kernel.git/drivers/vhost/vringh.c, branch linux-6.3.y

vringh: use bvec_set_page to initialize a bvec

2023-02-03T17:17:42Z

Use the bvec_set_page helper to initialize a bvec. Signed-off-by: Christoph Hellwig Acked-by: Jason Wang Link: https://lore.kernel.org/r/20230203150634.3199647-23-hch@lst.de Signed-off-by: Jens Axboe

vringh: fix range used in iotlb_translate()

2022-12-28T10:28:10Z

vhost_iotlb_itree_first() requires `start` and `last` parameters to search for a mapping that overlaps the range. In iotlb_translate() we cyclically call vhost_iotlb_itree_first(), incrementing `addr` by the amount already translated, so rightly we move the `start` parameter passed to vhost_iotlb_itree_first(), but we should hold the `last` parameter constant. Let's fix it by saving the `last` parameter value before incrementing `addr` in the loop. Fixes: 9ad9c49cfe97 ("vringh: IOTLB support") Acked-by: Jason Wang Signed-off-by: Stefano Garzarella Message-Id: <20221109102503.18816-2-sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin

use less confusing names for iov_iter direction initializers

2022-11-25T18:01:55Z

READ/WRITE proved to be actively confusing - the meanings are "data destination, as used with read(2)" and "data source, as used with write(2)", but people keep interpreting those as "we read data from it" and "we write data to it", i.e. exactly the wrong way. Call them ITER_DEST and ITER_SOURCE - at least that is harder to misinterpret... Signed-off-by: Al Viro

[vhost] fix 'direction' argument of iov_iter_{init,bvec}()

2022-11-25T18:01:21Z

READ means "data destination", WRITE - "data source". Signed-off-by: Al Viro

vringh: iterate on iotlb_translate to handle large translations

2022-08-11T08:06:37Z

iotlb_translate() can return -ENOBUFS if the bio_vec is not big enough to contain all the ranges for translation. This can happen for example if the VMM maps a large bounce buffer, without using hugepages, that requires more than 16 ranges to translate the addresses. To handle this case, let's extend iotlb_translate() to also return the number of bytes successfully translated. In copy_from_iotlb()/copy_to_iotlb() loops by calling iotlb_translate() several times until we complete the translation. Signed-off-by: Stefano Garzarella Message-Id: <20220624075656.13997-1-sgarzare@redhat.com> Signed-off-by: Michael S. Tsirkin

vringh: Fix loop descriptors check in the indirect cases

2022-06-08T12:56:03Z

We should use size of descriptor chain to test loop condition in the indirect case. And another statistical count is also introduced for indirect descriptors to avoid conflict with the statistical count of direct descriptors. Fixes: f87d0fbb5798 ("vringh: host-side implementation of virtio rings.") Signed-off-by: Xie Yongji Signed-off-by: Fam Zheng Message-Id: <20220505100910.137-1-xieyongji@bytedance.com> Signed-off-by: Michael S. Tsirkin Acked-by: Jason Wang

vringh: Use wiov->used to check for read/write desc order

2021-08-11T10:44:24Z

As __vringh_iov() traverses a descriptor chain, it populates each descriptor entry into either read or write vring iov and increments that iov's ->used member. So, as we iterate over a descriptor chain, at any point, (riov/wriov)->used value gives the number of descriptor enteries available, which are to be read or written by the device. As all read iovs must precede the write iovs, wiov->used should be zero when we are traversing a read descriptor. Current code checks for wiov->i, to figure out whether any previous entry in the current descriptor chain was a write descriptor. However, iov->i is only incremented, when these vring iovs are consumed, at a later point, and remain 0 in __vringh_iov(). So, correct the check for read and write descriptor order, to use wiov->used. Acked-by: Jason Wang Reviewed-by: Stefano Garzarella Signed-off-by: Neeraj Upadhyay Link: https://lore.kernel.org/r/1624591502-4827-1-git-send-email-neeraju@codeaurora.org Signed-off-by: Michael S. Tsirkin

vringh: implement vringh_kiov_advance()

2021-05-03T08:55:53Z

In some cases, it may be useful to provide a way to skip a number of bytes in a vringh_kiov. Let's implement vringh_kiov_advance() for this purpose, reusing the code from vringh_iov_xfer(). We replace that code calling the new vringh_kiov_advance(). Acked-by: Jason Wang Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20210315163450.254396-6-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin

vringh: explain more about cleaning riov and wiov

2021-05-03T08:55:53Z

riov and wiov can be reused with subsequent calls of vringh_getdesc_*(). Let's add a paragraph in the documentation of these functions to better explain when riov and wiov need to be cleaned up. Acked-by: Jason Wang Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20210315163450.254396-5-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin

vringh: reset kiov 'consumed' field in __vringh_iov()

2021-05-03T08:55:53Z

__vringh_iov() overwrites the contents of riov and wiov, in fact it resets the 'i' and 'used' fields, but also the 'consumed' field should be reset to avoid an inconsistent state. Acked-by: Jason Wang Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20210315163450.254396-4-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin