From nobody Mon Feb 9 00:30:52 2026 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1487363568143273.0406940244951; Fri, 17 Feb 2017 12:32:48 -0800 (PST) Received: from localhost ([::1]:55745 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cepCw-0005Va-VK for importer@patchew.org; Fri, 17 Feb 2017 15:32:47 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44161) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ceobq-00044j-Oc for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:28 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ceobp-0005Xh-CE for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:26 -0500 Received: from mail.kernel.org ([198.145.29.136]:34366) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ceobp-0005Wc-2i for qemu-devel@nongnu.org; Fri, 17 Feb 2017 14:54:25 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D40E32021A; Fri, 17 Feb 2017 19:54:22 +0000 (UTC) Received: from redhat.com (pool-96-237-235-121.bstnma.fios.verizon.net [96.237.235.121]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3F999201FE; Fri, 17 Feb 2017 19:54:21 +0000 (UTC) Date: Fri, 17 Feb 2017 21:54:20 +0200 From: "Michael S. Tsirkin" To: qemu-devel@nongnu.org Message-ID: <1487361200-29966-9-git-send-email-mst@redhat.com> References: <1487361200-29966-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1487361200-29966-1-git-send-email-mst@redhat.com> X-Mailer: git-send-email 2.8.0.287.g0deeb61 X-Mutt-Fcc: =sent X-Virus-Scanned: ClamAV using ClamSMTP X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 198.145.29.136 Subject: [Qemu-devel] [PULL 08/23] virtio: use MemoryRegionCache to access descriptors X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Peter Maydell , Stefan Hajnoczi , Paolo Bonzini Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Paolo Bonzini For now, the cache is created on every virtqueue_pop. Later on, direct descriptors will be able to reuse it. Reviewed-by: Stefan Hajnoczi Signed-off-by: Paolo Bonzini Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/exec/memory.h | 2 ++ hw/virtio/virtio.c | 80 +++++++++++++++++++++++++----------------------= ---- 2 files changed, 41 insertions(+), 41 deletions(-) diff --git a/include/exec/memory.h b/include/exec/memory.h index 987f925..6911023 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -1426,6 +1426,8 @@ struct MemoryRegionCache { bool is_write; }; =20 +#define MEMORY_REGION_CACHE_INVALID ((MemoryRegionCache) { .mr =3D NULL }) + /* address_space_cache_init: prepare for repeated access to a physical * memory region * diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 6ce6a26..71e41f6 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -120,9 +120,10 @@ void virtio_queue_update_rings(VirtIODevice *vdev, int= n) } =20 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 { }; =20 static int virtqueue_read_next_desc(VirtIODevice *vdev, VRingDesc *desc, - void *desc_ptr, unsigned int max, + MemoryRegionCache *desc_cache, unsigne= d 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; } =20 - vring_desc_read(vdev, desc, desc_ptr, *next); + vring_desc_read(vdev, desc, desc_cache, *next); return VIRTQUEUE_READ_DESC_MORE; } =20 @@ -436,24 +437,25 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigne= d int *in_bytes, VirtIODevice *vdev =3D vq->vdev; unsigned int max, idx; unsigned int total_bufs, in_total, out_total; - void *vring_desc_ptr; - void *indirect_desc_ptr =3D NULL; - hwaddr len =3D 0; + MemoryRegionCache vring_desc_cache; + MemoryRegionCache indirect_desc_cache =3D MEMORY_REGION_CACHE_INVALID; + int64_t len =3D 0; int rc; =20 idx =3D vq->last_avail_idx; total_bufs =3D in_total =3D out_total =3D 0; =20 max =3D vq->vring.num; - len =3D max * sizeof(VRingDesc); - vring_desc_ptr =3D address_space_map(vdev->dma_as, vq->vring.desc, &le= n, false); + len =3D 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; } =20 while ((rc =3D virtqueue_num_heads(vq, idx)) > 0) { - void *desc_ptr =3D vring_desc_ptr; + MemoryRegionCache *desc_cache =3D &vring_desc_cache; unsigned int num_bufs; VRingDesc desc; unsigned int i; @@ -464,10 +466,9 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned= int *in_bytes, goto err; } =20 - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); =20 if (desc.flags & VRING_DESC_F_INDIRECT) { - len =3D desc.len; if (desc.len % sizeof(VRingDesc)) { virtio_error(vdev, "Invalid size for indirect buffer table= "); goto err; @@ -480,9 +481,10 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned= int *in_bytes, } =20 /* loop over the indirect descriptor table */ - indirect_desc_ptr =3D address_space_map(vdev->dma_as, desc.add= r, - &len, false); - desc_ptr =3D indirect_desc_ptr; + len =3D address_space_cache_init(&indirect_desc_cache, + vdev->dma_as, + desc.addr, desc.len, false); + desc_cache =3D &indirect_desc_cache; if (len < desc.len) { virtio_error(vdev, "Cannot map indirect buffer"); goto err; @@ -490,7 +492,7 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned = int *in_bytes, =20 max =3D desc.len / sizeof(VRingDesc); num_bufs =3D i =3D 0; - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); } =20 do { @@ -509,16 +511,15 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigne= d int *in_bytes, goto done; } =20 - rc =3D virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i= ); + rc =3D virtqueue_read_next_desc(vdev, &desc, desc_cache, max, = &i); } while (rc =3D=3D VIRTQUEUE_READ_DESC_MORE); =20 if (rc =3D=3D VIRTQUEUE_READ_DESC_ERROR) { goto err; } =20 - if (desc_ptr =3D=3D indirect_desc_ptr) { - address_space_unmap(vdev->dma_as, desc_ptr, len, false, 0); - indirect_desc_ptr =3D NULL; + if (desc_cache =3D=3D &indirect_desc_cache) { + address_space_cache_destroy(&indirect_desc_cache); total_bufs++; } else { total_bufs =3D num_bufs; @@ -530,10 +531,8 @@ void virtqueue_get_avail_bytes(VirtQueue *vq, unsigned= int *in_bytes, } =20 done: - if (indirect_desc_ptr) { - address_space_unmap(vdev->dma_as, indirect_desc_ptr, len, false, 0= ); - } - address_space_unmap(vdev->dma_as, vring_desc_ptr, len, false, 0); + address_space_cache_destroy(&indirect_desc_cache); + address_space_cache_destroy(&vring_desc_cache); if (in_bytes) { *in_bytes =3D in_total; } @@ -673,10 +672,10 @@ static void *virtqueue_alloc_element(size_t sz, unsig= ned out_num, unsigned in_nu void *virtqueue_pop(VirtQueue *vq, size_t sz) { unsigned int i, head, max; - void *vring_desc_ptr; - void *indirect_desc_ptr =3D NULL; - void *desc_ptr; - hwaddr len; + MemoryRegionCache vring_desc_cache; + MemoryRegionCache indirect_desc_cache =3D MEMORY_REGION_CACHE_INVALID; + MemoryRegionCache *desc_cache; + int64_t len; VirtIODevice *vdev =3D vq->vdev; VirtQueueElement *elem =3D NULL; unsigned out_num, in_num; @@ -715,15 +714,16 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) =20 i =3D head; =20 - len =3D max * sizeof(VRingDesc); - vring_desc_ptr =3D address_space_map(vdev->dma_as, vq->vring.desc, &le= n, false); + len =3D 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 done; } =20 - desc_ptr =3D vring_desc_ptr; - vring_desc_read(vdev, &desc, desc_ptr, i); + desc_cache =3D &vring_desc_cache; + vring_desc_read(vdev, &desc, desc_cache, i); if (desc.flags & VRING_DESC_F_INDIRECT) { if (desc.len % sizeof(VRingDesc)) { virtio_error(vdev, "Invalid size for indirect buffer table"); @@ -731,9 +731,9 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) } =20 /* loop over the indirect descriptor table */ - len =3D desc.len; - indirect_desc_ptr =3D address_space_map(vdev->dma_as, desc.addr, &= len, false); - desc_ptr =3D indirect_desc_ptr; + len =3D address_space_cache_init(&indirect_desc_cache, vdev->dma_a= s, + desc.addr, desc.len, false); + desc_cache =3D &indirect_desc_cache; if (len < desc.len) { virtio_error(vdev, "Cannot map indirect buffer"); goto done; @@ -741,7 +741,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) =20 max =3D desc.len / sizeof(VRingDesc); i =3D 0; - vring_desc_read(vdev, &desc, desc_ptr, i); + vring_desc_read(vdev, &desc, desc_cache, i); } =20 /* Collect all the descriptors */ @@ -772,7 +772,7 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) goto err_undo_map; } =20 - rc =3D virtqueue_read_next_desc(vdev, &desc, desc_ptr, max, &i); + rc =3D virtqueue_read_next_desc(vdev, &desc, desc_cache, max, &i); } while (rc =3D=3D VIRTQUEUE_READ_DESC_MORE); =20 if (rc =3D=3D VIRTQUEUE_READ_DESC_ERROR) { @@ -795,10 +795,8 @@ void *virtqueue_pop(VirtQueue *vq, size_t sz) =20 trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num); done: - if (indirect_desc_ptr) { - address_space_unmap(vdev->dma_as, indirect_desc_ptr, len, false, 0= ); - } - address_space_unmap(vdev->dma_as, vring_desc_ptr, len, false, 0); + address_space_cache_destroy(&indirect_desc_cache); + address_space_cache_destroy(&vring_desc_cache); =20 return elem; =20 --=20 MST