File 0110-vhost-adapt-vhost_verify_ring_mappi.patch of Package qemu.5749
From f0ef7d20f960f74f76ec5bfe667e5f73b98c1b5f Mon Sep 17 00:00:00 2001
From: Greg Kurz <groug@kaod.org>
Date: Fri, 4 Nov 2016 09:39:15 +0100
Subject: [PATCH] vhost: adapt vhost_verify_ring_mappings() to virtio 1 ring
layout
With virtio 1, the vring layout is split in 3 separate regions of
contiguous memory for the descriptor table, the available ring and the
used ring, as opposed with legacy virtio which uses a single region.
In case of memory re-mapping, the code ensures it doesn't affect the
vring mapping. This is done in vhost_verify_ring_mappings() which assumes
the device is legacy.
This patch changes vhost_verify_ring_mappings() to check the mappings of
each part of the vring separately.
This works for legacy mappings as well.
Cc: qemu-stable@nongnu.org
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
(cherry picked from commit f1f9e6c5961ffb36fd4a81cd7edcded7bfad2ab2)
[BR: BSC#1013341]
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
hw/virtio/vhost.c | 79 +++++++++++++++++++++++++++++++++++------------
include/hw/virtio/vhost.h | 4 +++
2 files changed, 64 insertions(+), 19 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 4400718154..dcc2131e01 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -404,32 +404,73 @@ static inline void vhost_dev_log_resize(struct vhost_dev *dev, uint64_t size)
dev->log_size = size;
}
+
+static int vhost_verify_ring_part_mapping(void *part,
+ uint64_t part_addr,
+ uint64_t part_size,
+ uint64_t start_addr,
+ uint64_t size)
+{
+ hwaddr l;
+ void *p;
+ int r = 0;
+
+ if (!ranges_overlap(start_addr, size, part_addr, part_size)) {
+ return 0;
+ }
+ l = part_size;
+ p = cpu_physical_memory_map(part_addr, &l, 1);
+ if (!p || l != part_size) {
+ r = -ENOMEM;
+ }
+ if (p != part) {
+ r = -EBUSY;
+ }
+ cpu_physical_memory_unmap(p, l, 0, 0);
+ return r;
+}
+
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
uint64_t start_addr,
uint64_t size)
{
- int i;
+ int i, j;
int r = 0;
+ const char *part_name[] = {
+ "descriptor table",
+ "available ring",
+ "used ring"
+ };
- for (i = 0; !r && i < dev->nvqs; ++i) {
+ for (i = 0; i < dev->nvqs; ++i) {
struct vhost_virtqueue *vq = dev->vqs + i;
- hwaddr l;
- void *p;
- if (!ranges_overlap(start_addr, size, vq->ring_phys, vq->ring_size)) {
- continue;
+ j = 0;
+ r = vhost_verify_ring_part_mapping(vq->desc, vq->desc_phys,
+ vq->desc_size, start_addr, size);
+ if (!r) {
+ break;
}
- l = vq->ring_size;
- p = cpu_physical_memory_map(vq->ring_phys, &l, 1);
- if (!p || l != vq->ring_size) {
- fprintf(stderr, "Unable to map ring buffer for ring %d\n", i);
- r = -ENOMEM;
+
+ j++;
+ r = vhost_verify_ring_part_mapping(vq->avail, vq->avail_phys,
+ vq->avail_size, start_addr, size);
+ if (!r) {
+ break;
}
- if (p != vq->ring) {
- fprintf(stderr, "Ring buffer relocated for ring %d\n", i);
- r = -EBUSY;
+
+ j++;
+ r = vhost_verify_ring_part_mapping(vq->used, vq->used_phys,
+ vq->used_size, start_addr, size);
+ if (!r) {
+ break;
}
- cpu_physical_memory_unmap(p, l, 0, 0);
+ }
+
+ if (r == -ENOMEM) {
+ error_report("Unable to map %s for ring %d", part_name[j], i);
+ } else if (r == -EBUSY) {
+ error_report("%s relocated for ring %d", part_name[j], i);
}
return r;
}
@@ -837,15 +878,15 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
}
}
- s = l = virtio_queue_get_desc_size(vdev, idx);
- a = virtio_queue_get_desc_addr(vdev, idx);
+ vq->desc_size = s = l = virtio_queue_get_desc_size(vdev, idx);
+ vq->desc_phys = a = virtio_queue_get_desc_addr(vdev, idx);
vq->desc = cpu_physical_memory_map(a, &l, 0);
if (!vq->desc || l != s) {
r = -ENOMEM;
goto fail_alloc_desc;
}
- s = l = virtio_queue_get_avail_size(vdev, idx);
- a = virtio_queue_get_avail_addr(vdev, idx);
+ vq->avail_size = s = l = virtio_queue_get_avail_size(vdev, idx);
+ vq->avail_phys = a = virtio_queue_get_avail_addr(vdev, idx);
vq->avail = cpu_physical_memory_map(a, &l, 0);
if (!vq->avail || l != s) {
r = -ENOMEM;
diff --git a/include/hw/virtio/vhost.h b/include/hw/virtio/vhost.h
index b60d7585b4..6223daa941 100644
--- a/include/hw/virtio/vhost.h
+++ b/include/hw/virtio/vhost.h
@@ -14,6 +14,10 @@ struct vhost_virtqueue {
void *avail;
void *used;
int num;
+ unsigned long long desc_phys;
+ unsigned desc_size;
+ unsigned long long avail_phys;
+ unsigned avail_size;
unsigned long long used_phys;
unsigned used_size;
void *ring;