[Qemu-devel] [RFC v8.1 10/13] vfio: do hot bus reset when do virtual secondary bus reset

[Chen Fan <chen.fan.fnst@cn.fujitsu.com>]

when do virtual secondary bus reset, the vfio device under
this bus need to do host bus reset to reset the device.
so add this case.

Signed-off-by: Chen Fan <chen.fan.fnst@cn.fujitsu.com>
---
 hw/vfio/pci.c | 75 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 75 insertions(+)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index a8c5988..b05ccdf 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -3803,6 +3803,64 @@ out:
     g_free(info);
 }
 
+/* Check when device reset the affected devices is single or multi,
+ * because there was differentiate the hot reset of mulitple in-use
+ * devices and hot reset of a single in-use device. */
+static int vfio_pci_affect_devices_is_multi(VFIOPCIDevice *vdev)
+{
+    VFIOGroup *group;
+    struct vfio_pci_hot_reset_info *info = NULL;
+    struct vfio_pci_dependent_device *devices;
+    int ret, i, count = 0;
+
+    ret = vfio_get_hot_reset_info(vdev, &info);
+    if (ret < 0) {
+        goto out;
+    }
+
+    devices = &info->devices[0];
+
+    /* Verify that we have all the groups required */
+    for (i = 0; i < info->count; i++) {
+        PCIHostDeviceAddress host;
+        VFIODevice *vbasedev_iter;
+
+        host.domain = devices[i].segment;
+        host.bus = devices[i].bus;
+        host.slot = PCI_SLOT(devices[i].devfn);
+        host.function = PCI_FUNC(devices[i].devfn);
+
+        /* Skip the current device */
+        if (vfio_pci_host_match(&host, &vdev->host)) {
+            continue;
+        }
+
+        /* Ensure we own the group of the affected device */
+        QLIST_FOREACH(group, &vfio_group_list, next) {
+            if (group->groupid == devices[i].group_id) {
+                break;
+            }
+        }
+
+        if (!group) {
+            ret = -1;
+            goto out;
+        }
+
+        QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
+            if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                continue;
+            }
+            count++;
+        }
+    }
+
+    ret = count;
+out:
+    g_free(info);
+    return ret;
+}
+
 static void vfio_pci_machine_done_notify(Notifier *notifier, void *unused)
 {
     VFIOGroup *group;
@@ -4039,6 +4097,23 @@ static void vfio_pci_reset(DeviceState *dev)
 
     trace_vfio_pci_reset(vdev->vbasedev.name);
 
+    if (vdev->needs_bus_reset) {
+        vdev->needs_bus_reset = false;
+        if (vdev->vbasedev.needs_reset) {
+            int ret;
+
+            ret = vfio_pci_affect_devices_is_multi(vdev);
+            if (ret < 0) {
+                error_report("vfio: Cannot reset device %04x:%02x:%02x.%x, "
+                             "get hot reset info failed.", vdev->host.domain,
+                             vdev->host.bus, vdev->host.slot, vdev->host.function);
+            } else {
+                vfio_pci_hot_reset(vdev, ret ? true : false);
+            }
+        }
+        return;
+    }
+
     vfio_pci_pre_reset(vdev);
 
     if (vdev->resetfn && !vdev->resetfn(vdev)) {
-- 
1.9.3