* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-07 7:01 ` [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation Wei Wang
@ 2019-01-07 13:44 ` Michael S. Tsirkin
2019-01-07 13:47 ` Michael S. Tsirkin
2019-01-07 13:49 ` Christian Borntraeger
2 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-07 13:44 UTC (permalink / raw)
To: Wei Wang
Cc: virtio-dev, linux-kernel, virtualization, kvm, cohuck,
borntraeger, pbonzini, dgilbert, pasic
On Mon, Jan 07, 2019 at 03:01:04PM +0800, Wei Wang wrote:
> virtio-ccw has deadlock issues with reading the config space inside the
> interrupt context, so we tweak the virtballoon_changed implementation
> by moving the config read operations into the related workqueue contexts.
> The config_read_bitmap is used as a flag to the workqueue callbacks
> about the related config fields that need to be read.
>
> The cmd_id_received is also renamed to cmd_id_received_cache, and
> the value should be obtained via virtio_balloon_cmd_id_received.
>
> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> ---
> drivers/virtio/virtio_balloon.c | 98 +++++++++++++++++++++++++++--------------
> 1 file changed, 65 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 728ecd1..fb12fe2 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -61,6 +61,10 @@ enum virtio_balloon_vq {
> VIRTIO_BALLOON_VQ_MAX
> };
>
> +enum virtio_balloon_config_read {
> + VIRTIO_BALLOON_CONFIG_READ_CMD_ID = 0,
> +};
> +
> struct virtio_balloon {
> struct virtio_device *vdev;
> struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
> @@ -77,14 +81,20 @@ struct virtio_balloon {
> /* Prevent updating balloon when it is being canceled. */
> spinlock_t stop_update_lock;
> bool stop_update;
> + /* Bitmap to indicate if reading the related config fields are needed */
> + unsigned long config_read_bitmap;
>
> /* The list of allocated free pages, waiting to be given back to mm */
> struct list_head free_page_list;
> spinlock_t free_page_list_lock;
> /* The number of free page blocks on the above list */
> unsigned long num_free_page_blocks;
> - /* The cmd id received from host */
> - u32 cmd_id_received;
> + /*
> + * The cmd id received from host.
> + * Read it via virtio_balloon_cmd_id_received to get the latest value
> + * sent from host.
> + */
> + u32 cmd_id_received_cache;
> /* The cmd id that is actively in use */
> __virtio32 cmd_id_active;
> /* Buffer to store the stop sign */
> @@ -390,37 +400,31 @@ static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb,
> return num_returned;
> }
>
> +static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
> +{
> + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
> + return;
> +
> + /* No need to queue the work if the bit was already set. */
> + if (test_and_set_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + return;
> +
> + queue_work(vb->balloon_wq, &vb->report_free_page_work);
> +}
> +
> static void virtballoon_changed(struct virtio_device *vdev)
> {
> struct virtio_balloon *vb = vdev->priv;
> unsigned long flags;
> - s64 diff = towards_target(vb);
> -
> - if (diff) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update)
> - queue_work(system_freezable_wq,
> - &vb->update_balloon_size_work);
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
>
> - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
> - virtio_cread(vdev, struct virtio_balloon_config,
> - free_page_report_cmd_id, &vb->cmd_id_received);
> - if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> - /* Pass ULONG_MAX to give back all the free pages */
> - return_free_pages_to_mm(vb, ULONG_MAX);
> - } else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> - vb->cmd_id_received !=
> - virtio32_to_cpu(vdev, vb->cmd_id_active)) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update) {
> - queue_work(vb->balloon_wq,
> - &vb->report_free_page_work);
> - }
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
> + spin_lock_irqsave(&vb->stop_update_lock, flags);
> + if (!vb->stop_update) {
> + queue_work(system_freezable_wq,
> + &vb->update_balloon_size_work);
> + virtio_balloon_queue_free_page_work(vb);
> }
> + spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> }
>
> static void update_balloon_size(struct virtio_balloon *vb)
> @@ -527,6 +531,17 @@ static int init_vqs(struct virtio_balloon *vb)
> return 0;
> }
>
> +static u32 virtio_balloon_cmd_id_received(struct virtio_balloon *vb)
> +{
> + if (test_and_clear_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + virtio_cread(vb->vdev, struct virtio_balloon_config,
> + free_page_report_cmd_id,
> + &vb->cmd_id_received_cache);
> +
> + return vb->cmd_id_received_cache;
> +}
> +
> static int send_cmd_id_start(struct virtio_balloon *vb)
> {
> struct scatterlist sg;
> @@ -537,7 +552,8 @@ static int send_cmd_id_start(struct virtio_balloon *vb)
> while (virtqueue_get_buf(vq, &unused))
> ;
>
> - vb->cmd_id_active = cpu_to_virtio32(vb->vdev, vb->cmd_id_received);
> + vb->cmd_id_active = virtio32_to_cpu(vb->vdev,
> + virtio_balloon_cmd_id_received(vb));
You switches cpu_to_virtio32 to over to virtio32_to_cpu.
That will produce a sparse warning I think.
Pls always run the static checker when you submit patches.
> sg_init_one(&sg, &vb->cmd_id_active, sizeof(vb->cmd_id_active));
> err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_active, GFP_KERNEL);
> if (!err)
> @@ -620,7 +636,8 @@ static int send_free_pages(struct virtio_balloon *vb)
> * stop the reporting.
> */
> cmd_id_active = virtio32_to_cpu(vb->vdev, vb->cmd_id_active);
> - if (cmd_id_active != vb->cmd_id_received)
> + if (unlikely(cmd_id_active !=
> + virtio_balloon_cmd_id_received(vb)))
> break;
>
> /*
> @@ -637,11 +654,9 @@ static int send_free_pages(struct virtio_balloon *vb)
> return 0;
> }
>
> -static void report_free_page_func(struct work_struct *work)
> +static void virtio_balloon_report_free_page(struct virtio_balloon *vb)
> {
> int err;
> - struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> - report_free_page_work);
> struct device *dev = &vb->vdev->dev;
>
> /* Start by sending the received cmd id to host with an outbuf. */
> @@ -659,6 +674,23 @@ static void report_free_page_func(struct work_struct *work)
> dev_err(dev, "Failed to send a stop id, err = %d\n", err);
> }
>
> +static void report_free_page_func(struct work_struct *work)
> +{
> + struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> + report_free_page_work);
> + u32 cmd_id_received;
> +
> + cmd_id_received = virtio_balloon_cmd_id_received(vb);
> + if (cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> + /* Pass ULONG_MAX to give back all the free pages */
> + return_free_pages_to_mm(vb, ULONG_MAX);
> + } else if (cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> + cmd_id_received !=
> + virtio32_to_cpu(vb->vdev, vb->cmd_id_active)) {
> + virtio_balloon_report_free_page(vb);
> + }
> +}
> +
> #ifdef CONFIG_BALLOON_COMPACTION
> /*
> * virtballoon_migratepage - perform the balloon page migration on behalf of
> @@ -885,7 +917,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
> goto out_del_vqs;
> }
> INIT_WORK(&vb->report_free_page_work, report_free_page_func);
> - vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
> + vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP;
> vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
> VIRTIO_BALLOON_CMD_ID_STOP);
> vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
> --
> 2.7.4
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-07 7:01 ` [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation Wei Wang
2019-01-07 13:44 ` Michael S. Tsirkin
@ 2019-01-07 13:47 ` Michael S. Tsirkin
2019-01-07 13:49 ` Christian Borntraeger
2 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-07 13:47 UTC (permalink / raw)
To: Wei Wang
Cc: virtio-dev, linux-kernel, virtualization, kvm, cohuck,
borntraeger, pbonzini, dgilbert, pasic
On Mon, Jan 07, 2019 at 03:01:04PM +0800, Wei Wang wrote:
> virtio-ccw has deadlock issues with reading the config space inside the
> interrupt context, so we tweak the virtballoon_changed implementation
> by moving the config read operations into the related workqueue contexts.
> The config_read_bitmap is used as a flag to the workqueue callbacks
> about the related config fields that need to be read.
>
> The cmd_id_received is also renamed to cmd_id_received_cache, and
> the value should be obtained via virtio_balloon_cmd_id_received.
>
> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Please include a Fixes tag to list the problematic commit.
See Documentation/process/submitting-patches.rst for the appropriate format.
> ---
> drivers/virtio/virtio_balloon.c | 98 +++++++++++++++++++++++++++--------------
> 1 file changed, 65 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 728ecd1..fb12fe2 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -61,6 +61,10 @@ enum virtio_balloon_vq {
> VIRTIO_BALLOON_VQ_MAX
> };
>
> +enum virtio_balloon_config_read {
> + VIRTIO_BALLOON_CONFIG_READ_CMD_ID = 0,
> +};
> +
> struct virtio_balloon {
> struct virtio_device *vdev;
> struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
> @@ -77,14 +81,20 @@ struct virtio_balloon {
> /* Prevent updating balloon when it is being canceled. */
> spinlock_t stop_update_lock;
> bool stop_update;
> + /* Bitmap to indicate if reading the related config fields are needed */
> + unsigned long config_read_bitmap;
>
> /* The list of allocated free pages, waiting to be given back to mm */
> struct list_head free_page_list;
> spinlock_t free_page_list_lock;
> /* The number of free page blocks on the above list */
> unsigned long num_free_page_blocks;
> - /* The cmd id received from host */
> - u32 cmd_id_received;
> + /*
> + * The cmd id received from host.
> + * Read it via virtio_balloon_cmd_id_received to get the latest value
> + * sent from host.
> + */
> + u32 cmd_id_received_cache;
> /* The cmd id that is actively in use */
> __virtio32 cmd_id_active;
> /* Buffer to store the stop sign */
> @@ -390,37 +400,31 @@ static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb,
> return num_returned;
> }
>
> +static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
> +{
> + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
> + return;
> +
> + /* No need to queue the work if the bit was already set. */
> + if (test_and_set_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + return;
> +
> + queue_work(vb->balloon_wq, &vb->report_free_page_work);
> +}
> +
> static void virtballoon_changed(struct virtio_device *vdev)
> {
> struct virtio_balloon *vb = vdev->priv;
> unsigned long flags;
> - s64 diff = towards_target(vb);
> -
> - if (diff) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update)
> - queue_work(system_freezable_wq,
> - &vb->update_balloon_size_work);
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
>
> - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
> - virtio_cread(vdev, struct virtio_balloon_config,
> - free_page_report_cmd_id, &vb->cmd_id_received);
> - if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> - /* Pass ULONG_MAX to give back all the free pages */
> - return_free_pages_to_mm(vb, ULONG_MAX);
> - } else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> - vb->cmd_id_received !=
> - virtio32_to_cpu(vdev, vb->cmd_id_active)) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update) {
> - queue_work(vb->balloon_wq,
> - &vb->report_free_page_work);
> - }
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
> + spin_lock_irqsave(&vb->stop_update_lock, flags);
> + if (!vb->stop_update) {
> + queue_work(system_freezable_wq,
> + &vb->update_balloon_size_work);
> + virtio_balloon_queue_free_page_work(vb);
> }
> + spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> }
>
> static void update_balloon_size(struct virtio_balloon *vb)
> @@ -527,6 +531,17 @@ static int init_vqs(struct virtio_balloon *vb)
> return 0;
> }
>
> +static u32 virtio_balloon_cmd_id_received(struct virtio_balloon *vb)
> +{
> + if (test_and_clear_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + virtio_cread(vb->vdev, struct virtio_balloon_config,
> + free_page_report_cmd_id,
> + &vb->cmd_id_received_cache);
> +
> + return vb->cmd_id_received_cache;
> +}
> +
> static int send_cmd_id_start(struct virtio_balloon *vb)
> {
> struct scatterlist sg;
> @@ -537,7 +552,8 @@ static int send_cmd_id_start(struct virtio_balloon *vb)
> while (virtqueue_get_buf(vq, &unused))
> ;
>
> - vb->cmd_id_active = cpu_to_virtio32(vb->vdev, vb->cmd_id_received);
> + vb->cmd_id_active = virtio32_to_cpu(vb->vdev,
> + virtio_balloon_cmd_id_received(vb));
> sg_init_one(&sg, &vb->cmd_id_active, sizeof(vb->cmd_id_active));
> err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_active, GFP_KERNEL);
> if (!err)
> @@ -620,7 +636,8 @@ static int send_free_pages(struct virtio_balloon *vb)
> * stop the reporting.
> */
> cmd_id_active = virtio32_to_cpu(vb->vdev, vb->cmd_id_active);
> - if (cmd_id_active != vb->cmd_id_received)
> + if (unlikely(cmd_id_active !=
> + virtio_balloon_cmd_id_received(vb)))
> break;
>
> /*
> @@ -637,11 +654,9 @@ static int send_free_pages(struct virtio_balloon *vb)
> return 0;
> }
>
> -static void report_free_page_func(struct work_struct *work)
> +static void virtio_balloon_report_free_page(struct virtio_balloon *vb)
> {
> int err;
> - struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> - report_free_page_work);
> struct device *dev = &vb->vdev->dev;
>
> /* Start by sending the received cmd id to host with an outbuf. */
> @@ -659,6 +674,23 @@ static void report_free_page_func(struct work_struct *work)
> dev_err(dev, "Failed to send a stop id, err = %d\n", err);
> }
>
> +static void report_free_page_func(struct work_struct *work)
> +{
> + struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> + report_free_page_work);
> + u32 cmd_id_received;
> +
> + cmd_id_received = virtio_balloon_cmd_id_received(vb);
> + if (cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> + /* Pass ULONG_MAX to give back all the free pages */
> + return_free_pages_to_mm(vb, ULONG_MAX);
> + } else if (cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> + cmd_id_received !=
> + virtio32_to_cpu(vb->vdev, vb->cmd_id_active)) {
> + virtio_balloon_report_free_page(vb);
> + }
> +}
> +
> #ifdef CONFIG_BALLOON_COMPACTION
> /*
> * virtballoon_migratepage - perform the balloon page migration on behalf of
> @@ -885,7 +917,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
> goto out_del_vqs;
> }
> INIT_WORK(&vb->report_free_page_work, report_free_page_func);
> - vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
> + vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP;
> vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
> VIRTIO_BALLOON_CMD_ID_STOP);
> vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
> --
> 2.7.4
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-07 7:01 ` [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation Wei Wang
2019-01-07 13:44 ` Michael S. Tsirkin
2019-01-07 13:47 ` Michael S. Tsirkin
@ 2019-01-07 13:49 ` Christian Borntraeger
2019-01-08 5:35 ` Wei Wang
2019-01-15 0:53 ` Michael S. Tsirkin
2 siblings, 2 replies; 22+ messages in thread
From: Christian Borntraeger @ 2019-01-07 13:49 UTC (permalink / raw)
To: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, mst, cohuck
Cc: pbonzini, dgilbert, pasic
On 07.01.2019 08:01, Wei Wang wrote:
> virtio-ccw has deadlock issues with reading the config space inside the
> interrupt context, so we tweak the virtballoon_changed implementation
> by moving the config read operations into the related workqueue contexts.
> The config_read_bitmap is used as a flag to the workqueue callbacks
> about the related config fields that need to be read.
>
> The cmd_id_received is also renamed to cmd_id_received_cache, and
> the value should be obtained via virtio_balloon_cmd_id_received.
>
> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
Together with
virtio_pci: use queue idx instead of array idx to set up the vq
virtio: don't allocate vqs when names[i] = NULL
Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
as already said, would be good to add cc stable (and a Fixes: tag)
> ---
> drivers/virtio/virtio_balloon.c | 98 +++++++++++++++++++++++++++--------------
> 1 file changed, 65 insertions(+), 33 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index 728ecd1..fb12fe2 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -61,6 +61,10 @@ enum virtio_balloon_vq {
> VIRTIO_BALLOON_VQ_MAX
> };
>
> +enum virtio_balloon_config_read {
> + VIRTIO_BALLOON_CONFIG_READ_CMD_ID = 0,
> +};
> +
> struct virtio_balloon {
> struct virtio_device *vdev;
> struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
> @@ -77,14 +81,20 @@ struct virtio_balloon {
> /* Prevent updating balloon when it is being canceled. */
> spinlock_t stop_update_lock;
> bool stop_update;
> + /* Bitmap to indicate if reading the related config fields are needed */
> + unsigned long config_read_bitmap;
>
> /* The list of allocated free pages, waiting to be given back to mm */
> struct list_head free_page_list;
> spinlock_t free_page_list_lock;
> /* The number of free page blocks on the above list */
> unsigned long num_free_page_blocks;
> - /* The cmd id received from host */
> - u32 cmd_id_received;
> + /*
> + * The cmd id received from host.
> + * Read it via virtio_balloon_cmd_id_received to get the latest value
> + * sent from host.
> + */
> + u32 cmd_id_received_cache;
> /* The cmd id that is actively in use */
> __virtio32 cmd_id_active;
> /* Buffer to store the stop sign */
> @@ -390,37 +400,31 @@ static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb,
> return num_returned;
> }
>
> +static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
> +{
> + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
> + return;
> +
> + /* No need to queue the work if the bit was already set. */
> + if (test_and_set_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + return;
> +
> + queue_work(vb->balloon_wq, &vb->report_free_page_work);
> +}
> +
> static void virtballoon_changed(struct virtio_device *vdev)
> {
> struct virtio_balloon *vb = vdev->priv;
> unsigned long flags;
> - s64 diff = towards_target(vb);
> -
> - if (diff) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update)
> - queue_work(system_freezable_wq,
> - &vb->update_balloon_size_work);
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
>
> - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
> - virtio_cread(vdev, struct virtio_balloon_config,
> - free_page_report_cmd_id, &vb->cmd_id_received);
> - if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> - /* Pass ULONG_MAX to give back all the free pages */
> - return_free_pages_to_mm(vb, ULONG_MAX);
> - } else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> - vb->cmd_id_received !=
> - virtio32_to_cpu(vdev, vb->cmd_id_active)) {
> - spin_lock_irqsave(&vb->stop_update_lock, flags);
> - if (!vb->stop_update) {
> - queue_work(vb->balloon_wq,
> - &vb->report_free_page_work);
> - }
> - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> - }
> + spin_lock_irqsave(&vb->stop_update_lock, flags);
> + if (!vb->stop_update) {
> + queue_work(system_freezable_wq,
> + &vb->update_balloon_size_work);
> + virtio_balloon_queue_free_page_work(vb);
> }
> + spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> }
>
> static void update_balloon_size(struct virtio_balloon *vb)
> @@ -527,6 +531,17 @@ static int init_vqs(struct virtio_balloon *vb)
> return 0;
> }
>
> +static u32 virtio_balloon_cmd_id_received(struct virtio_balloon *vb)
> +{
> + if (test_and_clear_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> + &vb->config_read_bitmap))
> + virtio_cread(vb->vdev, struct virtio_balloon_config,
> + free_page_report_cmd_id,
> + &vb->cmd_id_received_cache);
> +
> + return vb->cmd_id_received_cache;
> +}
> +
> static int send_cmd_id_start(struct virtio_balloon *vb)
> {
> struct scatterlist sg;
> @@ -537,7 +552,8 @@ static int send_cmd_id_start(struct virtio_balloon *vb)
> while (virtqueue_get_buf(vq, &unused))
> ;
>
> - vb->cmd_id_active = cpu_to_virtio32(vb->vdev, vb->cmd_id_received);
> + vb->cmd_id_active = virtio32_to_cpu(vb->vdev,
> + virtio_balloon_cmd_id_received(vb));
> sg_init_one(&sg, &vb->cmd_id_active, sizeof(vb->cmd_id_active));
> err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_active, GFP_KERNEL);
> if (!err)
> @@ -620,7 +636,8 @@ static int send_free_pages(struct virtio_balloon *vb)
> * stop the reporting.
> */
> cmd_id_active = virtio32_to_cpu(vb->vdev, vb->cmd_id_active);
> - if (cmd_id_active != vb->cmd_id_received)
> + if (unlikely(cmd_id_active !=
> + virtio_balloon_cmd_id_received(vb)))
> break;
>
> /*
> @@ -637,11 +654,9 @@ static int send_free_pages(struct virtio_balloon *vb)
> return 0;
> }
>
> -static void report_free_page_func(struct work_struct *work)
> +static void virtio_balloon_report_free_page(struct virtio_balloon *vb)
> {
> int err;
> - struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> - report_free_page_work);
> struct device *dev = &vb->vdev->dev;
>
> /* Start by sending the received cmd id to host with an outbuf. */
> @@ -659,6 +674,23 @@ static void report_free_page_func(struct work_struct *work)
> dev_err(dev, "Failed to send a stop id, err = %d\n", err);
> }
>
> +static void report_free_page_func(struct work_struct *work)
> +{
> + struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> + report_free_page_work);
> + u32 cmd_id_received;
> +
> + cmd_id_received = virtio_balloon_cmd_id_received(vb);
> + if (cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> + /* Pass ULONG_MAX to give back all the free pages */
> + return_free_pages_to_mm(vb, ULONG_MAX);
> + } else if (cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> + cmd_id_received !=
> + virtio32_to_cpu(vb->vdev, vb->cmd_id_active)) {
> + virtio_balloon_report_free_page(vb);
> + }
> +}
> +
> #ifdef CONFIG_BALLOON_COMPACTION
> /*
> * virtballoon_migratepage - perform the balloon page migration on behalf of
> @@ -885,7 +917,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
> goto out_del_vqs;
> }
> INIT_WORK(&vb->report_free_page_work, report_free_page_func);
> - vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
> + vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP;
> vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
> VIRTIO_BALLOON_CMD_ID_STOP);
> vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
>
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-07 13:49 ` Christian Borntraeger
@ 2019-01-08 5:35 ` Wei Wang
2019-01-08 8:46 ` Christian Borntraeger
2019-01-15 0:53 ` Michael S. Tsirkin
1 sibling, 1 reply; 22+ messages in thread
From: Wei Wang @ 2019-01-08 5:35 UTC (permalink / raw)
To: Christian Borntraeger, virtio-dev, linux-kernel, virtualization,
kvm, mst, cohuck
Cc: pbonzini, dgilbert, pasic
On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
>
> On 07.01.2019 08:01, Wei Wang wrote:
>> virtio-ccw has deadlock issues with reading the config space inside the
>> interrupt context, so we tweak the virtballoon_changed implementation
>> by moving the config read operations into the related workqueue contexts.
>> The config_read_bitmap is used as a flag to the workqueue callbacks
>> about the related config fields that need to be read.
>>
>> The cmd_id_received is also renamed to cmd_id_received_cache, and
>> the value should be obtained via virtio_balloon_cmd_id_received.
>>
>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> Together with
> virtio_pci: use queue idx instead of array idx to set up the vq
> virtio: don't allocate vqs when names[i] = NULL
>
> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
OK. I don't plan to send a new version of the above patches as no
changes needed so far.
Michael, if the above two patches look good to you, please help add the
related tested-by
and reviewed-by tags. Thanks.
Best,
Wei
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-08 5:35 ` Wei Wang
@ 2019-01-08 8:46 ` Christian Borntraeger
2019-01-09 10:35 ` Wei Wang
0 siblings, 1 reply; 22+ messages in thread
From: Christian Borntraeger @ 2019-01-08 8:46 UTC (permalink / raw)
To: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, mst, cohuck
Cc: pbonzini, dgilbert, pasic
On 08.01.2019 06:35, Wei Wang wrote:
> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
>>
>> On 07.01.2019 08:01, Wei Wang wrote:
>>> virtio-ccw has deadlock issues with reading the config space inside the
>>> interrupt context, so we tweak the virtballoon_changed implementation
>>> by moving the config read operations into the related workqueue contexts.
>>> The config_read_bitmap is used as a flag to the workqueue callbacks
>>> about the related config fields that need to be read.
>>>
>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
>>> the value should be obtained via virtio_balloon_cmd_id_received.
>>>
>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>> Together with
>> virtio_pci: use queue idx instead of array idx to set up the vq
>> virtio: don't allocate vqs when names[i] = NULL
>>
>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
>
> OK. I don't plan to send a new version of the above patches as no changes needed so far.
>
> Michael, if the above two patches look good to you, please help add the related tested-by
> and reviewed-by tags. Thanks.
Can we also make sure that
virtio_pci: use queue idx instead of array idx to set up the vq
virtio: don't allocate vqs when names[i] = NULL
also land in stable?
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-08 8:46 ` Christian Borntraeger
@ 2019-01-09 10:35 ` Wei Wang
2019-01-09 12:07 ` Christian Borntraeger
2019-01-09 14:49 ` Michael S. Tsirkin
0 siblings, 2 replies; 22+ messages in thread
From: Wei Wang @ 2019-01-09 10:35 UTC (permalink / raw)
To: Christian Borntraeger, virtio-dev, linux-kernel, virtualization,
kvm, mst, cohuck
Cc: pbonzini, dgilbert, pasic
On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
>
> On 08.01.2019 06:35, Wei Wang wrote:
>> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
>>> On 07.01.2019 08:01, Wei Wang wrote:
>>>> virtio-ccw has deadlock issues with reading the config space inside the
>>>> interrupt context, so we tweak the virtballoon_changed implementation
>>>> by moving the config read operations into the related workqueue contexts.
>>>> The config_read_bitmap is used as a flag to the workqueue callbacks
>>>> about the related config fields that need to be read.
>>>>
>>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
>>>> the value should be obtained via virtio_balloon_cmd_id_received.
>>>>
>>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>>> Together with
>>> virtio_pci: use queue idx instead of array idx to set up the vq
>>> virtio: don't allocate vqs when names[i] = NULL
>>>
>>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
>> OK. I don't plan to send a new version of the above patches as no changes needed so far.
>>
>> Michael, if the above two patches look good to you, please help add the related tested-by
>> and reviewed-by tags. Thanks.
> Can we also make sure that
>
> virtio_pci: use queue idx instead of array idx to set up the vq
> virtio: don't allocate vqs when names[i] = NULL
>
> also land in stable?
>
You could also send the request to stable after it gets merged to Linus'
tree.
The stable review committee will decide whether to take it.
Please see Option 2:
https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
Best,
Wei
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-09 10:35 ` Wei Wang
@ 2019-01-09 12:07 ` Christian Borntraeger
2019-01-09 14:52 ` Michael S. Tsirkin
2019-01-09 14:49 ` Michael S. Tsirkin
1 sibling, 1 reply; 22+ messages in thread
From: Christian Borntraeger @ 2019-01-09 12:07 UTC (permalink / raw)
To: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, mst, cohuck
Cc: pbonzini, dgilbert, pasic
On 09.01.2019 11:35, Wei Wang wrote:
> On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
>>
>> On 08.01.2019 06:35, Wei Wang wrote:
>>> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
>>>> On 07.01.2019 08:01, Wei Wang wrote:
>>>>> virtio-ccw has deadlock issues with reading the config space inside the
>>>>> interrupt context, so we tweak the virtballoon_changed implementation
>>>>> by moving the config read operations into the related workqueue contexts.
>>>>> The config_read_bitmap is used as a flag to the workqueue callbacks
>>>>> about the related config fields that need to be read.
>>>>>
>>>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
>>>>> the value should be obtained via virtio_balloon_cmd_id_received.
>>>>>
>>>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>>>> Together with
>>>> virtio_pci: use queue idx instead of array idx to set up the vq
>>>> virtio: don't allocate vqs when names[i] = NULL
>>>>
>>>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>> OK. I don't plan to send a new version of the above patches as no changes needed so far.
>>>
>>> Michael, if the above two patches look good to you, please help add the related tested-by
>>> and reviewed-by tags. Thanks.
>> Can we also make sure that
>>
>> virtio_pci: use queue idx instead of array idx to set up the vq
>> virtio: don't allocate vqs when names[i] = NULL
>>
>> also land in stable?
>>
>
> You could also send the request to stable after it gets merged to Linus' tree.
> The stable review committee will decide whether to take it.
>
> Please see Option 2:
>
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
>
Those patches are not upstream yet, Correct?
Michael,
can you add the stable tag before submitting? If not, can you give me a heads up when doing the
pull request so that I can ping the stable folks.
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-09 12:07 ` Christian Borntraeger
@ 2019-01-09 14:52 ` Michael S. Tsirkin
2019-01-09 18:22 ` Christian Borntraeger
0 siblings, 1 reply; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-09 14:52 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, cohuck,
pbonzini, dgilbert, pasic
On Wed, Jan 09, 2019 at 01:07:16PM +0100, Christian Borntraeger wrote:
> On 09.01.2019 11:35, Wei Wang wrote:
> > On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
> >>
> >> On 08.01.2019 06:35, Wei Wang wrote:
> >>> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
> >>>> On 07.01.2019 08:01, Wei Wang wrote:
> >>>>> virtio-ccw has deadlock issues with reading the config space inside the
> >>>>> interrupt context, so we tweak the virtballoon_changed implementation
> >>>>> by moving the config read operations into the related workqueue contexts.
> >>>>> The config_read_bitmap is used as a flag to the workqueue callbacks
> >>>>> about the related config fields that need to be read.
> >>>>>
> >>>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
> >>>>> the value should be obtained via virtio_balloon_cmd_id_received.
> >>>>>
> >>>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >>>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> >>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> >>>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> >>>> Together with
> >>>> virtio_pci: use queue idx instead of array idx to set up the vq
> >>>> virtio: don't allocate vqs when names[i] = NULL
> >>>>
> >>>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >>> OK. I don't plan to send a new version of the above patches as no changes needed so far.
> >>>
> >>> Michael, if the above two patches look good to you, please help add the related tested-by
> >>> and reviewed-by tags. Thanks.
> >> Can we also make sure that
> >>
> >> virtio_pci: use queue idx instead of array idx to set up the vq
> >> virtio: don't allocate vqs when names[i] = NULL
> >>
> >> also land in stable?
> >>
> >
> > You could also send the request to stable after it gets merged to Linus' tree.
> > The stable review committee will decide whether to take it.
> >
> > Please see Option 2:
> >
> > https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> >
>
> Those patches are not upstream yet, Correct?
>
> Michael,
>
> can you add the stable tag before submitting? If not, can you give me a heads up when doing the
> pull request so that I can ping the stable folks.
Can you reply to patches that you feel are needed on stable with just
Cc: stable@vger.kernel.org
in the message body?
Then it's all automatically handled by ack attaching scripts.
--
MST
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-09 14:52 ` Michael S. Tsirkin
@ 2019-01-09 18:22 ` Christian Borntraeger
2019-01-09 18:31 ` Michael S. Tsirkin
0 siblings, 1 reply; 22+ messages in thread
From: Christian Borntraeger @ 2019-01-09 18:22 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, cohuck,
pbonzini, dgilbert, pasic
On 09.01.2019 15:52, Michael S. Tsirkin wrote:
> On Wed, Jan 09, 2019 at 01:07:16PM +0100, Christian Borntraeger wrote:
>> On 09.01.2019 11:35, Wei Wang wrote:
>>> On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
>>>>
>>>> On 08.01.2019 06:35, Wei Wang wrote:
>>>>> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
>>>>>> On 07.01.2019 08:01, Wei Wang wrote:
>>>>>>> virtio-ccw has deadlock issues with reading the config space inside the
>>>>>>> interrupt context, so we tweak the virtballoon_changed implementation
>>>>>>> by moving the config read operations into the related workqueue contexts.
>>>>>>> The config_read_bitmap is used as a flag to the workqueue callbacks
>>>>>>> about the related config fields that need to be read.
>>>>>>>
>>>>>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
>>>>>>> the value should be obtained via virtio_balloon_cmd_id_received.
>>>>>>>
>>>>>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>>>>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
>>>>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
>>>>>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>>>>>> Together with
>>>>>> virtio_pci: use queue idx instead of array idx to set up the vq
>>>>>> virtio: don't allocate vqs when names[i] = NULL
>>>>>>
>>>>>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
>>>>> OK. I don't plan to send a new version of the above patches as no changes needed so far.
>>>>>
>>>>> Michael, if the above two patches look good to you, please help add the related tested-by
>>>>> and reviewed-by tags. Thanks.
>>>> Can we also make sure that
>>>>
>>>> virtio_pci: use queue idx instead of array idx to set up the vq
>>>> virtio: don't allocate vqs when names[i] = NULL
>>>>
>>>> also land in stable?
>>>>
>>>
>>> You could also send the request to stable after it gets merged to Linus' tree.
>>> The stable review committee will decide whether to take it.
>>>
>>> Please see Option 2:
>>>
>>> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
>>>
>>
>> Those patches are not upstream yet, Correct?
>>
>> Michael,
>>
>> can you add the stable tag before submitting? If not, can you give me a heads up when doing the
>> pull request so that I can ping the stable folks.
>
> Can you reply to patches that you feel are needed on stable with just
>
> Cc: stable@vger.kernel.org
>
> in the message body?
>
> Then it's all automatically handled by ack attaching scripts.
Done. But this only works if those patches are not already part of a tree. I guess they have to go via
your tree, correct?
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-09 18:22 ` Christian Borntraeger
@ 2019-01-09 18:31 ` Michael S. Tsirkin
0 siblings, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-09 18:31 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, cohuck,
pbonzini, dgilbert, pasic
On Wed, Jan 09, 2019 at 07:22:50PM +0100, Christian Borntraeger wrote:
>
> On 09.01.2019 15:52, Michael S. Tsirkin wrote:
> > On Wed, Jan 09, 2019 at 01:07:16PM +0100, Christian Borntraeger wrote:
> >> On 09.01.2019 11:35, Wei Wang wrote:
> >>> On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
> >>>>
> >>>> On 08.01.2019 06:35, Wei Wang wrote:
> >>>>> On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
> >>>>>> On 07.01.2019 08:01, Wei Wang wrote:
> >>>>>>> virtio-ccw has deadlock issues with reading the config space inside the
> >>>>>>> interrupt context, so we tweak the virtballoon_changed implementation
> >>>>>>> by moving the config read operations into the related workqueue contexts.
> >>>>>>> The config_read_bitmap is used as a flag to the workqueue callbacks
> >>>>>>> about the related config fields that need to be read.
> >>>>>>>
> >>>>>>> The cmd_id_received is also renamed to cmd_id_received_cache, and
> >>>>>>> the value should be obtained via virtio_balloon_cmd_id_received.
> >>>>>>>
> >>>>>>> Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >>>>>>> Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> >>>>>>> Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> >>>>>>> Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> >>>>>> Together with
> >>>>>> virtio_pci: use queue idx instead of array idx to set up the vq
> >>>>>> virtio: don't allocate vqs when names[i] = NULL
> >>>>>>
> >>>>>> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
> >>>>> OK. I don't plan to send a new version of the above patches as no changes needed so far.
> >>>>>
> >>>>> Michael, if the above two patches look good to you, please help add the related tested-by
> >>>>> and reviewed-by tags. Thanks.
> >>>> Can we also make sure that
> >>>>
> >>>> virtio_pci: use queue idx instead of array idx to set up the vq
> >>>> virtio: don't allocate vqs when names[i] = NULL
> >>>>
> >>>> also land in stable?
> >>>>
> >>>
> >>> You could also send the request to stable after it gets merged to Linus' tree.
> >>> The stable review committee will decide whether to take it.
> >>>
> >>> Please see Option 2:
> >>>
> >>> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
> >>>
> >>
> >> Those patches are not upstream yet, Correct?
> >>
> >> Michael,
> >>
> >> can you add the stable tag before submitting? If not, can you give me a heads up when doing the
> >> pull request so that I can ping the stable folks.
> >
> > Can you reply to patches that you feel are needed on stable with just
> >
> > Cc: stable@vger.kernel.org
> >
> > in the message body?
> >
> > Then it's all automatically handled by ack attaching scripts.
>
> Done. But this only works if those patches are not already part of a tree. I guess they have to go via
> your tree, correct?
Yes. It works because I rebase my tree.
--
MST
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-09 10:35 ` Wei Wang
2019-01-09 12:07 ` Christian Borntraeger
@ 2019-01-09 14:49 ` Michael S. Tsirkin
1 sibling, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-09 14:49 UTC (permalink / raw)
To: Wei Wang
Cc: Christian Borntraeger, virtio-dev, linux-kernel, virtualization,
kvm, cohuck, pbonzini, dgilbert, pasic
On Wed, Jan 09, 2019 at 06:35:01PM +0800, Wei Wang wrote:
> On 01/08/2019 04:46 PM, Christian Borntraeger wrote:
> >
> > On 08.01.2019 06:35, Wei Wang wrote:
> > > On 01/07/2019 09:49 PM, Christian Borntraeger wrote:
> > > > On 07.01.2019 08:01, Wei Wang wrote:
> > > > > virtio-ccw has deadlock issues with reading the config space inside the
> > > > > interrupt context, so we tweak the virtballoon_changed implementation
> > > > > by moving the config read operations into the related workqueue contexts.
> > > > > The config_read_bitmap is used as a flag to the workqueue callbacks
> > > > > about the related config fields that need to be read.
> > > > >
> > > > > The cmd_id_received is also renamed to cmd_id_received_cache, and
> > > > > the value should be obtained via virtio_balloon_cmd_id_received.
> > > > >
> > > > > Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > > > > Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> > > > > Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> > > > > Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
> > > > Together with
> > > > virtio_pci: use queue idx instead of array idx to set up the vq
> > > > virtio: don't allocate vqs when names[i] = NULL
> > > >
> > > > Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > > OK. I don't plan to send a new version of the above patches as no changes needed so far.
> > >
> > > Michael, if the above two patches look good to you, please help add the related tested-by
> > > and reviewed-by tags. Thanks.
> > Can we also make sure that
> >
> > virtio_pci: use queue idx instead of array idx to set up the vq
> > virtio: don't allocate vqs when names[i] = NULL
> >
> > also land in stable?
> >
>
> You could also send the request to stable after it gets merged to Linus'
> tree.
> The stable review committee will decide whether to take it.
>
> Please see Option 2:
>
> https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
>
>
> Best,
> Wei
That's mostly for 3rd party reporters.
Why not Cc stable directly in the patches?
--
MST
^ permalink raw reply [flat|nested] 22+ messages in thread
* Re: [PATCH v3 1/3] virtio-balloon: tweak config_changed implementation
2019-01-07 13:49 ` Christian Borntraeger
2019-01-08 5:35 ` Wei Wang
@ 2019-01-15 0:53 ` Michael S. Tsirkin
1 sibling, 0 replies; 22+ messages in thread
From: Michael S. Tsirkin @ 2019-01-15 0:53 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Wei Wang, virtio-dev, linux-kernel, virtualization, kvm, cohuck,
pbonzini, dgilbert, pasic
On Mon, Jan 07, 2019 at 02:49:03PM +0100, Christian Borntraeger wrote:
>
>
> On 07.01.2019 08:01, Wei Wang wrote:
> > virtio-ccw has deadlock issues with reading the config space inside the
> > interrupt context, so we tweak the virtballoon_changed implementation
> > by moving the config read operations into the related workqueue contexts.
> > The config_read_bitmap is used as a flag to the workqueue callbacks
> > about the related config fields that need to be read.
> >
> > The cmd_id_received is also renamed to cmd_id_received_cache, and
> > the value should be obtained via virtio_balloon_cmd_id_received.
> >
> > Reported-by: Christian Borntraeger <borntraeger@de.ibm.com>
> > Signed-off-by: Wei Wang <wei.w.wang@intel.com>
> > Reviewed-by: Cornelia Huck <cohuck@redhat.com>
> > Reviewed-by: Halil Pasic <pasic@linux.ibm.com>
>
> Together with
> virtio_pci: use queue idx instead of array idx to set up the vq
> virtio: don't allocate vqs when names[i] = NULL
>
> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com>
>
> as already said, would be good to add cc stable (and a Fixes: tag)
I don't think you did that.
Did it manually as the pull needed some manual handling
but I won't next time and you will have to send it to
Greg yourself.
>
> > ---
> > drivers/virtio/virtio_balloon.c | 98 +++++++++++++++++++++++++++--------------
> > 1 file changed, 65 insertions(+), 33 deletions(-)
> >
> > diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> > index 728ecd1..fb12fe2 100644
> > --- a/drivers/virtio/virtio_balloon.c
> > +++ b/drivers/virtio/virtio_balloon.c
> > @@ -61,6 +61,10 @@ enum virtio_balloon_vq {
> > VIRTIO_BALLOON_VQ_MAX
> > };
> >
> > +enum virtio_balloon_config_read {
> > + VIRTIO_BALLOON_CONFIG_READ_CMD_ID = 0,
> > +};
> > +
> > struct virtio_balloon {
> > struct virtio_device *vdev;
> > struct virtqueue *inflate_vq, *deflate_vq, *stats_vq, *free_page_vq;
> > @@ -77,14 +81,20 @@ struct virtio_balloon {
> > /* Prevent updating balloon when it is being canceled. */
> > spinlock_t stop_update_lock;
> > bool stop_update;
> > + /* Bitmap to indicate if reading the related config fields are needed */
> > + unsigned long config_read_bitmap;
> >
> > /* The list of allocated free pages, waiting to be given back to mm */
> > struct list_head free_page_list;
> > spinlock_t free_page_list_lock;
> > /* The number of free page blocks on the above list */
> > unsigned long num_free_page_blocks;
> > - /* The cmd id received from host */
> > - u32 cmd_id_received;
> > + /*
> > + * The cmd id received from host.
> > + * Read it via virtio_balloon_cmd_id_received to get the latest value
> > + * sent from host.
> > + */
> > + u32 cmd_id_received_cache;
> > /* The cmd id that is actively in use */
> > __virtio32 cmd_id_active;
> > /* Buffer to store the stop sign */
> > @@ -390,37 +400,31 @@ static unsigned long return_free_pages_to_mm(struct virtio_balloon *vb,
> > return num_returned;
> > }
> >
> > +static void virtio_balloon_queue_free_page_work(struct virtio_balloon *vb)
> > +{
> > + if (!virtio_has_feature(vb->vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT))
> > + return;
> > +
> > + /* No need to queue the work if the bit was already set. */
> > + if (test_and_set_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> > + &vb->config_read_bitmap))
> > + return;
> > +
> > + queue_work(vb->balloon_wq, &vb->report_free_page_work);
> > +}
> > +
> > static void virtballoon_changed(struct virtio_device *vdev)
> > {
> > struct virtio_balloon *vb = vdev->priv;
> > unsigned long flags;
> > - s64 diff = towards_target(vb);
> > -
> > - if (diff) {
> > - spin_lock_irqsave(&vb->stop_update_lock, flags);
> > - if (!vb->stop_update)
> > - queue_work(system_freezable_wq,
> > - &vb->update_balloon_size_work);
> > - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> > - }
> >
> > - if (virtio_has_feature(vdev, VIRTIO_BALLOON_F_FREE_PAGE_HINT)) {
> > - virtio_cread(vdev, struct virtio_balloon_config,
> > - free_page_report_cmd_id, &vb->cmd_id_received);
> > - if (vb->cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> > - /* Pass ULONG_MAX to give back all the free pages */
> > - return_free_pages_to_mm(vb, ULONG_MAX);
> > - } else if (vb->cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> > - vb->cmd_id_received !=
> > - virtio32_to_cpu(vdev, vb->cmd_id_active)) {
> > - spin_lock_irqsave(&vb->stop_update_lock, flags);
> > - if (!vb->stop_update) {
> > - queue_work(vb->balloon_wq,
> > - &vb->report_free_page_work);
> > - }
> > - spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> > - }
> > + spin_lock_irqsave(&vb->stop_update_lock, flags);
> > + if (!vb->stop_update) {
> > + queue_work(system_freezable_wq,
> > + &vb->update_balloon_size_work);
> > + virtio_balloon_queue_free_page_work(vb);
> > }
> > + spin_unlock_irqrestore(&vb->stop_update_lock, flags);
> > }
> >
> > static void update_balloon_size(struct virtio_balloon *vb)
> > @@ -527,6 +531,17 @@ static int init_vqs(struct virtio_balloon *vb)
> > return 0;
> > }
> >
> > +static u32 virtio_balloon_cmd_id_received(struct virtio_balloon *vb)
> > +{
> > + if (test_and_clear_bit(VIRTIO_BALLOON_CONFIG_READ_CMD_ID,
> > + &vb->config_read_bitmap))
> > + virtio_cread(vb->vdev, struct virtio_balloon_config,
> > + free_page_report_cmd_id,
> > + &vb->cmd_id_received_cache);
> > +
> > + return vb->cmd_id_received_cache;
> > +}
> > +
> > static int send_cmd_id_start(struct virtio_balloon *vb)
> > {
> > struct scatterlist sg;
> > @@ -537,7 +552,8 @@ static int send_cmd_id_start(struct virtio_balloon *vb)
> > while (virtqueue_get_buf(vq, &unused))
> > ;
> >
> > - vb->cmd_id_active = cpu_to_virtio32(vb->vdev, vb->cmd_id_received);
> > + vb->cmd_id_active = virtio32_to_cpu(vb->vdev,
> > + virtio_balloon_cmd_id_received(vb));
> > sg_init_one(&sg, &vb->cmd_id_active, sizeof(vb->cmd_id_active));
> > err = virtqueue_add_outbuf(vq, &sg, 1, &vb->cmd_id_active, GFP_KERNEL);
> > if (!err)
> > @@ -620,7 +636,8 @@ static int send_free_pages(struct virtio_balloon *vb)
> > * stop the reporting.
> > */
> > cmd_id_active = virtio32_to_cpu(vb->vdev, vb->cmd_id_active);
> > - if (cmd_id_active != vb->cmd_id_received)
> > + if (unlikely(cmd_id_active !=
> > + virtio_balloon_cmd_id_received(vb)))
> > break;
> >
> > /*
> > @@ -637,11 +654,9 @@ static int send_free_pages(struct virtio_balloon *vb)
> > return 0;
> > }
> >
> > -static void report_free_page_func(struct work_struct *work)
> > +static void virtio_balloon_report_free_page(struct virtio_balloon *vb)
> > {
> > int err;
> > - struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> > - report_free_page_work);
> > struct device *dev = &vb->vdev->dev;
> >
> > /* Start by sending the received cmd id to host with an outbuf. */
> > @@ -659,6 +674,23 @@ static void report_free_page_func(struct work_struct *work)
> > dev_err(dev, "Failed to send a stop id, err = %d\n", err);
> > }
> >
> > +static void report_free_page_func(struct work_struct *work)
> > +{
> > + struct virtio_balloon *vb = container_of(work, struct virtio_balloon,
> > + report_free_page_work);
> > + u32 cmd_id_received;
> > +
> > + cmd_id_received = virtio_balloon_cmd_id_received(vb);
> > + if (cmd_id_received == VIRTIO_BALLOON_CMD_ID_DONE) {
> > + /* Pass ULONG_MAX to give back all the free pages */
> > + return_free_pages_to_mm(vb, ULONG_MAX);
> > + } else if (cmd_id_received != VIRTIO_BALLOON_CMD_ID_STOP &&
> > + cmd_id_received !=
> > + virtio32_to_cpu(vb->vdev, vb->cmd_id_active)) {
> > + virtio_balloon_report_free_page(vb);
> > + }
> > +}
> > +
> > #ifdef CONFIG_BALLOON_COMPACTION
> > /*
> > * virtballoon_migratepage - perform the balloon page migration on behalf of
> > @@ -885,7 +917,7 @@ static int virtballoon_probe(struct virtio_device *vdev)
> > goto out_del_vqs;
> > }
> > INIT_WORK(&vb->report_free_page_work, report_free_page_func);
> > - vb->cmd_id_received = VIRTIO_BALLOON_CMD_ID_STOP;
> > + vb->cmd_id_received_cache = VIRTIO_BALLOON_CMD_ID_STOP;
> > vb->cmd_id_active = cpu_to_virtio32(vb->vdev,
> > VIRTIO_BALLOON_CMD_ID_STOP);
> > vb->cmd_id_stop = cpu_to_virtio32(vb->vdev,
> >
^ permalink raw reply [flat|nested] 22+ messages in thread