tools/virtio: add missing compat definitions for vhost_net_test

Patch series "tools: Fix tools/virtio test build", v2.

This series fixes build failures hit by:

  make -C tools/virtio test

Patch 1 adds tools/virtio compatibility definitions needed by current
virtio headers when building the tools/virtio tests.  Patch 2 makes
tools/include/linux/overflow.h include stdint.h for SIZE_MAX, which is
used by its size helper functions.

With the series applied, make -C tools/virtio test builds virtio_test,
vringh_test and vhost_net_test successfully.

Tested on x86_64 and arm64 with:

  make -C tools/virtio clean
  make -C tools/virtio test


This patch (of 2):

vhost_net_test builds virtio_ring.c in userspace.

Recent virtio headers pull in helper headers that are not provided by the
tools/virtio compatibility layer, including asm/percpu_types.h,
linux/completion.h, linux/mod_devicetable.h and linux/virtio_features.h.

Add the missing compat definitions and the DMA attribute used by the
current virtio ring code.

Link: https://lore.kernel.org/20260629022124.131894-1-chenyichong@uniontech.com
Link: https://lore.kernel.org/20260629022124.131894-2-chenyichong@uniontech.com
Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Acked-by: Eugenio Pérez <eperezma@redhat.com>
Cc: chenyichong <chenyichong@uniontech.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

tools/virtio/asm/percpu_types.h

@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_PERCPU_TYPES_H
+#define _ASM_PERCPU_TYPES_H
+
+#define __percpu_qual
+
+#endif /* _ASM_PERCPU_TYPES_H */

tools/virtio/linux/completion.h

@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_COMPLETION_H
+#define _LINUX_COMPLETION_H
+
+struct completion {
+	unsigned int done;
+};
+
+#endif /* _LINUX_COMPLETION_H */

tools/virtio/linux/device.h

@@ -1,4 +1,5 @@
 #ifndef LINUX_DEVICE_H
+#define LINUX_DEVICE_H
 
 struct device {
 	void *parent;

tools/virtio/linux/dma-mapping.h

@@ -61,5 +61,6 @@ enum dma_data_direction {
 #define DMA_MAPPING_ERROR		(~(dma_addr_t)0)
 
 #define DMA_ATTR_CPU_CACHE_CLEAN	(1UL << 11)
+#define DMA_ATTR_DEBUGGING_IGNORE_CACHELINES	0
 
 #endif

tools/virtio/linux/mod_devicetable.h

@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_MOD_DEVICETABLE_H
+#define _LINUX_MOD_DEVICETABLE_H
+
+#include <linux/types.h>
+
+struct virtio_device_id {
+	__u32 device;
+	__u32 vendor;
+};
+
+#define VIRTIO_DEV_ANY_ID	0xffffffff
+
+#endif /* _LINUX_MOD_DEVICETABLE_H */

tools/virtio/linux/virtio_features.h

@@ -0,0 +1,79 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_VIRTIO_FEATURES_H
+#define _LINUX_VIRTIO_FEATURES_H
+
+#include <linux/bug.h>
+#include <linux/string.h>
+#include <linux/types.h>
+
+#define VIRTIO_FEATURES_U64S	2
+#define VIRTIO_FEATURES_BITS	(VIRTIO_FEATURES_U64S * 64)
+
+#define VIRTIO_BIT(b)		(1ULL << ((b) & 0x3f))
+#define VIRTIO_U64(b)		((b) >> 6)
+
+#define VIRTIO_DECLARE_FEATURES(name)			\
+	union {						\
+		u64 name;					\
+		u64 name##_array[VIRTIO_FEATURES_U64S];\
+	}
+
+static inline bool virtio_features_chk_bit(unsigned int bit)
+{
+	return bit < VIRTIO_FEATURES_BITS;
+}
+
+static inline bool virtio_features_test_bit(const u64 *features,
+					    unsigned int bit)
+{
+	return virtio_features_chk_bit(bit) &&
+	       !!(features[VIRTIO_U64(bit)] & VIRTIO_BIT(bit));
+}
+
+static inline void virtio_features_set_bit(u64 *features, unsigned int bit)
+{
+	if (virtio_features_chk_bit(bit))
+		features[VIRTIO_U64(bit)] |= VIRTIO_BIT(bit);
+}
+
+static inline void virtio_features_clear_bit(u64 *features, unsigned int bit)
+{
+	if (virtio_features_chk_bit(bit))
+		features[VIRTIO_U64(bit)] &= ~VIRTIO_BIT(bit);
+}
+
+static inline void virtio_features_zero(u64 *features)
+{
+	memset(features, 0, sizeof(features[0]) * VIRTIO_FEATURES_U64S);
+}
+
+static inline void virtio_features_from_u64(u64 *features, u64 from)
+{
+	virtio_features_zero(features);
+	features[0] = from;
+}
+
+static inline bool virtio_features_equal(const u64 *f1, const u64 *f2)
+{
+	int i;
+
+	for (i = 0; i < VIRTIO_FEATURES_U64S; ++i)
+		if (f1[i] != f2[i])
+			return false;
+	return true;
+}
+
+static inline void virtio_features_copy(u64 *to, const u64 *from)
+{
+	memcpy(to, from, sizeof(to[0]) * VIRTIO_FEATURES_U64S);
+}
+
+static inline void virtio_features_andnot(u64 *to, const u64 *f1, const u64 *f2)
+{
+	int i;
+
+	for (i = 0; i < VIRTIO_FEATURES_U64S; i++)
+		to[i] = f1[i] & ~f2[i];
+}
+
+#endif /* _LINUX_VIRTIO_FEATURES_H */