1 files changed, 89 insertions, 0 deletions
diff --git a/kernel/main.c b/kernel/main.c
index 637c79b..0a1ebc2 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -2560,5 +2560,94 @@ static const struct kernel_param_ops nv_vgpu_dump_vidmem_ops = {
 module_param_cb(dump_vidmem, &nv_vgpu_dump_vidmem_ops, NULL, 0200);
 MODULE_PARM_DESC(dump_vidmem, "Dump emulated vidmem range (hex offset,hex len)");
 
+/*
+ * Debug: hex-dump a guest physical range (kthread: guest-DMA needs it):
+ *   echo 0x<gpa>,0x<len> > .../parameters/dump_guest
+ */
+struct nv_vgpu_dump_guest_req {
+	u64 gpa;
+	unsigned long len;
+	struct completion done;
+};
+
+static int nv_vgpu_dump_guest_thread(void *arg)
+{
+	struct nv_vgpu_dump_guest_req *req = arg;
+	struct nv_vgpu_device *vgpu;
+	u32 *buf;
+	unsigned long i;
+
+	buf = kmalloc(256, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	mutex_lock(&nv_vgpu_driver.lock);
+	list_for_each_entry(vgpu, &nv_vgpu_driver.devices, list) {
+		u64 o;
+
+		if (atomic_read(&vgpu->vfio_dev_open_count) <= 0)
+			continue;
+		pr_info("gsp-resman-vfio: guest dump 0x%llx..0x%llx\n",
+			req->gpa, req->gpa + req->len);
+		for (o = 0; o < req->len; o += 256) {
+			unsigned long chunk = min_t(unsigned long, 256,
+						    req->len - o);
+
+			if (vfio_dma_rw(&vgpu->vfio_dev, req->gpa + o, buf,
+					chunk, false)) {
+				pr_info("gsp-resman-vfio: guest dump read failed at 0x%llx\n",
+					req->gpa + o);
+				break;
+			}
+			for (i = 0; i < chunk / 4; i += 4)
+				pr_info("gsp-resman-vfio: 0x%llx: %08x %08x %08x %08x\n",
+					req->gpa + o + i * 4, buf[i], buf[i + 1],
+					buf[i + 2], buf[i + 3]);
+		}
+	}
+	mutex_unlock(&nv_vgpu_driver.lock);
+
+	kfree(buf);
+	complete(&req->done);
+	return 0;
+}
+
+static int nv_vgpu_dump_guest_set(const char *val, const struct kernel_param *kp)
+{
+	static struct nv_vgpu_dump_guest_req req;
+	struct task_struct *task;
+	char buf[64];
+	char *comma;
+
+	memset(&req, 0, sizeof(req));
+	strscpy(buf, val, sizeof(buf));
+	comma = strchr(buf, ',');
+	if (comma)
+		*comma = '\0';
+	if (kstrtoull(buf, 0, &req.gpa))
+		return -EINVAL;
+	req.len = 0x100;
+	if (comma && kstrtoul(comma + 1, 0, &req.len))
+		return -EINVAL;
+	if (!req.len)
+		req.len = 0x100;
+	if (req.len > 0x4000)
+		req.len = 0x4000;
+
+	init_completion(&req.done);
+	task = kthread_run(nv_vgpu_dump_guest_thread, &req, "vgpu-dump");
+	if (IS_ERR(task))
+		return PTR_ERR(task);
+	wait_for_completion(&req.done);
+	return 0;
+}
+
+static const struct kernel_param_ops nv_vgpu_dump_guest_ops = {
+	.set = nv_vgpu_dump_guest_set,
+};
+
+module_param_cb(dump_guest, &nv_vgpu_dump_guest_ops, NULL, 0200);
+MODULE_PARM_DESC(dump_guest, "Hex-dump a guest physical range (hex gpa,hex len)");
+
 module_init(nv_vgpu_init);
 module_exit(nv_vgpu_exit);