From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44387) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cW5SJ-0006G6-1L for qemu-devel@nongnu.org; Tue, 24 Jan 2017 13:04:32 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cW5SI-0000Ap-7z for qemu-devel@nongnu.org; Tue, 24 Jan 2017 13:04:31 -0500 Received: from mail-wm0-x244.google.com ([2a00:1450:400c:c09::244]:33839) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cW5SI-0000Ag-2w for qemu-devel@nongnu.org; Tue, 24 Jan 2017 13:04:30 -0500 Received: by mail-wm0-x244.google.com with SMTP id c85so36300444wmi.1 for ; Tue, 24 Jan 2017 10:04:29 -0800 (PST) Sender: Paolo Bonzini From: Paolo Bonzini Date: Tue, 24 Jan 2017 19:04:19 +0100 Message-Id: <20170124180420.12430-8-pbonzini@redhat.com> In-Reply-To: <20170124180420.12430-1-pbonzini@redhat.com> References: <20170124180420.12430-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 7/8] virtio: use VRingMemoryRegionCaches for descriptor ring List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mst@redhat.com, stefanha@redhat.com Signed-off-by: Paolo Bonzini --- hw/virtio/virtio.c | 28 +++++++++++++--------------- 1 file changed, 13 insertions(+), 15 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 548a3c7..b664b6e 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -487,25 +487,24 @@ 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; @@ -582,13 +581,13 @@ 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: @@ -722,7 +721,7 @@ 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; @@ -764,15 +763,14 @@ 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"); - return NULL; + 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)) { @@ -846,7 +844,7 @@ 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; -- 2.9.3