On Mon, Oct 26, 2026 at 11:11:11AM +0100, Daniel Gomez wrote: > From: Daniel Gomez <[email protected]> > > Cap the initial iovec allocation at IOV_MAX instead of sizing it for the > whole sg list, which over-allocates for large IO where the number of sg > entries exceeds IOV_MAX. > > This is preparatory work for chunking dma_blk_cb() at IOV_MAX to batch > large IO: once chunked, dbs->iov never holds more than IOV_MAX iovecs. > > Acked-by: Jesper Wendel Devantier <[email protected]> > Reviewed-by: Keith Busch <[email protected]> > Signed-off-by: Daniel Gomez <[email protected]> > --- > system/dma-helpers.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/system/dma-helpers.c b/system/dma-helpers.c > index 9004ad50ae3..d4fd33a3d4c 100644 > --- a/system/dma-helpers.c > +++ b/system/dma-helpers.c > @@ -242,7 +242,7 @@ BlockAIOCB *dma_blk_io( > dbs->io_func = io_func; > dbs->io_func_opaque = io_func_opaque; > dbs->bh = NULL; > - qemu_iovec_init(&dbs->iov, sg->nsg); > + qemu_iovec_init(&dbs->iov, MIN(sg->nsg, IOV_MAX));
Please use blk_get_max_iov() instead of hardcoding IOV_MAX. > dma_blk_cb(dbs, 0); > return &dbs->common; > } > > -- > 2.56.0 > >
