From 96536427bf1f5aeaef726a695a0f218ac2bb091c Mon Sep 17 00:00:00 2001
From: Stone749990226 <749990226@qq.com>
Date: Wed, 15 Apr 2026 16:06:09 +0800
Subject: [PATCH] build: improve hvisor-tool cross-build compatibility and ivc
 kernel API support

Keep tools compiler selection flexible: only fall back to CROSS_COMPILE gcc when CC is the default from make, so explicit CC overrides still work.
Add a local virtio mmio UAPI compatibility header for environments where the cross sysroot lacks linux virtio_mmio definitions.
Make demo binaries optional via BUILD_DEMOS (default off), so the main userspace hvisor binary is not blocked by optional rpmsg demo headers.
Update ivc driver to include linux version checks and use the newer class_create API on Linux 6.4+, while keeping backward-compatible behavior for older kernels.
---
 driver/ivc_driver.c               |  7 +++
 tools/Makefile                    | 10 +++-
 tools/include/linux/virtio_mmio.h | 99 +++++++++++++++++++++++++++++++
 3 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 tools/include/linux/virtio_mmio.h

diff --git a/driver/ivc_driver.c b/driver/ivc_driver.c
index 189695f..7d1904b 100644
--- a/driver/ivc_driver.c
+++ b/driver/ivc_driver.c
@@ -25,6 +25,7 @@
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/uaccess.h>
+#include <linux/version.h>
 #include <linux/wait.h>
 
 #include "hvisor.h"
@@ -216,7 +217,13 @@ static int __init ivc_init(void) {
         goto err1;
     pr_info("ivc get major id: %d\n", MAJOR(mdev_id));
 
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 4, 0)
+    // Linux 6.4+
+    ivc_class = class_create("hivc");
+#else
+    // old interface
     ivc_class = class_create(THIS_MODULE, "hivc");
+#endif
     if (IS_ERR(ivc_class)) {
         err = PTR_ERR(ivc_class);
         goto err1;
diff --git a/tools/Makefile b/tools/Makefile
index 720378e..d4d4657 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -10,6 +10,7 @@ objects ?= $(sources:.c=.o)
 ivc_demo_object ?= ivc_demo.o
 rpmsg_demo_object ?= rpmsg_demo.o
 hvisor_objects ?= $(filter-out $(ivc_demo_object) $(rpmsg_demo_object), $(objects))
+BUILD_DEMOS ?= n
 ROOT ?=
 # gnu or musl
 LIBC ?= gnu
@@ -60,7 +61,9 @@ else
 	CFLAGS += -O2
 endif
 
+ifeq ($(origin CC), default)
 CC := $(CROSS_COMPILE)gcc
+endif
 
 ifeq ($(ARCH), arm64)
 	ifeq ($(VIRTIO_GPU), y)
@@ -76,9 +79,14 @@ else ifeq ($(ARCH), loongarch)
 	endif
 endif
 
+
+ifeq ($(BUILD_DEMOS),y)
+demo_targets := ivc_demo rpmsg_demo
+endif
+
 .PHONY: all clean
 
-all: hvisor ivc_demo rpmsg_demo
+all: hvisor $(demo_targets)
 
 %.d: %.c
 	@set -e; rm -f $@; \
diff --git a/tools/include/linux/virtio_mmio.h b/tools/include/linux/virtio_mmio.h
new file mode 100644
index 0000000..255c04b
--- /dev/null
+++ b/tools/include/linux/virtio_mmio.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+#ifndef _LINUX_VIRTIO_MMIO_H
+#define _LINUX_VIRTIO_MMIO_H
+
+/* Magic value ("virt" string) - Read Only */
+#define VIRTIO_MMIO_MAGIC_VALUE 0x000
+
+/* Virtio device version - Read Only */
+#define VIRTIO_MMIO_VERSION 0x004
+
+/* Virtio device ID - Read Only */
+#define VIRTIO_MMIO_DEVICE_ID 0x008
+
+/* Virtio vendor ID - Read Only */
+#define VIRTIO_MMIO_VENDOR_ID 0x00c
+
+/* Device features - Read Only */
+#define VIRTIO_MMIO_DEVICE_FEATURES 0x010
+
+/* Device features selector - Write Only */
+#define VIRTIO_MMIO_DEVICE_FEATURES_SEL 0x014
+
+/* Driver features - Write Only */
+#define VIRTIO_MMIO_DRIVER_FEATURES 0x020
+
+/* Driver features selector - Write Only */
+#define VIRTIO_MMIO_DRIVER_FEATURES_SEL 0x024
+
+#ifndef VIRTIO_MMIO_NO_LEGACY
+/* Legacy guest page size - Write Only */
+#define VIRTIO_MMIO_GUEST_PAGE_SIZE 0x028
+#endif
+
+/* Queue selector - Write Only */
+#define VIRTIO_MMIO_QUEUE_SEL 0x030
+
+/* Queue size max - Read Only */
+#define VIRTIO_MMIO_QUEUE_NUM_MAX 0x034
+
+/* Queue size - Write Only */
+#define VIRTIO_MMIO_QUEUE_NUM 0x038
+
+#ifndef VIRTIO_MMIO_NO_LEGACY
+/* Legacy used ring alignment - Write Only */
+#define VIRTIO_MMIO_QUEUE_ALIGN 0x03c
+
+/* Legacy queue PFN - Read Write */
+#define VIRTIO_MMIO_QUEUE_PFN 0x040
+#endif
+
+/* Queue ready - Read Write */
+#define VIRTIO_MMIO_QUEUE_READY 0x044
+
+/* Queue notifier - Write Only */
+#define VIRTIO_MMIO_QUEUE_NOTIFY 0x050
+
+/* Interrupt status - Read Only */
+#define VIRTIO_MMIO_INTERRUPT_STATUS 0x060
+
+/* Interrupt acknowledge - Write Only */
+#define VIRTIO_MMIO_INTERRUPT_ACK 0x064
+
+/* Device status - Read Write */
+#define VIRTIO_MMIO_STATUS 0x070
+
+/* Queue descriptor table address (64-bit split) */
+#define VIRTIO_MMIO_QUEUE_DESC_LOW 0x080
+#define VIRTIO_MMIO_QUEUE_DESC_HIGH 0x084
+
+/* Queue available ring address (64-bit split) */
+#define VIRTIO_MMIO_QUEUE_AVAIL_LOW 0x090
+#define VIRTIO_MMIO_QUEUE_AVAIL_HIGH 0x094
+
+/* Queue used ring address (64-bit split) */
+#define VIRTIO_MMIO_QUEUE_USED_LOW 0x0a0
+#define VIRTIO_MMIO_QUEUE_USED_HIGH 0x0a4
+
+/* Shared memory selector */
+#define VIRTIO_MMIO_SHM_SEL 0x0ac
+
+/* Shared memory length (64-bit split) */
+#define VIRTIO_MMIO_SHM_LEN_LOW 0x0b0
+#define VIRTIO_MMIO_SHM_LEN_HIGH 0x0b4
+
+/* Shared memory base address (64-bit split) */
+#define VIRTIO_MMIO_SHM_BASE_LOW 0x0b8
+#define VIRTIO_MMIO_SHM_BASE_HIGH 0x0bc
+
+/* Configuration atomicity value */
+#define VIRTIO_MMIO_CONFIG_GENERATION 0x0fc
+
+/* Per-device config space base */
+#define VIRTIO_MMIO_CONFIG 0x100
+
+/* Interrupt flags */
+#define VIRTIO_MMIO_INT_VRING (1 << 0)
+#define VIRTIO_MMIO_INT_CONFIG (1 << 1)
+
+#endif /* _LINUX_VIRTIO_MMIO_H */