[Qemu-devel] [RFC v10 14/19] vfio: add sec_bus_reset notifier to notify physical bus reset is needed

[Chen Fan]

Signed-off-by: Chen Fan <address@hidden>
---
 hw/vfio/pci.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)

diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 53fb544..fad6a80 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -156,6 +156,7 @@ typedef struct VFIOPCIDevice {
     PCIHostDeviceAddress host;
     EventNotifier err_notifier;
     EventNotifier req_notifier;
+    Notifier sec_bus_reset_notifier;
     int (*resetfn)(struct VFIOPCIDevice *);
     uint32_t features;
 #define VFIO_FEATURE_ENABLE_VGA_BIT 0
@@ -171,6 +172,7 @@ typedef struct VFIOPCIDevice {
     bool req_enabled;
     bool has_flr;
     bool has_pm_reset;
+    bool needs_bus_reset;
     bool rom_read_failed;
 } VFIOPCIDevice;
 
@@ -3093,6 +3095,81 @@ static int vfio_check_devices_host_bus_reset(void)
     return 0;
 }
 
+/* Update all the reset state of the affected devices in VM */
+static void vfio_pci_host_needs_bus_reset(Notifier *n, void *opaque)
+{
+    VFIOPCIDevice *vdev = container_of(n, VFIOPCIDevice, 
sec_bus_reset_notifier);
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    PCIDevice *parent = opaque;
+    VFIOGroup *group;
+    struct vfio_pci_hot_reset_info *info = NULL;
+    struct vfio_pci_dependent_device *devices;
+    int i, ret;
+
+    ret = vfio_get_hot_reset_info(vdev, &info);
+    if (ret) {
+        goto out;
+    }
+
+    vdev->needs_bus_reset = true;
+    /*
+     * qbus_reset_all always reset the devices from the depth level,
+     * here only need to do the reset for the device encounter the aer,
+     * in order to avoid reset the affected device first below the bus,
+     * we only set the top level devices as needs_reset.
+     */
+    if (parent == pci_bridge_get_device(vdev->pdev.bus)) {
+        vbasedev->needs_reset = true;
+    }
+
+    /* List all affected devices by bus reset */
+    devices = &info->devices[0];
+
+    /* Verify that we have all the groups required */
+    for (i = 0; i < info->count; i++) {
+        PCIHostDeviceAddress host;
+        VFIOPCIDevice *tmp;
+        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) {
+            goto out;
+        }
+
+        /* Ensure affected devices for reset under the same bus */
+        QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
+            if (vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                continue;
+            }
+            tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
+            if (vfio_pci_host_match(&host, &tmp->host)) {
+                tmp->needs_bus_reset = true;
+                tmp->vbasedev.needs_reset = false;
+                break;
+            }
+        }
+    }
+
+out:
+    g_free(info);
+}
+
 static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t cap_ver,
                           int pos, uint16_t size)
 {
@@ -3165,6 +3242,9 @@ static int vfio_setup_aer(VFIOPCIDevice *vdev, uint8_t 
cap_ver,
                    pdev->exp.aer_cap + PCI_ERR_UNCOR_SEVER, 4);
     pci_long_test_and_clear_mask(exp_cap + PCI_ERR_UNCOR_SEVER, ~severity);
 
+    vdev->sec_bus_reset_notifier.notify = vfio_pci_host_needs_bus_reset;
+    pci_bus_add_reset_notifier(pdev->bus, &vdev->sec_bus_reset_notifier);
+
     return 0;
 
 error:
@@ -4138,6 +4218,7 @@ static void vfio_exitfn(PCIDevice *pdev)
 
     vfio_unregister_req_notifier(vdev);
     vfio_unregister_err_notifier(vdev);
+    pci_bus_remove_reset_notifier(&vdev->sec_bus_reset_notifier);
     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
     vfio_disable_interrupts(vdev);
     if (vdev->intx.mmap_timer) {
-- 
1.9.3