pve-qemu-qoup/debian/patches/extra/0005-memory-Allow-disabling-re-entrancy-checking-per-MR.patch
Fiona Ebner bf251437e9 update submodule and patches to QEMU 8.0.0
Many changes were necessary this time around:

* QAPI was changed to avoid redundant has_* variables, see commit
44ea9d9be3 ("qapi: Start to elide redundant has_FOO in generated C")
for details. This affected many QMP commands added by Proxmox too.

* Pending querying for migration got split into two functions, one to
estimate, one for exact value, see commit c8df4a7aef ("migration:
Split save_live_pending() into state_pending_*") for details. Relevant
for savevm-async and PBS dirty bitmap.

* Some block (driver) functions got converted to coroutines, so the
Proxmox block drivers needed to be adapted.

* Alloc track auto-detaching during PBS live restore got broken by
AioContext-related changes resulting in a deadlock. The current, hacky
method was replaced by a simpler one. Stefan apparently ran into a
problem with that when he wrote the driver, but there were
improvements in the stream job code since then and I didn't manage to
reproduce the issue. It's a separate patch "alloc-track: fix deadlock
during drop" for now, you can find the details there.

* Async snapshot-related changes:
  - The pending querying got adapted to the above-mentioned split and
  a patch is added to optimize it/make it more similar to what
  upstream code does.
  - Added initialization of the compression counters (for
    future-proofing).
  - It's necessary the hold the BQL (big QEMU lock = iothread mutex)
  during the setup phase, because block layer functions are used there
  and not doing so leads to racy, hard-to-debug crashes or hangs. It's
  necessary to change some upstream code too for this, a version of
  the patch "migration: for snapshots, hold the BQL during setup
  callbacks" is intended to be upstreamed.
  - Need to take the bdrv graph read lock before flushing.

* hmp_info_balloon was moved to a different file.

* Needed to include a new headers from time to time to still get the
correct functions.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
2023-05-22 15:09:14 +02:00

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1.4 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Alexander Bulekov <alxndr@bu.edu>
Date: Mon, 13 Mar 2023 04:24:16 -0400
Subject: [PATCH] memory: Allow disabling re-entrancy checking per-MR
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
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 15ade918ba..e6819e3c39 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 e4d2268d32..d88acb204b 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) {