From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44215) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceoc4-0004H0-CK for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ceobz-0005fU-DV for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:40 -0500 Received: from mail.kernel.org ([198.145.29.136]:34414) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ceobz-0005es-3B for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:35 -0500 Date: Fri, 17 Feb 2017 21:54:30 +0200 From: "Michael S. Tsirkin" Message-ID: <1487361200-29966-11-git-send-email-mst@redhat.com> References: <1487361200-29966-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1487361200-29966-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 10/23] virtio: use VRingMemoryRegionCaches for descriptor ring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , Paolo Bonzini , Stefan Hajnoczi From: Paolo Bonzini Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/virtio/virtio.c | 26 ++++++++++++-------------- 1 file changed, 12 insertions(+), 14 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index b75cb52..d62509d 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -491,25 +491,24 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, VirtIODevice *vdev = vq->vdev; unsigned int max, idx; unsigned int total_bufs, in_total, out_total; - MemoryRegionCache vring_desc_cache; + VRingMemoryRegionCaches *caches; MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; int64_t len = 0; int rc; + rcu_read_lock(); idx = vq->last_avail_idx; total_bufs = in_total = out_total = 0; max = vq->vring.num; - len = address_space_cache_init(&vring_desc_cache, vdev->dma_as, - vq->vring.desc, max * sizeof(VRingDesc), - false); - if (len < max * sizeof(VRingDesc)) { + caches = atomic_rcu_read(&vq->vring.caches); + if (caches->desc.len < max * sizeof(VRingDesc)) { virtio_error(vdev, "Cannot map descriptor ring"); goto err; } while ((rc = virtqueue_num_heads(vq, idx)) > 0) { - MemoryRegionCache *desc_cache = &vring_desc_cache; + MemoryRegionCache *desc_cache = &caches->desc; unsigned int num_bufs; VRingDesc desc; unsigned int i; @@ -586,13 +585,13 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, done: address_space_cache_destroy(&indirect_desc_cache); - address_space_cache_destroy(&vring_desc_cache); if (in_bytes) { *in_bytes = in_total; } if (out_bytes) { *out_bytes = out_total; } + rcu_read_unlock(); return; err: @@ -726,7 +725,7 @@ static void *virtqueue_alloc_element(size_t sz, unsigned out_num, unsigned in_nu void *virtqueue_pop(VirtQueue *vq, size_t sz) { unsigned int i, head, max; - MemoryRegionCache vring_desc_cache; + VRingMemoryRegionCaches *caches; MemoryRegionCache indirect_desc_cache = MEMORY_REGION_CACHE_INVALID; MemoryRegionCache *desc_cache; int64_t len; @@ -768,15 +767,14 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) i = head; - len = address_space_cache_init(&vring_desc_cache, vdev->dma_as, - vq->vring.desc, max * sizeof(VRingDesc), - false); - if (len < max * sizeof(VRingDesc)) { + rcu_read_lock(); + caches = atomic_rcu_read(&vq->vring.caches); + if (caches->desc.len < max * sizeof(VRingDesc)) { virtio_error(vdev, "Cannot map descriptor ring"); goto done; } - desc_cache = &vring_desc_cache; + desc_cache = &caches->desc; vring_desc_read(vdev, &desc, desc_cache, i); if (desc.flags & VRING_DESC_F_INDIRECT) { if (desc.len % sizeof(VRingDesc)) { @@ -850,7 +848,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); done: address_space_cache_destroy(&indirect_desc_cache); - address_space_cache_destroy(&vring_desc_cache); + rcu_read_unlock(); return elem; -- MST