[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PULL 05/26] vhost: Simplify ring verification checks
From: |
Michael S. Tsirkin |
Subject: |
[Qemu-devel] [PULL 05/26] vhost: Simplify ring verification checks |
Date: |
Thu, 8 Feb 2018 21:09:02 +0200 |
From: "Dr. David Alan Gilbert" <address@hidden>
vhost_verify_ring_mappings() were used to verify that
rings are still accessible and related memory hasn't
been moved after flatview is updated.
It was doing checks by mapping ring's GPA+len and
checking that HVA hadn't changed with new memory map.
To avoid maybe expensive mapping call, we were
identifying address range that changed and were doing
mapping only if ring was in changed range.
However it's not neccessary to perform ring's GPA
mapping as we already have its current HVA and all
we need is to verify that ring's GPA translates to
the same HVA in updated flatview.
This will allow the following patches to simplify the range
comparison that was previously needed to avoid expensive
verify_ring_mapping calls.
Signed-off-by: Igor Mammedov <address@hidden>
with modifications by:
Signed-off-by: Dr. David Alan Gilbert <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
Reviewed-by: Michael S. Tsirkin <address@hidden>
Signed-off-by: Michael S. Tsirkin <address@hidden>
---
hw/virtio/vhost.c | 79 +++++++++++++++++++++++++++++--------------------------
1 file changed, 42 insertions(+), 37 deletions(-)
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 92c9500..91cab51 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -455,35 +455,37 @@ static void vhost_memory_unmap(struct vhost_dev *dev,
void *buffer,
}
}
-static int vhost_verify_ring_part_mapping(struct vhost_dev *dev,
- 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)) {
+static int vhost_verify_ring_part_mapping(void *ring_hva,
+ uint64_t ring_gpa,
+ uint64_t ring_size,
+ void *reg_hva,
+ uint64_t reg_gpa,
+ uint64_t reg_size)
+{
+ uint64_t hva_ring_offset;
+ uint64_t ring_last = range_get_last(ring_gpa, ring_size);
+ uint64_t reg_last = range_get_last(reg_gpa, reg_size);
+
+ if (ring_last < reg_gpa || ring_gpa > reg_last) {
return 0;
}
- l = part_size;
- p = vhost_memory_map(dev, part_addr, &l, 1);
- if (!p || l != part_size) {
- r = -ENOMEM;
+ /* check that whole ring's is mapped */
+ if (ring_last > reg_last) {
+ return -ENOMEM;
}
- if (p != part) {
- r = -EBUSY;
+ /* check that ring's MemoryRegion wasn't replaced */
+ hva_ring_offset = ring_gpa - reg_gpa;
+ if (ring_hva != reg_hva + hva_ring_offset) {
+ return -EBUSY;
}
- vhost_memory_unmap(dev, p, l, 0, 0);
- return r;
+
+ return 0;
}
static int vhost_verify_ring_mappings(struct vhost_dev *dev,
- uint64_t start_addr,
- uint64_t size)
+ void *reg_hva,
+ uint64_t reg_gpa,
+ uint64_t reg_size)
{
int i, j;
int r = 0;
@@ -497,22 +499,25 @@ static int vhost_verify_ring_mappings(struct vhost_dev
*dev,
struct vhost_virtqueue *vq = dev->vqs + i;
j = 0;
- r = vhost_verify_ring_part_mapping(dev, vq->desc, vq->desc_phys,
- vq->desc_size, start_addr, size);
+ r = vhost_verify_ring_part_mapping(
+ vq->desc, vq->desc_phys, vq->desc_size,
+ reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
j++;
- r = vhost_verify_ring_part_mapping(dev, vq->avail, vq->avail_phys,
- vq->avail_size, start_addr, size);
+ r = vhost_verify_ring_part_mapping(
+ vq->desc, vq->desc_phys, vq->desc_size,
+ reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
j++;
- r = vhost_verify_ring_part_mapping(dev, vq->used, vq->used_phys,
- vq->used_size, start_addr, size);
+ r = vhost_verify_ring_part_mapping(
+ vq->desc, vq->desc_phys, vq->desc_size,
+ reg_hva, reg_gpa, reg_size);
if (r) {
break;
}
@@ -635,13 +640,11 @@ static void vhost_commit(MemoryListener *listener)
{
struct vhost_dev *dev = container_of(listener, struct vhost_dev,
memory_listener);
- hwaddr start_addr = 0;
- ram_addr_t size = 0;
MemoryRegionSection *old_sections;
int n_old_sections;
-
uint64_t log_size;
int r;
+ int i;
old_sections = dev->mem_sections;
n_old_sections = dev->n_mem_sections;
@@ -658,12 +661,14 @@ static void vhost_commit(MemoryListener *listener)
goto out;
}
- if (dev->started) {
- start_addr = dev->mem_changed_start_addr;
- size = dev->mem_changed_end_addr - dev->mem_changed_start_addr + 1;
-
- r = vhost_verify_ring_mappings(dev, start_addr, size);
- assert(r >= 0);
+ for (i = 0; i < dev->mem->nregions; i++) {
+ if (vhost_verify_ring_mappings(dev,
+ (void *)(uintptr_t)dev->mem->regions[i].userspace_addr,
+ dev->mem->regions[i].guest_phys_addr,
+ dev->mem->regions[i].memory_size)) {
+ error_report("Verify ring failure on region %d", i);
+ abort();
+ }
}
if (!dev->log_enabled) {
--
MST
- [Qemu-devel] [PULL 00/26] virtio, vhost, pci, pc: features, fixes and cleanups, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 01/26] Revert "vhost: add traces for memory listeners", Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 04/26] vhost: Build temporary section list and deref after commit, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 02/26] virtio: remove event notifier cleanup call on de-assign, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 05/26] vhost: Simplify ring verification checks,
Michael S. Tsirkin <=
- [Qemu-devel] [PULL 06/26] vhost: Merge sections added to temporary list, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 07/26] vhost: Regenerate region list from changed sections list, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 09/26] vhost: Merge and delete unused callbacks, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 10/26] vhost: Move log_dirty check, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 11/26] pci-bridge/i82801b11: clear bridge registers on platform reset, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 08/26] vhost: Clean out old vhost_set_memory and friends, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 13/26] virtio-blk: enable multiple vectors when using multiple I/O queues, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 12/26] pci/bus: let it has higher migration priority, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 17/26] cryptodev-vhost-user: add crypto session handler, Michael S. Tsirkin, 2018/02/08
- [Qemu-devel] [PULL 16/26] cryptodev: add vhost support, Michael S. Tsirkin, 2018/02/08