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-rw-r--r--drivers/vhost/vhost.c67
1 files changed, 51 insertions, 16 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 9e8e004bb1c3..a9fe859f43c8 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -22,14 +22,20 @@
#include <linux/file.h>
#include <linux/highmem.h>
#include <linux/slab.h>
+#include <linux/vmalloc.h>
#include <linux/kthread.h>
#include <linux/cgroup.h>
#include <linux/module.h>
+#include <linux/sort.h>
#include "vhost.h"
+static ushort max_mem_regions = 64;
+module_param(max_mem_regions, ushort, 0444);
+MODULE_PARM_DESC(max_mem_regions,
+ "Maximum number of memory regions in memory map. (default: 64)");
+
enum {
- VHOST_MEMORY_MAX_NREGIONS = 64,
VHOST_MEMORY_F_LOG = 0x1,
};
@@ -543,7 +549,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev, bool locked)
fput(dev->log_file);
dev->log_file = NULL;
/* No one will access memory at this point */
- kfree(dev->memory);
+ kvfree(dev->memory);
dev->memory = NULL;
WARN_ON(!list_empty(&dev->work_list));
if (dev->worker) {
@@ -663,6 +669,28 @@ int vhost_vq_access_ok(struct vhost_virtqueue *vq)
}
EXPORT_SYMBOL_GPL(vhost_vq_access_ok);
+static int vhost_memory_reg_sort_cmp(const void *p1, const void *p2)
+{
+ const struct vhost_memory_region *r1 = p1, *r2 = p2;
+ if (r1->guest_phys_addr < r2->guest_phys_addr)
+ return 1;
+ if (r1->guest_phys_addr > r2->guest_phys_addr)
+ return -1;
+ return 0;
+}
+
+static void *vhost_kvzalloc(unsigned long size)
+{
+ void *n = kzalloc(size, GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+
+ if (!n) {
+ n = vzalloc(size);
+ if (!n)
+ return ERR_PTR(-ENOMEM);
+ }
+ return n;
+}
+
static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
{
struct vhost_memory mem, *newmem, *oldmem;
@@ -673,21 +701,23 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
return -EFAULT;
if (mem.padding)
return -EOPNOTSUPP;
- if (mem.nregions > VHOST_MEMORY_MAX_NREGIONS)
+ if (mem.nregions > max_mem_regions)
return -E2BIG;
- newmem = kmalloc(size + mem.nregions * sizeof *m->regions, GFP_KERNEL);
+ newmem = vhost_kvzalloc(size + mem.nregions * sizeof(*m->regions));
if (!newmem)
return -ENOMEM;
memcpy(newmem, &mem, size);
if (copy_from_user(newmem->regions, m->regions,
mem.nregions * sizeof *m->regions)) {
- kfree(newmem);
+ kvfree(newmem);
return -EFAULT;
}
+ sort(newmem->regions, newmem->nregions, sizeof(*newmem->regions),
+ vhost_memory_reg_sort_cmp, NULL);
if (!memory_access_ok(d, newmem, 0)) {
- kfree(newmem);
+ kvfree(newmem);
return -EFAULT;
}
oldmem = d->memory;
@@ -699,7 +729,7 @@ static long vhost_set_memory(struct vhost_dev *d, struct vhost_memory __user *m)
d->vqs[i]->memory = newmem;
mutex_unlock(&d->vqs[i]->mutex);
}
- kfree(oldmem);
+ kvfree(oldmem);
return 0;
}
@@ -992,17 +1022,22 @@ EXPORT_SYMBOL_GPL(vhost_dev_ioctl);
static const struct vhost_memory_region *find_region(struct vhost_memory *mem,
__u64 addr, __u32 len)
{
- struct vhost_memory_region *reg;
- int i;
+ const struct vhost_memory_region *reg;
+ int start = 0, end = mem->nregions;
- /* linear search is not brilliant, but we really have on the order of 6
- * regions in practice */
- for (i = 0; i < mem->nregions; ++i) {
- reg = mem->regions + i;
- if (reg->guest_phys_addr <= addr &&
- reg->guest_phys_addr + reg->memory_size - 1 >= addr)
- return reg;
+ while (start < end) {
+ int slot = start + (end - start) / 2;
+ reg = mem->regions + slot;
+ if (addr >= reg->guest_phys_addr)
+ end = slot;
+ else
+ start = slot + 1;
}
+
+ reg = mem->regions + start;
+ if (addr >= reg->guest_phys_addr &&
+ reg->guest_phys_addr + reg->memory_size > addr)
+ return reg;
return NULL;
}