From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932122Ab2JQKOx (ORCPT ); Wed, 17 Oct 2012 06:14:53 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:33230 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756571Ab2JQKOv (ORCPT ); Wed, 17 Oct 2012 06:14:51 -0400 From: Will Deacon To: linux-kernel@vger.kernel.org Cc: Will Deacon , Rusty Russell , Sasha Levin , Marc Zyngier Subject: [PATCH] virtio: 9p: correctly pass physical address to userspace for high pages Date: Wed, 17 Oct 2012 11:14:37 +0100 Message-Id: <1350468877-7677-1-git-send-email-will.deacon@arm.com> X-Mailer: git-send-email 1.7.4.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When using a virtio transport, the 9p net device allocates pages to back the descriptors inserted into the virtqueue. These allocations may be performed from atomic context (under the channel lock) and can therefore return high mappings which aren't suitable for virt_to_phys. This patch ensures that virtual addresses for virtio queue descriptors are converted to physical addresses using kmap_to_page, which handles high memory correctly. Cc: Rusty Russell Cc: Sasha Levin Signed-off-by: Marc Zyngier Signed-off-by: Will Deacon --- drivers/virtio/virtio_ring.c | 4 +++- net/9p/trans_virtio.c | 3 ++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index e639584..be93946 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -22,6 +22,7 @@ #include #include #include +#include #include /* virtio guest is communicating with a virtual "device" that actually runs on @@ -165,7 +166,8 @@ static int vring_add_indirect(struct vring_virtqueue *vq, /* Use a single buffer which doesn't continue */ head = vq->free_head; vq->vring.desc[head].flags = VRING_DESC_F_INDIRECT; - vq->vring.desc[head].addr = virt_to_phys(desc); + vq->vring.desc[head].addr = page_to_phys(kmap_to_page(desc)) + + ((unsigned long)desc & ~PAGE_MASK); vq->vring.desc[head].len = i * sizeof(struct vring_desc); /* Update free pointer */ diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 35b8911..fd05c81 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -39,6 +39,7 @@ #include #include #include +#include #include #include #include @@ -325,7 +326,7 @@ static int p9_get_mapped_pages(struct virtio_chan *chan, int count = nr_pages; while (nr_pages) { s = rest_of_page(data); - pages[index++] = virt_to_page(data); + pages[index++] = kmap_to_page(data); data += s; nr_pages--; } -- 1.7.4.1