On Monday, 2023-03-13 at 04:24:16 -04, Alexander Bulekov wrote:
> Signed-off-by: Alexander Bulekov <alx...@bu.edu>
Reviewed-by: Darren Kenny <darren.ke...@oracle.com>
> ---
> include/exec/memory.h | 3 +++
> softmmu/memory.c | 2 +-
> 2 files changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/include/exec/memory.h b/include/exec/memory.h
> index 6fa0b071f0..5154b123d8 100644
> --- a/include/exec/memory.h
> +++ b/include/exec/memory.h
> @@ -791,6 +791,9 @@ struct MemoryRegion {
> unsigned ioeventfd_nb;
> MemoryRegionIoeventfd *ioeventfds;
> RamDiscardManager *rdm; /* Only for RAM */
> +
> + /* For devices designed to perform re-entrant IO into their own IO MRs */
> + bool disable_reentrancy_guard;
> };
>
> struct IOMMUMemoryRegion {
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index 57bf18a257..3018fa2edb 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -544,7 +544,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
> }
>
> /* Do not allow more than one simultanous access to a device's IO
> Regions */
> - if (mr->owner &&
> + if (mr->owner && !mr->disable_reentrancy_guard &&
> !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
> dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
> if (dev) {
> --
> 2.39.0
