From e0e9b406470b8dd75a115cf82c4791f41615c4c3 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 14 Sep 2010 23:53:05 +0800 Subject: vhost: max s/g to match qemu Qemu supports up to UIO_MAXIOV s/g so we have to match that because guest drivers may rely on this. Allocate indirect and log arrays dynamically to avoid using too much contigious memory and make the length of hdr array to match the header length since each iovec entry has a least one byte. Test with copying large files w/ and w/o migration in both linux and windows guests. Signed-off-by: Jason Wang Signed-off-by: Michael S. Tsirkin --- drivers/vhost/net.c | 2 +- drivers/vhost/vhost.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++++- drivers/vhost/vhost.h | 18 ++++++++---------- 3 files changed, 57 insertions(+), 12 deletions(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 7c8008225ee3..72ab71fdf053 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -243,7 +243,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, int r, nlogs = 0; while (datalen > 0) { - if (unlikely(seg >= VHOST_NET_MAX_SG)) { + if (unlikely(seg >= UIO_MAXIOV)) { r = -ENOBUFS; goto err; } diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index dd3d6f7406f8..344019774ddd 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -212,6 +212,45 @@ static int vhost_worker(void *data) } } +/* Helper to allocate iovec buffers for all vqs. */ +static long vhost_dev_alloc_iovecs(struct vhost_dev *dev) +{ + int i; + for (i = 0; i < dev->nvqs; ++i) { + dev->vqs[i].indirect = kmalloc(sizeof *dev->vqs[i].indirect * + UIO_MAXIOV, GFP_KERNEL); + dev->vqs[i].log = kmalloc(sizeof *dev->vqs[i].log * UIO_MAXIOV, + GFP_KERNEL); + dev->vqs[i].heads = kmalloc(sizeof *dev->vqs[i].heads * + UIO_MAXIOV, GFP_KERNEL); + + if (!dev->vqs[i].indirect || !dev->vqs[i].log || + !dev->vqs[i].heads) + goto err_nomem; + } + return 0; +err_nomem: + for (; i >= 0; --i) { + kfree(dev->vqs[i].indirect); + kfree(dev->vqs[i].log); + kfree(dev->vqs[i].heads); + } + return -ENOMEM; +} + +static void vhost_dev_free_iovecs(struct vhost_dev *dev) +{ + int i; + for (i = 0; i < dev->nvqs; ++i) { + kfree(dev->vqs[i].indirect); + dev->vqs[i].indirect = NULL; + kfree(dev->vqs[i].log); + dev->vqs[i].log = NULL; + kfree(dev->vqs[i].heads); + dev->vqs[i].heads = NULL; + } +} + long vhost_dev_init(struct vhost_dev *dev, struct vhost_virtqueue *vqs, int nvqs) { @@ -229,6 +268,9 @@ long vhost_dev_init(struct vhost_dev *dev, dev->worker = NULL; for (i = 0; i < dev->nvqs; ++i) { + dev->vqs[i].log = NULL; + dev->vqs[i].indirect = NULL; + dev->vqs[i].heads = NULL; dev->vqs[i].dev = dev; mutex_init(&dev->vqs[i].mutex); vhost_vq_reset(dev, dev->vqs + i); @@ -295,6 +337,10 @@ static long vhost_dev_set_owner(struct vhost_dev *dev) if (err) goto err_cgroup; + err = vhost_dev_alloc_iovecs(dev); + if (err) + goto err_cgroup; + return 0; err_cgroup: kthread_stop(worker); @@ -345,6 +391,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) fput(dev->vqs[i].call); vhost_vq_reset(dev, dev->vqs + i); } + vhost_dev_free_iovecs(dev); if (dev->log_ctx) eventfd_ctx_put(dev->log_ctx); dev->log_ctx = NULL; @@ -947,7 +994,7 @@ static int get_indirect(struct vhost_dev *dev, struct vhost_virtqueue *vq, } ret = translate_desc(dev, indirect->addr, indirect->len, vq->indirect, - ARRAY_SIZE(vq->indirect)); + UIO_MAXIOV); if (unlikely(ret < 0)) { vq_err(vq, "Translation failure %d in indirect.\n", ret); return ret; diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index afd77295971c..edc892989992 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -15,11 +15,6 @@ struct vhost_device; -enum { - /* Enough place for all fragments, head, and virtio net header. */ - VHOST_NET_MAX_SG = MAX_SKB_FRAGS + 2, -}; - struct vhost_work; typedef void (*vhost_work_fn_t)(struct vhost_work *work); @@ -93,12 +88,15 @@ struct vhost_virtqueue { bool log_used; u64 log_addr; - struct iovec indirect[VHOST_NET_MAX_SG]; - struct iovec iov[VHOST_NET_MAX_SG]; - struct iovec hdr[VHOST_NET_MAX_SG]; + struct iovec iov[UIO_MAXIOV]; + /* hdr is used to store the virtio header. + * Since each iovec has >= 1 byte length, we never need more than + * header length entries to store the header. */ + struct iovec hdr[sizeof(struct virtio_net_hdr_mrg_rxbuf)]; + struct iovec *indirect; size_t vhost_hlen; size_t sock_hlen; - struct vring_used_elem heads[VHOST_NET_MAX_SG]; + struct vring_used_elem *heads; /* We use a kind of RCU to access private pointer. * All readers access it from worker, which makes it possible to * flush the vhost_work instead of synchronize_rcu. Therefore readers do @@ -109,7 +107,7 @@ struct vhost_virtqueue { void *private_data; /* Log write descriptors */ void __user *log_base; - struct vhost_log log[VHOST_NET_MAX_SG]; + struct vhost_log *log; }; struct vhost_dev { -- cgit v1.2.3-58-ga151 From 6d97e55f7172303082850c1de085d06fc1e57d17 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Mon, 11 Oct 2010 19:24:19 +0200 Subject: vhost: fix return code for log_access_ok() access_ok() returns 1 if it's OK otherwise it should return 0. Signed-off-by: Dan Carpenter Signed-off-by: Michael S. Tsirkin --- drivers/vhost/vhost.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/vhost') diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index dd3d6f7406f8..158004e46e56 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -371,7 +371,7 @@ static int log_access_ok(void __user *log_base, u64 addr, unsigned long sz) /* Make sure 64 bit math will not overflow. */ if (a > ULONG_MAX - (unsigned long)log_base || a + (unsigned long)log_base > ULONG_MAX) - return -EFAULT; + return 0; return access_ok(VERIFY_WRITE, log_base + a, (sz + VHOST_PAGE_SIZE * 8 - 1) / VHOST_PAGE_SIZE / 8); -- cgit v1.2.3-58-ga151