vfio/iommufd: cpr state

VFIO iommufd devices will need access to ioas_id, devid, and hwpt_id in
new QEMU at realize time, so add them to CPR state.  Define CprVFIODevice
as the object which holds the state and is serialized to the vmstate file.
Define accessors to copy state between VFIODevice and CprVFIODevice.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Link: https://lore.kernel.org/qemu-devel/1751493538-202042-15-git-send-email-steven.sistare@oracle.com
Signed-off-by: Cédric Le Goater <clg@redhat.com>

Author: Steve Sistare

hw/vfio/cpr-iommufd.c

@@ -7,14 +7,98 @@
 #include "qemu/osdep.h"
 #include "qapi/error.h"
 #include "hw/vfio/vfio-cpr.h"
+#include "hw/vfio/vfio-device.h"
 #include "migration/blocker.h"
 #include "migration/cpr.h"
 #include "migration/migration.h"
 #include "migration/vmstate.h"
 #include "system/iommufd.h"
 #include "vfio-iommufd.h"
+#include "trace.h"
+
+typedef struct CprVFIODevice {
+    char *name;
+    unsigned int namelen;
+    uint32_t ioas_id;
+    int devid;
+    uint32_t hwpt_id;
+    QLIST_ENTRY(CprVFIODevice) next;
+} CprVFIODevice;
+
+static const VMStateDescription vmstate_cpr_vfio_device = {
+    .name = "cpr vfio device",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(namelen, CprVFIODevice),
+        VMSTATE_VBUFFER_ALLOC_UINT32(name, CprVFIODevice, 0, NULL, namelen),
+        VMSTATE_INT32(devid, CprVFIODevice),
+        VMSTATE_UINT32(ioas_id, CprVFIODevice),
+        VMSTATE_UINT32(hwpt_id, CprVFIODevice),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+const VMStateDescription vmstate_cpr_vfio_devices = {
+    .name = CPR_STATE "/vfio devices",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (const VMStateField[]){
+        VMSTATE_QLIST_V(vfio_devices, CprState, 1, vmstate_cpr_vfio_device,
+                        CprVFIODevice, next),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void vfio_cpr_save_device(VFIODevice *vbasedev)
+{
+    CprVFIODevice *elem = g_new0(CprVFIODevice, 1);
+
+    elem->name = g_strdup(vbasedev->name);
+    elem->namelen = strlen(vbasedev->name) + 1;
+    elem->ioas_id = vbasedev->cpr.ioas_id;
+    elem->devid = vbasedev->devid;
+    elem->hwpt_id = vbasedev->cpr.hwpt_id;
+    QLIST_INSERT_HEAD(&cpr_state.vfio_devices, elem, next);
+}
+
+static CprVFIODevice *find_device(const char *name)
+{
+    CprVFIODeviceList *head = &cpr_state.vfio_devices;
+    CprVFIODevice *elem;
+
+    QLIST_FOREACH(elem, head, next) {
+        if (!strcmp(elem->name, name)) {
+            return elem;
+        }
+    }
+    return NULL;
+}
+
+static void vfio_cpr_delete_device(const char *name)
+{
+    CprVFIODevice *elem = find_device(name);
 
-const VMStateDescription vmstate_cpr_vfio_devices;  /* TBD in a later patch */
+    if (elem) {
+        QLIST_REMOVE(elem, next);
+        g_free(elem->name);
+        g_free(elem);
+    }
+}
+
+static bool vfio_cpr_find_device(VFIODevice *vbasedev)
+{
+    CprVFIODevice *elem = find_device(vbasedev->name);
+
+    if (elem) {
+        vbasedev->cpr.ioas_id = elem->ioas_id;
+        vbasedev->devid = elem->devid;
+        vbasedev->cpr.hwpt_id = elem->hwpt_id;
+        trace_vfio_cpr_find_device(elem->ioas_id, elem->devid, elem->hwpt_id);
+        return true;
+    }
+    return false;
+}
 
 static bool vfio_cpr_supported(IOMMUFDBackend *be, Error **errp)
 {
@@ -81,8 +165,20 @@ void vfio_iommufd_cpr_unregister_container(VFIOIOMMUFDContainer *container)
 
 void vfio_iommufd_cpr_register_device(VFIODevice *vbasedev)
 {
+    if (!cpr_is_incoming()) {
+        vfio_cpr_save_device(vbasedev);
+    }
 }
 
 void vfio_iommufd_cpr_unregister_device(VFIODevice *vbasedev)
 {
+    vfio_cpr_delete_device(vbasedev->name);
+}
+
+void vfio_cpr_load_device(VFIODevice *vbasedev)
+{
+    if (cpr_is_incoming()) {
+        bool ret = vfio_cpr_find_device(vbasedev);
+        g_assert(ret);
+    }
 }

hw/vfio/iommufd.c

@@ -515,6 +515,8 @@ static bool iommufd_cdev_attach(const char *name, VFIODevice *vbasedev,
     const VFIOIOMMUClass *iommufd_vioc =
         VFIO_IOMMU_CLASS(object_class_by_name(TYPE_VFIO_IOMMU_IOMMUFD));
 
+    vfio_cpr_load_device(vbasedev);
+
     if (vbasedev->fd < 0) {
         devfd = iommufd_cdev_getfd(vbasedev->sysfsdev, errp);
         if (devfd < 0) {

hw/vfio/trace-events

@@ -197,6 +197,9 @@ iommufd_cdev_alloc_ioas(int iommufd, int ioas_id) " [iommufd=%d] new IOMMUFD con
 iommufd_cdev_device_info(char *name, int devfd, int num_irqs, int num_regions, int flags) " %s (%d) num_irqs=%d num_regions=%d flags=%d"
 iommufd_cdev_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int dev_id) "\t%04x:%02x:%02x.%x devid %d"
 
+# cpr-iommufd.c
+vfio_cpr_find_device(uint32_t ioas_id, int devid, uint32_t hwpt_id) "ioas_id %u, devid %d, hwpt_id %u"
+
 # device.c
 vfio_device_get_region_info_type(const char *name, int index, uint32_t type, uint32_t subtype) "%s index %d, %08x/%08x"
 vfio_device_reset_handler(void) ""

include/hw/vfio/vfio-cpr.h

@@ -34,6 +34,8 @@ typedef struct VFIOContainerCPR {
 typedef struct VFIODeviceCPR {
     Error *mdev_blocker;
     Error *id_blocker;
+    uint32_t hwpt_id;
+    uint32_t ioas_id;
 } VFIODeviceCPR;
 
 bool vfio_legacy_cpr_register_container(struct VFIOContainer *container,
@@ -55,6 +57,7 @@ bool vfio_iommufd_cpr_register_iommufd(struct IOMMUFDBackend *be, Error **errp);
 void vfio_iommufd_cpr_unregister_iommufd(struct IOMMUFDBackend *be);
 void vfio_iommufd_cpr_register_device(struct VFIODevice *vbasedev);
 void vfio_iommufd_cpr_unregister_device(struct VFIODevice *vbasedev);
+void vfio_cpr_load_device(struct VFIODevice *vbasedev);
 
 int vfio_cpr_group_get_device_fd(int d, const char *name);