost_net_stop_one(net, dev);
> + }
> +
> + /* We only reset backend vdpa device */
> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> + vhost_dev_reset(&net->dev);
> }
So we've already reset the device in vhost_vdpa_dev_start(), any
reason we need to do it again here?
>
> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index c5ed7a3..3ef0199 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>
> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
> trace_vhost_vdpa_reset_device(dev, status);
> +
> + /* Add back this status, so that the device could work next time*/
> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> + VIRTIO_CONFIG_S_DRIVER);
This seems to contradict the semantic of reset.
> +
> return ret;
> }
>
> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
> return idx;
> }
>
> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
> {
> int i;
> trace_vhost_vdpa_set_vring_ready(dev);
> for (i = 0; i < dev->nvqs; ++i) {
> struct vhost_vring_state state = {
> .index = dev->vq_index + i,
> - .num = 1,
> + .num = ready,
> };
> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
> }
> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> if (unlikely(!ok)) {
> return -1;
> }
> - vhost_vdpa_set_vring_ready(dev);
> + vhost_vdpa_set_vring_ready(dev, 1);
> } else {
> + vhost_vdpa_set_vring_ready(dev, 0);
> ok = vhost_vdpa_svqs_stop(dev);
> if (unlikely(!ok)) {
> return -1;
> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> memory_listener_register(&v->listener, &address_space_memory);
> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> } else {
> - vhost_vdpa_reset_device(dev);
> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> - VIRTIO_CONFIG_S_DRIVER);
> memory_listener_unregister(&v->listener);
>
> return 0;
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index b643f42..7e0cdb6 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1820,7 +1820,6 @@ fail_features:
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> {
> int i;
> -
Unnecessary changes.
> /* should only be called after backend is connected */
> assert(hdev->vhost_ops);
>
> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>
> return -ENOSYS;
> }
> +
> +int vhost_dev_reset(struct vhost_dev *hdev)
> +{
Let's use a separate patch for this.
Thanks
> + int ret = 0;
> +
> + /* should only be called after backend is connected */
> + assert(hdev->vhost_ops);
> +
> + if (hdev->vhost_ops->vhost_reset_device) {
> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> + }
> +
> + return ret;
> +}
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 58a73e7..b8b7c20 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> void vhost_dev_cleanup(struct vhost_dev *hdev);
> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> +int vhost_dev_reset(struct vhost_dev *hdev);
> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>
> --
> 1.8.3.1
>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 2:53 ` Jason Wang
@ 2022-04-01 3:20 ` Michael Qiu
2022-04-01 23:07 ` Si-Wei Liu
[not found] ` <62466fff.1c69fb81.8817a.d813SMTPIN_ADDED_BROKEN@mx.google.com>
2 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 3:20 UTC (permalink / raw)
To: Jason Wang; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Si-Wei Liu, Zhu Lingshan
On 2022/4/1 10:53, Jason Wang wrote:
> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>>
>> Currently, when VM poweroff, it will trigger vdpa
>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>> queue pair and one control queue, triggered 3 times), this
>> leads to below issue:
>>
>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>
>> This because in vhost_net_stop(), it will stop all vhost device bind to
>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
>> , then stop the queue: vhost_virtqueue_stop().
>>
>> In vhost_dev_stop(), it resets the device, which clear some flags
>> in low level driver, and in next loop(stop other vhost backends),
>> qemu try to stop the queue corresponding to the vhost backend,
>> the driver finds that the VQ is invalied, this is the root cause.
>>
>> To solve the issue, vdpa should set vring unready, and
>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>
>> and implement a new function vhost_dev_reset, only reset backend
>> device after all vhost(per-queue) stoped.
>
> Typo.
>
>>
>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>> Acked-by: Jason Wang <jasowang@redhat.com>
>
> Rethink this patch, consider there're devices that don't support
> set_vq_ready(). I wonder if we need
>
> 1) uAPI to tell the user space whether or not it supports set_vq_ready()
> 2) userspace will call SET_VRING_ENABLE() when the device supports
> otherwise it will use RESET.
if the device does not support set_vq_ready() in kernel, it will trigger
kernel oops, at least in current kernel, it does not check where
set_vq_ready has been implemented.
And I checked all vdpa driver in kernel, all drivers has implemented
this ops.
So I think it is OK to call set_vq_ready without check.
>
> And for safety, I suggest tagging this as 7.1.
>
>> ---
>> v4 --> v3
>> Nothing changed, becasue of issue with mimecast,
>> when the From: tag is different from the sender,
>> the some mail client will take the patch as an
>> attachment, RESEND v3 does not work, So resend
>> the patch as v4
>>
>> v3 --> v2:
>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>
>> Since the vDPA device need re-add the status bit
>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>> simply, add them inside vhost_vdpa_reset_device, and
>> the only way calling vhost_vdpa_reset_device is in
>> vhost_net_stop(), so it keeps the same behavior as before.
>>
>> v2 --> v1:
>> Implement a new function vhost_dev_reset,
>> reset the backend kernel device at last.
>> ---
>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>> hw/virtio/vhost.c | 15 ++++++++++++++-
>> include/hw/virtio/vhost.h | 1 +
>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>> index 30379d2..422c9bf 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> VirtIONet *n = VIRTIO_NET(dev);
>> int nvhosts = data_queue_pairs + cvq;
>> - struct vhost_net *net;
>> + struct vhost_net *net = NULL;
>> int r, e, i, index_end = data_queue_pairs * 2;
>> NetClientState *peer;
>>
>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>> err_start:
>> while (--i >= 0) {
>> peer = qemu_get_peer(ncs , i);
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>> + vhost_dev_reset(&net->dev);
>> + }
>> +
>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> if (e < 0) {
>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>> VirtIONet *n = VIRTIO_NET(dev);
>> NetClientState *peer;
>> + struct vhost_net *net = NULL;
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> int nvhosts = data_queue_pairs + cvq;
>> int i, r;
>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>> } else {
>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>> }
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> + }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>> + vhost_dev_reset(&net->dev);
>> }
>
> So we've already reset the device in vhost_vdpa_dev_start(), any
> reason we need to do it again here?
reset device in vhost_vdpa_dev_start if there is some error with start.
>
>>
>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>> index c5ed7a3..3ef0199 100644
>> --- a/hw/virtio/vhost-vdpa.c
>> +++ b/hw/virtio/vhost-vdpa.c
>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>>
>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>> trace_vhost_vdpa_reset_device(dev, status);
>> +
>> + /* Add back this status, so that the device could work next time*/
>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> + VIRTIO_CONFIG_S_DRIVER);
>
> This seems to contradict the semantic of reset
Yes, but it's hard to put it in other place, seems only vhost-vdpa need
it, and for VM shutdown, qemu_del_nic() will do cleanup this like close
vhost fds, which will call reset in kernel space without set those features.
So at last I put it here with no other inpact.
Thanks,
Michael
>
>> +
>> return ret;
>> }
>>
>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
>> return idx;
>> }
>>
>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
>> {
>> int i;
>> trace_vhost_vdpa_set_vring_ready(dev);
>> for (i = 0; i < dev->nvqs; ++i) {
>> struct vhost_vring_state state = {
>> .index = dev->vq_index + i,
>> - .num = 1,
>> + .num = ready,
>> };
>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>> }
>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>> if (unlikely(!ok)) {
>> return -1;
>> }
>> - vhost_vdpa_set_vring_ready(dev);
>> + vhost_vdpa_set_vring_ready(dev, 1);
>> } else {
>> + vhost_vdpa_set_vring_ready(dev, 0);
>> ok = vhost_vdpa_svqs_stop(dev);
>> if (unlikely(!ok)) {
>> return -1;
>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>> memory_listener_register(&v->listener, &address_space_memory);
>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>> } else {
>> - vhost_vdpa_reset_device(dev);
>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> - VIRTIO_CONFIG_S_DRIVER);
>> memory_listener_unregister(&v->listener);
>>
>> return 0;
>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>> index b643f42..7e0cdb6 100644
>> --- a/hw/virtio/vhost.c
>> +++ b/hw/virtio/vhost.c
>> @@ -1820,7 +1820,6 @@ fail_features:
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>> {
>> int i;
>> -
>
> Unnecessary changes.
>
>> /* should only be called after backend is connected */
>> assert(hdev->vhost_ops);
>>
>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>>
>> return -ENOSYS;
>> }
>> +
>> +int vhost_dev_reset(struct vhost_dev *hdev)
>> +{
>
> Let's use a separate patch for this.
>
> Thanks
>
>> + int ret = 0;
>> +
>> + /* should only be called after backend is connected */
>> + assert(hdev->vhost_ops);
>> +
>> + if (hdev->vhost_ops->vhost_reset_device) {
>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>> + }
>> +
>> + return ret;
>> +}
>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>> index 58a73e7..b8b7c20 100644
>> --- a/include/hw/virtio/vhost.h
>> +++ b/include/hw/virtio/vhost.h
>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>> +int vhost_dev_reset(struct vhost_dev *hdev);
>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>
>> --
>> 1.8.3.1
>>
>>
>>
>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 2:53 ` Jason Wang
2022-04-01 3:20 ` Michael Qiu
@ 2022-04-01 23:07 ` Si-Wei Liu
2022-04-02 2:20 ` Jason Wang
[not found] ` <62466fff.1c69fb81.8817a.d813SMTPIN_ADDED_BROKEN@mx.google.com>
2 siblings, 1 reply; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-01 23:07 UTC (permalink / raw)
To: Jason Wang, Michael Qiu; +Cc: eperezma, Zhu Lingshan, qemu-devel, Cindy Lu, mst
On 3/31/2022 7:53 PM, Jason Wang wrote:
> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>> Currently, when VM poweroff, it will trigger vdpa
>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>> queue pair and one control queue, triggered 3 times), this
>> leads to below issue:
>>
>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>
>> This because in vhost_net_stop(), it will stop all vhost device bind to
>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
>> , then stop the queue: vhost_virtqueue_stop().
>>
>> In vhost_dev_stop(), it resets the device, which clear some flags
>> in low level driver, and in next loop(stop other vhost backends),
>> qemu try to stop the queue corresponding to the vhost backend,
>> the driver finds that the VQ is invalied, this is the root cause.
>>
>> To solve the issue, vdpa should set vring unready, and
>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>
>> and implement a new function vhost_dev_reset, only reset backend
>> device after all vhost(per-queue) stoped.
> Typo.
>
>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>> Acked-by: Jason Wang <jasowang@redhat.com>
> Rethink this patch, consider there're devices that don't support
> set_vq_ready(). I wonder if we need
>
> 1) uAPI to tell the user space whether or not it supports set_vq_ready()
I guess what's more relevant here is to define the uAPI semantics for
unready i.e. set_vq_ready(0) for resuming/stopping virtqueue processing,
as starting vq is comparatively less ambiguous. Considering the
likelihood that this interface may be used for live migration, it would
be nice to come up with variants such as 1) discard inflight request
v.s. 2) waiting for inflight processing to be done, and 3) timeout in
waiting.
> 2) userspace will call SET_VRING_ENABLE() when the device supports
> otherwise it will use RESET.
Are you looking to making virtqueue resume-able through the new
SET_VRING_ENABLE() uAPI?
I think RESET is inevitable in some case, i.e. when guest initiates
device reset by writing 0 to the status register. For suspend/resume and
live migration use cases, indeed RESET can be substituted with
SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
accommodate this change. Although I'm all for it, it'd be the best to
lay out the plan for multiple phases rather than overload this single
patch too much. You can count my time on this endeavor if you don't mind. :)
>
> And for safety, I suggest tagging this as 7.1.
+1
Regards,
-Siwei
>
>> ---
>> v4 --> v3
>> Nothing changed, becasue of issue with mimecast,
>> when the From: tag is different from the sender,
>> the some mail client will take the patch as an
>> attachment, RESEND v3 does not work, So resend
>> the patch as v4
>>
>> v3 --> v2:
>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>
>> Since the vDPA device need re-add the status bit
>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>> simply, add them inside vhost_vdpa_reset_device, and
>> the only way calling vhost_vdpa_reset_device is in
>> vhost_net_stop(), so it keeps the same behavior as before.
>>
>> v2 --> v1:
>> Implement a new function vhost_dev_reset,
>> reset the backend kernel device at last.
>> ---
>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>> hw/virtio/vhost.c | 15 ++++++++++++++-
>> include/hw/virtio/vhost.h | 1 +
>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>
>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>> index 30379d2..422c9bf 100644
>> --- a/hw/net/vhost_net.c
>> +++ b/hw/net/vhost_net.c
>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> VirtIONet *n = VIRTIO_NET(dev);
>> int nvhosts = data_queue_pairs + cvq;
>> - struct vhost_net *net;
>> + struct vhost_net *net = NULL;
>> int r, e, i, index_end = data_queue_pairs * 2;
>> NetClientState *peer;
>>
>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>> err_start:
>> while (--i >= 0) {
>> peer = qemu_get_peer(ncs , i);
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>> + vhost_dev_reset(&net->dev);
>> + }
>> +
>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> if (e < 0) {
>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>> VirtIONet *n = VIRTIO_NET(dev);
>> NetClientState *peer;
>> + struct vhost_net *net = NULL;
>> int total_notifiers = data_queue_pairs * 2 + cvq;
>> int nvhosts = data_queue_pairs + cvq;
>> int i, r;
>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>> } else {
>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>> }
>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>> +
>> + net = get_vhost_net(peer);
>> +
>> + vhost_net_stop_one(net, dev);
>> + }
>> +
>> + /* We only reset backend vdpa device */
>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>> + vhost_dev_reset(&net->dev);
>> }
> So we've already reset the device in vhost_vdpa_dev_start(), any
> reason we need to do it again here?
>
>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>> index c5ed7a3..3ef0199 100644
>> --- a/hw/virtio/vhost-vdpa.c
>> +++ b/hw/virtio/vhost-vdpa.c
>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>>
>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>> trace_vhost_vdpa_reset_device(dev, status);
>> +
>> + /* Add back this status, so that the device could work next time*/
>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> + VIRTIO_CONFIG_S_DRIVER);
> This seems to contradict the semantic of reset.
>
>> +
>> return ret;
>> }
>>
>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
>> return idx;
>> }
>>
>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
>> {
>> int i;
>> trace_vhost_vdpa_set_vring_ready(dev);
>> for (i = 0; i < dev->nvqs; ++i) {
>> struct vhost_vring_state state = {
>> .index = dev->vq_index + i,
>> - .num = 1,
>> + .num = ready,
>> };
>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>> }
>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>> if (unlikely(!ok)) {
>> return -1;
>> }
>> - vhost_vdpa_set_vring_ready(dev);
>> + vhost_vdpa_set_vring_ready(dev, 1);
>> } else {
>> + vhost_vdpa_set_vring_ready(dev, 0);
>> ok = vhost_vdpa_svqs_stop(dev);
>> if (unlikely(!ok)) {
>> return -1;
>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>> memory_listener_register(&v->listener, &address_space_memory);
>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>> } else {
>> - vhost_vdpa_reset_device(dev);
>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> - VIRTIO_CONFIG_S_DRIVER);
>> memory_listener_unregister(&v->listener);
>>
>> return 0;
>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>> index b643f42..7e0cdb6 100644
>> --- a/hw/virtio/vhost.c
>> +++ b/hw/virtio/vhost.c
>> @@ -1820,7 +1820,6 @@ fail_features:
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>> {
>> int i;
>> -
> Unnecessary changes.
>
>> /* should only be called after backend is connected */
>> assert(hdev->vhost_ops);
>>
>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>>
>> return -ENOSYS;
>> }
>> +
>> +int vhost_dev_reset(struct vhost_dev *hdev)
>> +{
> Let's use a separate patch for this.
>
> Thanks
>
>> + int ret = 0;
>> +
>> + /* should only be called after backend is connected */
>> + assert(hdev->vhost_ops);
>> +
>> + if (hdev->vhost_ops->vhost_reset_device) {
>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>> + }
>> +
>> + return ret;
>> +}
>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>> index 58a73e7..b8b7c20 100644
>> --- a/include/hw/virtio/vhost.h
>> +++ b/include/hw/virtio/vhost.h
>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>> +int vhost_dev_reset(struct vhost_dev *hdev);
>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>
>> --
>> 1.8.3.1
>>
>>
>>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 23:07 ` Si-Wei Liu
@ 2022-04-02 2:20 ` Jason Wang
2022-04-02 3:53 ` Michael Qiu
` (2 more replies)
0 siblings, 3 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-02 2:20 UTC (permalink / raw)
To: Si-Wei Liu; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Michael Qiu, Zhu Lingshan
Adding Michael.
On Sat, Apr 2, 2022 at 7:08 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>
>
>
> On 3/31/2022 7:53 PM, Jason Wang wrote:
> > On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
> >> Currently, when VM poweroff, it will trigger vdpa
> >> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
> >> queue pair and one control queue, triggered 3 times), this
> >> leads to below issue:
> >>
> >> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
> >>
> >> This because in vhost_net_stop(), it will stop all vhost device bind to
> >> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
> >> , then stop the queue: vhost_virtqueue_stop().
> >>
> >> In vhost_dev_stop(), it resets the device, which clear some flags
> >> in low level driver, and in next loop(stop other vhost backends),
> >> qemu try to stop the queue corresponding to the vhost backend,
> >> the driver finds that the VQ is invalied, this is the root cause.
> >>
> >> To solve the issue, vdpa should set vring unready, and
> >> remove reset ops in device stop: vhost_dev_start(hdev, false).
> >>
> >> and implement a new function vhost_dev_reset, only reset backend
> >> device after all vhost(per-queue) stoped.
> > Typo.
> >
> >> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
> >> Acked-by: Jason Wang <jasowang@redhat.com>
> > Rethink this patch, consider there're devices that don't support
> > set_vq_ready(). I wonder if we need
> >
> > 1) uAPI to tell the user space whether or not it supports set_vq_ready()
> I guess what's more relevant here is to define the uAPI semantics for
> unready i.e. set_vq_ready(0) for resuming/stopping virtqueue processing,
> as starting vq is comparatively less ambiguous.
Yes.
> Considering the
> likelihood that this interface may be used for live migration, it would
> be nice to come up with variants such as 1) discard inflight request
> v.s. 2) waiting for inflight processing to be done,
Or inflight descriptor reporting (which seems to be tricky). But we
can start from net that a discarding may just work.
>and 3) timeout in
> waiting.
Actually, that's the plan and Eugenio is proposing something like this
via virtio spec:
https://lists.oasis-open.org/archives/virtio-dev/202111/msg00020.html
>
> > 2) userspace will call SET_VRING_ENABLE() when the device supports
> > otherwise it will use RESET.
> Are you looking to making virtqueue resume-able through the new
> SET_VRING_ENABLE() uAPI?
>
> I think RESET is inevitable in some case, i.e. when guest initiates
> device reset by writing 0 to the status register.
Yes, that's all my plan.
> For suspend/resume and
> live migration use cases, indeed RESET can be substituted with
> SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
> accommodate this change. Although I'm all for it, it'd be the best to
> lay out the plan for multiple phases rather than overload this single
> patch too much. You can count my time on this endeavor if you don't mind. :)
You're welcome, I agree we should choose a way to go first:
1) manage to use SET_VRING_ENABLE (more like a workaround anyway)
2) go with virtio-spec (may take a while)
3) don't wait for the spec, have a vDPA specific uAPI first. Note that
I've chatted with most of the vendors and they seem to be fine with
the _S_STOP. If we go this way, we can still provide the forward
compatibility of _S_STOP
4) or do them all (in parallel)
Any thoughts?
Thanks
>
> >
> > And for safety, I suggest tagging this as 7.1.
> +1
>
> Regards,
> -Siwei
>
> >
> >> ---
> >> v4 --> v3
> >> Nothing changed, becasue of issue with mimecast,
> >> when the From: tag is different from the sender,
> >> the some mail client will take the patch as an
> >> attachment, RESEND v3 does not work, So resend
> >> the patch as v4
> >>
> >> v3 --> v2:
> >> Call vhost_dev_reset() at the end of vhost_net_stop().
> >>
> >> Since the vDPA device need re-add the status bit
> >> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
> >> simply, add them inside vhost_vdpa_reset_device, and
> >> the only way calling vhost_vdpa_reset_device is in
> >> vhost_net_stop(), so it keeps the same behavior as before.
> >>
> >> v2 --> v1:
> >> Implement a new function vhost_dev_reset,
> >> reset the backend kernel device at last.
> >> ---
> >> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
> >> hw/virtio/vhost-vdpa.c | 15 +++++++++------
> >> hw/virtio/vhost.c | 15 ++++++++++++++-
> >> include/hw/virtio/vhost.h | 1 +
> >> 4 files changed, 45 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> >> index 30379d2..422c9bf 100644
> >> --- a/hw/net/vhost_net.c
> >> +++ b/hw/net/vhost_net.c
> >> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> >> int total_notifiers = data_queue_pairs * 2 + cvq;
> >> VirtIONet *n = VIRTIO_NET(dev);
> >> int nvhosts = data_queue_pairs + cvq;
> >> - struct vhost_net *net;
> >> + struct vhost_net *net = NULL;
> >> int r, e, i, index_end = data_queue_pairs * 2;
> >> NetClientState *peer;
> >>
> >> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> >> err_start:
> >> while (--i >= 0) {
> >> peer = qemu_get_peer(ncs , i);
> >> - vhost_net_stop_one(get_vhost_net(peer), dev);
> >> +
> >> + net = get_vhost_net(peer);
> >> +
> >> + vhost_net_stop_one(net, dev);
> >> }
> >> +
> >> + /* We only reset backend vdpa device */
> >> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> >> + vhost_dev_reset(&net->dev);
> >> + }
> >> +
> >> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> >> if (e < 0) {
> >> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
> >> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> >> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> >> VirtIONet *n = VIRTIO_NET(dev);
> >> NetClientState *peer;
> >> + struct vhost_net *net = NULL;
> >> int total_notifiers = data_queue_pairs * 2 + cvq;
> >> int nvhosts = data_queue_pairs + cvq;
> >> int i, r;
> >> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> >> } else {
> >> peer = qemu_get_peer(ncs, n->max_queue_pairs);
> >> }
> >> - vhost_net_stop_one(get_vhost_net(peer), dev);
> >> +
> >> + net = get_vhost_net(peer);
> >> +
> >> + vhost_net_stop_one(net, dev);
> >> + }
> >> +
> >> + /* We only reset backend vdpa device */
> >> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> >> + vhost_dev_reset(&net->dev);
> >> }
> > So we've already reset the device in vhost_vdpa_dev_start(), any
> > reason we need to do it again here?
> >
> >> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> >> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> >> index c5ed7a3..3ef0199 100644
> >> --- a/hw/virtio/vhost-vdpa.c
> >> +++ b/hw/virtio/vhost-vdpa.c
> >> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
> >>
> >> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
> >> trace_vhost_vdpa_reset_device(dev, status);
> >> +
> >> + /* Add back this status, so that the device could work next time*/
> >> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> >> + VIRTIO_CONFIG_S_DRIVER);
> > This seems to contradict the semantic of reset.
> >
> >> +
> >> return ret;
> >> }
> >>
> >> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
> >> return idx;
> >> }
> >>
> >> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
> >> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
> >> {
> >> int i;
> >> trace_vhost_vdpa_set_vring_ready(dev);
> >> for (i = 0; i < dev->nvqs; ++i) {
> >> struct vhost_vring_state state = {
> >> .index = dev->vq_index + i,
> >> - .num = 1,
> >> + .num = ready,
> >> };
> >> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
> >> }
> >> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >> if (unlikely(!ok)) {
> >> return -1;
> >> }
> >> - vhost_vdpa_set_vring_ready(dev);
> >> + vhost_vdpa_set_vring_ready(dev, 1);
> >> } else {
> >> + vhost_vdpa_set_vring_ready(dev, 0);
> >> ok = vhost_vdpa_svqs_stop(dev);
> >> if (unlikely(!ok)) {
> >> return -1;
> >> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >> memory_listener_register(&v->listener, &address_space_memory);
> >> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> >> } else {
> >> - vhost_vdpa_reset_device(dev);
> >> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> >> - VIRTIO_CONFIG_S_DRIVER);
> >> memory_listener_unregister(&v->listener);
> >>
> >> return 0;
> >> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> >> index b643f42..7e0cdb6 100644
> >> --- a/hw/virtio/vhost.c
> >> +++ b/hw/virtio/vhost.c
> >> @@ -1820,7 +1820,6 @@ fail_features:
> >> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> >> {
> >> int i;
> >> -
> > Unnecessary changes.
> >
> >> /* should only be called after backend is connected */
> >> assert(hdev->vhost_ops);
> >>
> >> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
> >>
> >> return -ENOSYS;
> >> }
> >> +
> >> +int vhost_dev_reset(struct vhost_dev *hdev)
> >> +{
> > Let's use a separate patch for this.
> >
> > Thanks
> >
> >> + int ret = 0;
> >> +
> >> + /* should only be called after backend is connected */
> >> + assert(hdev->vhost_ops);
> >> +
> >> + if (hdev->vhost_ops->vhost_reset_device) {
> >> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> >> + }
> >> +
> >> + return ret;
> >> +}
> >> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> >> index 58a73e7..b8b7c20 100644
> >> --- a/include/hw/virtio/vhost.h
> >> +++ b/include/hw/virtio/vhost.h
> >> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> >> void vhost_dev_cleanup(struct vhost_dev *hdev);
> >> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> +int vhost_dev_reset(struct vhost_dev *hdev);
> >> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> >>
> >> --
> >> 1.8.3.1
> >>
> >>
> >>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-02 2:20 ` Jason Wang
@ 2022-04-02 3:53 ` Michael Qiu
2022-04-06 0:56 ` Si-Wei Liu
[not found] ` <6247c8f5.1c69fb81.848e0.8b49SMTPIN_ADDED_BROKEN@mx.google.com>
2 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-02 3:53 UTC (permalink / raw)
To: Jason Wang, Si-Wei Liu; +Cc: eperezma, Zhu Lingshan, qemu-devel, Cindy Lu, mst
On 2022/4/2 10:20, Jason Wang wrote:
> Adding Michael.
>
> On Sat, Apr 2, 2022 at 7:08 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>>
>>
>>
>> On 3/31/2022 7:53 PM, Jason Wang wrote:
>>> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>>>> Currently, when VM poweroff, it will trigger vdpa
>>>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>>>> queue pair and one control queue, triggered 3 times), this
>>>> leads to below issue:
>>>>
>>>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>>>
>>>> This because in vhost_net_stop(), it will stop all vhost device bind to
>>>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
>>>> , then stop the queue: vhost_virtqueue_stop().
>>>>
>>>> In vhost_dev_stop(), it resets the device, which clear some flags
>>>> in low level driver, and in next loop(stop other vhost backends),
>>>> qemu try to stop the queue corresponding to the vhost backend,
>>>> the driver finds that the VQ is invalied, this is the root cause.
>>>>
>>>> To solve the issue, vdpa should set vring unready, and
>>>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>>>
>>>> and implement a new function vhost_dev_reset, only reset backend
>>>> device after all vhost(per-queue) stoped.
>>> Typo.
>>>
>>>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>>>> Acked-by: Jason Wang <jasowang@redhat.com>
>>> Rethink this patch, consider there're devices that don't support
>>> set_vq_ready(). I wonder if we need
>>>
>>> 1) uAPI to tell the user space whether or not it supports set_vq_ready()
>> I guess what's more relevant here is to define the uAPI semantics for
>> unready i.e. set_vq_ready(0) for resuming/stopping virtqueue processing,
>> as starting vq is comparatively less ambiguous.
>
> Yes.
>
>> Considering the
>> likelihood that this interface may be used for live migration, it would
>> be nice to come up with variants such as 1) discard inflight request
>> v.s. 2) waiting for inflight processing to be done,
>
> Or inflight descriptor reporting (which seems to be tricky). But we
> can start from net that a discarding may just work.
>
>> and 3) timeout in
>> waiting.
>
> Actually, that's the plan and Eugenio is proposing something like this
> via virtio spec:
>
> https://lists.oasis-open.org/archives/virtio-dev/202111/msg00020.html
>
>>
>>> 2) userspace will call SET_VRING_ENABLE() when the device supports
>>> otherwise it will use RESET.
>> Are you looking to making virtqueue resume-able through the new
>> SET_VRING_ENABLE() uAPI?
>>
>> I think RESET is inevitable in some case, i.e. when guest initiates
>> device reset by writing 0 to the status register.
>
> Yes, that's all my plan.
>
>> For suspend/resume and
>> live migration use cases, indeed RESET can be substituted with
>> SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
>> accommodate this change. Although I'm all for it, it'd be the best to
>> lay out the plan for multiple phases rather than overload this single
>> patch too much. You can count my time on this endeavor if you don't mind. :)
>
> You're welcome, I agree we should choose a way to go first:
>
> 1) manage to use SET_VRING_ENABLE (more like a workaround anyway)
> 2) go with virtio-spec (may take a while)
> 3) don't wait for the spec, have a vDPA specific uAPI first. Note that
> I've chatted with most of the vendors and they seem to be fine with
> the _S_STOP. If we go this way, we can still provide the forward
> compatibility of _S_STOP
> 4) or do them all (in parallel)
>
> Any thoughts?
>
virtio-spec should be long-term, not only because the spec goes very
slowly, but also the hardware upgrade should be a problem.
For short-term, better to take the first one?
Thanks,
Michael
> Thanks
>
>>
>>>
>>> And for safety, I suggest tagging this as 7.1.
>> +1
>>
>> Regards,
>> -Siwei
>>
>>>
>>>> ---
>>>> v4 --> v3
>>>> Nothing changed, becasue of issue with mimecast,
>>>> when the From: tag is different from the sender,
>>>> the some mail client will take the patch as an
>>>> attachment, RESEND v3 does not work, So resend
>>>> the patch as v4
>>>>
>>>> v3 --> v2:
>>>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>>>
>>>> Since the vDPA device need re-add the status bit
>>>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>>>> simply, add them inside vhost_vdpa_reset_device, and
>>>> the only way calling vhost_vdpa_reset_device is in
>>>> vhost_net_stop(), so it keeps the same behavior as before.
>>>>
>>>> v2 --> v1:
>>>> Implement a new function vhost_dev_reset,
>>>> reset the backend kernel device at last.
>>>> ---
>>>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>>>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>>>> hw/virtio/vhost.c | 15 ++++++++++++++-
>>>> include/hw/virtio/vhost.h | 1 +
>>>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>>>> index 30379d2..422c9bf 100644
>>>> --- a/hw/net/vhost_net.c
>>>> +++ b/hw/net/vhost_net.c
>>>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> - struct vhost_net *net;
>>>> + struct vhost_net *net = NULL;
>>>> int r, e, i, index_end = data_queue_pairs * 2;
>>>> NetClientState *peer;
>>>>
>>>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> err_start:
>>>> while (--i >= 0) {
>>>> peer = qemu_get_peer(ncs , i);
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> + }
>>>> +
>>>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> if (e < 0) {
>>>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
>>>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> NetClientState *peer;
>>>> + struct vhost_net *net = NULL;
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> int i, r;
>>>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> } else {
>>>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>>>> }
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> + }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> }
>>> So we've already reset the device in vhost_vdpa_dev_start(), any
>>> reason we need to do it again here?
>>>
>>>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>>>> index c5ed7a3..3ef0199 100644
>>>> --- a/hw/virtio/vhost-vdpa.c
>>>> +++ b/hw/virtio/vhost-vdpa.c
>>>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>>>>
>>>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>>>> trace_vhost_vdpa_reset_device(dev, status);
>>>> +
>>>> + /* Add back this status, so that the device could work next time*/
>>>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> + VIRTIO_CONFIG_S_DRIVER);
>>> This seems to contradict the semantic of reset.
>>>
>>>> +
>>>> return ret;
>>>> }
>>>>
>>>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
>>>> return idx;
>>>> }
>>>>
>>>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>>>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
>>>> {
>>>> int i;
>>>> trace_vhost_vdpa_set_vring_ready(dev);
>>>> for (i = 0; i < dev->nvqs; ++i) {
>>>> struct vhost_vring_state state = {
>>>> .index = dev->vq_index + i,
>>>> - .num = 1,
>>>> + .num = ready,
>>>> };
>>>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>>>> }
>>>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> }
>>>> - vhost_vdpa_set_vring_ready(dev);
>>>> + vhost_vdpa_set_vring_ready(dev, 1);
>>>> } else {
>>>> + vhost_vdpa_set_vring_ready(dev, 0);
>>>> ok = vhost_vdpa_svqs_stop(dev);
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> memory_listener_register(&v->listener, &address_space_memory);
>>>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>>>> } else {
>>>> - vhost_vdpa_reset_device(dev);
>>>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> - VIRTIO_CONFIG_S_DRIVER);
>>>> memory_listener_unregister(&v->listener);
>>>>
>>>> return 0;
>>>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>>>> index b643f42..7e0cdb6 100644
>>>> --- a/hw/virtio/vhost.c
>>>> +++ b/hw/virtio/vhost.c
>>>> @@ -1820,7 +1820,6 @@ fail_features:
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>>> {
>>>> int i;
>>>> -
>>> Unnecessary changes.
>>>
>>>> /* should only be called after backend is connected */
>>>> assert(hdev->vhost_ops);
>>>>
>>>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>>>>
>>>> return -ENOSYS;
>>>> }
>>>> +
>>>> +int vhost_dev_reset(struct vhost_dev *hdev)
>>>> +{
>>> Let's use a separate patch for this.
>>>
>>> Thanks
>>>
>>>> + int ret = 0;
>>>> +
>>>> + /* should only be called after backend is connected */
>>>> + assert(hdev->vhost_ops);
>>>> +
>>>> + if (hdev->vhost_ops->vhost_reset_device) {
>>>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>>>> + }
>>>> +
>>>> + return ret;
>>>> +}
>>>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>>>> index 58a73e7..b8b7c20 100644
>>>> --- a/include/hw/virtio/vhost.h
>>>> +++ b/include/hw/virtio/vhost.h
>>>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>>>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>>>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> +int vhost_dev_reset(struct vhost_dev *hdev);
>>>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>
>>>> --
>>>> 1.8.3.1
>>>>
>>>>
>>>>
>>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-02 2:20 ` Jason Wang
2022-04-02 3:53 ` Michael Qiu
@ 2022-04-06 0:56 ` Si-Wei Liu
2022-04-07 7:50 ` Jason Wang
[not found] ` <6247c8f5.1c69fb81.848e0.8b49SMTPIN_ADDED_BROKEN@mx.google.com>
2 siblings, 1 reply; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-06 0:56 UTC (permalink / raw)
To: Jason Wang; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Michael Qiu, Zhu Lingshan
On 4/1/2022 7:20 PM, Jason Wang wrote:
> Adding Michael.
>
> On Sat, Apr 2, 2022 at 7:08 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>>
>>
>> On 3/31/2022 7:53 PM, Jason Wang wrote:
>>> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>>>> Currently, when VM poweroff, it will trigger vdpa
>>>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>>>> queue pair and one control queue, triggered 3 times), this
>>>> leads to below issue:
>>>>
>>>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>>>
>>>> This because in vhost_net_stop(), it will stop all vhost device bind to
>>>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
>>>> , then stop the queue: vhost_virtqueue_stop().
>>>>
>>>> In vhost_dev_stop(), it resets the device, which clear some flags
>>>> in low level driver, and in next loop(stop other vhost backends),
>>>> qemu try to stop the queue corresponding to the vhost backend,
>>>> the driver finds that the VQ is invalied, this is the root cause.
>>>>
>>>> To solve the issue, vdpa should set vring unready, and
>>>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>>>
>>>> and implement a new function vhost_dev_reset, only reset backend
>>>> device after all vhost(per-queue) stoped.
>>> Typo.
>>>
>>>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>>>> Acked-by: Jason Wang <jasowang@redhat.com>
>>> Rethink this patch, consider there're devices that don't support
>>> set_vq_ready(). I wonder if we need
>>>
>>> 1) uAPI to tell the user space whether or not it supports set_vq_ready()
>> I guess what's more relevant here is to define the uAPI semantics for
>> unready i.e. set_vq_ready(0) for resuming/stopping virtqueue processing,
>> as starting vq is comparatively less ambiguous.
> Yes.
>
>> Considering the
>> likelihood that this interface may be used for live migration, it would
>> be nice to come up with variants such as 1) discard inflight request
>> v.s. 2) waiting for inflight processing to be done,
> Or inflight descriptor reporting (which seems to be tricky). But we
> can start from net that a discarding may just work.
>
>> and 3) timeout in
>> waiting.
> Actually, that's the plan and Eugenio is proposing something like this
> via virtio spec:
>
> https://urldefense.com/v3/__https://lists.oasis-open.org/archives/virtio-dev/202111/msg00020.html__;!!ACWV5N9M2RV99hQ!bcX6i6_atR-6Gcl-4q5Tekab_xDuXr7lDAMw2E1hilZ_1cZIX1c5mztQtvsnjiiy$
Thanks for the pointer, I seem to recall I saw it some time back though
I wonder if there's follow-up for the v3? My impression was that this is
still a work-in-progress spec proposal, while the semantics of various
F_STOP scenario is unclear yet and not all of the requirements (ex:
STOP_FAILED, rewind & !IN_ORDER) for live migration do seem to get
accommodated?
>
>>> 2) userspace will call SET_VRING_ENABLE() when the device supports
>>> otherwise it will use RESET.
>> Are you looking to making virtqueue resume-able through the new
>> SET_VRING_ENABLE() uAPI?
>>
>> I think RESET is inevitable in some case, i.e. when guest initiates
>> device reset by writing 0 to the status register.
> Yes, that's all my plan.
>
>> For suspend/resume and
>> live migration use cases, indeed RESET can be substituted with
>> SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
>> accommodate this change. Although I'm all for it, it'd be the best to
>> lay out the plan for multiple phases rather than overload this single
>> patch too much. You can count my time on this endeavor if you don't mind. :)
> You're welcome, I agree we should choose a way to go first:
>
> 1) manage to use SET_VRING_ENABLE (more like a workaround anyway)
For networking device and the vq suspend/resume and live migration use
cases to support, I thought it might suffice? We may drop inflight or
unused ones for Ethernet... What other part do you think may limit its
extension to become a general uAPI or add new uAPI to address similar VQ
stop requirement if need be? Or we might well define subsystem specific
uAPI to stop the virtqueue, for vdpa device specifically? I think the
point here is given that we would like to avoid guest side modification
to support live migration, we can define specific uAPI for specific live
migration requirement without having to involve guest driver change.
It'd be easy to get started this way and generalize them all to a full
blown _S_STOP when things are eventually settled.
> 2) go with virtio-spec (may take a while)
I feel it might be still quite early for now to get to a full blown
_S_STOP spec level amendment that works for all types of virtio (vendor)
devices. Generally there can be very specific subsystem-dependent ways
to stop each type of virtio devices that satisfies the live migration of
virtio subsystem devices. For now the discussion mostly concerns with vq
index rewind, inflight handling, notification interrupt and
configuration space such kind of virtio level things, but real device
backend has implication on the other parts such as the order of IO/DMA
quiescing and interrupt masking. If the subsystem virtio guest drivers
today somehow don't support any of those _S_STOP new behaviors, I guess
it's with little point to introduce the same or similar _S_STOP
functionality to the guest driver to effectively support live migration.
Thanks,
-Siwei
> 3) don't wait for the spec, have a vDPA specific uAPI first. Note that
> I've chatted with most of the vendors and they seem to be fine with
> the _S_STOP. If we go this way, we can still provide the forward
> compatibility of _S_STOP
> 4) or do them all (in parallel)
>
> Any thoughts?
>
> Thanks
>
>>> And for safety, I suggest tagging this as 7.1.
>> +1
>>
>> Regards,
>> -Siwei
>>
>>>> ---
>>>> v4 --> v3
>>>> Nothing changed, becasue of issue with mimecast,
>>>> when the From: tag is different from the sender,
>>>> the some mail client will take the patch as an
>>>> attachment, RESEND v3 does not work, So resend
>>>> the patch as v4
>>>>
>>>> v3 --> v2:
>>>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>>>
>>>> Since the vDPA device need re-add the status bit
>>>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>>>> simply, add them inside vhost_vdpa_reset_device, and
>>>> the only way calling vhost_vdpa_reset_device is in
>>>> vhost_net_stop(), so it keeps the same behavior as before.
>>>>
>>>> v2 --> v1:
>>>> Implement a new function vhost_dev_reset,
>>>> reset the backend kernel device at last.
>>>> ---
>>>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>>>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>>>> hw/virtio/vhost.c | 15 ++++++++++++++-
>>>> include/hw/virtio/vhost.h | 1 +
>>>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>>>> index 30379d2..422c9bf 100644
>>>> --- a/hw/net/vhost_net.c
>>>> +++ b/hw/net/vhost_net.c
>>>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> - struct vhost_net *net;
>>>> + struct vhost_net *net = NULL;
>>>> int r, e, i, index_end = data_queue_pairs * 2;
>>>> NetClientState *peer;
>>>>
>>>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> err_start:
>>>> while (--i >= 0) {
>>>> peer = qemu_get_peer(ncs , i);
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> + }
>>>> +
>>>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> if (e < 0) {
>>>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
>>>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> NetClientState *peer;
>>>> + struct vhost_net *net = NULL;
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> int i, r;
>>>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> } else {
>>>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>>>> }
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> + }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> }
>>> So we've already reset the device in vhost_vdpa_dev_start(), any
>>> reason we need to do it again here?
>>>
>>>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>>>> index c5ed7a3..3ef0199 100644
>>>> --- a/hw/virtio/vhost-vdpa.c
>>>> +++ b/hw/virtio/vhost-vdpa.c
>>>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>>>>
>>>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>>>> trace_vhost_vdpa_reset_device(dev, status);
>>>> +
>>>> + /* Add back this status, so that the device could work next time*/
>>>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> + VIRTIO_CONFIG_S_DRIVER);
>>> This seems to contradict the semantic of reset.
>>>
>>>> +
>>>> return ret;
>>>> }
>>>>
>>>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
>>>> return idx;
>>>> }
>>>>
>>>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>>>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
>>>> {
>>>> int i;
>>>> trace_vhost_vdpa_set_vring_ready(dev);
>>>> for (i = 0; i < dev->nvqs; ++i) {
>>>> struct vhost_vring_state state = {
>>>> .index = dev->vq_index + i,
>>>> - .num = 1,
>>>> + .num = ready,
>>>> };
>>>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>>>> }
>>>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> }
>>>> - vhost_vdpa_set_vring_ready(dev);
>>>> + vhost_vdpa_set_vring_ready(dev, 1);
>>>> } else {
>>>> + vhost_vdpa_set_vring_ready(dev, 0);
>>>> ok = vhost_vdpa_svqs_stop(dev);
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> memory_listener_register(&v->listener, &address_space_memory);
>>>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>>>> } else {
>>>> - vhost_vdpa_reset_device(dev);
>>>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> - VIRTIO_CONFIG_S_DRIVER);
>>>> memory_listener_unregister(&v->listener);
>>>>
>>>> return 0;
>>>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>>>> index b643f42..7e0cdb6 100644
>>>> --- a/hw/virtio/vhost.c
>>>> +++ b/hw/virtio/vhost.c
>>>> @@ -1820,7 +1820,6 @@ fail_features:
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>>> {
>>>> int i;
>>>> -
>>> Unnecessary changes.
>>>
>>>> /* should only be called after backend is connected */
>>>> assert(hdev->vhost_ops);
>>>>
>>>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>>>>
>>>> return -ENOSYS;
>>>> }
>>>> +
>>>> +int vhost_dev_reset(struct vhost_dev *hdev)
>>>> +{
>>> Let's use a separate patch for this.
>>>
>>> Thanks
>>>
>>>> + int ret = 0;
>>>> +
>>>> + /* should only be called after backend is connected */
>>>> + assert(hdev->vhost_ops);
>>>> +
>>>> + if (hdev->vhost_ops->vhost_reset_device) {
>>>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>>>> + }
>>>> +
>>>> + return ret;
>>>> +}
>>>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>>>> index 58a73e7..b8b7c20 100644
>>>> --- a/include/hw/virtio/vhost.h
>>>> +++ b/include/hw/virtio/vhost.h
>>>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>>>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>>>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> +int vhost_dev_reset(struct vhost_dev *hdev);
>>>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>
>>>> --
>>>> 1.8.3.1
>>>>
>>>>
>>>>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-06 0:56 ` Si-Wei Liu
@ 2022-04-07 7:50 ` Jason Wang
0 siblings, 0 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-07 7:50 UTC (permalink / raw)
To: Si-Wei Liu; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Michael Qiu, Zhu Lingshan
在 2022/4/6 上午8:56, Si-Wei Liu 写道:
>
>
> On 4/1/2022 7:20 PM, Jason Wang wrote:
>> Adding Michael.
>>
>> On Sat, Apr 2, 2022 at 7:08 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>>>
>>>
>>> On 3/31/2022 7:53 PM, Jason Wang wrote:
>>>> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com>
>>>> wrote:
>>>>> Currently, when VM poweroff, it will trigger vdpa
>>>>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>>>>> queue pair and one control queue, triggered 3 times), this
>>>>> leads to below issue:
>>>>>
>>>>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>>>>
>>>>> This because in vhost_net_stop(), it will stop all vhost device
>>>>> bind to
>>>>> this virtio device, and in vhost_dev_stop(), qemu tries to stop
>>>>> the device
>>>>> , then stop the queue: vhost_virtqueue_stop().
>>>>>
>>>>> In vhost_dev_stop(), it resets the device, which clear some flags
>>>>> in low level driver, and in next loop(stop other vhost backends),
>>>>> qemu try to stop the queue corresponding to the vhost backend,
>>>>> the driver finds that the VQ is invalied, this is the root cause.
>>>>>
>>>>> To solve the issue, vdpa should set vring unready, and
>>>>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>>>>
>>>>> and implement a new function vhost_dev_reset, only reset backend
>>>>> device after all vhost(per-queue) stoped.
>>>> Typo.
>>>>
>>>>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>>>>> Acked-by: Jason Wang <jasowang@redhat.com>
>>>> Rethink this patch, consider there're devices that don't support
>>>> set_vq_ready(). I wonder if we need
>>>>
>>>> 1) uAPI to tell the user space whether or not it supports
>>>> set_vq_ready()
>>> I guess what's more relevant here is to define the uAPI semantics for
>>> unready i.e. set_vq_ready(0) for resuming/stopping virtqueue
>>> processing,
>>> as starting vq is comparatively less ambiguous.
>> Yes.
>>
>>> Considering the
>>> likelihood that this interface may be used for live migration, it would
>>> be nice to come up with variants such as 1) discard inflight request
>>> v.s. 2) waiting for inflight processing to be done,
>> Or inflight descriptor reporting (which seems to be tricky). But we
>> can start from net that a discarding may just work.
>>
>>> and 3) timeout in
>>> waiting.
>> Actually, that's the plan and Eugenio is proposing something like this
>> via virtio spec:
>>
>> https://urldefense.com/v3/__https://lists.oasis-open.org/archives/virtio-dev/202111/msg00020.html__;!!ACWV5N9M2RV99hQ!bcX6i6_atR-6Gcl-4q5Tekab_xDuXr7lDAMw2E1hilZ_1cZIX1c5mztQtvsnjiiy$
>>
> Thanks for the pointer, I seem to recall I saw it some time back
> though I wonder if there's follow-up for the v3? My impression was
> that this is still a work-in-progress spec proposal, while the
> semantics of various F_STOP scenario is unclear yet and not all of the
> requirements (ex: STOP_FAILED, rewind & !IN_ORDER) for live migration
> do seem to get accommodated?
My understanding is that, the reason for STOP_FAILED and IN_ORDER is
because we don't have a way to report inflight descriptors. We will try
to overcome those by allow the device to report inflight descriptors in
the next version.
>
>>
>>>> 2) userspace will call SET_VRING_ENABLE() when the device supports
>>>> otherwise it will use RESET.
>>> Are you looking to making virtqueue resume-able through the new
>>> SET_VRING_ENABLE() uAPI?
>>>
>>> I think RESET is inevitable in some case, i.e. when guest initiates
>>> device reset by writing 0 to the status register.
>> Yes, that's all my plan.
>>
>>> For suspend/resume and
>>> live migration use cases, indeed RESET can be substituted with
>>> SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
>>> accommodate this change. Although I'm all for it, it'd be the best to
>>> lay out the plan for multiple phases rather than overload this single
>>> patch too much. You can count my time on this endeavor if you don't
>>> mind. :)
>> You're welcome, I agree we should choose a way to go first:
>>
>> 1) manage to use SET_VRING_ENABLE (more like a workaround anyway)
> For networking device and the vq suspend/resume and live migration use
> cases to support, I thought it might suffice?
Without config space change it would be sufficient. And anyhow the vDPA
parent can prevent the config change if all the virtqueue is disabled.
> We may drop inflight or unused ones for Ethernet...
Yes.
> What other part do you think may limit its extension to become a
> general uAPI or add new uAPI to address similar VQ stop requirement if
> need be?
For networking, we don't need other.
> Or we might well define subsystem specific uAPI to stop the virtqueue,
> for vdpa device specifically?
Anyhow we need a uAPI consider we have some parent that doesn't support
virtqueue stop. So this could be another way to go.
But if we decide to bother with new uAPI, I would rather go with a new
uAPI for stop the device. It can help for the config space change as well.
> I think the point here is given that we would like to avoid guest side
> modification to support live migration, we can define specific uAPI
> for specific live migration requirement without having to involve
> guest driver change. It'd be easy to get started this way and
> generalize them all to a full blown _S_STOP when things are eventually
> settled.
Yes, note that the status seen by guest is mediated by the hypervisor.
So the hypervisor can choose not to hide the _S_STOP from the guest to
keep the migration work without modifications in the guest driver.
>
>> 2) go with virtio-spec (may take a while)
> I feel it might be still quite early for now to get to a full blown
> _S_STOP spec level amendment that works for all types of virtio
> (vendor) devices. Generally there can be very specific
> subsystem-dependent ways to stop each type of virtio devices that
> satisfies the live migration of virtio subsystem devices.
Yes.
> For now the discussion mostly concerns with vq index rewind, inflight
> handling, notification interrupt and configuration space such kind of
> virtio level things, but real device backend has implication on the
> other parts such as the order of IO/DMA quiescing and interrupt masking.
It's the charge of the vDPA parent to perform any necessary quiescing to
satisfy the semantic of _S_STOP, it's an implementation detail which is
out of the scope of the spec.
> If the subsystem virtio guest drivers today somehow don't support any
> of those _S_STOP new behaviors, I guess it's with little point to
> introduce the same or similar _S_STOP functionality to the guest
> driver to effectively support live migration.
See above, the live migration is transparent to the guest. For the
driver that doesn't support _S_STOP, we can still live migrate it. The
only interesting part is nesting: if we want to live migrate a nested
guest we need to the guest driver must support _S_STOP.
Thanks
>
>
> Thanks,
> -Siwei
>> 3) don't wait for the spec, have a vDPA specific uAPI first. Note that
>> I've chatted with most of the vendors and they seem to be fine with
>> the _S_STOP. If we go this way, we can still provide the forward
>> compatibility of _S_STOP
>> 4) or do them all (in parallel)
>>
>> Any thoughts?
>>
>> Thanks
>>
>>>> And for safety, I suggest tagging this as 7.1.
>>> +1
>>>
>>> Regards,
>>> -Siwei
>>>
>>>>> ---
>>>>> v4 --> v3
>>>>> Nothing changed, becasue of issue with mimecast,
>>>>> when the From: tag is different from the sender,
>>>>> the some mail client will take the patch as an
>>>>> attachment, RESEND v3 does not work, So resend
>>>>> the patch as v4
>>>>>
>>>>> v3 --> v2:
>>>>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>>>>
>>>>> Since the vDPA device need re-add the status bit
>>>>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>>>>> simply, add them inside vhost_vdpa_reset_device, and
>>>>> the only way calling vhost_vdpa_reset_device is in
>>>>> vhost_net_stop(), so it keeps the same behavior as before.
>>>>>
>>>>> v2 --> v1:
>>>>> Implement a new function vhost_dev_reset,
>>>>> reset the backend kernel device at last.
>>>>> ---
>>>>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>>>>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>>>>> hw/virtio/vhost.c | 15 ++++++++++++++-
>>>>> include/hw/virtio/vhost.h | 1 +
>>>>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>>>>
>>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>>>>> index 30379d2..422c9bf 100644
>>>>> --- a/hw/net/vhost_net.c
>>>>> +++ b/hw/net/vhost_net.c
>>>>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>>> int nvhosts = data_queue_pairs + cvq;
>>>>> - struct vhost_net *net;
>>>>> + struct vhost_net *net = NULL;
>>>>> int r, e, i, index_end = data_queue_pairs * 2;
>>>>> NetClientState *peer;
>>>>>
>>>>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> err_start:
>>>>> while (--i >= 0) {
>>>>> peer = qemu_get_peer(ncs , i);
>>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>>> +
>>>>> + net = get_vhost_net(peer);
>>>>> +
>>>>> + vhost_net_stop_one(net, dev);
>>>>> }
>>>>> +
>>>>> + /* We only reset backend vdpa device */
>>>>> + if (net && net->dev.vhost_ops->backend_type ==
>>>>> VHOST_BACKEND_TYPE_VDPA) {
>>>>> + vhost_dev_reset(&net->dev);
>>>>> + }
>>>>> +
>>>>> e = k->set_guest_notifiers(qbus->parent, total_notifiers,
>>>>> false);
>>>>> if (e < 0) {
>>>>> fprintf(stderr, "vhost guest notifier cleanup failed:
>>>>> %d\n", e);
>>>>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>>> NetClientState *peer;
>>>>> + struct vhost_net *net = NULL;
>>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>>> int nvhosts = data_queue_pairs + cvq;
>>>>> int i, r;
>>>>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> } else {
>>>>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>>>>> }
>>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>>> +
>>>>> + net = get_vhost_net(peer);
>>>>> +
>>>>> + vhost_net_stop_one(net, dev);
>>>>> + }
>>>>> +
>>>>> + /* We only reset backend vdpa device */
>>>>> + if (net && net->dev.vhost_ops->backend_type ==
>>>>> VHOST_BACKEND_TYPE_VDPA) {
>>>>> + vhost_dev_reset(&net->dev);
>>>>> }
>>>> So we've already reset the device in vhost_vdpa_dev_start(), any
>>>> reason we need to do it again here?
>>>>
>>>>> r = k->set_guest_notifiers(qbus->parent, total_notifiers,
>>>>> false);
>>>>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>>>>> index c5ed7a3..3ef0199 100644
>>>>> --- a/hw/virtio/vhost-vdpa.c
>>>>> +++ b/hw/virtio/vhost-vdpa.c
>>>>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct
>>>>> vhost_dev *dev)
>>>>>
>>>>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>>>>> trace_vhost_vdpa_reset_device(dev, status);
>>>>> +
>>>>> + /* Add back this status, so that the device could work next
>>>>> time*/
>>>>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>>> + VIRTIO_CONFIG_S_DRIVER);
>>>> This seems to contradict the semantic of reset.
>>>>
>>>>> +
>>>>> return ret;
>>>>> }
>>>>>
>>>>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct
>>>>> vhost_dev *dev, int idx)
>>>>> return idx;
>>>>> }
>>>>>
>>>>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>>>>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev,
>>>>> unsigned int ready)
>>>>> {
>>>>> int i;
>>>>> trace_vhost_vdpa_set_vring_ready(dev);
>>>>> for (i = 0; i < dev->nvqs; ++i) {
>>>>> struct vhost_vring_state state = {
>>>>> .index = dev->vq_index + i,
>>>>> - .num = 1,
>>>>> + .num = ready,
>>>>> };
>>>>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>>>>> }
>>>>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct
>>>>> vhost_dev *dev, bool started)
>>>>> if (unlikely(!ok)) {
>>>>> return -1;
>>>>> }
>>>>> - vhost_vdpa_set_vring_ready(dev);
>>>>> + vhost_vdpa_set_vring_ready(dev, 1);
>>>>> } else {
>>>>> + vhost_vdpa_set_vring_ready(dev, 0);
>>>>> ok = vhost_vdpa_svqs_stop(dev);
>>>>> if (unlikely(!ok)) {
>>>>> return -1;
>>>>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct
>>>>> vhost_dev *dev, bool started)
>>>>> memory_listener_register(&v->listener,
>>>>> &address_space_memory);
>>>>> return vhost_vdpa_add_status(dev,
>>>>> VIRTIO_CONFIG_S_DRIVER_OK);
>>>>> } else {
>>>>> - vhost_vdpa_reset_device(dev);
>>>>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>>> - VIRTIO_CONFIG_S_DRIVER);
>>>>> memory_listener_unregister(&v->listener);
>>>>>
>>>>> return 0;
>>>>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>>>>> index b643f42..7e0cdb6 100644
>>>>> --- a/hw/virtio/vhost.c
>>>>> +++ b/hw/virtio/vhost.c
>>>>> @@ -1820,7 +1820,6 @@ fail_features:
>>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>>>> {
>>>>> int i;
>>>>> -
>>>> Unnecessary changes.
>>>>
>>>>> /* should only be called after backend is connected */
>>>>> assert(hdev->vhost_ops);
>>>>>
>>>>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev
>>>>> *hdev,
>>>>>
>>>>> return -ENOSYS;
>>>>> }
>>>>> +
>>>>> +int vhost_dev_reset(struct vhost_dev *hdev)
>>>>> +{
>>>> Let's use a separate patch for this.
>>>>
>>>> Thanks
>>>>
>>>>> + int ret = 0;
>>>>> +
>>>>> + /* should only be called after backend is connected */
>>>>> + assert(hdev->vhost_ops);
>>>>> +
>>>>> + if (hdev->vhost_ops->vhost_reset_device) {
>>>>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>>>>> + }
>>>>> +
>>>>> + return ret;
>>>>> +}
>>>>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>>>>> index 58a73e7..b8b7c20 100644
>>>>> --- a/include/hw/virtio/vhost.h
>>>>> +++ b/include/hw/virtio/vhost.h
>>>>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev,
>>>>> void *opaque,
>>>>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>>>>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>> +int vhost_dev_reset(struct vhost_dev *hdev);
>>>>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev,
>>>>> VirtIODevice *vdev);
>>>>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev,
>>>>> VirtIODevice *vdev);
>>>>>
>>>>> --
>>>>> 1.8.3.1
>>>>>
>>>>>
>>>>>
>
^ permalink raw reply [flat|nested] 47+ messages in thread
[parent not found: <6247c8f5.1c69fb81.848e0.8b49SMTPIN_ADDED_BROKEN@mx.google.com>]
* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
[not found] ` <6247c8f5.1c69fb81.848e0.8b49SMTPIN_ADDED_BROKEN@mx.google.com>
@ 2022-04-07 7:52 ` Jason Wang
0 siblings, 0 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-07 7:52 UTC (permalink / raw)
To: qemu-devel
在 2022/4/2 上午11:53, Michael Qiu 写道:
>
>
> On 2022/4/2 10:20, Jason Wang wrote:
>> Adding Michael.
>>
>> On Sat, Apr 2, 2022 at 7:08 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>>>
>>>
>>>
>>> On 3/31/2022 7:53 PM, Jason Wang wrote:
>>>> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com>
>>>> wrote:
>>>>> Currently, when VM poweroff, it will trigger vdpa
>>>>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>>>>> queue pair and one control queue, triggered 3 times), this
>>>>> leads to below issue:
>>>>>
>>>>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>>>>
>>>>> This because in vhost_net_stop(), it will stop all vhost device
>>>>> bind to
>>>>> this virtio device, and in vhost_dev_stop(), qemu tries to stop
>>>>> the device
>>>>> , then stop the queue: vhost_virtqueue_stop().
>>>>>
>>>>> In vhost_dev_stop(), it resets the device, which clear some flags
>>>>> in low level driver, and in next loop(stop other vhost backends),
>>>>> qemu try to stop the queue corresponding to the vhost backend,
>>>>> the driver finds that the VQ is invalied, this is the root cause.
>>>>>
>>>>> To solve the issue, vdpa should set vring unready, and
>>>>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>>>>
>>>>> and implement a new function vhost_dev_reset, only reset backend
>>>>> device after all vhost(per-queue) stoped.
>>>> Typo.
>>>>
>>>>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>>>>> Acked-by: Jason Wang <jasowang@redhat.com>
>>>> Rethink this patch, consider there're devices that don't support
>>>> set_vq_ready(). I wonder if we need
>>>>
>>>> 1) uAPI to tell the user space whether or not it supports
>>>> set_vq_ready()
>>> I guess what's more relevant here is to define the uAPI semantics for
>>> unready i.e. set_vq_ready(0) for resuming/stopping virtqueue
>>> processing,
>>> as starting vq is comparatively less ambiguous.
>>
>> Yes.
>>
>>> Considering the
>>> likelihood that this interface may be used for live migration, it would
>>> be nice to come up with variants such as 1) discard inflight request
>>> v.s. 2) waiting for inflight processing to be done,
>>
>> Or inflight descriptor reporting (which seems to be tricky). But we
>> can start from net that a discarding may just work.
>>
>>> and 3) timeout in
>>> waiting.
>>
>> Actually, that's the plan and Eugenio is proposing something like this
>> via virtio spec:
>>
>> https://lists.oasis-open.org/archives/virtio-dev/202111/msg00020.html
>>
>>>
>>>> 2) userspace will call SET_VRING_ENABLE() when the device supports
>>>> otherwise it will use RESET.
>>> Are you looking to making virtqueue resume-able through the new
>>> SET_VRING_ENABLE() uAPI?
>>>
>>> I think RESET is inevitable in some case, i.e. when guest initiates
>>> device reset by writing 0 to the status register.
>>
>> Yes, that's all my plan.
>>
>>> For suspend/resume and
>>> live migration use cases, indeed RESET can be substituted with
>>> SET_VRING_ENABLE. Again, it'd need quite some code refactoring to
>>> accommodate this change. Although I'm all for it, it'd be the best to
>>> lay out the plan for multiple phases rather than overload this single
>>> patch too much. You can count my time on this endeavor if you don't
>>> mind. :)
>>
>> You're welcome, I agree we should choose a way to go first:
>>
>> 1) manage to use SET_VRING_ENABLE (more like a workaround anyway)
>> 2) go with virtio-spec (may take a while)
>> 3) don't wait for the spec, have a vDPA specific uAPI first. Note that
>> I've chatted with most of the vendors and they seem to be fine with
>> the _S_STOP. If we go this way, we can still provide the forward
>> compatibility of _S_STOP
>> 4) or do them all (in parallel)
>>
>> Any thoughts?
>>
>
> virtio-spec should be long-term, not only because the spec goes very
> slowly, but also the hardware upgrade should be a problem.
>
> For short-term, better to take the first one?
Consider we need a new uAPI anyhow, I prefer for 2) but you can try 1)
and see what people think.
Thanks
>
> Thanks,
> Michael
>> Thanks
>>
>>>
>>>>
>>>> And for safety, I suggest tagging this as 7.1.
>>> +1
>>>
>>> Regards,
>>> -Siwei
>>>
>>>>
>>>>> ---
>>>>> v4 --> v3
>>>>> Nothing changed, becasue of issue with mimecast,
>>>>> when the From: tag is different from the sender,
>>>>> the some mail client will take the patch as an
>>>>> attachment, RESEND v3 does not work, So resend
>>>>> the patch as v4
>>>>>
>>>>> v3 --> v2:
>>>>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>>>>
>>>>> Since the vDPA device need re-add the status bit
>>>>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>>>>> simply, add them inside vhost_vdpa_reset_device, and
>>>>> the only way calling vhost_vdpa_reset_device is in
>>>>> vhost_net_stop(), so it keeps the same behavior as before.
>>>>>
>>>>> v2 --> v1:
>>>>> Implement a new function vhost_dev_reset,
>>>>> reset the backend kernel device at last.
>>>>> ---
>>>>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>>>>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>>>>> hw/virtio/vhost.c | 15 ++++++++++++++-
>>>>> include/hw/virtio/vhost.h | 1 +
>>>>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>>>>
>>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>>>>> index 30379d2..422c9bf 100644
>>>>> --- a/hw/net/vhost_net.c
>>>>> +++ b/hw/net/vhost_net.c
>>>>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>>> int nvhosts = data_queue_pairs + cvq;
>>>>> - struct vhost_net *net;
>>>>> + struct vhost_net *net = NULL;
>>>>> int r, e, i, index_end = data_queue_pairs * 2;
>>>>> NetClientState *peer;
>>>>>
>>>>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> err_start:
>>>>> while (--i >= 0) {
>>>>> peer = qemu_get_peer(ncs , i);
>>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>>> +
>>>>> + net = get_vhost_net(peer);
>>>>> +
>>>>> + vhost_net_stop_one(net, dev);
>>>>> }
>>>>> +
>>>>> + /* We only reset backend vdpa device */
>>>>> + if (net && net->dev.vhost_ops->backend_type ==
>>>>> VHOST_BACKEND_TYPE_VDPA) {
>>>>> + vhost_dev_reset(&net->dev);
>>>>> + }
>>>>> +
>>>>> e = k->set_guest_notifiers(qbus->parent, total_notifiers,
>>>>> false);
>>>>> if (e < 0) {
>>>>> fprintf(stderr, "vhost guest notifier cleanup failed:
>>>>> %d\n", e);
>>>>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>>> NetClientState *peer;
>>>>> + struct vhost_net *net = NULL;
>>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>>> int nvhosts = data_queue_pairs + cvq;
>>>>> int i, r;
>>>>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev,
>>>>> NetClientState *ncs,
>>>>> } else {
>>>>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>>>>> }
>>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>>> +
>>>>> + net = get_vhost_net(peer);
>>>>> +
>>>>> + vhost_net_stop_one(net, dev);
>>>>> + }
>>>>> +
>>>>> + /* We only reset backend vdpa device */
>>>>> + if (net && net->dev.vhost_ops->backend_type ==
>>>>> VHOST_BACKEND_TYPE_VDPA) {
>>>>> + vhost_dev_reset(&net->dev);
>>>>> }
>>>> So we've already reset the device in vhost_vdpa_dev_start(), any
>>>> reason we need to do it again here?
>>>>
>>>>> r = k->set_guest_notifiers(qbus->parent, total_notifiers,
>>>>> false);
>>>>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>>>>> index c5ed7a3..3ef0199 100644
>>>>> --- a/hw/virtio/vhost-vdpa.c
>>>>> +++ b/hw/virtio/vhost-vdpa.c
>>>>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct
>>>>> vhost_dev *dev)
>>>>>
>>>>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>>>>> trace_vhost_vdpa_reset_device(dev, status);
>>>>> +
>>>>> + /* Add back this status, so that the device could work next
>>>>> time*/
>>>>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>>> + VIRTIO_CONFIG_S_DRIVER);
>>>> This seems to contradict the semantic of reset.
>>>>
>>>>> +
>>>>> return ret;
>>>>> }
>>>>>
>>>>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct
>>>>> vhost_dev *dev, int idx)
>>>>> return idx;
>>>>> }
>>>>>
>>>>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>>>>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev,
>>>>> unsigned int ready)
>>>>> {
>>>>> int i;
>>>>> trace_vhost_vdpa_set_vring_ready(dev);
>>>>> for (i = 0; i < dev->nvqs; ++i) {
>>>>> struct vhost_vring_state state = {
>>>>> .index = dev->vq_index + i,
>>>>> - .num = 1,
>>>>> + .num = ready,
>>>>> };
>>>>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>>>>> }
>>>>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct
>>>>> vhost_dev *dev, bool started)
>>>>> if (unlikely(!ok)) {
>>>>> return -1;
>>>>> }
>>>>> - vhost_vdpa_set_vring_ready(dev);
>>>>> + vhost_vdpa_set_vring_ready(dev, 1);
>>>>> } else {
>>>>> + vhost_vdpa_set_vring_ready(dev, 0);
>>>>> ok = vhost_vdpa_svqs_stop(dev);
>>>>> if (unlikely(!ok)) {
>>>>> return -1;
>>>>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct
>>>>> vhost_dev *dev, bool started)
>>>>> memory_listener_register(&v->listener,
>>>>> &address_space_memory);
>>>>> return vhost_vdpa_add_status(dev,
>>>>> VIRTIO_CONFIG_S_DRIVER_OK);
>>>>> } else {
>>>>> - vhost_vdpa_reset_device(dev);
>>>>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>>> - VIRTIO_CONFIG_S_DRIVER);
>>>>> memory_listener_unregister(&v->listener);
>>>>>
>>>>> return 0;
>>>>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>>>>> index b643f42..7e0cdb6 100644
>>>>> --- a/hw/virtio/vhost.c
>>>>> +++ b/hw/virtio/vhost.c
>>>>> @@ -1820,7 +1820,6 @@ fail_features:
>>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>>>> {
>>>>> int i;
>>>>> -
>>>> Unnecessary changes.
>>>>
>>>>> /* should only be called after backend is connected */
>>>>> assert(hdev->vhost_ops);
>>>>>
>>>>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev
>>>>> *hdev,
>>>>>
>>>>> return -ENOSYS;
>>>>> }
>>>>> +
>>>>> +int vhost_dev_reset(struct vhost_dev *hdev)
>>>>> +{
>>>> Let's use a separate patch for this.
>>>>
>>>> Thanks
>>>>
>>>>> + int ret = 0;
>>>>> +
>>>>> + /* should only be called after backend is connected */
>>>>> + assert(hdev->vhost_ops);
>>>>> +
>>>>> + if (hdev->vhost_ops->vhost_reset_device) {
>>>>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>>>>> + }
>>>>> +
>>>>> + return ret;
>>>>> +}
>>>>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>>>>> index 58a73e7..b8b7c20 100644
>>>>> --- a/include/hw/virtio/vhost.h
>>>>> +++ b/include/hw/virtio/vhost.h
>>>>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev,
>>>>> void *opaque,
>>>>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>>>>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>> +int vhost_dev_reset(struct vhost_dev *hdev);
>>>>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev,
>>>>> VirtIODevice *vdev);
>>>>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev,
>>>>> VirtIODevice *vdev);
>>>>>
>>>>> --
>>>>> 1.8.3.1
>>>>>
>>>>>
>>>>>
>>>
>>
>>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread
[parent not found: <62466fff.1c69fb81.8817a.d813SMTPIN_ADDED_BROKEN@mx.google.com>]
* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
[not found] ` <62466fff.1c69fb81.8817a.d813SMTPIN_ADDED_BROKEN@mx.google.com>
@ 2022-04-02 1:48 ` Jason Wang
2022-04-02 3:43 ` Michael Qiu
0 siblings, 1 reply; 47+ messages in thread
From: Jason Wang @ 2022-04-02 1:48 UTC (permalink / raw)
To: Michael Qiu; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Si-Wei Liu, Zhu Lingshan
On Fri, Apr 1, 2022 at 11:22 AM Michael Qiu <qiudayu@archeros.com> wrote:
>
>
>
> On 2022/4/1 10:53, Jason Wang wrote:
> > On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
> >>
> >> Currently, when VM poweroff, it will trigger vdpa
> >> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
> >> queue pair and one control queue, triggered 3 times), this
> >> leads to below issue:
> >>
> >> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
> >>
> >> This because in vhost_net_stop(), it will stop all vhost device bind to
> >> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
> >> , then stop the queue: vhost_virtqueue_stop().
> >>
> >> In vhost_dev_stop(), it resets the device, which clear some flags
> >> in low level driver, and in next loop(stop other vhost backends),
> >> qemu try to stop the queue corresponding to the vhost backend,
> >> the driver finds that the VQ is invalied, this is the root cause.
> >>
> >> To solve the issue, vdpa should set vring unready, and
> >> remove reset ops in device stop: vhost_dev_start(hdev, false).
> >>
> >> and implement a new function vhost_dev_reset, only reset backend
> >> device after all vhost(per-queue) stoped.
> >
> > Typo.
> >
> >>
> >> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
> >> Acked-by: Jason Wang <jasowang@redhat.com>
> >
> > Rethink this patch, consider there're devices that don't support
> > set_vq_ready(). I wonder if we need
> >
> > 1) uAPI to tell the user space whether or not it supports set_vq_ready()
> > 2) userspace will call SET_VRING_ENABLE() when the device supports
> > otherwise it will use RESET.
>
> if the device does not support set_vq_ready() in kernel, it will trigger
> kernel oops, at least in current kernel, it does not check where
> set_vq_ready has been implemented.
>
> And I checked all vdpa driver in kernel, all drivers has implemented
> this ops.
Actually, it's not about whether or not the set_vq_ready() is
implemented. It's about whether the parent supports it correctly:
The ability to suspend and resume a virtqueue is currently beyond the
ability of some transport (e.g PCI).
For IFCVF:
static void ifcvf_vdpa_set_vq_ready(struct vdpa_device *vdpa_dev,
u16 qid, bool ready)
{
struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
vf->vring[qid].ready = ready;
}
It seems to follow the PCI transport, so if you just set it to zero,
it simply doesn't work at all. I can see some tricks that are used in
the DPDK driver, maybe we can use the same to "fix" this.
For VDUSE, we are basically the same:
static void vduse_vdpa_set_vq_ready(struct vdpa_device *vdpa,
u16 idx, bool ready)
{
struct vduse_dev *dev = vdpa_to_vduse(vdpa);
struct vduse_virtqueue *vq = &dev->vqs[idx];
vq->ready = ready;
}
It can't be stopped correctly if we just set it to zero.
For vp_vdpa, it basically wants to abuse the queue_enable, which may
result in a warning in Qemu (and the device isn't stopped).
static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa,
u16 qid, bool ready)
{
struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
vp_modern_set_queue_enable(mdev, qid, ready);
}
ENI did a trick in writing 0 to virtqueue address, so it works for
stop but not the start.
static void eni_vdpa_set_vq_ready(struct vdpa_device *vdpa, u16 qid,
bool ready)
{
struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
/* ENI is a legacy virtio-pci device. This is not supported
* by specification. But we can disable virtqueue by setting
* address to 0.
*/
if (!ready)
vp_legacy_set_queue_address(ldev, qid, 0);
}
mlx5 call suspend_vq() which should be fine.
Simulator is probably fine.
So I worry if we use the set_vq_ready(0) it won't work correctly and
will have other issues. The idea is:
- advertise the suspend/resume capability via uAPI, then mlx5_vdpa and
simulator can go with set_vq_ready()
- others can still go with reset(), and we can try to fix them
gradually (and introduce this in the virtio spec).
>
> So I think it is OK to call set_vq_ready without check.
>
> >
> > And for safety, I suggest tagging this as 7.1.
> >
> >> ---
> >> v4 --> v3
> >> Nothing changed, becasue of issue with mimecast,
> >> when the From: tag is different from the sender,
> >> the some mail client will take the patch as an
> >> attachment, RESEND v3 does not work, So resend
> >> the patch as v4
> >>
> >> v3 --> v2:
> >> Call vhost_dev_reset() at the end of vhost_net_stop().
> >>
> >> Since the vDPA device need re-add the status bit
> >> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
> >> simply, add them inside vhost_vdpa_reset_device, and
> >> the only way calling vhost_vdpa_reset_device is in
> >> vhost_net_stop(), so it keeps the same behavior as before.
> >>
> >> v2 --> v1:
> >> Implement a new function vhost_dev_reset,
> >> reset the backend kernel device at last.
> >> ---
> >> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
> >> hw/virtio/vhost-vdpa.c | 15 +++++++++------
> >> hw/virtio/vhost.c | 15 ++++++++++++++-
> >> include/hw/virtio/vhost.h | 1 +
> >> 4 files changed, 45 insertions(+), 10 deletions(-)
> >>
> >> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> >> index 30379d2..422c9bf 100644
> >> --- a/hw/net/vhost_net.c
> >> +++ b/hw/net/vhost_net.c
> >> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> >> int total_notifiers = data_queue_pairs * 2 + cvq;
> >> VirtIONet *n = VIRTIO_NET(dev);
> >> int nvhosts = data_queue_pairs + cvq;
> >> - struct vhost_net *net;
> >> + struct vhost_net *net = NULL;
> >> int r, e, i, index_end = data_queue_pairs * 2;
> >> NetClientState *peer;
> >>
> >> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
> >> err_start:
> >> while (--i >= 0) {
> >> peer = qemu_get_peer(ncs , i);
> >> - vhost_net_stop_one(get_vhost_net(peer), dev);
> >> +
> >> + net = get_vhost_net(peer);
> >> +
> >> + vhost_net_stop_one(net, dev);
> >> }
> >> +
> >> + /* We only reset backend vdpa device */
> >> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> >> + vhost_dev_reset(&net->dev);
> >> + }
> >> +
> >> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> >> if (e < 0) {
> >> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
> >> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> >> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
> >> VirtIONet *n = VIRTIO_NET(dev);
> >> NetClientState *peer;
> >> + struct vhost_net *net = NULL;
> >> int total_notifiers = data_queue_pairs * 2 + cvq;
> >> int nvhosts = data_queue_pairs + cvq;
> >> int i, r;
> >> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
> >> } else {
> >> peer = qemu_get_peer(ncs, n->max_queue_pairs);
> >> }
> >> - vhost_net_stop_one(get_vhost_net(peer), dev);
> >> +
> >> + net = get_vhost_net(peer);
> >> +
> >> + vhost_net_stop_one(net, dev);
> >> + }
> >> +
> >> + /* We only reset backend vdpa device */
> >> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
> >> + vhost_dev_reset(&net->dev);
> >> }
> >
> > So we've already reset the device in vhost_vdpa_dev_start(), any
> > reason we need to do it again here?
>
> reset device in vhost_vdpa_dev_start if there is some error with start.
The rest should have been done in vhost_net_stop_one()?
>
>
> >
> >>
> >> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
> >> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> >> index c5ed7a3..3ef0199 100644
> >> --- a/hw/virtio/vhost-vdpa.c
> >> +++ b/hw/virtio/vhost-vdpa.c
> >> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
> >>
> >> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
> >> trace_vhost_vdpa_reset_device(dev, status);
> >> +
> >> + /* Add back this status, so that the device could work next time*/
> >> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> >> + VIRTIO_CONFIG_S_DRIVER);
> >
> > This seems to contradict the semantic of reset
>
> Yes, but it's hard to put it in other place, seems only vhost-vdpa need
> it, and for VM shutdown, qemu_del_nic() will do cleanup this like close
> vhost fds, which will call reset in kernel space without set those features.
>
> So at last I put it here with no other inpact.
Can we move this to the suitable caller of this function?
Thanks
>
> Thanks,
> Michael
> >
> >> +
> >> return ret;
> >> }
> >>
> >> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
> >> return idx;
> >> }
> >>
> >> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
> >> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
> >> {
> >> int i;
> >> trace_vhost_vdpa_set_vring_ready(dev);
> >> for (i = 0; i < dev->nvqs; ++i) {
> >> struct vhost_vring_state state = {
> >> .index = dev->vq_index + i,
> >> - .num = 1,
> >> + .num = ready,
> >> };
> >> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
> >> }
> >> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >> if (unlikely(!ok)) {
> >> return -1;
> >> }
> >> - vhost_vdpa_set_vring_ready(dev);
> >> + vhost_vdpa_set_vring_ready(dev, 1);
> >> } else {
> >> + vhost_vdpa_set_vring_ready(dev, 0);
> >> ok = vhost_vdpa_svqs_stop(dev);
> >> if (unlikely(!ok)) {
> >> return -1;
> >> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >> memory_listener_register(&v->listener, &address_space_memory);
> >> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> >> } else {
> >> - vhost_vdpa_reset_device(dev);
> >> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> >> - VIRTIO_CONFIG_S_DRIVER);
> >> memory_listener_unregister(&v->listener);
> >>
> >> return 0;
> >> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> >> index b643f42..7e0cdb6 100644
> >> --- a/hw/virtio/vhost.c
> >> +++ b/hw/virtio/vhost.c
> >> @@ -1820,7 +1820,6 @@ fail_features:
> >> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
> >> {
> >> int i;
> >> -
> >
> > Unnecessary changes.
> >
> >> /* should only be called after backend is connected */
> >> assert(hdev->vhost_ops);
> >>
> >> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
> >>
> >> return -ENOSYS;
> >> }
> >> +
> >> +int vhost_dev_reset(struct vhost_dev *hdev)
> >> +{
> >
> > Let's use a separate patch for this.
> >
> > Thanks
> >
> >> + int ret = 0;
> >> +
> >> + /* should only be called after backend is connected */
> >> + assert(hdev->vhost_ops);
> >> +
> >> + if (hdev->vhost_ops->vhost_reset_device) {
> >> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> >> + }
> >> +
> >> + return ret;
> >> +}
> >> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> >> index 58a73e7..b8b7c20 100644
> >> --- a/include/hw/virtio/vhost.h
> >> +++ b/include/hw/virtio/vhost.h
> >> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> >> void vhost_dev_cleanup(struct vhost_dev *hdev);
> >> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> +int vhost_dev_reset(struct vhost_dev *hdev);
> >> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> >> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> >>
> >> --
> >> 1.8.3.1
> >>
> >>
> >>
> >
> >
> >
>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH v4] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-02 1:48 ` Jason Wang
@ 2022-04-02 3:43 ` Michael Qiu
0 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-02 3:43 UTC (permalink / raw)
To: Jason Wang; +Cc: Cindy Lu, mst, qemu-devel, eperezma, Si-Wei Liu, Zhu Lingshan
On 2022/4/2 9:48, Jason Wang wrote:
> On Fri, Apr 1, 2022 at 11:22 AM Michael Qiu <qiudayu@archeros.com> wrote:
>>
>>
>>
>> On 2022/4/1 10:53, Jason Wang wrote:
>>> On Fri, Apr 1, 2022 at 9:31 AM Michael Qiu <qiudayu@archeros.com> wrote:
>>>>
>>>> Currently, when VM poweroff, it will trigger vdpa
>>>> device(such as mlx bluefield2 VF) reset many times(with 1 datapath
>>>> queue pair and one control queue, triggered 3 times), this
>>>> leads to below issue:
>>>>
>>>> vhost VQ 2 ring restore failed: -22: Invalid argument (22)
>>>>
>>>> This because in vhost_net_stop(), it will stop all vhost device bind to
>>>> this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
>>>> , then stop the queue: vhost_virtqueue_stop().
>>>>
>>>> In vhost_dev_stop(), it resets the device, which clear some flags
>>>> in low level driver, and in next loop(stop other vhost backends),
>>>> qemu try to stop the queue corresponding to the vhost backend,
>>>> the driver finds that the VQ is invalied, this is the root cause.
>>>>
>>>> To solve the issue, vdpa should set vring unready, and
>>>> remove reset ops in device stop: vhost_dev_start(hdev, false).
>>>>
>>>> and implement a new function vhost_dev_reset, only reset backend
>>>> device after all vhost(per-queue) stoped.
>>>
>>> Typo.
>>>
>>>>
>>>> Signed-off-by: Michael Qiu<qiudayu@archeros.com>
>>>> Acked-by: Jason Wang <jasowang@redhat.com>
>>>
>>> Rethink this patch, consider there're devices that don't support
>>> set_vq_ready(). I wonder if we need
>>>
>>> 1) uAPI to tell the user space whether or not it supports set_vq_ready()
>>> 2) userspace will call SET_VRING_ENABLE() when the device supports
>>> otherwise it will use RESET.
>>
>> if the device does not support set_vq_ready() in kernel, it will trigger
>> kernel oops, at least in current kernel, it does not check where
>> set_vq_ready has been implemented.
>>
>> And I checked all vdpa driver in kernel, all drivers has implemented
>> this ops.
>
> Actually, it's not about whether or not the set_vq_ready() is
> implemented. It's about whether the parent supports it correctly:
>
> The ability to suspend and resume a virtqueue is currently beyond the
> ability of some transport (e.g PCI).
>
OK, Got it
> For IFCVF:
>
> static void ifcvf_vdpa_set_vq_ready(struct vdpa_device *vdpa_dev,
> u16 qid, bool ready)
> {
> struct ifcvf_hw *vf = vdpa_to_vf(vdpa_dev);
>
> vf->vring[qid].ready = ready;
> }
>
> It seems to follow the PCI transport, so if you just set it to zero,
> it simply doesn't work at all. I can see some tricks that are used in
> the DPDK driver, maybe we can use the same to "fix" this.
>
> For VDUSE, we are basically the same:
>
> static void vduse_vdpa_set_vq_ready(struct vdpa_device *vdpa,
> u16 idx, bool ready)
> {
> struct vduse_dev *dev = vdpa_to_vduse(vdpa);
> struct vduse_virtqueue *vq = &dev->vqs[idx];
>
> vq->ready = ready;
> }
>
> It can't be stopped correctly if we just set it to zero.
>
> For vp_vdpa, it basically wants to abuse the queue_enable, which may
> result in a warning in Qemu (and the device isn't stopped).
>
> static void vp_vdpa_set_vq_ready(struct vdpa_device *vdpa,
> u16 qid, bool ready)
> {
> struct virtio_pci_modern_device *mdev = vdpa_to_mdev(vdpa);
>
> vp_modern_set_queue_enable(mdev, qid, ready);
> }
>
> ENI did a trick in writing 0 to virtqueue address, so it works for
> stop but not the start.
>
> static void eni_vdpa_set_vq_ready(struct vdpa_device *vdpa, u16 qid,
> bool ready)
> {
> struct virtio_pci_legacy_device *ldev = vdpa_to_ldev(vdpa);
>
> /* ENI is a legacy virtio-pci device. This is not supported
> * by specification. But we can disable virtqueue by setting
> * address to 0.
> */
> if (!ready)
> vp_legacy_set_queue_address(ldev, qid, 0);
> }
>
> mlx5 call suspend_vq() which should be fine.
>
> Simulator is probably fine.
>
> So I worry if we use the set_vq_ready(0) it won't work correctly and
> will have other issues. The idea is:
>
> - advertise the suspend/resume capability via uAPI, then mlx5_vdpa and
> simulator can go with set_vq_ready()
> - others can still go with reset(), and we can try to fix them
> gradually (and introduce this in the virtio spec).
>
Totally agreet.
>>
>> So I think it is OK to call set_vq_ready without check.
>>
>>>
>>> And for safety, I suggest tagging this as 7.1.
>>>
>>>> ---
>>>> v4 --> v3
>>>> Nothing changed, becasue of issue with mimecast,
>>>> when the From: tag is different from the sender,
>>>> the some mail client will take the patch as an
>>>> attachment, RESEND v3 does not work, So resend
>>>> the patch as v4
>>>>
>>>> v3 --> v2:
>>>> Call vhost_dev_reset() at the end of vhost_net_stop().
>>>>
>>>> Since the vDPA device need re-add the status bit
>>>> VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
>>>> simply, add them inside vhost_vdpa_reset_device, and
>>>> the only way calling vhost_vdpa_reset_device is in
>>>> vhost_net_stop(), so it keeps the same behavior as before.
>>>>
>>>> v2 --> v1:
>>>> Implement a new function vhost_dev_reset,
>>>> reset the backend kernel device at last.
>>>> ---
>>>> hw/net/vhost_net.c | 24 +++++++++++++++++++++---
>>>> hw/virtio/vhost-vdpa.c | 15 +++++++++------
>>>> hw/virtio/vhost.c | 15 ++++++++++++++-
>>>> include/hw/virtio/vhost.h | 1 +
>>>> 4 files changed, 45 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
>>>> index 30379d2..422c9bf 100644
>>>> --- a/hw/net/vhost_net.c
>>>> +++ b/hw/net/vhost_net.c
>>>> @@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> - struct vhost_net *net;
>>>> + struct vhost_net *net = NULL;
>>>> int r, e, i, index_end = data_queue_pairs * 2;
>>>> NetClientState *peer;
>>>>
>>>> @@ -391,8 +391,17 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>>>> err_start:
>>>> while (--i >= 0) {
>>>> peer = qemu_get_peer(ncs , i);
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> + }
>>>> +
>>>> e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> if (e < 0) {
>>>> fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
>>>> @@ -410,6 +419,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
>>>> VirtIONet *n = VIRTIO_NET(dev);
>>>> NetClientState *peer;
>>>> + struct vhost_net *net = NULL;
>>>> int total_notifiers = data_queue_pairs * 2 + cvq;
>>>> int nvhosts = data_queue_pairs + cvq;
>>>> int i, r;
>>>> @@ -420,7 +430,15 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
>>>> } else {
>>>> peer = qemu_get_peer(ncs, n->max_queue_pairs);
>>>> }
>>>> - vhost_net_stop_one(get_vhost_net(peer), dev);
>>>> +
>>>> + net = get_vhost_net(peer);
>>>> +
>>>> + vhost_net_stop_one(net, dev);
>>>> + }
>>>> +
>>>> + /* We only reset backend vdpa device */
>>>> + if (net && net->dev.vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA) {
>>>> + vhost_dev_reset(&net->dev);
>>>> }
>>>
>>> So we've already reset the device in vhost_vdpa_dev_start(), any
>>> reason we need to do it again here?
>>
>> reset device in vhost_vdpa_dev_start if there is some error with start.
>
> The rest should have been done in vhost_net_stop_one()?
>
>>
>>
>>>
>>>>
>>>> r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
>>>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>>>> index c5ed7a3..3ef0199 100644
>>>> --- a/hw/virtio/vhost-vdpa.c
>>>> +++ b/hw/virtio/vhost-vdpa.c
>>>> @@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>>>>
>>>> ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>>>> trace_vhost_vdpa_reset_device(dev, status);
>>>> +
>>>> + /* Add back this status, so that the device could work next time*/
>>>> + vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> + VIRTIO_CONFIG_S_DRIVER);
>>>
>>> This seems to contradict the semantic of reset
>>
>> Yes, but it's hard to put it in other place, seems only vhost-vdpa need
>> it, and for VM shutdown, qemu_del_nic() will do cleanup this like close
>> vhost fds, which will call reset in kernel space without set those features.
>>
>> So at last I put it here with no other inpact.
>
> Can we move this to the suitable caller of this function?
>
This is vhost_vdpa backend specific requirement, if we move to the
caller, we need a backend check after each vhost_dev_reset() been called.
Otherwise we need a new vhost API vhost_add_status(), it a bit
complex because we should consider live migration and error recovery as
Si-Wei mentioned.
Could we just leave it here and move it to right place next time.
Thanks,
Michael
> Thanks
>
>>
>> Thanks,
>> Michael
>>>
>>>> +
>>>> return ret;
>>>> }
>>>>
>>>> @@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
>>>> return idx;
>>>> }
>>>>
>>>> -static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
>>>> +static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
>>>> {
>>>> int i;
>>>> trace_vhost_vdpa_set_vring_ready(dev);
>>>> for (i = 0; i < dev->nvqs; ++i) {
>>>> struct vhost_vring_state state = {
>>>> .index = dev->vq_index + i,
>>>> - .num = 1,
>>>> + .num = ready,
>>>> };
>>>> vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
>>>> }
>>>> @@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> }
>>>> - vhost_vdpa_set_vring_ready(dev);
>>>> + vhost_vdpa_set_vring_ready(dev, 1);
>>>> } else {
>>>> + vhost_vdpa_set_vring_ready(dev, 0);
>>>> ok = vhost_vdpa_svqs_stop(dev);
>>>> if (unlikely(!ok)) {
>>>> return -1;
>>>> @@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
>>>> memory_listener_register(&v->listener, &address_space_memory);
>>>> return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>>>> } else {
>>>> - vhost_vdpa_reset_device(dev);
>>>> - vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>>>> - VIRTIO_CONFIG_S_DRIVER);
>>>> memory_listener_unregister(&v->listener);
>>>>
>>>> return 0;
>>>> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
>>>> index b643f42..7e0cdb6 100644
>>>> --- a/hw/virtio/vhost.c
>>>> +++ b/hw/virtio/vhost.c
>>>> @@ -1820,7 +1820,6 @@ fail_features:
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev)
>>>> {
>>>> int i;
>>>> -
>>>
>>> Unnecessary changes.
>>>
>>>> /* should only be called after backend is connected */
>>>> assert(hdev->vhost_ops);
>>>>
>>>> @@ -1854,3 +1853,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>>>>
>>>> return -ENOSYS;
>>>> }
>>>> +
>>>> +int vhost_dev_reset(struct vhost_dev *hdev)
>>>> +{
>>>
>>> Let's use a separate patch for this.
>>>
>>> Thanks
>>>
>>>> + int ret = 0;
>>>> +
>>>> + /* should only be called after backend is connected */
>>>> + assert(hdev->vhost_ops);
>>>> +
>>>> + if (hdev->vhost_ops->vhost_reset_device) {
>>>> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
>>>> + }
>>>> +
>>>> + return ret;
>>>> +}
>>>> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
>>>> index 58a73e7..b8b7c20 100644
>>>> --- a/include/hw/virtio/vhost.h
>>>> +++ b/include/hw/virtio/vhost.h
>>>> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
>>>> void vhost_dev_cleanup(struct vhost_dev *hdev);
>>>> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> +int vhost_dev_reset(struct vhost_dev *hdev);
>>>> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>>>>
>>>> --
>>>> 1.8.3.1
>>>>
>>>>
>>>>
>>>
>>>
>>>
>>
>>
>>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread
* [PATCH 0/3] Refactor vhost device reset
2022-04-01 1:31 ` [PATCH v4] " Michael Qiu
2022-04-01 2:53 ` Jason Wang
@ 2022-04-01 11:06 ` Michael Qiu
2022-04-01 11:06 ` [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps Michael Qiu
` (2 more replies)
1 sibling, 3 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 11:06 UTC (permalink / raw)
To: jasowang, mst, si-wei.liu
Cc: Michael Qiu, eperezma, lingshan.zhu, qemu-devel, lulu
Now adays, vhost framework does a misnamed for
vhost_reset_device(), actually we need seperate vhost_reset_device()
and vhost_reset_owner(), this patchset refactor it, and make different
backend call the right function.
Base on those work, fix an issue of vdpa device reset for several times.
Test with kernel vhost, vhost-vdpa, DPDK vhost-user(vdpa), with shutdown
,reboot, and load/unload virtio_net driver in guest.
Michael Qiu (3):
vhost: Refactor vhost_reset_device() in VhostOps
vhost: add vhost_dev_reset()
vdpa: reset the backend device in the end of vhost_net_stop()
hw/net/vhost_net.c | 22 +++++++++++++++++++---
hw/scsi/vhost-user-scsi.c | 6 +++++-
hw/virtio/vhost-backend.c | 4 ++--
hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
hw/virtio/vhost-vdpa.c | 15 +++++++++------
hw/virtio/vhost.c | 14 ++++++++++++++
include/hw/virtio/vhost-backend.h | 2 ++
include/hw/virtio/vhost.h | 1 +
8 files changed, 70 insertions(+), 16 deletions(-)
--
1.8.3.1
^ permalink raw reply [flat|nested] 47+ messages in thread* [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-01 11:06 ` [PATCH 0/3] Refactor vhost device reset Michael Qiu
@ 2022-04-01 11:06 ` Michael Qiu
2022-04-02 0:44 ` Si-Wei Liu
2022-04-02 2:38 ` Jason Wang
2022-04-01 11:06 ` [PATCH 2/3] vhost: add vhost_dev_reset() Michael Qiu
2022-04-01 11:06 ` [PATCH 3/3 v5] vdpa: reset the backend device in the end of vhost_net_stop() Michael Qiu
2 siblings, 2 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 11:06 UTC (permalink / raw)
To: jasowang, mst, si-wei.liu
Cc: Michael Qiu, eperezma, lingshan.zhu, qemu-devel, lulu
Currently in vhost framwork, vhost_reset_device() is misnamed.
Actually, it should be vhost_reset_owner().
In vhost user, it make compatible with reset device ops, but
vhost kernel does not compatible with it, for vhost vdpa, it
only implement reset device action.
So we need seperate the function into vhost_reset_owner() and
vhost_reset_device(). So that different backend could use the
correct function.
Signde-off-by: Michael Qiu <qiudayu@archeros.com>
---
hw/scsi/vhost-user-scsi.c | 6 +++++-
hw/virtio/vhost-backend.c | 4 ++--
hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
include/hw/virtio/vhost-backend.h | 2 ++
4 files changed, 27 insertions(+), 7 deletions(-)
diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
index 1b2f7ee..f179626 100644
--- a/hw/scsi/vhost-user-scsi.c
+++ b/hw/scsi/vhost-user-scsi.c
@@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
return;
}
- if (dev->vhost_ops->vhost_reset_device) {
+ if (virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
+ dev->vhost_ops->vhost_reset_device) {
dev->vhost_ops->vhost_reset_device(dev);
+ } else if (dev->vhost_ops->vhost_reset_owner) {
+ dev->vhost_ops->vhost_reset_owner(dev);
}
}
diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
index e409a86..abbaa8b 100644
--- a/hw/virtio/vhost-backend.c
+++ b/hw/virtio/vhost-backend.c
@@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev *dev)
return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
}
-static int vhost_kernel_reset_device(struct vhost_dev *dev)
+static int vhost_kernel_reset_owner(struct vhost_dev *dev)
{
return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
}
@@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
.vhost_get_features = vhost_kernel_get_features,
.vhost_set_backend_cap = vhost_kernel_set_backend_cap,
.vhost_set_owner = vhost_kernel_set_owner,
- .vhost_reset_device = vhost_kernel_reset_device,
+ .vhost_reset_owner = vhost_kernel_reset_owner,
.vhost_get_vq_index = vhost_kernel_get_vq_index,
#ifdef CONFIG_VHOST_VSOCK
.vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
index 6abbc9d..4412008 100644
--- a/hw/virtio/vhost-user.c
+++ b/hw/virtio/vhost-user.c
@@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct vhost_dev *dev,
return 0;
}
+static int vhost_user_reset_owner(struct vhost_dev *dev)
+{
+ VhostUserMsg msg = {
+ .hdr.request = VHOST_USER_RESET_OWNER,
+ .hdr.flags = VHOST_USER_VERSION,
+ };
+
+ return vhost_user_write(dev, &msg, NULL, 0);
+}
+
static int vhost_user_reset_device(struct vhost_dev *dev)
{
VhostUserMsg msg = {
+ .hdr.request = VHOST_USER_RESET_DEVICE,
.hdr.flags = VHOST_USER_VERSION,
};
- msg.hdr.request = virtio_has_feature(dev->protocol_features,
- VHOST_USER_PROTOCOL_F_RESET_DEVICE)
- ? VHOST_USER_RESET_DEVICE
- : VHOST_USER_RESET_OWNER;
+ /* Caller must ensure the backend has VHOST_USER_PROTOCOL_F_RESET_DEVICE
+ * support */
+ if (!virtio_has_feature(dev->protocol_features,
+ VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
+ return -EPERM;
+ }
return vhost_user_write(dev, &msg, NULL, 0);
}
@@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
.vhost_set_features = vhost_user_set_features,
.vhost_get_features = vhost_user_get_features,
.vhost_set_owner = vhost_user_set_owner,
+ .vhost_reset_owner = vhost_user_reset_owner,
.vhost_reset_device = vhost_user_reset_device,
.vhost_get_vq_index = vhost_user_get_vq_index,
.vhost_set_vring_enable = vhost_user_set_vring_enable,
diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
index 81bf310..affeeb0 100644
--- a/include/hw/virtio/vhost-backend.h
+++ b/include/hw/virtio/vhost-backend.h
@@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
uint64_t *features);
typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
+typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
@@ -150,6 +151,7 @@ typedef struct VhostOps {
vhost_get_features_op vhost_get_features;
vhost_set_backend_cap_op vhost_set_backend_cap;
vhost_set_owner_op vhost_set_owner;
+ vhost_reset_owner_op vhost_reset_owner;
vhost_reset_device_op vhost_reset_device;
vhost_get_vq_index_op vhost_get_vq_index;
vhost_set_vring_enable_op vhost_set_vring_enable;
--
1.8.3.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-01 11:06 ` [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps Michael Qiu
@ 2022-04-02 0:44 ` Si-Wei Liu
2022-04-02 2:08 ` Michael Qiu
2022-04-02 2:38 ` Jason Wang
1 sibling, 1 reply; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-02 0:44 UTC (permalink / raw)
To: Michael Qiu, jasowang, mst; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 4/1/2022 4:06 AM, Michael Qiu wrote:
> Currently in vhost framwork, vhost_reset_device() is misnamed.
> Actually, it should be vhost_reset_owner().
>
> In vhost user, it make compatible with reset device ops, but
> vhost kernel does not compatible with it, for vhost vdpa, it
> only implement reset device action.
>
> So we need seperate the function into vhost_reset_owner() and
> vhost_reset_device(). So that different backend could use the
> correct function.
>
> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
> ---
> hw/scsi/vhost-user-scsi.c | 6 +++++-
> hw/virtio/vhost-backend.c | 4 ++--
> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
> include/hw/virtio/vhost-backend.h | 2 ++
> 4 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> index 1b2f7ee..f179626 100644
> --- a/hw/scsi/vhost-user-scsi.c
> +++ b/hw/scsi/vhost-user-scsi.c
> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
> return;
> }
>
> - if (dev->vhost_ops->vhost_reset_device) {
> + if (virtio_has_feature(dev->protocol_features,
> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
This line change is not needed. VHOST_USER_PROTOCOL_F_RESET_DEVICE is
guaranteed to be available if getting here.
> + dev->vhost_ops->vhost_reset_device) {
> dev->vhost_ops->vhost_reset_device(dev);
> + } else if (dev->vhost_ops->vhost_reset_owner) {
> + dev->vhost_ops->vhost_reset_owner(dev);
Nope, drop these two lines. The caller of vhost_user_scsi_reset()
doesn't expect vhost_reset_owner to be called in case vhost_reset_device
is not implemented.
> }
> }
>
> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> index e409a86..abbaa8b 100644
> --- a/hw/virtio/vhost-backend.c
> +++ b/hw/virtio/vhost-backend.c
> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev *dev)
> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
> }
>
> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
> {
> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
> }
> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
> .vhost_get_features = vhost_kernel_get_features,
> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
> .vhost_set_owner = vhost_kernel_set_owner,
> - .vhost_reset_device = vhost_kernel_reset_device,
> + .vhost_reset_owner = vhost_kernel_reset_owner,
> .vhost_get_vq_index = vhost_kernel_get_vq_index,
> #ifdef CONFIG_VHOST_VSOCK
> .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 6abbc9d..4412008 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct vhost_dev *dev,
> return 0;
> }
>
> +static int vhost_user_reset_owner(struct vhost_dev *dev)
> +{
> + VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_RESET_OWNER,
> + .hdr.flags = VHOST_USER_VERSION,
> + };
> +
> + return vhost_user_write(dev, &msg, NULL, 0);
> +}
> +
> static int vhost_user_reset_device(struct vhost_dev *dev)
> {
> VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_RESET_DEVICE,
> .hdr.flags = VHOST_USER_VERSION,
> };
>
> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
> - ? VHOST_USER_RESET_DEVICE
> - : VHOST_USER_RESET_OWNER;
> + /* Caller must ensure the backend has VHOST_USER_PROTOCOL_F_RESET_DEVICE
> + * support */
> + if (!virtio_has_feature(dev->protocol_features,
> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
> + return -EPERM;
> + }
I think we can safely remove this check, since the caller already
guarantees VHOST_USER_PROTOCOL_F_RESET_DEVICE is around as what your
comment mentions.
The previous branch condition is to reuse the vhost_reset_device op for
two different ends, but there's no actual user for
VHOST_USER_RESET_OWNER historically.
Thanks,
-Siwei
>
> return vhost_user_write(dev, &msg, NULL, 0);
> }
> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
> .vhost_set_features = vhost_user_set_features,
> .vhost_get_features = vhost_user_get_features,
> .vhost_set_owner = vhost_user_set_owner,
> + .vhost_reset_owner = vhost_user_reset_owner,
> .vhost_reset_device = vhost_user_reset_device,
> .vhost_get_vq_index = vhost_user_get_vq_index,
> .vhost_set_vring_enable = vhost_user_set_vring_enable,
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 81bf310..affeeb0 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
> uint64_t *features);
> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
> @@ -150,6 +151,7 @@ typedef struct VhostOps {
> vhost_get_features_op vhost_get_features;
> vhost_set_backend_cap_op vhost_set_backend_cap;
> vhost_set_owner_op vhost_set_owner;
> + vhost_reset_owner_op vhost_reset_owner;
> vhost_reset_device_op vhost_reset_device;
> vhost_get_vq_index_op vhost_get_vq_index;
> vhost_set_vring_enable_op vhost_set_vring_enable;
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-02 0:44 ` Si-Wei Liu
@ 2022-04-02 2:08 ` Michael Qiu
0 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-02 2:08 UTC (permalink / raw)
To: Si-Wei Liu, jasowang, mst; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 2022/4/2 8:44, Si-Wei Liu wrote:
>
>
> On 4/1/2022 4:06 AM, Michael Qiu wrote:
>> Currently in vhost framwork, vhost_reset_device() is misnamed.
>> Actually, it should be vhost_reset_owner().
>>
>> In vhost user, it make compatible with reset device ops, but
>> vhost kernel does not compatible with it, for vhost vdpa, it
>> only implement reset device action.
>>
>> So we need seperate the function into vhost_reset_owner() and
>> vhost_reset_device(). So that different backend could use the
>> correct function.
>>
>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
>> ---
>> hw/scsi/vhost-user-scsi.c | 6 +++++-
>> hw/virtio/vhost-backend.c | 4 ++--
>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
>> include/hw/virtio/vhost-backend.h | 2 ++
>> 4 files changed, 27 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>> index 1b2f7ee..f179626 100644
>> --- a/hw/scsi/vhost-user-scsi.c
>> +++ b/hw/scsi/vhost-user-scsi.c
>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
>> return;
>> }
>> - if (dev->vhost_ops->vhost_reset_device) {
>> + if (virtio_has_feature(dev->protocol_features,
>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
> This line change is not needed. VHOST_USER_PROTOCOL_F_RESET_DEVICE is
> guaranteed to be available if getting here.
>> + dev->vhost_ops->vhost_reset_device) {
>> dev->vhost_ops->vhost_reset_device(dev);
>> + } else if (dev->vhost_ops->vhost_reset_owner) {
>> + dev->vhost_ops->vhost_reset_owner(dev);
> Nope, drop these two lines. The caller of vhost_user_scsi_reset()
> doesn't expect vhost_reset_owner to be called in case vhost_reset_device
> is not implemented.
>
You are right, I will drop these two lines and remove
VHOST_USER_PROTOCOL_F_RESET_DEVICE check.
>> }
>> }
>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
>> index e409a86..abbaa8b 100644
>> --- a/hw/virtio/vhost-backend.c
>> +++ b/hw/virtio/vhost-backend.c
>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev
>> *dev)
>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
>> }
>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
>> {
>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
>> }
>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
>> .vhost_get_features = vhost_kernel_get_features,
>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
>> .vhost_set_owner = vhost_kernel_set_owner,
>> - .vhost_reset_device = vhost_kernel_reset_device,
>> + .vhost_reset_owner = vhost_kernel_reset_owner,
>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
>> #ifdef CONFIG_VHOST_VSOCK
>> .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
>> index 6abbc9d..4412008 100644
>> --- a/hw/virtio/vhost-user.c
>> +++ b/hw/virtio/vhost-user.c
>> @@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct
>> vhost_dev *dev,
>> return 0;
>> }
>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
>> +{
>> + VhostUserMsg msg = {
>> + .hdr.request = VHOST_USER_RESET_OWNER,
>> + .hdr.flags = VHOST_USER_VERSION,
>> + };
>> +
>> + return vhost_user_write(dev, &msg, NULL, 0);
>> +}
>> +
>> static int vhost_user_reset_device(struct vhost_dev *dev)
>> {
>> VhostUserMsg msg = {
>> + .hdr.request = VHOST_USER_RESET_DEVICE,
>> .hdr.flags = VHOST_USER_VERSION,
>> };
>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
>> -
>> VHOST_USER_PROTOCOL_F_RESET_DEVICE)
>> - ? VHOST_USER_RESET_DEVICE
>> - : VHOST_USER_RESET_OWNER;
>> + /* Caller must ensure the backend has
>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
>> + * support */
>> + if (!virtio_has_feature(dev->protocol_features,
>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
>> + return -EPERM;
>> + }
> I think we can safely remove this check, since the caller already
> guarantees VHOST_USER_PROTOCOL_F_RESET_DEVICE is around as what your
> comment mentions.
>
I think it probely worth to check, because for vhost_net_stop() it does
not check this flag, otherwise we should check if the backend is vhost
user with this flag enabled.
> The previous branch condition is to reuse the vhost_reset_device op for
> two different ends, but there's no actual user for
> VHOST_USER_RESET_OWNER historically.
>
> Thanks,
> -Siwei
>
>> return vhost_user_write(dev, &msg, NULL, 0);
>> }
>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
>> .vhost_set_features = vhost_user_set_features,
>> .vhost_get_features = vhost_user_get_features,
>> .vhost_set_owner = vhost_user_set_owner,
>> + .vhost_reset_owner = vhost_user_reset_owner,
>> .vhost_reset_device = vhost_user_reset_device,
>> .vhost_get_vq_index = vhost_user_get_vq_index,
>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
>> diff --git a/include/hw/virtio/vhost-backend.h
>> b/include/hw/virtio/vhost-backend.h
>> index 81bf310..affeeb0 100644
>> --- a/include/hw/virtio/vhost-backend.h
>> +++ b/include/hw/virtio/vhost-backend.h
>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
>> vhost_dev *dev,
>> uint64_t *features);
>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
>> vhost_get_features_op vhost_get_features;
>> vhost_set_backend_cap_op vhost_set_backend_cap;
>> vhost_set_owner_op vhost_set_owner;
>> + vhost_reset_owner_op vhost_reset_owner;
>> vhost_reset_device_op vhost_reset_device;
>> vhost_get_vq_index_op vhost_get_vq_index;
>> vhost_set_vring_enable_op vhost_set_vring_enable;
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread
* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-01 11:06 ` [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps Michael Qiu
2022-04-02 0:44 ` Si-Wei Liu
@ 2022-04-02 2:38 ` Jason Wang
2022-04-02 5:14 ` Michael Qiu
[not found] ` <6247dc22.1c69fb81.4244.a88bSMTPIN_ADDED_BROKEN@mx.google.com>
1 sibling, 2 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-02 2:38 UTC (permalink / raw)
To: Michael Qiu, mst, si-wei.liu; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
在 2022/4/1 下午7:06, Michael Qiu 写道:
> Currently in vhost framwork, vhost_reset_device() is misnamed.
> Actually, it should be vhost_reset_owner().
>
> In vhost user, it make compatible with reset device ops, but
> vhost kernel does not compatible with it, for vhost vdpa, it
> only implement reset device action.
>
> So we need seperate the function into vhost_reset_owner() and
> vhost_reset_device(). So that different backend could use the
> correct function.
I see no reason when RESET_OWNER needs to be done for kernel backend.
And if I understand the code correctly, vhost-user "abuse" RESET_OWNER
for reset. So the current code looks fine?
>
> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
> ---
> hw/scsi/vhost-user-scsi.c | 6 +++++-
> hw/virtio/vhost-backend.c | 4 ++--
> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
> include/hw/virtio/vhost-backend.h | 2 ++
> 4 files changed, 27 insertions(+), 7 deletions(-)
>
> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> index 1b2f7ee..f179626 100644
> --- a/hw/scsi/vhost-user-scsi.c
> +++ b/hw/scsi/vhost-user-scsi.c
> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
> return;
> }
>
> - if (dev->vhost_ops->vhost_reset_device) {
> + if (virtio_has_feature(dev->protocol_features,
> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
> + dev->vhost_ops->vhost_reset_device) {
> dev->vhost_ops->vhost_reset_device(dev);
> + } else if (dev->vhost_ops->vhost_reset_owner) {
> + dev->vhost_ops->vhost_reset_owner(dev);
Actually, I fail to understand why we need an indirection via vhost_ops.
It's guaranteed to be vhost_user_ops.
> }
> }
>
> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> index e409a86..abbaa8b 100644
> --- a/hw/virtio/vhost-backend.c
> +++ b/hw/virtio/vhost-backend.c
> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev *dev)
> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
> }
>
> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
> {
> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
> }
> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
> .vhost_get_features = vhost_kernel_get_features,
> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
> .vhost_set_owner = vhost_kernel_set_owner,
> - .vhost_reset_device = vhost_kernel_reset_device,
> + .vhost_reset_owner = vhost_kernel_reset_owner,
I think we can delete the current vhost_reset_device() since it not used
in any code path.
Thanks
> .vhost_get_vq_index = vhost_kernel_get_vq_index,
> #ifdef CONFIG_VHOST_VSOCK
> .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> index 6abbc9d..4412008 100644
> --- a/hw/virtio/vhost-user.c
> +++ b/hw/virtio/vhost-user.c
> @@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct vhost_dev *dev,
> return 0;
> }
>
> +static int vhost_user_reset_owner(struct vhost_dev *dev)
> +{
> + VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_RESET_OWNER,
> + .hdr.flags = VHOST_USER_VERSION,
> + };
> +
> + return vhost_user_write(dev, &msg, NULL, 0);
> +}
> +
> static int vhost_user_reset_device(struct vhost_dev *dev)
> {
> VhostUserMsg msg = {
> + .hdr.request = VHOST_USER_RESET_DEVICE,
> .hdr.flags = VHOST_USER_VERSION,
> };
>
> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
> - ? VHOST_USER_RESET_DEVICE
> - : VHOST_USER_RESET_OWNER;
> + /* Caller must ensure the backend has VHOST_USER_PROTOCOL_F_RESET_DEVICE
> + * support */
> + if (!virtio_has_feature(dev->protocol_features,
> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
> + return -EPERM;
> + }
>
> return vhost_user_write(dev, &msg, NULL, 0);
> }
> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
> .vhost_set_features = vhost_user_set_features,
> .vhost_get_features = vhost_user_get_features,
> .vhost_set_owner = vhost_user_set_owner,
> + .vhost_reset_owner = vhost_user_reset_owner,
> .vhost_reset_device = vhost_user_reset_device,
> .vhost_get_vq_index = vhost_user_get_vq_index,
> .vhost_set_vring_enable = vhost_user_set_vring_enable,
> diff --git a/include/hw/virtio/vhost-backend.h b/include/hw/virtio/vhost-backend.h
> index 81bf310..affeeb0 100644
> --- a/include/hw/virtio/vhost-backend.h
> +++ b/include/hw/virtio/vhost-backend.h
> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct vhost_dev *dev,
> uint64_t *features);
> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
> @@ -150,6 +151,7 @@ typedef struct VhostOps {
> vhost_get_features_op vhost_get_features;
> vhost_set_backend_cap_op vhost_set_backend_cap;
> vhost_set_owner_op vhost_set_owner;
> + vhost_reset_owner_op vhost_reset_owner;
> vhost_reset_device_op vhost_reset_device;
> vhost_get_vq_index_op vhost_get_vq_index;
> vhost_set_vring_enable_op vhost_set_vring_enable;
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-02 2:38 ` Jason Wang
@ 2022-04-02 5:14 ` Michael Qiu
[not found] ` <6247dc22.1c69fb81.4244.a88bSMTPIN_ADDED_BROKEN@mx.google.com>
1 sibling, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-02 5:14 UTC (permalink / raw)
To: Jason Wang, mst, si-wei.liu; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 2022/4/2 10:38, Jason Wang wrote:
>
> 在 2022/4/1 下午7:06, Michael Qiu 写道:
>> Currently in vhost framwork, vhost_reset_device() is misnamed.
>> Actually, it should be vhost_reset_owner().
>>
>> In vhost user, it make compatible with reset device ops, but
>> vhost kernel does not compatible with it, for vhost vdpa, it
>> only implement reset device action.
>>
>> So we need seperate the function into vhost_reset_owner() and
>> vhost_reset_device(). So that different backend could use the
>> correct function.
>
>
> I see no reason when RESET_OWNER needs to be done for kernel backend.
>
In kernel vhost, RESET_OWNER indeed do vhost device level reset:
vhost_net_reset_owner()
static long vhost_net_reset_owner(struct vhost_net *n)
{
[...]
err = vhost_dev_check_owner(&n->dev);
if (err)
goto done;
umem = vhost_dev_reset_owner_prepare();
if (!umem) {
err = -ENOMEM;
goto done;
}
vhost_net_stop(n, &tx_sock, &rx_sock);
vhost_net_flush(n);
vhost_dev_stop(&n->dev);
vhost_dev_reset_owner(&n->dev, umem);
vhost_net_vq_reset(n);
[...]
}
In the history of QEMU, There is a commit:
commit d1f8b30ec8dde0318fd1b98d24a64926feae9625
Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Date: Wed Sep 23 12:19:57 2015 +0800
vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
Quote from Michael:
We really should rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE.
but finally, it has been reverted by the author:
commit 60915dc4691768c4dc62458bb3e16c843fab091d
Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
Date: Wed Nov 11 21:24:37 2015 +0800
vhost: rename RESET_DEVICE backto RESET_OWNER
This patch basically reverts commit d1f8b30e.
It turned out that it breaks stuff, so revert it:
http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html
Seems kernel take RESET_OWNER for reset,but QEMU never call to this
function to do a reset.
> And if I understand the code correctly, vhost-user "abuse" RESET_OWNER
> for reset. So the current code looks fine?
>
>
>>
>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
>> ---
>> hw/scsi/vhost-user-scsi.c | 6 +++++-
>> hw/virtio/vhost-backend.c | 4 ++--
>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
>> include/hw/virtio/vhost-backend.h | 2 ++
>> 4 files changed, 27 insertions(+), 7 deletions(-)
>>
>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>> index 1b2f7ee..f179626 100644
>> --- a/hw/scsi/vhost-user-scsi.c
>> +++ b/hw/scsi/vhost-user-scsi.c
>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice *vdev)
>> return;
>> }
>> - if (dev->vhost_ops->vhost_reset_device) {
>> + if (virtio_has_feature(dev->protocol_features,
>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
>> + dev->vhost_ops->vhost_reset_device) {
>> dev->vhost_ops->vhost_reset_device(dev);
>> + } else if (dev->vhost_ops->vhost_reset_owner) {
>> + dev->vhost_ops->vhost_reset_owner(dev);
>
>
> Actually, I fail to understand why we need an indirection via vhost_ops.
> It's guaranteed to be vhost_user_ops.
>
>
>> }
>> }
>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
>> index e409a86..abbaa8b 100644
>> --- a/hw/virtio/vhost-backend.c
>> +++ b/hw/virtio/vhost-backend.c
>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct vhost_dev
>> *dev)
>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
>> }
>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
>> {
>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
>> }
>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
>> .vhost_get_features = vhost_kernel_get_features,
>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
>> .vhost_set_owner = vhost_kernel_set_owner,
>> - .vhost_reset_device = vhost_kernel_reset_device,
>> + .vhost_reset_owner = vhost_kernel_reset_owner,
>
>
> I think we can delete the current vhost_reset_device() since it not used
> in any code path.
>
I planned to use it for vDPA reset, and vhost-user-scsi also use device
reset.
Thanks,
Michael
> Thanks
>
>
>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
>> #ifdef CONFIG_VHOST_VSOCK
>> .vhost_vsock_set_guest_cid = vhost_kernel_vsock_set_guest_cid,
>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
>> index 6abbc9d..4412008 100644
>> --- a/hw/virtio/vhost-user.c
>> +++ b/hw/virtio/vhost-user.c
>> @@ -1475,16 +1475,29 @@ static int vhost_user_get_max_memslots(struct
>> vhost_dev *dev,
>> return 0;
>> }
>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
>> +{
>> + VhostUserMsg msg = {
>> + .hdr.request = VHOST_USER_RESET_OWNER,
>> + .hdr.flags = VHOST_USER_VERSION,
>> + };
>> +
>> + return vhost_user_write(dev, &msg, NULL, 0);
>> +}
>> +
>> static int vhost_user_reset_device(struct vhost_dev *dev)
>> {
>> VhostUserMsg msg = {
>> + .hdr.request = VHOST_USER_RESET_DEVICE,
>> .hdr.flags = VHOST_USER_VERSION,
>> };
>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
>> -
>> VHOST_USER_PROTOCOL_F_RESET_DEVICE)
>> - ? VHOST_USER_RESET_DEVICE
>> - : VHOST_USER_RESET_OWNER;
>> + /* Caller must ensure the backend has
>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
>> + * support */
>> + if (!virtio_has_feature(dev->protocol_features,
>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
>> + return -EPERM;
>> + }
>> return vhost_user_write(dev, &msg, NULL, 0);
>> }
>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
>> .vhost_set_features = vhost_user_set_features,
>> .vhost_get_features = vhost_user_get_features,
>> .vhost_set_owner = vhost_user_set_owner,
>> + .vhost_reset_owner = vhost_user_reset_owner,
>> .vhost_reset_device = vhost_user_reset_device,
>> .vhost_get_vq_index = vhost_user_get_vq_index,
>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
>> diff --git a/include/hw/virtio/vhost-backend.h
>> b/include/hw/virtio/vhost-backend.h
>> index 81bf310..affeeb0 100644
>> --- a/include/hw/virtio/vhost-backend.h
>> +++ b/include/hw/virtio/vhost-backend.h
>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
>> vhost_dev *dev,
>> uint64_t *features);
>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
>> vhost_get_features_op vhost_get_features;
>> vhost_set_backend_cap_op vhost_set_backend_cap;
>> vhost_set_owner_op vhost_set_owner;
>> + vhost_reset_owner_op vhost_reset_owner;
>> vhost_reset_device_op vhost_reset_device;
>> vhost_get_vq_index_op vhost_get_vq_index;
>> vhost_set_vring_enable_op vhost_set_vring_enable;
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread[parent not found: <6247dc22.1c69fb81.4244.a88bSMTPIN_ADDED_BROKEN@mx.google.com>]
* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
[not found] ` <6247dc22.1c69fb81.4244.a88bSMTPIN_ADDED_BROKEN@mx.google.com>
@ 2022-04-07 7:35 ` Jason Wang
2022-04-08 8:38 ` Michael Qiu
0 siblings, 1 reply; 47+ messages in thread
From: Jason Wang @ 2022-04-07 7:35 UTC (permalink / raw)
To: qemu-devel, Michael Qiu
Cc: Si-Wei Liu, Eugenio Perez Martin, Zhu, Lingshan, Cindy Lu
在 2022/4/2 下午1:14, Michael Qiu 写道:
>
>
> On 2022/4/2 10:38, Jason Wang wrote:
>>
>> 在 2022/4/1 下午7:06, Michael Qiu 写道:
>>> Currently in vhost framwork, vhost_reset_device() is misnamed.
>>> Actually, it should be vhost_reset_owner().
>>>
>>> In vhost user, it make compatible with reset device ops, but
>>> vhost kernel does not compatible with it, for vhost vdpa, it
>>> only implement reset device action.
>>>
>>> So we need seperate the function into vhost_reset_owner() and
>>> vhost_reset_device(). So that different backend could use the
>>> correct function.
>>
>>
>> I see no reason when RESET_OWNER needs to be done for kernel backend.
>>
>
> In kernel vhost, RESET_OWNER indeed do vhost device level reset:
> vhost_net_reset_owner()
>
> static long vhost_net_reset_owner(struct vhost_net *n)
> {
> [...]
> err = vhost_dev_check_owner(&n->dev);
> if (err)
> goto done;
> umem = vhost_dev_reset_owner_prepare();
> if (!umem) {
> err = -ENOMEM;
> goto done;
> }
> vhost_net_stop(n, &tx_sock, &rx_sock);
> vhost_net_flush(n);
> vhost_dev_stop(&n->dev);
> vhost_dev_reset_owner(&n->dev, umem);
> vhost_net_vq_reset(n);
> [...]
>
> }
>
> In the history of QEMU, There is a commit:
> commit d1f8b30ec8dde0318fd1b98d24a64926feae9625
> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Date: Wed Sep 23 12:19:57 2015 +0800
>
> vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
>
> Quote from Michael:
>
> We really should rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE.
>
> but finally, it has been reverted by the author:
> commit 60915dc4691768c4dc62458bb3e16c843fab091d
> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> Date: Wed Nov 11 21:24:37 2015 +0800
>
> vhost: rename RESET_DEVICE backto RESET_OWNER
>
> This patch basically reverts commit d1f8b30e.
>
> It turned out that it breaks stuff, so revert it:
>
> http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html
>
> Seems kernel take RESET_OWNER for reset,but QEMU never call to this
> function to do a reset.
The question is, we manage to survive by not using RESET_OWNER for past
10 years. Any reason that we want to use that now?
Note that the RESET_OWNER is only useful the process want to drop the
its mm refcnt from vhost, it doesn't reset the device (e.g it does not
even call vhost_vq_reset()).
(Especially, it was deprecated in by the vhost-user protocol since its
semantics is ambiguous)
>
>> And if I understand the code correctly, vhost-user "abuse"
>> RESET_OWNER for reset. So the current code looks fine?
>>
>>
>>>
>>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
>>> ---
>>> hw/scsi/vhost-user-scsi.c | 6 +++++-
>>> hw/virtio/vhost-backend.c | 4 ++--
>>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
>>> include/hw/virtio/vhost-backend.h | 2 ++
>>> 4 files changed, 27 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>>> index 1b2f7ee..f179626 100644
>>> --- a/hw/scsi/vhost-user-scsi.c
>>> +++ b/hw/scsi/vhost-user-scsi.c
>>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice
>>> *vdev)
>>> return;
>>> }
>>> - if (dev->vhost_ops->vhost_reset_device) {
>>> + if (virtio_has_feature(dev->protocol_features,
>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
>>> + dev->vhost_ops->vhost_reset_device) {
>>> dev->vhost_ops->vhost_reset_device(dev);
>>> + } else if (dev->vhost_ops->vhost_reset_owner) {
>>> + dev->vhost_ops->vhost_reset_owner(dev);
>>
>>
>> Actually, I fail to understand why we need an indirection via
>> vhost_ops. It's guaranteed to be vhost_user_ops.
>>
>>
>>> }
>>> }
>>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
>>> index e409a86..abbaa8b 100644
>>> --- a/hw/virtio/vhost-backend.c
>>> +++ b/hw/virtio/vhost-backend.c
>>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct
>>> vhost_dev *dev)
>>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
>>> }
>>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
>>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
>>> {
>>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
>>> }
>>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
>>> .vhost_get_features = vhost_kernel_get_features,
>>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
>>> .vhost_set_owner = vhost_kernel_set_owner,
>>> - .vhost_reset_device = vhost_kernel_reset_device,
>>> + .vhost_reset_owner = vhost_kernel_reset_owner,
>>
>>
>> I think we can delete the current vhost_reset_device() since it not
>> used in any code path.
>>
>
> I planned to use it for vDPA reset,
For vhost-vDPA it can call vhost_vdpa_reset_device() directly.
As I mentioned before, the only user of vhost_reset_device config ops is
vhost-user-scsi but it should directly call the vhost_user_reset_device().
Thanks
> and vhost-user-scsi also use device reset.
>
> Thanks,
> Michael
>
>> Thanks
>>
>>
>>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
>>> #ifdef CONFIG_VHOST_VSOCK
>>> .vhost_vsock_set_guest_cid =
>>> vhost_kernel_vsock_set_guest_cid,
>>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
>>> index 6abbc9d..4412008 100644
>>> --- a/hw/virtio/vhost-user.c
>>> +++ b/hw/virtio/vhost-user.c
>>> @@ -1475,16 +1475,29 @@ static int
>>> vhost_user_get_max_memslots(struct vhost_dev *dev,
>>> return 0;
>>> }
>>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
>>> +{
>>> + VhostUserMsg msg = {
>>> + .hdr.request = VHOST_USER_RESET_OWNER,
>>> + .hdr.flags = VHOST_USER_VERSION,
>>> + };
>>> +
>>> + return vhost_user_write(dev, &msg, NULL, 0);
>>> +}
>>> +
>>> static int vhost_user_reset_device(struct vhost_dev *dev)
>>> {
>>> VhostUserMsg msg = {
>>> + .hdr.request = VHOST_USER_RESET_DEVICE,
>>> .hdr.flags = VHOST_USER_VERSION,
>>> };
>>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
>>> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
>>> - ? VHOST_USER_RESET_DEVICE
>>> - : VHOST_USER_RESET_OWNER;
>>> + /* Caller must ensure the backend has
>>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
>>> + * support */
>>> + if (!virtio_has_feature(dev->protocol_features,
>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
>>> + return -EPERM;
>>> + }
>>> return vhost_user_write(dev, &msg, NULL, 0);
>>> }
>>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
>>> .vhost_set_features = vhost_user_set_features,
>>> .vhost_get_features = vhost_user_get_features,
>>> .vhost_set_owner = vhost_user_set_owner,
>>> + .vhost_reset_owner = vhost_user_reset_owner,
>>> .vhost_reset_device = vhost_user_reset_device,
>>> .vhost_get_vq_index = vhost_user_get_vq_index,
>>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
>>> diff --git a/include/hw/virtio/vhost-backend.h
>>> b/include/hw/virtio/vhost-backend.h
>>> index 81bf310..affeeb0 100644
>>> --- a/include/hw/virtio/vhost-backend.h
>>> +++ b/include/hw/virtio/vhost-backend.h
>>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
>>> vhost_dev *dev,
>>> uint64_t *features);
>>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
>>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
>>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
>>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
>>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
>>> vhost_get_features_op vhost_get_features;
>>> vhost_set_backend_cap_op vhost_set_backend_cap;
>>> vhost_set_owner_op vhost_set_owner;
>>> + vhost_reset_owner_op vhost_reset_owner;
>>> vhost_reset_device_op vhost_reset_device;
>>> vhost_get_vq_index_op vhost_get_vq_index;
>>> vhost_set_vring_enable_op vhost_set_vring_enable;
>>
>>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-07 7:35 ` Jason Wang
@ 2022-04-08 8:38 ` Michael Qiu
2022-04-08 17:17 ` Si-Wei Liu
0 siblings, 1 reply; 47+ messages in thread
From: Michael Qiu @ 2022-04-08 8:38 UTC (permalink / raw)
To: Jason Wang, qemu-devel
Cc: Si-Wei Liu, Eugenio Perez Martin, Zhu, Lingshan, Cindy Lu
在 2022/4/7 15:35, Jason Wang 写道:
>
> 在 2022/4/2 下午1:14, Michael Qiu 写道:
>>
>>
>> On 2022/4/2 10:38, Jason Wang wrote:
>>>
>>> 在 2022/4/1 下午7:06, Michael Qiu 写道:
>>>> Currently in vhost framwork, vhost_reset_device() is misnamed.
>>>> Actually, it should be vhost_reset_owner().
>>>>
>>>> In vhost user, it make compatible with reset device ops, but
>>>> vhost kernel does not compatible with it, for vhost vdpa, it
>>>> only implement reset device action.
>>>>
>>>> So we need seperate the function into vhost_reset_owner() and
>>>> vhost_reset_device(). So that different backend could use the
>>>> correct function.
>>>
>>>
>>> I see no reason when RESET_OWNER needs to be done for kernel backend.
>>>
>>
>> In kernel vhost, RESET_OWNER indeed do vhost device level reset:
>> vhost_net_reset_owner()
>>
>> static long vhost_net_reset_owner(struct vhost_net *n)
>> {
>> [...]
>> err = vhost_dev_check_owner(&n->dev);
>> if (err)
>> goto done;
>> umem = vhost_dev_reset_owner_prepare();
>> if (!umem) {
>> err = -ENOMEM;
>> goto done;
>> }
>> vhost_net_stop(n, &tx_sock, &rx_sock);
>> vhost_net_flush(n);
>> vhost_dev_stop(&n->dev);
>> vhost_dev_reset_owner(&n->dev, umem);
>> vhost_net_vq_reset(n);
>> [...]
>>
>> }
>>
>> In the history of QEMU, There is a commit:
>> commit d1f8b30ec8dde0318fd1b98d24a64926feae9625
>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>> Date: Wed Sep 23 12:19:57 2015 +0800
>>
>> vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
>>
>> Quote from Michael:
>>
>> We really should rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE.
>>
>> but finally, it has been reverted by the author:
>> commit 60915dc4691768c4dc62458bb3e16c843fab091d
>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>> Date: Wed Nov 11 21:24:37 2015 +0800
>>
>> vhost: rename RESET_DEVICE backto RESET_OWNER
>>
>> This patch basically reverts commit d1f8b30e.
>>
>> It turned out that it breaks stuff, so revert it:
>>
>> http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html
>>
>> Seems kernel take RESET_OWNER for reset,but QEMU never call to this
>> function to do a reset.
>
>
> The question is, we manage to survive by not using RESET_OWNER for past
> 10 years. Any reason that we want to use that now?
>
> Note that the RESET_OWNER is only useful the process want to drop the
> its mm refcnt from vhost, it doesn't reset the device (e.g it does not
> even call vhost_vq_reset()).
>
> (Especially, it was deprecated in by the vhost-user protocol since its
> semantics is ambiguous)
>
>
So, you prefer to directly remove RESET_OWNER support now?
>>
>>> And if I understand the code correctly, vhost-user "abuse"
>>> RESET_OWNER for reset. So the current code looks fine?
>>>
>>>
>>>>
>>>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
>>>> ---
>>>> hw/scsi/vhost-user-scsi.c | 6 +++++-
>>>> hw/virtio/vhost-backend.c | 4 ++--
>>>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
>>>> include/hw/virtio/vhost-backend.h | 2 ++
>>>> 4 files changed, 27 insertions(+), 7 deletions(-)
>>>>
>>>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>>>> index 1b2f7ee..f179626 100644
>>>> --- a/hw/scsi/vhost-user-scsi.c
>>>> +++ b/hw/scsi/vhost-user-scsi.c
>>>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice
>>>> *vdev)
>>>> return;
>>>> }
>>>> - if (dev->vhost_ops->vhost_reset_device) {
>>>> + if (virtio_has_feature(dev->protocol_features,
>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
>>>> + dev->vhost_ops->vhost_reset_device) {
>>>> dev->vhost_ops->vhost_reset_device(dev);
>>>> + } else if (dev->vhost_ops->vhost_reset_owner) {
>>>> + dev->vhost_ops->vhost_reset_owner(dev);
>>>
>>>
>>> Actually, I fail to understand why we need an indirection via
>>> vhost_ops. It's guaranteed to be vhost_user_ops.
>>>
>>>
>>>> }
>>>> }
>>>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
>>>> index e409a86..abbaa8b 100644
>>>> --- a/hw/virtio/vhost-backend.c
>>>> +++ b/hw/virtio/vhost-backend.c
>>>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct
>>>> vhost_dev *dev)
>>>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
>>>> }
>>>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
>>>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
>>>> {
>>>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
>>>> }
>>>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
>>>> .vhost_get_features = vhost_kernel_get_features,
>>>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
>>>> .vhost_set_owner = vhost_kernel_set_owner,
>>>> - .vhost_reset_device = vhost_kernel_reset_device,
>>>> + .vhost_reset_owner = vhost_kernel_reset_owner,
>>>
>>>
>>> I think we can delete the current vhost_reset_device() since it not
>>> used in any code path.
>>>
>>
>> I planned to use it for vDPA reset,
>
>
> For vhost-vDPA it can call vhost_vdpa_reset_device() directly.
>
> As I mentioned before, the only user of vhost_reset_device config ops is
> vhost-user-scsi but it should directly call the vhost_user_reset_device().
>
Yes, but in the next patch I reuse it to reset backend device in vhost_net.
> Thanks
>
>
>> and vhost-user-scsi also use device reset.
>>
>> Thanks,
>> Michael
>>
>>> Thanks
>>>
>>>
>>>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
>>>> #ifdef CONFIG_VHOST_VSOCK
>>>> .vhost_vsock_set_guest_cid =
>>>> vhost_kernel_vsock_set_guest_cid,
>>>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
>>>> index 6abbc9d..4412008 100644
>>>> --- a/hw/virtio/vhost-user.c
>>>> +++ b/hw/virtio/vhost-user.c
>>>> @@ -1475,16 +1475,29 @@ static int
>>>> vhost_user_get_max_memslots(struct vhost_dev *dev,
>>>> return 0;
>>>> }
>>>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
>>>> +{
>>>> + VhostUserMsg msg = {
>>>> + .hdr.request = VHOST_USER_RESET_OWNER,
>>>> + .hdr.flags = VHOST_USER_VERSION,
>>>> + };
>>>> +
>>>> + return vhost_user_write(dev, &msg, NULL, 0);
>>>> +}
>>>> +
>>>> static int vhost_user_reset_device(struct vhost_dev *dev)
>>>> {
>>>> VhostUserMsg msg = {
>>>> + .hdr.request = VHOST_USER_RESET_DEVICE,
>>>> .hdr.flags = VHOST_USER_VERSION,
>>>> };
>>>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
>>>> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
>>>> - ? VHOST_USER_RESET_DEVICE
>>>> - : VHOST_USER_RESET_OWNER;
>>>> + /* Caller must ensure the backend has
>>>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
>>>> + * support */
>>>> + if (!virtio_has_feature(dev->protocol_features,
>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
>>>> + return -EPERM;
>>>> + }
>>>> return vhost_user_write(dev, &msg, NULL, 0);
>>>> }
>>>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
>>>> .vhost_set_features = vhost_user_set_features,
>>>> .vhost_get_features = vhost_user_get_features,
>>>> .vhost_set_owner = vhost_user_set_owner,
>>>> + .vhost_reset_owner = vhost_user_reset_owner,
>>>> .vhost_reset_device = vhost_user_reset_device,
>>>> .vhost_get_vq_index = vhost_user_get_vq_index,
>>>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
>>>> diff --git a/include/hw/virtio/vhost-backend.h
>>>> b/include/hw/virtio/vhost-backend.h
>>>> index 81bf310..affeeb0 100644
>>>> --- a/include/hw/virtio/vhost-backend.h
>>>> +++ b/include/hw/virtio/vhost-backend.h
>>>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
>>>> vhost_dev *dev,
>>>> uint64_t *features);
>>>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
>>>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
>>>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
>>>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>>>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int idx);
>>>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>>>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
>>>> vhost_get_features_op vhost_get_features;
>>>> vhost_set_backend_cap_op vhost_set_backend_cap;
>>>> vhost_set_owner_op vhost_set_owner;
>>>> + vhost_reset_owner_op vhost_reset_owner;
>>>> vhost_reset_device_op vhost_reset_device;
>>>> vhost_get_vq_index_op vhost_get_vq_index;
>>>> vhost_set_vring_enable_op vhost_set_vring_enable;
>>>
>>>
>>
>
>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-08 8:38 ` Michael Qiu
@ 2022-04-08 17:17 ` Si-Wei Liu
2022-04-11 8:51 ` Jason Wang
0 siblings, 1 reply; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-08 17:17 UTC (permalink / raw)
To: Michael Qiu, Jason Wang, qemu-devel
Cc: Eugenio Perez Martin, Zhu, Lingshan, Cindy Lu
On 4/8/2022 1:38 AM, Michael Qiu wrote:
>
>
> 在 2022/4/7 15:35, Jason Wang 写道:
>>
>> 在 2022/4/2 下午1:14, Michael Qiu 写道:
>>>
>>>
>>> On 2022/4/2 10:38, Jason Wang wrote:
>>>>
>>>> 在 2022/4/1 下午7:06, Michael Qiu 写道:
>>>>> Currently in vhost framwork, vhost_reset_device() is misnamed.
>>>>> Actually, it should be vhost_reset_owner().
>>>>>
>>>>> In vhost user, it make compatible with reset device ops, but
>>>>> vhost kernel does not compatible with it, for vhost vdpa, it
>>>>> only implement reset device action.
>>>>>
>>>>> So we need seperate the function into vhost_reset_owner() and
>>>>> vhost_reset_device(). So that different backend could use the
>>>>> correct function.
>>>>
>>>>
>>>> I see no reason when RESET_OWNER needs to be done for kernel backend.
>>>>
>>>
>>> In kernel vhost, RESET_OWNER indeed do vhost device level reset:
>>> vhost_net_reset_owner()
>>>
>>> static long vhost_net_reset_owner(struct vhost_net *n)
>>> {
>>> [...]
>>> err = vhost_dev_check_owner(&n->dev);
>>> if (err)
>>> goto done;
>>> umem = vhost_dev_reset_owner_prepare();
>>> if (!umem) {
>>> err = -ENOMEM;
>>> goto done;
>>> }
>>> vhost_net_stop(n, &tx_sock, &rx_sock);
>>> vhost_net_flush(n);
>>> vhost_dev_stop(&n->dev);
>>> vhost_dev_reset_owner(&n->dev, umem);
>>> vhost_net_vq_reset(n);
>>> [...]
>>>
>>> }
>>>
>>> In the history of QEMU, There is a commit:
>>> commit d1f8b30ec8dde0318fd1b98d24a64926feae9625
>>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>>> Date: Wed Sep 23 12:19:57 2015 +0800
>>>
>>> vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
>>>
>>> Quote from Michael:
>>>
>>> We really should rename VHOST_RESET_OWNER to
>>> VHOST_RESET_DEVICE.
>>>
>>> but finally, it has been reverted by the author:
>>> commit 60915dc4691768c4dc62458bb3e16c843fab091d
>>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
>>> Date: Wed Nov 11 21:24:37 2015 +0800
>>>
>>> vhost: rename RESET_DEVICE backto RESET_OWNER
>>>
>>> This patch basically reverts commit d1f8b30e.
>>>
>>> It turned out that it breaks stuff, so revert it:
>>>
>>> https://urldefense.com/v3/__http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html__;!!ACWV5N9M2RV99hQ!bgCEUDnSCLVO8LxXlwcdiHrtwqH5ip_sVcKscrtJve5eSzJfNN9JZuf-8HQIQ1Re$
>>>
>>> Seems kernel take RESET_OWNER for reset,but QEMU never call to this
>>> function to do a reset.
>>
>>
>> The question is, we manage to survive by not using RESET_OWNER for
>> past 10 years. Any reason that we want to use that now?
>>
>> Note that the RESET_OWNER is only useful the process want to drop the
>> its mm refcnt from vhost, it doesn't reset the device (e.g it does
>> not even call vhost_vq_reset()).
>>
>> (Especially, it was deprecated in by the vhost-user protocol since
>> its semantics is ambiguous)
>>
>>
>
> So, you prefer to directly remove RESET_OWNER support now?
>
>>>
>>>> And if I understand the code correctly, vhost-user "abuse"
>>>> RESET_OWNER for reset. So the current code looks fine?
>>>>
>>>>
>>>>>
>>>>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
>>>>> ---
>>>>> hw/scsi/vhost-user-scsi.c | 6 +++++-
>>>>> hw/virtio/vhost-backend.c | 4 ++--
>>>>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
>>>>> include/hw/virtio/vhost-backend.h | 2 ++
>>>>> 4 files changed, 27 insertions(+), 7 deletions(-)
>>>>>
>>>>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
>>>>> index 1b2f7ee..f179626 100644
>>>>> --- a/hw/scsi/vhost-user-scsi.c
>>>>> +++ b/hw/scsi/vhost-user-scsi.c
>>>>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice
>>>>> *vdev)
>>>>> return;
>>>>> }
>>>>> - if (dev->vhost_ops->vhost_reset_device) {
>>>>> + if (virtio_has_feature(dev->protocol_features,
>>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
>>>>> + dev->vhost_ops->vhost_reset_device) {
>>>>> dev->vhost_ops->vhost_reset_device(dev);
>>>>> + } else if (dev->vhost_ops->vhost_reset_owner) {
>>>>> + dev->vhost_ops->vhost_reset_owner(dev);
>>>>
>>>>
>>>> Actually, I fail to understand why we need an indirection via
>>>> vhost_ops. It's guaranteed to be vhost_user_ops.
>>>>
>>>>
>>>>> }
>>>>> }
>>>>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
>>>>> index e409a86..abbaa8b 100644
>>>>> --- a/hw/virtio/vhost-backend.c
>>>>> +++ b/hw/virtio/vhost-backend.c
>>>>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct
>>>>> vhost_dev *dev)
>>>>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
>>>>> }
>>>>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
>>>>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
>>>>> {
>>>>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
>>>>> }
>>>>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
>>>>> .vhost_get_features = vhost_kernel_get_features,
>>>>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
>>>>> .vhost_set_owner = vhost_kernel_set_owner,
>>>>> - .vhost_reset_device = vhost_kernel_reset_device,
>>>>> + .vhost_reset_owner = vhost_kernel_reset_owner,
>>>>
>>>>
>>>> I think we can delete the current vhost_reset_device() since it not
>>>> used in any code path.
>>>>
>>>
>>> I planned to use it for vDPA reset,
>>
>>
>> For vhost-vDPA it can call vhost_vdpa_reset_device() directly.
>>
>> As I mentioned before, the only user of vhost_reset_device config ops
>> is vhost-user-scsi but it should directly call the
>> vhost_user_reset_device().
>>
>
>
> Yes, but in the next patch I reuse it to reset backend device in
> vhost_net.
I recall vhost-user has a different way to reset the net backend, so
probably we can leave out implementing the .vhost_reset_device() op for
vhost-user as Jason suggested. In that case vhost-user-scsi will call
into vhost_user_reset_device() directly without using the
.vhost_reset_device() op.
-Siwei
>
>
>> Thanks
>>
>>
>>> and vhost-user-scsi also use device reset.
>>>
>>> Thanks,
>>> Michael
>>>
>>>> Thanks
>>>>
>>>>
>>>>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
>>>>> #ifdef CONFIG_VHOST_VSOCK
>>>>> .vhost_vsock_set_guest_cid =
>>>>> vhost_kernel_vsock_set_guest_cid,
>>>>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
>>>>> index 6abbc9d..4412008 100644
>>>>> --- a/hw/virtio/vhost-user.c
>>>>> +++ b/hw/virtio/vhost-user.c
>>>>> @@ -1475,16 +1475,29 @@ static int
>>>>> vhost_user_get_max_memslots(struct vhost_dev *dev,
>>>>> return 0;
>>>>> }
>>>>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
>>>>> +{
>>>>> + VhostUserMsg msg = {
>>>>> + .hdr.request = VHOST_USER_RESET_OWNER,
>>>>> + .hdr.flags = VHOST_USER_VERSION,
>>>>> + };
>>>>> +
>>>>> + return vhost_user_write(dev, &msg, NULL, 0);
>>>>> +}
>>>>> +
>>>>> static int vhost_user_reset_device(struct vhost_dev *dev)
>>>>> {
>>>>> VhostUserMsg msg = {
>>>>> + .hdr.request = VHOST_USER_RESET_DEVICE,
>>>>> .hdr.flags = VHOST_USER_VERSION,
>>>>> };
>>>>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
>>>>> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
>>>>> - ? VHOST_USER_RESET_DEVICE
>>>>> - : VHOST_USER_RESET_OWNER;
>>>>> + /* Caller must ensure the backend has
>>>>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
>>>>> + * support */
>>>>> + if (!virtio_has_feature(dev->protocol_features,
>>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
>>>>> + return -EPERM;
>>>>> + }
>>>>> return vhost_user_write(dev, &msg, NULL, 0);
>>>>> }
>>>>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
>>>>> .vhost_set_features = vhost_user_set_features,
>>>>> .vhost_get_features = vhost_user_get_features,
>>>>> .vhost_set_owner = vhost_user_set_owner,
>>>>> + .vhost_reset_owner = vhost_user_reset_owner,
>>>>> .vhost_reset_device = vhost_user_reset_device,
>>>>> .vhost_get_vq_index = vhost_user_get_vq_index,
>>>>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
>>>>> diff --git a/include/hw/virtio/vhost-backend.h
>>>>> b/include/hw/virtio/vhost-backend.h
>>>>> index 81bf310..affeeb0 100644
>>>>> --- a/include/hw/virtio/vhost-backend.h
>>>>> +++ b/include/hw/virtio/vhost-backend.h
>>>>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
>>>>> vhost_dev *dev,
>>>>> uint64_t *features);
>>>>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
>>>>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
>>>>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
>>>>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
>>>>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int
>>>>> idx);
>>>>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
>>>>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
>>>>> vhost_get_features_op vhost_get_features;
>>>>> vhost_set_backend_cap_op vhost_set_backend_cap;
>>>>> vhost_set_owner_op vhost_set_owner;
>>>>> + vhost_reset_owner_op vhost_reset_owner;
>>>>> vhost_reset_device_op vhost_reset_device;
>>>>> vhost_get_vq_index_op vhost_get_vq_index;
>>>>> vhost_set_vring_enable_op vhost_set_vring_enable;
>>>>
>>>>
>>>
>>
>>
>>
>
^ permalink raw reply [flat|nested] 47+ messages in thread* Re: [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps
2022-04-08 17:17 ` Si-Wei Liu
@ 2022-04-11 8:51 ` Jason Wang
0 siblings, 0 replies; 47+ messages in thread
From: Jason Wang @ 2022-04-11 8:51 UTC (permalink / raw)
To: Si-Wei Liu
Cc: Eugenio Perez Martin, Michael Qiu, Cindy Lu, qemu-devel,
Zhu, Lingshan
On Sat, Apr 9, 2022 at 1:17 AM Si-Wei Liu <si-wei.liu@oracle.com> wrote:
>
>
>
> On 4/8/2022 1:38 AM, Michael Qiu wrote:
> >
> >
> > 在 2022/4/7 15:35, Jason Wang 写道:
> >>
> >> 在 2022/4/2 下午1:14, Michael Qiu 写道:
> >>>
> >>>
> >>> On 2022/4/2 10:38, Jason Wang wrote:
> >>>>
> >>>> 在 2022/4/1 下午7:06, Michael Qiu 写道:
> >>>>> Currently in vhost framwork, vhost_reset_device() is misnamed.
> >>>>> Actually, it should be vhost_reset_owner().
> >>>>>
> >>>>> In vhost user, it make compatible with reset device ops, but
> >>>>> vhost kernel does not compatible with it, for vhost vdpa, it
> >>>>> only implement reset device action.
> >>>>>
> >>>>> So we need seperate the function into vhost_reset_owner() and
> >>>>> vhost_reset_device(). So that different backend could use the
> >>>>> correct function.
> >>>>
> >>>>
> >>>> I see no reason when RESET_OWNER needs to be done for kernel backend.
> >>>>
> >>>
> >>> In kernel vhost, RESET_OWNER indeed do vhost device level reset:
> >>> vhost_net_reset_owner()
> >>>
> >>> static long vhost_net_reset_owner(struct vhost_net *n)
> >>> {
> >>> [...]
> >>> err = vhost_dev_check_owner(&n->dev);
> >>> if (err)
> >>> goto done;
> >>> umem = vhost_dev_reset_owner_prepare();
> >>> if (!umem) {
> >>> err = -ENOMEM;
> >>> goto done;
> >>> }
> >>> vhost_net_stop(n, &tx_sock, &rx_sock);
> >>> vhost_net_flush(n);
> >>> vhost_dev_stop(&n->dev);
> >>> vhost_dev_reset_owner(&n->dev, umem);
> >>> vhost_net_vq_reset(n);
> >>> [...]
> >>>
> >>> }
> >>>
> >>> In the history of QEMU, There is a commit:
> >>> commit d1f8b30ec8dde0318fd1b98d24a64926feae9625
> >>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> >>> Date: Wed Sep 23 12:19:57 2015 +0800
> >>>
> >>> vhost: rename VHOST_RESET_OWNER to VHOST_RESET_DEVICE
> >>>
> >>> Quote from Michael:
> >>>
> >>> We really should rename VHOST_RESET_OWNER to
> >>> VHOST_RESET_DEVICE.
> >>>
> >>> but finally, it has been reverted by the author:
> >>> commit 60915dc4691768c4dc62458bb3e16c843fab091d
> >>> Author: Yuanhan Liu <yuanhan.liu@linux.intel.com>
> >>> Date: Wed Nov 11 21:24:37 2015 +0800
> >>>
> >>> vhost: rename RESET_DEVICE backto RESET_OWNER
> >>>
> >>> This patch basically reverts commit d1f8b30e.
> >>>
> >>> It turned out that it breaks stuff, so revert it:
> >>>
> >>> https://urldefense.com/v3/__http://lists.nongnu.org/archive/html/qemu-devel/2015-10/msg00949.html__;!!ACWV5N9M2RV99hQ!bgCEUDnSCLVO8LxXlwcdiHrtwqH5ip_sVcKscrtJve5eSzJfNN9JZuf-8HQIQ1Re$
> >>>
> >>> Seems kernel take RESET_OWNER for reset,but QEMU never call to this
> >>> function to do a reset.
> >>
> >>
> >> The question is, we manage to survive by not using RESET_OWNER for
> >> past 10 years. Any reason that we want to use that now?
> >>
> >> Note that the RESET_OWNER is only useful the process want to drop the
> >> its mm refcnt from vhost, it doesn't reset the device (e.g it does
> >> not even call vhost_vq_reset()).
> >>
> >> (Especially, it was deprecated in by the vhost-user protocol since
> >> its semantics is ambiguous)
> >>
> >>
> >
> > So, you prefer to directly remove RESET_OWNER support now?
> >
> >>>
> >>>> And if I understand the code correctly, vhost-user "abuse"
> >>>> RESET_OWNER for reset. So the current code looks fine?
> >>>>
> >>>>
> >>>>>
> >>>>> Signde-off-by: Michael Qiu <qiudayu@archeros.com>
> >>>>> ---
> >>>>> hw/scsi/vhost-user-scsi.c | 6 +++++-
> >>>>> hw/virtio/vhost-backend.c | 4 ++--
> >>>>> hw/virtio/vhost-user.c | 22 ++++++++++++++++++----
> >>>>> include/hw/virtio/vhost-backend.h | 2 ++
> >>>>> 4 files changed, 27 insertions(+), 7 deletions(-)
> >>>>>
> >>>>> diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> >>>>> index 1b2f7ee..f179626 100644
> >>>>> --- a/hw/scsi/vhost-user-scsi.c
> >>>>> +++ b/hw/scsi/vhost-user-scsi.c
> >>>>> @@ -80,8 +80,12 @@ static void vhost_user_scsi_reset(VirtIODevice
> >>>>> *vdev)
> >>>>> return;
> >>>>> }
> >>>>> - if (dev->vhost_ops->vhost_reset_device) {
> >>>>> + if (virtio_has_feature(dev->protocol_features,
> >>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE) &&
> >>>>> + dev->vhost_ops->vhost_reset_device) {
> >>>>> dev->vhost_ops->vhost_reset_device(dev);
> >>>>> + } else if (dev->vhost_ops->vhost_reset_owner) {
> >>>>> + dev->vhost_ops->vhost_reset_owner(dev);
> >>>>
> >>>>
> >>>> Actually, I fail to understand why we need an indirection via
> >>>> vhost_ops. It's guaranteed to be vhost_user_ops.
> >>>>
> >>>>
> >>>>> }
> >>>>> }
> >>>>> diff --git a/hw/virtio/vhost-backend.c b/hw/virtio/vhost-backend.c
> >>>>> index e409a86..abbaa8b 100644
> >>>>> --- a/hw/virtio/vhost-backend.c
> >>>>> +++ b/hw/virtio/vhost-backend.c
> >>>>> @@ -191,7 +191,7 @@ static int vhost_kernel_set_owner(struct
> >>>>> vhost_dev *dev)
> >>>>> return vhost_kernel_call(dev, VHOST_SET_OWNER, NULL);
> >>>>> }
> >>>>> -static int vhost_kernel_reset_device(struct vhost_dev *dev)
> >>>>> +static int vhost_kernel_reset_owner(struct vhost_dev *dev)
> >>>>> {
> >>>>> return vhost_kernel_call(dev, VHOST_RESET_OWNER, NULL);
> >>>>> }
> >>>>> @@ -317,7 +317,7 @@ const VhostOps kernel_ops = {
> >>>>> .vhost_get_features = vhost_kernel_get_features,
> >>>>> .vhost_set_backend_cap = vhost_kernel_set_backend_cap,
> >>>>> .vhost_set_owner = vhost_kernel_set_owner,
> >>>>> - .vhost_reset_device = vhost_kernel_reset_device,
> >>>>> + .vhost_reset_owner = vhost_kernel_reset_owner,
> >>>>
> >>>>
> >>>> I think we can delete the current vhost_reset_device() since it not
> >>>> used in any code path.
> >>>>
> >>>
> >>> I planned to use it for vDPA reset,
> >>
> >>
> >> For vhost-vDPA it can call vhost_vdpa_reset_device() directly.
> >>
> >> As I mentioned before, the only user of vhost_reset_device config ops
> >> is vhost-user-scsi but it should directly call the
> >> vhost_user_reset_device().
> >>
> >
> >
> > Yes, but in the next patch I reuse it to reset backend device in
> > vhost_net.
> I recall vhost-user has a different way to reset the net backend,
Yes, it has VHOST_USER_RESET_DEVICE.
Thanks
> so
> probably we can leave out implementing the .vhost_reset_device() op for
> vhost-user as Jason suggested. In that case vhost-user-scsi will call
> into vhost_user_reset_device() directly without using the
> .vhost_reset_device() op.
>
> -Siwei
>
> >
> >
> >> Thanks
> >>
> >>
> >>> and vhost-user-scsi also use device reset.
> >>>
> >>> Thanks,
> >>> Michael
> >>>
> >>>> Thanks
> >>>>
> >>>>
> >>>>> .vhost_get_vq_index = vhost_kernel_get_vq_index,
> >>>>> #ifdef CONFIG_VHOST_VSOCK
> >>>>> .vhost_vsock_set_guest_cid =
> >>>>> vhost_kernel_vsock_set_guest_cid,
> >>>>> diff --git a/hw/virtio/vhost-user.c b/hw/virtio/vhost-user.c
> >>>>> index 6abbc9d..4412008 100644
> >>>>> --- a/hw/virtio/vhost-user.c
> >>>>> +++ b/hw/virtio/vhost-user.c
> >>>>> @@ -1475,16 +1475,29 @@ static int
> >>>>> vhost_user_get_max_memslots(struct vhost_dev *dev,
> >>>>> return 0;
> >>>>> }
> >>>>> +static int vhost_user_reset_owner(struct vhost_dev *dev)
> >>>>> +{
> >>>>> + VhostUserMsg msg = {
> >>>>> + .hdr.request = VHOST_USER_RESET_OWNER,
> >>>>> + .hdr.flags = VHOST_USER_VERSION,
> >>>>> + };
> >>>>> +
> >>>>> + return vhost_user_write(dev, &msg, NULL, 0);
> >>>>> +}
> >>>>> +
> >>>>> static int vhost_user_reset_device(struct vhost_dev *dev)
> >>>>> {
> >>>>> VhostUserMsg msg = {
> >>>>> + .hdr.request = VHOST_USER_RESET_DEVICE,
> >>>>> .hdr.flags = VHOST_USER_VERSION,
> >>>>> };
> >>>>> - msg.hdr.request = virtio_has_feature(dev->protocol_features,
> >>>>> - VHOST_USER_PROTOCOL_F_RESET_DEVICE)
> >>>>> - ? VHOST_USER_RESET_DEVICE
> >>>>> - : VHOST_USER_RESET_OWNER;
> >>>>> + /* Caller must ensure the backend has
> >>>>> VHOST_USER_PROTOCOL_F_RESET_DEVICE
> >>>>> + * support */
> >>>>> + if (!virtio_has_feature(dev->protocol_features,
> >>>>> + VHOST_USER_PROTOCOL_F_RESET_DEVICE)) {
> >>>>> + return -EPERM;
> >>>>> + }
> >>>>> return vhost_user_write(dev, &msg, NULL, 0);
> >>>>> }
> >>>>> @@ -2548,6 +2561,7 @@ const VhostOps user_ops = {
> >>>>> .vhost_set_features = vhost_user_set_features,
> >>>>> .vhost_get_features = vhost_user_get_features,
> >>>>> .vhost_set_owner = vhost_user_set_owner,
> >>>>> + .vhost_reset_owner = vhost_user_reset_owner,
> >>>>> .vhost_reset_device = vhost_user_reset_device,
> >>>>> .vhost_get_vq_index = vhost_user_get_vq_index,
> >>>>> .vhost_set_vring_enable = vhost_user_set_vring_enable,
> >>>>> diff --git a/include/hw/virtio/vhost-backend.h
> >>>>> b/include/hw/virtio/vhost-backend.h
> >>>>> index 81bf310..affeeb0 100644
> >>>>> --- a/include/hw/virtio/vhost-backend.h
> >>>>> +++ b/include/hw/virtio/vhost-backend.h
> >>>>> @@ -77,6 +77,7 @@ typedef int (*vhost_get_features_op)(struct
> >>>>> vhost_dev *dev,
> >>>>> uint64_t *features);
> >>>>> typedef int (*vhost_set_backend_cap_op)(struct vhost_dev *dev);
> >>>>> typedef int (*vhost_set_owner_op)(struct vhost_dev *dev);
> >>>>> +typedef int (*vhost_reset_owner_op)(struct vhost_dev *dev);
> >>>>> typedef int (*vhost_reset_device_op)(struct vhost_dev *dev);
> >>>>> typedef int (*vhost_get_vq_index_op)(struct vhost_dev *dev, int
> >>>>> idx);
> >>>>> typedef int (*vhost_set_vring_enable_op)(struct vhost_dev *dev,
> >>>>> @@ -150,6 +151,7 @@ typedef struct VhostOps {
> >>>>> vhost_get_features_op vhost_get_features;
> >>>>> vhost_set_backend_cap_op vhost_set_backend_cap;
> >>>>> vhost_set_owner_op vhost_set_owner;
> >>>>> + vhost_reset_owner_op vhost_reset_owner;
> >>>>> vhost_reset_device_op vhost_reset_device;
> >>>>> vhost_get_vq_index_op vhost_get_vq_index;
> >>>>> vhost_set_vring_enable_op vhost_set_vring_enable;
> >>>>
> >>>>
> >>>
> >>
> >>
> >>
> >
>
^ permalink raw reply [flat|nested] 47+ messages in thread
* [PATCH 2/3] vhost: add vhost_dev_reset()
2022-04-01 11:06 ` [PATCH 0/3] Refactor vhost device reset Michael Qiu
2022-04-01 11:06 ` [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps Michael Qiu
@ 2022-04-01 11:06 ` Michael Qiu
2022-04-02 0:48 ` Si-Wei Liu
2022-04-01 11:06 ` [PATCH 3/3 v5] vdpa: reset the backend device in the end of vhost_net_stop() Michael Qiu
2 siblings, 1 reply; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 11:06 UTC (permalink / raw)
To: jasowang, mst, si-wei.liu
Cc: Michael Qiu, eperezma, lingshan.zhu, qemu-devel, lulu
Not all vhost-user backends support ops->vhost_reset_device(). Instead
of adding backend check and call backend ops directly, it's better to
implement a function in vhost framework, so that it could hide vhost_ops
details.
SIgned-off-by: Michael Qiu <qiudayu@archeros.com>
---
hw/virtio/vhost.c | 14 ++++++++++++++
include/hw/virtio/vhost.h | 1 +
2 files changed, 15 insertions(+)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index b643f42..26667ae 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -1854,3 +1854,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
return -ENOSYS;
}
+
+int vhost_dev_reset(struct vhost_dev *hdev)
+{
+ int ret = 0;
+
+ /* should only be called after backend is connected */
+ assert(hdev->vhost_ops);
+
+ if (hdev->vhost_ops->vhost_reset_device) {
+ ret = hdev->vhost_ops->vhost_reset_device(hdev);
+ }
+
+ return ret;
+}
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index 58a73e7..b8b7c20 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
void vhost_dev_cleanup(struct vhost_dev *hdev);
int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
+int vhost_dev_reset(struct vhost_dev *hdev);
int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
--
1.8.3.1
^ permalink raw reply related [flat|nested] 47+ messages in thread* Re: [PATCH 2/3] vhost: add vhost_dev_reset()
2022-04-01 11:06 ` [PATCH 2/3] vhost: add vhost_dev_reset() Michael Qiu
@ 2022-04-02 0:48 ` Si-Wei Liu
0 siblings, 0 replies; 47+ messages in thread
From: Si-Wei Liu @ 2022-04-02 0:48 UTC (permalink / raw)
To: Michael Qiu, jasowang, mst; +Cc: eperezma, lingshan.zhu, qemu-devel, lulu
On 4/1/2022 4:06 AM, Michael Qiu wrote:
> Not all vhost-user backends support ops->vhost_reset_device(). Instead
> of adding backend check and call backend ops directly, it's better to
> implement a function in vhost framework, so that it could hide vhost_ops
> details.
>
> SIgned-off-by: Michael Qiu <qiudayu@archeros.com>
> ---
> hw/virtio/vhost.c | 14 ++++++++++++++
> include/hw/virtio/vhost.h | 1 +
> 2 files changed, 15 insertions(+)
>
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index b643f42..26667ae 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -1854,3 +1854,17 @@ int vhost_net_set_backend(struct vhost_dev *hdev,
>
> return -ENOSYS;
> }
> +
> +int vhost_dev_reset(struct vhost_dev *hdev)
Maybe vhost_user_scsi_reset() can call this function instead?
-Siwei
> +{
> + int ret = 0;
> +
> + /* should only be called after backend is connected */
> + assert(hdev->vhost_ops);
> +
> + if (hdev->vhost_ops->vhost_reset_device) {
> + ret = hdev->vhost_ops->vhost_reset_device(hdev);
> + }
> +
> + return ret;
> +}
> diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
> index 58a73e7..b8b7c20 100644
> --- a/include/hw/virtio/vhost.h
> +++ b/include/hw/virtio/vhost.h
> @@ -114,6 +114,7 @@ int vhost_dev_init(struct vhost_dev *hdev, void *opaque,
> void vhost_dev_cleanup(struct vhost_dev *hdev);
> int vhost_dev_start(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_stop(struct vhost_dev *hdev, VirtIODevice *vdev);
> +int vhost_dev_reset(struct vhost_dev *hdev);
> int vhost_dev_enable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
> void vhost_dev_disable_notifiers(struct vhost_dev *hdev, VirtIODevice *vdev);
>
^ permalink raw reply [flat|nested] 47+ messages in thread
* [PATCH 3/3 v5] vdpa: reset the backend device in the end of vhost_net_stop()
2022-04-01 11:06 ` [PATCH 0/3] Refactor vhost device reset Michael Qiu
2022-04-01 11:06 ` [PATCH 1/3] vhost: Refactor vhost_reset_device() in VhostOps Michael Qiu
2022-04-01 11:06 ` [PATCH 2/3] vhost: add vhost_dev_reset() Michael Qiu
@ 2022-04-01 11:06 ` Michael Qiu
2 siblings, 0 replies; 47+ messages in thread
From: Michael Qiu @ 2022-04-01 11:06 UTC (permalink / raw)
To: jasowang, mst, si-wei.liu
Cc: Michael Qiu, eperezma, lingshan.zhu, qemu-devel, lulu
Currently, when VM poweroff, it will trigger vdpa
device(such as mlx bluefield2 VF) reset many times(with 1 datapath
queue pair and one control queue, triggered 3 times), this
leads to below issue:
vhost VQ 2 ring restore failed: -22: Invalid argument (22)
This because in vhost_net_stop(), it will stop all vhost device bind to
this virtio device, and in vhost_dev_stop(), qemu tries to stop the device
, then stop the queue: vhost_virtqueue_stop().
In vhost_dev_stop(), it resets the device, which clear some flags
in low level driver, and in next loop(stop other vhost backends),
qemu try to stop the queue corresponding to the vhost backend,
the driver finds that the VQ is invalied, this is the root cause.
To solve the issue, vdpa should set vring unready, and
remove reset ops in device stop: vhost_dev_start(hdev, false).
and implement a new function vhost_dev_reset, only reset backend
device after all vhost(per-queue) stopped.
Signed-off-by: Michael Qiu<qiudayu@archeros.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
v5 --> v4:
move vhost_dev_reset() call after set_guest_notifiers
remove implementation of vhost_dev_reset()
remove backend check for VHOST_BACKEND_TYPE_VDPA
v4 --> v3:
Nothing changed, becasue of issue with mimecast,
when the From: tag is different from the sender,
the some mail client will take the patch as an
attachment, RESEND v3 does not work, So resend
the patch as v4
v3 --> v2:
Call vhost_dev_reset() at the end of vhost_net_stop().
Since the vDPA device need re-add the status bit
VIRTIO_CONFIG_S_ACKNOWLEDGE and VIRTIO_CONFIG_S_DRIVER,
simply, add them inside vhost_vdpa_reset_device, and
the only way calling vhost_vdpa_reset_device is in
vhost_net_stop(), so it keeps the same behavior as before.
v2 --> v1:
Implement a new function vhost_dev_reset,
reset the backend kernel device at last.
---
hw/net/vhost_net.c | 22 +++++++++++++++++++---
hw/virtio/vhost-vdpa.c | 15 +++++++++------
2 files changed, 28 insertions(+), 9 deletions(-)
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 30379d2..30c76ca 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -325,7 +325,7 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
int total_notifiers = data_queue_pairs * 2 + cvq;
VirtIONet *n = VIRTIO_NET(dev);
int nvhosts = data_queue_pairs + cvq;
- struct vhost_net *net;
+ struct vhost_net *net = NULL;
int r, e, i, index_end = data_queue_pairs * 2;
NetClientState *peer;
@@ -391,13 +391,21 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
err_start:
while (--i >= 0) {
peer = qemu_get_peer(ncs , i);
- vhost_net_stop_one(get_vhost_net(peer), dev);
+
+ net = get_vhost_net(peer);
+
+ vhost_net_stop_one(net, dev);
}
+
e = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
if (e < 0) {
fprintf(stderr, "vhost guest notifier cleanup failed: %d\n", e);
fflush(stderr);
}
+
+ if (net) {
+ vhost_dev_reset(&net->dev);
+ }
err:
return r;
}
@@ -410,6 +418,7 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
VirtioBusClass *k = VIRTIO_BUS_GET_CLASS(vbus);
VirtIONet *n = VIRTIO_NET(dev);
NetClientState *peer;
+ struct vhost_net *net = NULL;
int total_notifiers = data_queue_pairs * 2 + cvq;
int nvhosts = data_queue_pairs + cvq;
int i, r;
@@ -420,7 +429,10 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
} else {
peer = qemu_get_peer(ncs, n->max_queue_pairs);
}
- vhost_net_stop_one(get_vhost_net(peer), dev);
+
+ net = get_vhost_net(peer);
+
+ vhost_net_stop_one(net, dev);
}
r = k->set_guest_notifiers(qbus->parent, total_notifiers, false);
@@ -429,6 +441,10 @@ void vhost_net_stop(VirtIODevice *dev, NetClientState *ncs,
fflush(stderr);
}
assert(r >= 0);
+
+ if (net) {
+ vhost_dev_reset(&net->dev);
+ }
}
void vhost_net_cleanup(struct vhost_net *net)
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index c5ed7a3..3ef0199 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -708,6 +708,11 @@ static int vhost_vdpa_reset_device(struct vhost_dev *dev)
ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
trace_vhost_vdpa_reset_device(dev, status);
+
+ /* Add back this status, so that the device could work next time*/
+ vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
+ VIRTIO_CONFIG_S_DRIVER);
+
return ret;
}
@@ -719,14 +724,14 @@ static int vhost_vdpa_get_vq_index(struct vhost_dev *dev, int idx)
return idx;
}
-static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev)
+static int vhost_vdpa_set_vring_ready(struct vhost_dev *dev, unsigned int ready)
{
int i;
trace_vhost_vdpa_set_vring_ready(dev);
for (i = 0; i < dev->nvqs; ++i) {
struct vhost_vring_state state = {
.index = dev->vq_index + i,
- .num = 1,
+ .num = ready,
};
vhost_vdpa_call(dev, VHOST_VDPA_SET_VRING_ENABLE, &state);
}
@@ -1088,8 +1093,9 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
if (unlikely(!ok)) {
return -1;
}
- vhost_vdpa_set_vring_ready(dev);
+ vhost_vdpa_set_vring_ready(dev, 1);
} else {
+ vhost_vdpa_set_vring_ready(dev, 0);
ok = vhost_vdpa_svqs_stop(dev);
if (unlikely(!ok)) {
return -1;
@@ -1105,9 +1111,6 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
memory_listener_register(&v->listener, &address_space_memory);
return vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
} else {
- vhost_vdpa_reset_device(dev);
- vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
- VIRTIO_CONFIG_S_DRIVER);
memory_listener_unregister(&v->listener);
return 0;
--
1.8.3.1
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