search for: scatterlist

OK, so I've spent a few days benchmarking. Turns out 80% of virtio_add_buf cases are uni-directional (including the always-performance-sensitive networking code), and that gets no performance penalty (though tests with real networking would be appreciated!). I'm not reposting all the "convert driver to virtio_add_outbuf()" patches: just the scsi one which I didn't have

OK, so I've spent a few days benchmarking. Turns out 80% of virtio_add_buf cases are uni-directional (including the always-performance-sensitive networking code), and that gets no performance penalty (though tests with real networking would be appreciated!). I'm not reposting all the "convert driver to virtio_add_outbuf()" patches: just the scsi one which I didn't have

...s/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 4d08f45a9c29..374399c62080 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c @@ -99,28 +99,10 @@ struct vring_virtqueue #define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq) -static inline struct scatterlist *sg_next_chained(struct scatterlist *sg, - unsigned int *count) -{ - return sg_next(sg); -} - -static inline struct scatterlist *sg_next_arr(struct scatterlist *sg, - unsigned int *count) -{ - if (--(*count) == 0) - return NULL; - return sg + 1; -} - /* Set up an indirect table o...

Andy Lutomirski <luto at amacapital.net> writes: > The only unusual thing about virtio's use of scatterlists is that > two of the APIs accept scatterlists that might not be terminated. > Using function pointers to handle this case is overkill; for_each_sg > can do it. > > There's a small subtlely here: for_each_sg assumes that the provided > count is correct, but, because of the way...

Andy Lutomirski <luto at amacapital.net> writes: > The only unusual thing about virtio's use of scatterlists is that > two of the APIs accept scatterlists that might not be terminated. > Using function pointers to handle this case is overkill; for_each_sg > can do it. > > There's a small subtlely here: for_each_sg assumes that the provided > count is correct, but, because of the way...

The virtqueue_add_buf function has two limitations: 1) it requires the caller to provide all the buffers in a single call; 2) it does not support chained scatterlists: the buffers must be provided as an array of struct scatterlist. Because of these limitations, virtio-scsi has to copy each request into a scatterlist internal to the driver. It cannot just use the one that was prepared by the upper SCSI layers. This series adds a different set of APIs for addi...

The virtqueue_add_buf function has two limitations: 1) it requires the caller to provide all the buffers in a single call; 2) it does not support chained scatterlists: the buffers must be provided as an array of struct scatterlist. Because of these limitations, virtio-scsi has to copy each request into a scatterlist internal to the driver. It cannot just use the one that was prepared by the upper SCSI layers. This series adds a different set of APIs for addi...

...er, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo Bonzini (4): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on bio path virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (17): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio_ring: don't count elements twice for add_buf pat...

...er, then add virtqueue_add_inbuf and virtqueue_add_outbuf which handle the more general case, and finally delete virtqueue_add_buf(). I'm hoping this will be the final post of the whole series, and it can move from my pending-rebases tree into virtio-next. Thanks! Rusty. Paolo Bonzini (4): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on bio path virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (17): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio_ring: don't count elements twice for add_buf pat...

The only unusual thing about virtio's use of scatterlists is that two of the APIs accept scatterlists that might not be terminated. Using function pointers to handle this case is overkill; for_each_sg can do it. There's a small subtlely here: for_each_sg assumes that the provided count is correct, but, because of the way that virtio_ring handles mul...

This is a note to let you know that I've just added the patch titled crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req() to the 5.7-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: crypto-virtio-fix-src-dst-scatterlist-calculation-in-__virtio_crypto_skcipher_do_re...

This is a note to let you know that I've just added the patch titled crypto: virtio: Fix src/dst scatterlist calculation in __virtio_crypto_skcipher_do_req() to the 5.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: crypto-virtio-fix-src-dst-scatterlist-calculation-in-__virtio_crypto_skcipher_do_re...

Most device drivers do not need to perform any postprocessing on the scatterlists they receive from higher-level drivers (e.g. the block or SCSI layer), because they translate the request metadata directly from the various C structs into the data that is required by the device. virtio devices however do this translation in two steps: a device-specific step in the device driver...

Most device drivers do not need to perform any postprocessing on the scatterlists they receive from higher-level drivers (e.g. the block or SCSI layer), because they translate the request metadata directly from the various C structs into the data that is required by the device. virtio devices however do this translation in two steps: a device-specific step in the device driver...

Rather than handing a scatterlist[] and out and in numbers to virtqueue_add_buf(), hand two separate ones which can be chained. I shall refrain from ranting about what a disgusting hack chained scatterlists are. I'll just note that this doesn't make things simpler (see diff). The scatterlists we use can be too large for...

Rather than handing a scatterlist[] and out and in numbers to virtqueue_add_buf(), hand two separate ones which can be chained. I shall refrain from ranting about what a disgusting hack chained scatterlists are. I'll just note that this doesn't make things simpler (see diff). The scatterlists we use can be too large for...

OK, this is (ab)uses some of Paolo's patches. The first 7 are candidates for this merge window (maybe), the rest I'm not so sure about. Thanks, Rusty. Paolo Bonzini (3): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (13): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio-blk: use virtqueue_start_buf on bio path virtio_blk: remove nents member. virtio_ring: don't...

OK, this is (ab)uses some of Paolo's patches. The first 7 are candidates for this merge window (maybe), the rest I'm not so sure about. Thanks, Rusty. Paolo Bonzini (3): scatterlist: introduce sg_unmark_end virtio-blk: reorganize virtblk_add_req virtio-blk: use virtqueue_add_sgs on req path Rusty Russell (13): virtio_ring: virtqueue_add_sgs, to add multiple sgs. virtio-blk: use virtqueue_start_buf on bio path virtio_blk: remove nents member. virtio_ring: don't...

...lt;longpeng2 at huawei.com> commit b02989f37fc5e865ceeee9070907e4493b3a21e2 upstream. The system will crash when the users insmod crypto/tcrypt.ko with mode=38 ( testing "cts(cbc(aes))" ). Usually the next entry of one sg will be @sg@ + 1, but if this sg element is part of a chained scatterlist, it could jump to the start of a new scatterlist array. Fix it by sg_next() on calculation of src/dst scatterlist. Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver") Reported-by: LABBE Corentin <clabbe at baylibre.com> Cc: Herbert Xu <herbert at gondor.apana.org.au> Cc:...

...lt;longpeng2 at huawei.com> commit b02989f37fc5e865ceeee9070907e4493b3a21e2 upstream. The system will crash when the users insmod crypto/tcrypt.ko with mode=38 ( testing "cts(cbc(aes))" ). Usually the next entry of one sg will be @sg@ + 1, but if this sg element is part of a chained scatterlist, it could jump to the start of a new scatterlist array. Fix it by sg_next() on calculation of src/dst scatterlist. Fixes: dbaf0624ffa5 ("crypto: add virtio-crypto driver") Reported-by: LABBE Corentin <clabbe at baylibre.com> Cc: Herbert Xu <herbert at gondor.apana.org.au> Cc:...