Re: [PATCH] virtio_ring: switch to dma_XX barriers for rpmsg

On Thu, Apr 19, 2018 at 07:48:24PM +0200, Paolo Bonzini wrote:

On 19/04/2018 19:46, Michael S. Tsirkin wrote:

quoted

quoted

This should be okay, but I wonder if there should be a virtio_wmb(...)
or an "if (weak_barriers) wmb()" before the "writel" in vm_notify
(drivers/virtio/virtio_mmio.c).

Thanks,

Paolo

That one uses weak barriers AFAIK.

IIUC you mean rproc_virtio_notify.

I suspect it works because specific kick callbacks have a barrier internally.

Yes, that one.  At least keystone_rproc_kick doesn't seem to have a barrier.

Paolo

Any feedback from rproc maintainers?

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MST