vfio/pci: Introduce a vfio pci hot reset interface

Legacy vfio pci and iommufd cdev have different process to hot reset
vfio device, expand current code to abstract out pci_hot_reset callback
for legacy vfio, this same interface will also be used by iommufd
cdev vfio device.

Rename vfio_pci_hot_reset to vfio_legacy_pci_hot_reset and move it
into container.c.

vfio_pci_[pre/post]_reset and vfio_pci_host_match are exported so
they could be called in legacy and iommufd pci_hot_reset callback.

Suggested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>

1 files changed, 170 insertions, 0 deletions

diff --git a/hw/vfio/container.c b/hw/vfio/container.c
index ed2d721b2b..1dbf9b9a17 100644
--- a/hw/vfio/container.c
+++ b/hw/vfio/container.c
@@ -33,6 +33,7 @@
 #include "trace.h"
 #include "qapi/error.h"
 #include "migration/migration.h"
+#include "pci.h"
 
 VFIOGroupList vfio_group_list =
     QLIST_HEAD_INITIALIZER(vfio_group_list);
@@ -922,6 +923,174 @@ static void vfio_legacy_detach_device(VFIODevice *vbasedev)
     vfio_put_group(group);
 }
 
+static int vfio_legacy_pci_hot_reset(VFIODevice *vbasedev, bool single)
+{
+    VFIOPCIDevice *vdev = container_of(vbasedev, VFIOPCIDevice, vbasedev);
+    VFIOGroup *group;
+    struct vfio_pci_hot_reset_info *info = NULL;
+    struct vfio_pci_dependent_device *devices;
+    struct vfio_pci_hot_reset *reset;
+    int32_t *fds;
+    int ret, i, count;
+    bool multi = false;
+
+    trace_vfio_pci_hot_reset(vdev->vbasedev.name, single ? "one" : "multi");
+
+    if (!single) {
+        vfio_pci_pre_reset(vdev);
+    }
+    vdev->vbasedev.needs_reset = false;
+
+    ret = vfio_pci_get_pci_hot_reset_info(vdev, &info);
+
+    if (ret) {
+        goto out_single;
+    }
+    devices = &info->devices[0];
+
+    trace_vfio_pci_hot_reset_has_dep_devices(vdev->vbasedev.name);
+
+    /* 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);
+
+        trace_vfio_pci_hot_reset_dep_devices(host.domain,
+                host.bus, host.slot, host.function, devices[i].group_id);
+
+        if (vfio_pci_host_match(&host, vdev->vbasedev.name)) {
+            continue;
+        }
+
+        QLIST_FOREACH(group, &vfio_group_list, next) {
+            if (group->groupid == devices[i].group_id) {
+                break;
+            }
+        }
+
+        if (!group) {
+            if (!vdev->has_pm_reset) {
+                error_report("vfio: Cannot reset device %s, "
+                             "depends on group %d which is not owned.",
+                             vdev->vbasedev.name, devices[i].group_id);
+            }
+            ret = -EPERM;
+            goto out;
+        }
+
+        /* Prep dependent devices for reset and clear our marker. */
+        QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
+            if (!vbasedev_iter->dev->realized ||
+                vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                continue;
+            }
+            tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
+            if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
+                if (single) {
+                    ret = -EINVAL;
+                    goto out_single;
+                }
+                vfio_pci_pre_reset(tmp);
+                tmp->vbasedev.needs_reset = false;
+                multi = true;
+                break;
+            }
+        }
+    }
+
+    if (!single && !multi) {
+        ret = -EINVAL;
+        goto out_single;
+    }
+
+    /* Determine how many group fds need to be passed */
+    count = 0;
+    QLIST_FOREACH(group, &vfio_group_list, next) {
+        for (i = 0; i < info->count; i++) {
+            if (group->groupid == devices[i].group_id) {
+                count++;
+                break;
+            }
+        }
+    }
+
+    reset = g_malloc0(sizeof(*reset) + (count * sizeof(*fds)));
+    reset->argsz = sizeof(*reset) + (count * sizeof(*fds));
+    fds = &reset->group_fds[0];
+
+    /* Fill in group fds */
+    QLIST_FOREACH(group, &vfio_group_list, next) {
+        for (i = 0; i < info->count; i++) {
+            if (group->groupid == devices[i].group_id) {
+                fds[reset->count++] = group->fd;
+                break;
+            }
+        }
+    }
+
+    /* Bus reset! */
+    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_PCI_HOT_RESET, reset);
+    g_free(reset);
+    if (ret) {
+        ret = -errno;
+    }
+
+    trace_vfio_pci_hot_reset_result(vdev->vbasedev.name,
+                                    ret ? strerror(errno) : "Success");
+
+out:
+    /* Re-enable INTx on affected devices */
+    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);
+
+        if (vfio_pci_host_match(&host, vdev->vbasedev.name)) {
+            continue;
+        }
+
+        QLIST_FOREACH(group, &vfio_group_list, next) {
+            if (group->groupid == devices[i].group_id) {
+                break;
+            }
+        }
+
+        if (!group) {
+            break;
+        }
+
+        QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
+            if (!vbasedev_iter->dev->realized ||
+                vbasedev_iter->type != VFIO_DEVICE_TYPE_PCI) {
+                continue;
+            }
+            tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
+            if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
+                vfio_pci_post_reset(tmp);
+                break;
+            }
+        }
+    }
+out_single:
+    if (!single) {
+        vfio_pci_post_reset(vdev);
+    }
+    g_free(info);
+
+    return ret;
+}
+
 const VFIOIOMMUOps vfio_legacy_ops = {
     .dma_map = vfio_legacy_dma_map,
     .dma_unmap = vfio_legacy_dma_unmap,
@@ -929,4 +1098,5 @@ const VFIOIOMMUOps vfio_legacy_ops = {
     .detach_device = vfio_legacy_detach_device,
     .set_dirty_page_tracking = vfio_legacy_set_dirty_page_tracking,
     .query_dirty_bitmap = vfio_legacy_query_dirty_bitmap,
+    .pci_hot_reset = vfio_legacy_pci_hot_reset,
 };