debian/patches/extra/0021-memory-Allow-disabling-re-entrancy-checking-per-MR.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Alexander Bulekov <alxndr@bu.edu>
   3 Date: Mon, 13 Mar 2023 04:24:16 -0400
   4 Subject: [PATCH] memory: Allow disabling re-entrancy checking per-MR
   5
   6 Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
   7 ---
   8  include/exec/memory.h | 3 +++
   9  softmmu/memory.c      | 2 +-
  10  2 files changed, 4 insertions(+), 1 deletion(-)
  11
  12 diff --git a/include/exec/memory.h b/include/exec/memory.h
  13 index 91f8a2395a..d7268d9f39 100644
  14 --- a/include/exec/memory.h
  15 +++ b/include/exec/memory.h
  16 @@ -765,6 +765,9 @@ struct MemoryRegion {
  17      unsigned ioeventfd_nb;
  18      MemoryRegionIoeventfd *ioeventfds;
  19      RamDiscardManager *rdm; /* Only for RAM */
  20 +
  21 +    /* For devices designed to perform re-entrant IO into their own IO MRs */
  22 +    bool disable_reentrancy_guard;
  23  };
  24
  25  struct IOMMUMemoryRegion {
  26 diff --git a/softmmu/memory.c b/softmmu/memory.c
  27 index 7dcb3347aa..2b46714191 100644
  28 --- a/softmmu/memory.c
  29 +++ b/softmmu/memory.c
  30 @@ -544,7 +544,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
  31      }
  32
  33      /* Do not allow more than one simultanous access to a device's IO Regions */
  34 -    if (mr->owner &&
  35 +    if (mr->owner && !mr->disable_reentrancy_guard &&
  36          !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
  37          dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
  38          if (dev) {