On Mon, Mar 14, 2022 at 10:22:01PM +0900, Suwan Kim wrote: > On Mon, Mar 14, 2022 at 07:15:18AM -0400, Michael S. Tsirkin wrote: > > On Mon, Mar 14, 2022 at 12:25:08PM +0200, Max Gurtovoy wrote: > > > > > > On 3/14/2022 11:43 AM, Suwan Kim wrote: > > > > On Sun, Mar 13, 2022 at 12:37:21PM +0200, Max Gurtovoy wrote: > > > > > On 3/11/2022 6:07 PM, Suwan Kim wrote: > > > > > > On Fri, Mar 11, 2022 at 10:38:07AM -0500, Michael S. Tsirkin wrote: > > > > > > > On Sat, Mar 12, 2022 at 12:28:32AM +0900, Suwan Kim wrote: > > > > > > > > diff --git a/include/uapi/linux/virtio_blk.h > > > > > > > > b/include/uapi/linux/virtio_blk.h > > > > > > > > index d888f013d9ff..3fcaf937afe1 100644 > > > > > > > > --- a/include/uapi/linux/virtio_blk.h > > > > > > > > +++ b/include/uapi/linux/virtio_blk.h > > > > > > > > @@ -119,8 +119,9 @@ struct virtio_blk_config { > > > > > > > > * deallocation of one or more of the sectors. > > > > > > > > */ > > > > > > > > __u8 write_zeroes_may_unmap; > > > > > > > > + __u8 unused1; > > > > > > > > - __u8 unused1[3]; > > > > > > > > + __virtio16 num_poll_queues; > > > > > > > > } __attribute__((packed)); > > > > > > > Same as any virtio UAPI change, this has to go through the virtio > > > > > > > TC. > > > > > > > In particular I don't think gating a new config field on > > > > > > > an existing feature flag is a good idea. > > > > > > Did you mean that the polling should be based on a new feature like > > > > > > "VIRTIO_BLK_F_POLL" and be added at the end of features_legacy[] > > > > > > and features[]? If then, I will add the new feture flag and resend > > > > > > it. > > > > > Isn't there a way in the SPEC today to create a queue without > > > > > interrupt > > > > > vector ? > > > > It seems that it is not possible to create a queue without interrupt > > > > vector. If it is possible, we can expect more polling improvement. > > > > Yes, it's possible: > > > > Writing a valid MSI-X Table entry number, 0 to 0x7FF, to > > \field{config_msix_vector}/\field{queue_msix_vector} maps interrupts > > triggered > > by the configuration change/selected queue events respectively to > > the corresponding MSI-X vector. To disable interrupts for an > > event type, the driver unmaps this event by writing a special NO_VECTOR > > value: > > > > \begin{lstlisting} > > /* Vector value used to disable MSI for queue */ > > #define VIRTIO_MSI_NO_VECTOR 0xffff > > \end{lstlisting} > > Thanks for the information. > > Then, in function vp_find_vqs_msix() at virtio_pci_common.c, it sets > VIRTIO_MSI_NO_VECTOR if vritqueue->callback is NULL as below code. > > static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs, > struct virtqueue *vqs[], vq_callback_t *callbacks[], > ... > if (!callbacks[i]) > msix_vec = VIRTIO_MSI_NO_VECTOR; > ... > > In oder to create poll queue in virtio-blk, I set NULL callback for > poll virtqueues and it will create queue without irq. > > Regards, > Suwan Kim
Yes, it will. -- MST _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization