On 2023/8/18 23:08, Eugenio Perez Martin wrote:
> On Wed, Jul 19, 2023 at 9:54 AM Hawkins Jiawei <yin31...@gmail.com> wrote:
>>
>
> The subject could be more explicit. What about "add count argument to
> vhost_svq_poll"?
Hi Eugenio,
Thanks for reviewing.
You are right, I will use this new subject in the v4 patch.
Thanks!
>
> Apart from that:
> Acked-by: Eugenio Pérez <epere...@redhat.com>
>
>> Next patches in this series will no longer perform an
>> immediate poll and check of the device's used buffers
>> for each CVQ state load command. Instead, they will
>> send CVQ state load commands in parallel by polling
>> multiple pending buffers at once.
>>
>> To achieve this, this patch refactoring vhost_svq_poll()
>> to accept a new argument `num`, which allows vhost_svq_poll()
>> to wait for the device to use multiple elements,
>> rather than polling for a single element.
>>
>> Signed-off-by: Hawkins Jiawei <yin31...@gmail.com>
>> ---
>> hw/virtio/vhost-shadow-virtqueue.c | 36 ++++++++++++++++++------------
>> hw/virtio/vhost-shadow-virtqueue.h | 2 +-
>> net/vhost-vdpa.c | 2 +-
>> 3 files changed, 24 insertions(+), 16 deletions(-)
>>
>> diff --git a/hw/virtio/vhost-shadow-virtqueue.c
>> b/hw/virtio/vhost-shadow-virtqueue.c
>> index 49e5aed931..e731b1d2ea 100644
>> --- a/hw/virtio/vhost-shadow-virtqueue.c
>> +++ b/hw/virtio/vhost-shadow-virtqueue.c
>> @@ -514,29 +514,37 @@ static void vhost_svq_flush(VhostShadowVirtqueue *svq,
>> }
>>
>> /**
>> - * Poll the SVQ for one device used buffer.
>> + * Poll the SVQ to wait for the device to use the specified number
>> + * of elements and return the total length written by the device.
>> *
>> * This function race with main event loop SVQ polling, so extra
>> * synchronization is needed.
>> *
>> - * Return the length written by the device.
>> + * @svq: The svq
>> + * @num: The number of elements that need to be used
>> */
>> -size_t vhost_svq_poll(VhostShadowVirtqueue *svq)
>> +size_t vhost_svq_poll(VhostShadowVirtqueue *svq, size_t num)
>> {
>> - int64_t start_us = g_get_monotonic_time();
>> - uint32_t len = 0;
>> + size_t len = 0;
>> + uint32_t r;
>>
>> - do {
>> - if (vhost_svq_more_used(svq)) {
>> - break;
>> - }
>> + while (num--) {
>> + int64_t start_us = g_get_monotonic_time();
>>
>> - if (unlikely(g_get_monotonic_time() - start_us > 10e6)) {
>> - return 0;
>> - }
>> - } while (true);
>> + do {
>> + if (vhost_svq_more_used(svq)) {
>> + break;
>> + }
>> +
>> + if (unlikely(g_get_monotonic_time() - start_us > 10e6)) {
>> + return len;
>> + }
>> + } while (true);
>> +
>> + vhost_svq_get_buf(svq, &r);
>> + len += r;
>> + }
>>
>> - vhost_svq_get_buf(svq, &len);
>> return len;
>> }
>>
>> diff --git a/hw/virtio/vhost-shadow-virtqueue.h
>> b/hw/virtio/vhost-shadow-virtqueue.h
>> index 6efe051a70..5bce67837b 100644
>> --- a/hw/virtio/vhost-shadow-virtqueue.h
>> +++ b/hw/virtio/vhost-shadow-virtqueue.h
>> @@ -119,7 +119,7 @@ void vhost_svq_push_elem(VhostShadowVirtqueue *svq,
>> int vhost_svq_add(VhostShadowVirtqueue *svq, const struct iovec *out_sg,
>> size_t out_num, const struct iovec *in_sg, size_t in_num,
>> VirtQueueElement *elem);
>> -size_t vhost_svq_poll(VhostShadowVirtqueue *svq);
>> +size_t vhost_svq_poll(VhostShadowVirtqueue *svq, size_t num);
>>
>> void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd);
>> void vhost_svq_set_svq_call_fd(VhostShadowVirtqueue *svq, int call_fd);
>> diff --git a/net/vhost-vdpa.c b/net/vhost-vdpa.c
>> index dfd271c456..d1dd140bf6 100644
>> --- a/net/vhost-vdpa.c
>> +++ b/net/vhost-vdpa.c
>> @@ -625,7 +625,7 @@ static ssize_t vhost_vdpa_net_cvq_add(VhostVDPAState *s,
>> size_t out_len,
>> * descriptor. Also, we need to take the answer before SVQ pulls by
>> itself,
>> * when BQL is released
>> */
>> - return vhost_svq_poll(svq);
>> + return vhost_svq_poll(svq, 1);
>> }
>>
>> static ssize_t vhost_vdpa_net_load_cmd(VhostVDPAState *s, uint8_t class,
>> --
>> 2.25.1
>>
>
