Il 09/03/2012 06:01, David Gibson ha scritto:
> dma-helpers.c contains a number of helper functions for doing
> scatter/gather DMA, and various block device related DMA. Currently,
> these directly access guest memory using cpu_physical_memory_*(),
> assuming no IOMMU translation.
>
> This patch updates this code to use the new universal DMA helper
> functions. qemu_sglist_init() now takes a DMAContext * to describe
> the DMA address space in which the scatter/gather will take place.
>
> We minimally update the callers qemu_sglist_init() to pass NULL
> (i.e. no translation, same as current behaviour). Some of those
> callers should pass something else in some cases to allow proper IOMMU
> translation in future, but that will be fixed in later patches.
>
> Cc: Kevin Wolf <kw...@redhat.com>
> Cc: Michael S. Tsirkin <m...@redhat.com>
>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> dma-helpers.c | 26 ++++++++++++++++++--------
> dma.h | 3 ++-
> hw/ide/ahci.c | 3 ++-
> hw/ide/macio.c | 4 ++--
> hw/pci.h | 2 +-
> 5 files changed, 25 insertions(+), 13 deletions(-)
>
> diff --git a/dma-helpers.c b/dma-helpers.c
> index 5f19a85..9dcfb2c 100644
> --- a/dma-helpers.c
> +++ b/dma-helpers.c
> @@ -11,12 +11,13 @@
> #include "block_int.h"
> #include "trace.h"
>
> -void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint)
> +void qemu_sglist_init(QEMUSGList *qsg, int alloc_hint, DMAContext *dma)
> {
> qsg->sg = g_malloc(alloc_hint * sizeof(ScatterGatherEntry));
> qsg->nsg = 0;
> qsg->nalloc = alloc_hint;
> qsg->size = 0;
> + qsg->dma = dma;
> }
>
> void qemu_sglist_add(QEMUSGList *qsg, dma_addr_t base, dma_addr_t len)
> @@ -75,10 +76,9 @@ static void dma_bdrv_unmap(DMAAIOCB *dbs)
> int i;
>
> for (i = 0; i < dbs->iov.niov; ++i) {
> - cpu_physical_memory_unmap(dbs->iov.iov[i].iov_base,
> - dbs->iov.iov[i].iov_len,
> - dbs->dir != DMA_DIRECTION_TO_DEVICE,
> - dbs->iov.iov[i].iov_len);
> + dma_memory_unmap(dbs->sg->dma, dbs->iov.iov[i].iov_base,
> + dbs->iov.iov[i].iov_len, dbs->dir,
> + dbs->iov.iov[i].iov_len);
> }
> qemu_iovec_reset(&dbs->iov);
> }
> @@ -104,10 +104,20 @@ static void dma_complete(DMAAIOCB *dbs, int ret)
> }
> }
>
> +static void dma_bdrv_cancel(void *opaque)
> +{
> + DMAAIOCB *dbs = opaque;
> +
> + bdrv_aio_cancel(dbs->acb);
> + dma_bdrv_unmap(dbs);
> + qemu_iovec_destroy(&dbs->iov);
> + qemu_aio_release(dbs);
> +}
What Kevin said. Instead of a generic callback, dma_memory_map should
probably just receive the AIOCB (in this case &dbs->common) and call
bdrv_aio_cancel on it.
> static void dma_bdrv_cb(void *opaque, int ret)
> {
> DMAAIOCB *dbs = (DMAAIOCB *)opaque;
> - target_phys_addr_t cur_addr, cur_len;
> + dma_addr_t cur_addr, cur_len;
> void *mem;
>
> trace_dma_bdrv_cb(dbs, ret);
> @@ -124,8 +134,8 @@ static void dma_bdrv_cb(void *opaque, int ret)
> while (dbs->sg_cur_index < dbs->sg->nsg) {
> cur_addr = dbs->sg->sg[dbs->sg_cur_index].base + dbs->sg_cur_byte;
> cur_len = dbs->sg->sg[dbs->sg_cur_index].len - dbs->sg_cur_byte;
> - mem = cpu_physical_memory_map(cur_addr, &cur_len,
> - dbs->dir != DMA_DIRECTION_TO_DEVICE);
> + mem = dma_memory_map(dbs->sg->dma, dma_bdrv_cancel, dbs,
> + cur_addr, &cur_len, dbs->dir);
> if (!mem)
> break;
> qemu_iovec_add(&dbs->iov, mem, cur_len);
dma_buf_rw should also use the DMAContext here (passing a NULL
invalidate function).
Paolo
