From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50548) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cUcfX-0006pu-Oq for qemu-devel@nongnu.org; Fri, 20 Jan 2017 12:08:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cUcfU-0001KO-Ug for qemu-devel@nongnu.org; Fri, 20 Jan 2017 12:08:07 -0500 Received: from mx1.redhat.com ([209.132.183.28]:45852) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cUcfU-0001Ja-LX for qemu-devel@nongnu.org; Fri, 20 Jan 2017 12:08:04 -0500 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id DA4FC80E4A for ; Fri, 20 Jan 2017 17:08:04 +0000 (UTC) From: Paolo Bonzini Date: Fri, 20 Jan 2017 18:07:54 +0100 Message-Id: <20170120170757.30308-5-pbonzini@redhat.com> In-Reply-To: <20170120170757.30308-1-pbonzini@redhat.com> References: <20170120170757.30308-1-pbonzini@redhat.com> Subject: [Qemu-devel] [PATCH 4/7] virtio: use MemoryRegionCache to access descriptors List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: mst@redhat.com, stefanha@redhat.com For now, the cache is created on every virtqueue_pop. Later on, direct descriptors will be able to reuse it. Signed-off-by: Paolo Bonzini --- hw/virtio/virtio.c | 91 ++++++++++++++++++++++++++++++------------------------ 1 file changed, 50 insertions(+), 41 deletions(-) diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 7a49f2e..52673d1 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -120,9 +120,10 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int n) } static void vring_desc_read(VirtIODevice *vdev, VRingDesc *desc, - uint8_t *desc_ptr, int i) + MemoryRegionCache *cache, int i) { - memcpy(desc, desc_ptr + i * sizeof(VRingDesc), sizeof(VRingDesc)); + address_space_read_cached(cache, i * sizeof(VRingDesc), + desc, sizeof(VRingDesc)); virtio_tswap64s(vdev, &desc->addr); virtio_tswap32s(vdev, &desc->len); virtio_tswap16s(vdev, &desc->flags); @@ -407,7 +408,7 @@ enum { }; static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, - void *desc_ptr, unsigned int max, + MemoryRegionCache *desc_cache, unsigned int max, unsigned int *next) { /* If this descriptor says it doesn't chain, we're done. */ @@ -425,7 +426,7 @@ static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, return VIRTQUEUE_READ_DESC_ERROR; } - vring_desc_read(vdev, desc, desc_ptr, *next); + vring_desc_read(vdev, desc, desc_cache, *next); return VIRTQUEUE_READ_DESC_MORE; } @@ -434,39 +435,40 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, unsigned max_in_bytes, unsigned max_out_bytes) { VirtIODevice *vdev = vq->vdev; - unsigned int idx; + unsigned int max, idx; unsigned int total_bufs, in_total, out_total; - void *desc_ptr = NULL; - hwaddr len = 0; + MemoryRegionCache *desc_cache = NULL; + MemoryRegionCache vring_desc_cache; + MemoryRegionCache indirect_desc_cache; + int64_t len = 0; int rc; idx = vq->last_avail_idx; + 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)) { + virtio_error(vdev, "Cannot map descriptor ring"); + goto err; + } total_bufs = in_total = out_total = 0; while ((rc = virtqueue_num_heads(vq, idx)) > 0) { - unsigned int max, num_bufs, indirect = 0; + unsigned int num_bufs; VRingDesc desc; unsigned int i; - max = vq->vring.num; num_bufs = total_bufs; if (!virtqueue_get_head(vq, idx++, &i)) { goto err; } - len = max * sizeof(VRingDesc); - desc_ptr = address_space_map(vdev->dma_as, vq->vring.desc, &len, false); - if (len < max * sizeof(VRingDesc)) { - virtio_error(vdev, "Cannot map descriptor ring"); - goto err; - } - - vring_desc_read(vdev, &desc, desc_ptr, i); + desc_cache = &vring_desc_cache; + vring_desc_read(vdev, &desc, desc_cache, i); if (desc.flags & VRING_DESC_F_INDIRECT) { - address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0); - len = desc.len; if (desc.len % sizeof(VRingDesc)) { virtio_error(vdev, "Invalid size for indirect buffer table"); goto err; @@ -479,16 +481,18 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, } /* loop over the indirect descriptor table */ - desc_ptr = address_space_map(vdev->dma_as, desc.addr, &len, false); + len = address_space_cache_init(&indirect_desc_cache, + vdev->dma_as, + desc.addr, desc.len, false); + desc_cache = &indirect_desc_cache; if (len < desc.len) { virtio_error(vdev, "Cannot map indirect buffer"); goto err; } - indirect = 1; max = desc.len / sizeof(VRingDesc); num_bufs = i = 0; - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); } do { @@ -507,17 +511,19 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, goto done; } - rc = virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i); + rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); } while (rc == VIRTQUEUE_READ_DESC_MORE); if (rc == VIRTQUEUE_READ_DESC_ERROR) { goto err; } - if (!indirect) - total_bufs = num_bufs; - else + if (desc_cache == &indirect_desc_cache) { + address_space_cache_destroy(&indirect_desc_cache); total_bufs++; + } else { + total_bufs = num_bufs; + } } if (rc < 0) { @@ -525,9 +531,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned int *in_bytes, } done: - if (desc_ptr) { - address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0); - } + address_space_cache_destroy(&vring_desc_cache); if (in_bytes) { *in_bytes = in_total; } @@ -667,8 +671,10 @@ 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; - void *desc_ptr = NULL; - hwaddr len; + MemoryRegionCache *desc_cache = NULL; + MemoryRegionCache indirect_desc_cache; + MemoryRegionCache vring_desc_cache; + int64_t len; VirtIODevice *vdev = vq->vdev; VirtQueueElement *elem = NULL; unsigned out_num, in_num; @@ -707,24 +713,26 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) i = head; - len = max * sizeof(VRingDesc); - desc_ptr = address_space_map(vdev->dma_as, vq->vring.desc, &len, false); + len = address_space_cache_init(&vring_desc_cache, vdev->dma_as, + vq->vring.desc, max * sizeof(VRingDesc), + false); + desc_cache = &vring_desc_cache; if (len < max * sizeof(VRingDesc)) { virtio_error(vdev, "Cannot map descriptor ring"); return NULL; } - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); if (desc.flags & VRING_DESC_F_INDIRECT) { - address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0); if (desc.len % sizeof(VRingDesc)) { virtio_error(vdev, "Invalid size for indirect buffer table"); return NULL; } /* loop over the indirect descriptor table */ - len = desc.len; - desc_ptr = address_space_map(vdev->dma_as, desc.addr, &len, false); + len = address_space_cache_init(&indirect_desc_cache, vdev->dma_as, + desc.addr, desc.len, false); + desc_cache = &indirect_desc_cache; if (len < desc.len) { virtio_error(vdev, "Cannot map indirect buffer"); return NULL; @@ -732,7 +740,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) max = desc.len / sizeof(VRingDesc); i = 0; - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); } /* Collect all the descriptors */ @@ -763,7 +771,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) goto err_undo_map; } - rc = virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i); + rc = virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); } while (rc == VIRTQUEUE_READ_DESC_MORE); if (rc == VIRTQUEUE_READ_DESC_ERROR) { @@ -786,9 +794,10 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); done: - if (desc_ptr) { - address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0); + if (desc_cache == &indirect_desc_cache) { + address_space_cache_destroy(&indirect_desc_cache); } + address_space_cache_destroy(&vring_desc_cache); return elem; -- 2.9.3