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-rw-r--r--tools/lguest/Makefile1
-rw-r--r--tools/lguest/lguest.c32
-rw-r--r--tools/virtio/linux/module.h5
-rw-r--r--tools/virtio/linux/virtio.h3
4 files changed, 28 insertions, 13 deletions
diff --git a/tools/lguest/Makefile b/tools/lguest/Makefile
index 0ac3420..97bca48 100644
--- a/tools/lguest/Makefile
+++ b/tools/lguest/Makefile
@@ -1,5 +1,4 @@
# This creates the demonstration utility "lguest" which runs a Linux guest.
-# Missing headers? Add "-I../../../include -I../../../arch/x86/include"
CFLAGS:=-m32 -Wall -Wmissing-declarations -Wmissing-prototypes -O3 -U_FORTIFY_SOURCE
all: lguest
diff --git a/tools/lguest/lguest.c b/tools/lguest/lguest.c
index 07a0345..68f67cf 100644
--- a/tools/lguest/lguest.c
+++ b/tools/lguest/lguest.c
@@ -42,14 +42,6 @@
#include <pwd.h>
#include <grp.h>
-#include <linux/virtio_config.h>
-#include <linux/virtio_net.h>
-#include <linux/virtio_blk.h>
-#include <linux/virtio_console.h>
-#include <linux/virtio_rng.h>
-#include <linux/virtio_ring.h>
-#include <asm/bootparam.h>
-#include "../../include/linux/lguest_launcher.h"
/*L:110
* We can ignore the 43 include files we need for this program, but I do want
* to draw attention to the use of kernel-style types.
@@ -65,6 +57,15 @@ typedef uint16_t u16;
typedef uint8_t u8;
/*:*/
+#include <linux/virtio_config.h>
+#include <linux/virtio_net.h>
+#include <linux/virtio_blk.h>
+#include <linux/virtio_console.h>
+#include <linux/virtio_rng.h>
+#include <linux/virtio_ring.h>
+#include <asm/bootparam.h>
+#include "../../include/linux/lguest_launcher.h"
+
#define BRIDGE_PFX "bridge:"
#ifndef SIOCBRADDIF
#define SIOCBRADDIF 0x89a2 /* add interface to bridge */
@@ -177,7 +178,8 @@ static struct termios orig_term;
* in precise order.
*/
#define wmb() __asm__ __volatile__("" : : : "memory")
-#define mb() __asm__ __volatile__("" : : : "memory")
+#define rmb() __asm__ __volatile__("lock; addl $0,0(%%esp)" : : : "memory")
+#define mb() __asm__ __volatile__("lock; addl $0,0(%%esp)" : : : "memory")
/* Wrapper for the last available index. Makes it easier to change. */
#define lg_last_avail(vq) ((vq)->last_avail_idx)
@@ -676,6 +678,12 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq,
errx(1, "Guest moved used index from %u to %u",
last_avail, vq->vring.avail->idx);
+ /*
+ * Make sure we read the descriptor number *after* we read the ring
+ * update; don't let the cpu or compiler change the order.
+ */
+ rmb();
+
/*
* Grab the next descriptor number they're advertising, and increment
* the index we've seen.
@@ -695,6 +703,12 @@ static unsigned wait_for_vq_desc(struct virtqueue *vq,
i = head;
/*
+ * We have to read the descriptor after we read the descriptor number,
+ * but there's a data dependency there so the CPU shouldn't reorder
+ * that: no rmb() required.
+ */
+
+ /*
* If this is an indirect entry, then this buffer contains a descriptor
* table which we handle as if it's any normal descriptor chain.
*/
diff --git a/tools/virtio/linux/module.h b/tools/virtio/linux/module.h
index 3039a7e..28ce95a 100644
--- a/tools/virtio/linux/module.h
+++ b/tools/virtio/linux/module.h
@@ -1 +1,6 @@
#include <linux/export.h>
+
+#define MODULE_LICENSE(__MODULE_LICENSE_value) \
+ static __attribute__((unused)) const char *__MODULE_LICENSE_name = \
+ __MODULE_LICENSE_value
+
diff --git a/tools/virtio/linux/virtio.h b/tools/virtio/linux/virtio.h
index cd80183..8447830 100644
--- a/tools/virtio/linux/virtio.h
+++ b/tools/virtio/linux/virtio.h
@@ -45,9 +45,6 @@ struct virtqueue {
void *priv;
};
-#define MODULE_LICENSE(__MODULE_LICENSE_value) \
- const char *__MODULE_LICENSE_name = __MODULE_LICENSE_value
-
/* Interfaces exported by virtio_ring. */
int virtqueue_add_sgs(struct virtqueue *vq,
struct scatterlist *sgs[],
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