virtio-iommu: Record whether a probe request has been issued

Add an IOMMUDevice 'probe_done' flag to record that the driver
already issued a probe request on that device.

This will be useful to double check host reserved regions aren't
notified after the probe and hence are not taken into account
by the driver.

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Suggested-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: "Michael S. Tsirkin" <mst@redhat.com>
Tested-by: Yanghang Liu <yanghliu@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

hw/virtio/virtio-iommu.c

@@ -639,19 +639,13 @@ static int virtio_iommu_unmap(VirtIOIOMMU *s,
     return ret;
 }
 
-static ssize_t virtio_iommu_fill_resv_mem_prop(VirtIOIOMMU *s, uint32_t ep,
+static ssize_t virtio_iommu_fill_resv_mem_prop(IOMMUDevice *sdev, uint32_t ep,
                                                uint8_t *buf, size_t free)
 {
     struct virtio_iommu_probe_resv_mem prop = {};
     size_t size = sizeof(prop), length = size - sizeof(prop.head), total;
-    IOMMUDevice *sdev;
     GList *l;
 
-    sdev = container_of(virtio_iommu_mr(s, ep), IOMMUDevice, iommu_mr);
-    if (!sdev) {
-        return -EINVAL;
-    }
-
     total = size * g_list_length(sdev->resv_regions);
     if (total > free) {
         return -ENOSPC;
@@ -688,19 +682,27 @@ static int virtio_iommu_probe(VirtIOIOMMU *s,
                               uint8_t *buf)
 {
     uint32_t ep_id = le32_to_cpu(req->endpoint);
+    IOMMUMemoryRegion *iommu_mr = virtio_iommu_mr(s, ep_id);
     size_t free = VIOMMU_PROBE_SIZE;
+    IOMMUDevice *sdev;
     ssize_t count;
 
-    if (!virtio_iommu_mr(s, ep_id)) {
+    if (!iommu_mr) {
         return VIRTIO_IOMMU_S_NOENT;
     }
 
-    count = virtio_iommu_fill_resv_mem_prop(s, ep_id, buf, free);
+    sdev = container_of(iommu_mr, IOMMUDevice, iommu_mr);
+    if (!sdev) {
+        return -EINVAL;
+    }
+
+    count = virtio_iommu_fill_resv_mem_prop(sdev, ep_id, buf, free);
     if (count < 0) {
         return VIRTIO_IOMMU_S_INVAL;
     }
     buf += count;
     free -= count;
+    sdev->probe_done = true;
 
     return VIRTIO_IOMMU_S_OK;
 }

include/hw/virtio/virtio-iommu.h

@@ -40,6 +40,7 @@ typedef struct IOMMUDevice {
     MemoryRegion root;          /* The root container of the device */
     MemoryRegion bypass_mr;     /* The alias of shared memory MR */
     GList *resv_regions;
+    bool probe_done;
 } IOMMUDevice;
 
 typedef struct IOMMUPciBus {