[PATCH 3/3] vdpa: Check for iova range at mappings changes

["Eugenio Pérez" <eperezma@redhat.com>]

Check vdpa device range before updating memory regions so we don't add
any outside of it, and report the invalid change if any.

Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
---
 include/hw/virtio/vhost-vdpa.h |  2 +
 hw/virtio/vhost-vdpa.c         | 68 ++++++++++++++++++++++++++--------
 hw/virtio/trace-events         |  1 +
 3 files changed, 55 insertions(+), 16 deletions(-)

diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index a8963da2d9..c288cf7ecb 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -13,6 +13,7 @@
 #define HW_VIRTIO_VHOST_VDPA_H
 
 #include "hw/virtio/virtio.h"
+#include "standard-headers/linux/vhost_types.h"
 
 typedef struct VhostVDPAHostNotifier {
     MemoryRegion mr;
@@ -24,6 +25,7 @@ typedef struct vhost_vdpa {
     uint32_t msg_type;
     bool iotlb_batch_begin_sent;
     MemoryListener listener;
+    struct vhost_vdpa_iova_range iova_range;
     struct vhost_dev *dev;
     VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
 } VhostVDPA;
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index a1de6c7c9c..26d0258723 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -33,20 +33,34 @@ static Int128 vhost_vdpa_section_end(const MemoryRegionSection *section)
     return llend;
 }
 
-static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section)
-{
-    return (!memory_region_is_ram(section->mr) &&
-            !memory_region_is_iommu(section->mr)) ||
-            memory_region_is_protected(section->mr) ||
-           /* vhost-vDPA doesn't allow MMIO to be mapped  */
-            memory_region_is_ram_device(section->mr) ||
-           /*
-            * Sizing an enabled 64-bit BAR can cause spurious mappings to
-            * addresses in the upper part of the 64-bit address space.  These
-            * are never accessed by the CPU and beyond the address width of
-            * some IOMMU hardware.  TODO: VDPA should tell us the IOMMU width.
-            */
-           section->offset_within_address_space & (1ULL << 63);
+static bool vhost_vdpa_listener_skipped_section(MemoryRegionSection *section,
+                                                uint64_t iova_min,
+                                                uint64_t iova_max)
+{
+    Int128 llend;
+    bool r = (!memory_region_is_ram(section->mr) &&
+              !memory_region_is_iommu(section->mr)) ||
+              memory_region_is_protected(section->mr) ||
+              /* vhost-vDPA doesn't allow MMIO to be mapped  */
+              memory_region_is_ram_device(section->mr);
+    if (r) {
+        return true;
+    }
+
+    if (section->offset_within_address_space < iova_min) {
+        error_report("RAM section out of device range (min=%lu, addr=%lu)",
+                     iova_min, section->offset_within_address_space);
+        return true;
+    }
+
+    llend = vhost_vdpa_section_end(section);
+    if (int128_make64(llend) > iova_max) {
+        error_report("RAM section out of device range (max=%lu, end addr=%lu)",
+                     iova_max, (uint64_t)int128_make64(llend));
+        return true;
+    }
+
+    return false;
 }
 
 static int vhost_vdpa_dma_map(struct vhost_vdpa *v, hwaddr iova, hwaddr size,
@@ -158,7 +172,8 @@ static void vhost_vdpa_listener_region_add(MemoryListener *listener,
     void *vaddr;
     int ret;
 
-    if (vhost_vdpa_listener_skipped_section(section)) {
+    if (vhost_vdpa_listener_skipped_section(section, v->iova_range.first,
+                                            v->iova_range.last)) {
         return;
     }
 
@@ -216,7 +231,8 @@ static void vhost_vdpa_listener_region_del(MemoryListener *listener,
     Int128 llend, llsize;
     int ret;
 
-    if (vhost_vdpa_listener_skipped_section(section)) {
+    if (vhost_vdpa_listener_skipped_section(section, v->iova_range.first,
+                                            v->iova_range.last)) {
         return;
     }
 
@@ -284,9 +300,24 @@ static void vhost_vdpa_add_status(struct vhost_dev *dev, uint8_t status)
     vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &s);
 }
 
+static int vhost_vdpa_get_iova_range(struct vhost_vdpa *v)
+{
+    int ret;
+
+    ret = vhost_vdpa_call(v->dev, VHOST_VDPA_GET_IOVA_RANGE, &v->iova_range);
+    if (ret != 0) {
+        return ret;
+    }
+
+    trace_vhost_vdpa_get_iova_range(v->dev, v->iova_range.first,
+                                    v->iova_range.last);
+    return ret;
+}
+
 static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
 {
     struct vhost_vdpa *v;
+    int r;
     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
     trace_vhost_vdpa_init(dev, opaque);
 
@@ -296,6 +327,11 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
     v->listener = vhost_vdpa_memory_listener;
     v->msg_type = VHOST_IOTLB_MSG_V2;
 
+    r = vhost_vdpa_get_iova_range(v);
+    if (unlikely(!r)) {
+        return r;
+    }
+
     vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
                                VIRTIO_CONFIG_S_DRIVER);
 
diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
index 8ed19e9d0c..650e521e35 100644
--- a/hw/virtio/trace-events
+++ b/hw/virtio/trace-events
@@ -52,6 +52,7 @@ vhost_vdpa_set_vring_call(void *dev, unsigned int index, int fd) "dev: %p index:
 vhost_vdpa_get_features(void *dev, uint64_t features) "dev: %p features: 0x%"PRIx64
 vhost_vdpa_set_owner(void *dev) "dev: %p"
 vhost_vdpa_vq_get_addr(void *dev, void *vq, uint64_t desc_user_addr, uint64_t avail_user_addr, uint64_t used_user_addr) "dev: %p vq: %p desc_user_addr: 0x%"PRIx64" avail_user_addr: 0x%"PRIx64" used_user_addr: 0x%"PRIx64
+vhost_vdpa_get_iova_range(void *dev, uint64_t first, uint64_t last) "dev: %p first: 0x%"PRIx64" last: 0x%"PRIx64
 
 # virtio.c
 virtqueue_alloc_element(void *elem, size_t sz, unsigned in_num, unsigned out_num) "elem %p size %zd in_num %u out_num %u"
-- 
2.27.0