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vringh: add 'iotlb_lock' to synchronize iotlb accesses

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Usually iotlb accesses are synchronized with a spinlock.
Let's request it as a new parameter in vringh_set_iotlb() and
hold it when we navigate the iotlb in iotlb_translate() to avoid
race conditions with any new additions/deletions of ranges from
the ioltb.

Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20210315163450.254396-3-sgarzare@redhat.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Stefano Garzarella 2021-03-15 17:34:38 +01:00 committed by Michael S. Tsirkin
parent 4080fc1067
commit f53d9910d0
3 changed files with 15 additions and 3 deletions
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3
drivers/vdpa/vdpa_sim/vdpa_sim.c
View File

@ -284,7 +284,8 @@ struct vdpasim *vdpasim_create(struct vdpasim_dev_attr *dev_attr)
goto err_iommu; goto err_iommu;
for (i = 0; i < dev_attr->nvqs; i++) for (i = 0; i < dev_attr->nvqs; i++)
vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu); vringh_set_iotlb(&vdpasim->vqs[i].vring, vdpasim->iommu,
&vdpasim->iommu_lock);
ret = iova_cache_get(); ret = iova_cache_get();
if (ret) if (ret)

9
drivers/vhost/vringh.c
View File

@ -1074,6 +1074,8 @@ static int iotlb_translate(const struct vringh *vrh,
int ret = 0; int ret = 0;
u64 s = 0; u64 s = 0;
spin_lock(vrh->iotlb_lock);
while (len > s) { while (len > s) {
u64 size, pa, pfn; u64 size, pa, pfn;
@ -1103,6 +1105,8 @@ static int iotlb_translate(const struct vringh *vrh,
++ret; ++ret;
} }
spin_unlock(vrh->iotlb_lock);
return ret; return ret;
} }
@ -1262,10 +1266,13 @@ EXPORT_SYMBOL(vringh_init_iotlb);
* vringh_set_iotlb - initialize a vringh for a ring with IOTLB. * vringh_set_iotlb - initialize a vringh for a ring with IOTLB.
* @vrh: the vring * @vrh: the vring
* @iotlb: iotlb associated with this vring * @iotlb: iotlb associated with this vring
* @iotlb_lock: spinlock to synchronize the iotlb accesses
*/ */
void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb) void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb,
spinlock_t *iotlb_lock)
{ {
vrh->iotlb = iotlb; vrh->iotlb = iotlb;
vrh->iotlb_lock = iotlb_lock;
} }
EXPORT_SYMBOL(vringh_set_iotlb); EXPORT_SYMBOL(vringh_set_iotlb);

6
include/linux/vringh.h
View File

@ -46,6 +46,9 @@ struct vringh {
/* IOTLB for this vring */ /* IOTLB for this vring */
struct vhost_iotlb *iotlb; struct vhost_iotlb *iotlb;
/* spinlock to synchronize IOTLB accesses */
spinlock_t *iotlb_lock;
/* The function to call to notify the guest about added buffers */ /* The function to call to notify the guest about added buffers */
void (*notify)(struct vringh *); void (*notify)(struct vringh *);
}; };
@ -258,7 +261,8 @@ static inline __virtio64 cpu_to_vringh64(const struct vringh *vrh, u64 val)
#if IS_REACHABLE(CONFIG_VHOST_IOTLB) #if IS_REACHABLE(CONFIG_VHOST_IOTLB)
void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb); void vringh_set_iotlb(struct vringh *vrh, struct vhost_iotlb *iotlb,
spinlock_t *iotlb_lock);
int vringh_init_iotlb(struct vringh *vrh, u64 features, int vringh_init_iotlb(struct vringh *vrh, u64 features,
unsigned int num, bool weak_barriers, unsigned int num, bool weak_barriers,