vhost: access vq metadata through kernel virtual address

[linux.git] / drivers / vhost / vhost.h

diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h
index e9ed2722b63333404b444f55dd4638a5358c59fa..c5d950cf7627aefeec63ff3aefdf82da18ef4bd8 100644 (file)
--- a/drivers/vhost/vhost.h
+++ b/drivers/vhost/vhost.h
@@ -12,6 +12,9 @@
 #include <linux/virtio_config.h>
 #include <linux/virtio_ring.h>
 #include <linux/atomic.h>
+#include <linux/pagemap.h>
+#include <linux/mmu_notifier.h>
+#include <asm/cacheflush.h>
 
 struct vhost_work;
 typedef void (*vhost_work_fn_t)(struct vhost_work *work);
@@ -80,6 +83,21 @@ enum vhost_uaddr_type {
        VHOST_NUM_ADDRS = 3,
 };
 
+struct vhost_map {
+       int npages;
+       void *addr;
+       struct page **pages;
+};
+
+struct vhost_uaddr {
+       unsigned long uaddr;
+       size_t size;
+       bool write;
+};
+
+#define VHOST_ARCH_CAN_ACCEL_UACCESS defined(CONFIG_MMU_NOTIFIER) && \
+       ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE == 0
+
 /* The virtqueue structure describes a queue attached to a device. */
 struct vhost_virtqueue {
        struct vhost_dev *dev;
@@ -90,7 +108,22 @@ struct vhost_virtqueue {
        struct vring_desc __user *desc;
        struct vring_avail __user *avail;
        struct vring_used __user *used;
+
+#if VHOST_ARCH_CAN_ACCEL_UACCESS
+       /* Read by memory accessors, modified by meta data
+        * prefetching, MMU notifier and vring ioctl().
+        * Synchonrized through mmu_lock (writers) and RCU (writers
+        * and readers).
+        */
+       struct vhost_map __rcu *maps[VHOST_NUM_ADDRS];
+       /* Read by MMU notifier, modified by vring ioctl(),
+        * synchronized through MMU notifier
+        * registering/unregistering.
+        */
+       struct vhost_uaddr uaddrs[VHOST_NUM_ADDRS];
+#endif
        const struct vhost_umem_node *meta_iotlb[VHOST_NUM_ADDRS];
+
        struct file *kick;
        struct eventfd_ctx *call_ctx;
        struct eventfd_ctx *error_ctx;
@@ -145,6 +178,8 @@ struct vhost_virtqueue {
        bool user_be;
 #endif
        u32 busyloop_timeout;
+       spinlock_t mmu_lock;
+       int invalidate_count;
 };
 
 struct vhost_msg_node {
@@ -158,6 +193,9 @@ struct vhost_msg_node {
 
 struct vhost_dev {
        struct mm_struct *mm;
+#ifdef CONFIG_MMU_NOTIFIER
+       struct mmu_notifier mmu_notifier;
+#endif
        struct mutex mutex;
        struct vhost_virtqueue **vqs;
        int nvqs;