VFIO device registration fix + IOMMUFD callbacks + VFIO ioctl handlers

- Removed IOMMU group addition before vfio_register_emulated_iommu_dev() in nv_vgpu_mdev_create()
- Added IOMMUFD callbacks (bind_iommufd, unbind_iommufd, attach_ioas, detach_ioas) using kernel's vfio_iommufd_emulated_* functions
- Implemented VFIO ioctl handlers: GET_INFO, GET_REGION_INFO, GET_IRQ_INFO, SET_IRQS, MMAP
- Added config space read/write handlers at offset 0x70000000000
- Mmap handler for config space, BAR0 (emulation shadow), BAR1-5 (physical VRAM/registers)
- Interrupt handler for VFIO_DEVICE_SET_IRQS (DATA_EVENTFD, DATA_NONE, DATA_BOOL)
- Added udev rules for vfio group permissions
- Created stack_manager.sh unified tool
- Fixed mdev remove crash with deferred cleanup in vfio_device_release callback
- Kernel 6.8+ IOMMUFD compatibility
- QEMU launches successfully with vGPU passthrough

1 files changed, 49 insertions, 4 deletions

diff --git a/kernel/gsp_rpc_client.c b/kernel/gsp_rpc_client.c
index 46d0d50..e91d5f6 100644
--- a/kernel/gsp_rpc_client.c
+++ b/kernel/gsp_rpc_client.c
@@ -132,6 +132,7 @@ struct gsp_client {
     wait_queue_head_t resp_wq;    /* Response wait queue */
     struct workqueue_struct *wq;  /* Workqueue for async */
     bool initialized;
+    bool emulation_mode;          /* Using already-mapped virtual addresses */
 };
 
 struct gsp_pending_rpc {
@@ -962,6 +963,47 @@ struct gsp_client *gsp_client_init(struct device *dev, phys_addr_t fw_base, phys
     return client;
 }
 
+/* Emulation variant: uses already-mapped virtual addresses */
+struct gsp_client *gsp_client_init_emulation(struct device *dev, void __iomem *fw_base_virt, void __iomem *doorbell_virt)
+{
+    struct gsp_client *client;
+
+    client = kzalloc(sizeof(*client), GFP_KERNEL);
+    if (!client)
+        return ERR_PTR(-ENOMEM);
+
+    client->dev = dev;
+    spin_lock_init(&client->lock);
+    mutex_init(&client->rpc_mutex);
+    INIT_LIST_HEAD(&client->pending_rpcs);
+    init_waitqueue_head(&client->resp_wq);
+    atomic_set(&client->seq_counter, 0);
+
+    /* Use already-mapped virtual addresses directly */
+    client->gsp_fw_base = fw_base_virt;
+    client->rpc_doorbell = doorbell_virt;
+
+    client->wq = alloc_workqueue("gsp_rpc", WQ_UNBOUND, 0);
+    if (!client->wq) {
+        kfree(client);
+        return ERR_PTR(-ENOMEM);
+    }
+
+    /* Init emulation workqueue for scheduling */
+    gsp_sched_wq = alloc_workqueue("gsp_sched", WQ_UNBOUND, 0);
+    if (!gsp_sched_wq) {
+        destroy_workqueue(client->wq);
+        kfree(client);
+        return ERR_PTR(-ENOMEM);
+    }
+
+    client->initialized = true;
+    client->emulation_mode = true;
+    pr_info("GSP RPC client initialized (emulation): fw_base=%p, doorbell=%p\n", fw_base_virt, doorbell_virt);
+
+    return client;
+}
+
 void gsp_client_fini(struct gsp_client *client)
 {
     if (!client)
@@ -975,11 +1017,14 @@ void gsp_client_fini(struct gsp_client *client)
         gsp_sched_wq = NULL;
     }
 
-    if (client->rpc_doorbell)
-        iounmap(client->rpc_doorbell);
+    /* Only iounmap if not in emulation mode (addresses were ioremap'd by us) */
+    if (!client->emulation_mode) {
+        if (client->rpc_doorbell)
+            iounmap(client->rpc_doorbell);
 
-    if (client->gsp_fw_base)
-        iounmap(client->gsp_fw_base);
+        if (client->gsp_fw_base)
+            iounmap(client->gsp_fw_base);
+    }
 
     kfree(client);
 }