From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:48334) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ebJAR-0000By-0P for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:48:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ebJAP-000519-Ts for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:48:11 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48170) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1ebJAP-000510-Jg for qemu-devel@nongnu.org; Mon, 15 Jan 2018 23:48:09 -0500 Date: Tue, 16 Jan 2018 06:48:07 +0200 From: "Michael S. Tsirkin" Message-ID: <1516077852-7974-24-git-send-email-mst@redhat.com> References: <1516077852-7974-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1516077852-7974-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PULL 23/33] vhost: Simplify ring verification checks List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Maydell , "Dr. David Alan Gilbert" , Igor Mammedov From: "Dr. David Alan Gilbert" 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 with modifications by: Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin Reviewed-by: Igor Mammedov --- 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 83df043..0bdd833 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -450,35 +450,37 @@ 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; @@ -492,22 +494,25 @@ 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 *)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