vhost: logging thinko fix (86e9424d) · Commits · 戴 / test

vhost was dong some complex math to get offset to log at, and got it wrong by a couple of bytes, while in fact it's simple: get address where we write, subtract start of buffer, add log base. Do it this way. Reviewed-by:

Juan Quintela <quintela@redhat.com> Signed-off-by:

Michael S. Tsirkin <mst@redhat.com>

drivers/vhost/vhost.c

+8 −4

Original line number	Diff line number	Diff line
		@@ -1004,10 +1004,14 @@ int vhost_add_used(struct vhost_virtqueue *vq, unsigned int head, int len)
		if (unlikely(vq->log_used)) {
		/* Make sure data is seen before log. */
		smp_wmb();
		log_write(vq->log_base, vq->log_addr + sizeof vq->used->ring
		(vq->last_used_idx % vq->num),
		sizeof *vq->used->ring);
		log_write(vq->log_base, vq->log_addr, sizeof *vq->used->ring);
		/* Log used ring entry write. */
		log_write(vq->log_base,
		vq->log_addr + ((void )used - (void )vq->used),
		sizeof *used);
		/* Log used index update. */
		log_write(vq->log_base,
		vq->log_addr + offsetof(struct vring_used, idx),
		sizeof vq->used->idx);
		if (vq->log_ctx)
		eventfd_signal(vq->log_ctx, 1);
		}

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