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[PATCH v2 2/3] memory: fix PIO/MMIO-initiated dma-reentracy issues
From: |
Alexander Bulekov |
Subject: |
[PATCH v2 2/3] memory: fix PIO/MMIO-initiated dma-reentracy issues |
Date: |
Fri, 27 May 2022 12:19:36 -0400 |
Set/check the engaged_in_io DeviceState flag, prior to calling
MemoryRegion handlers.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
softmmu/memory.c | 15 +++++++++++++++
softmmu/trace-events | 1 +
2 files changed, 16 insertions(+)
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 7ba2048836..44a14bb4f5 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -532,6 +532,7 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
uint64_t access_mask;
unsigned access_size;
unsigned i;
+ DeviceState *dev = NULL;
MemTxResult r = MEMTX_OK;
if (!access_size_min) {
@@ -541,6 +542,17 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_size_max = 4;
}
+ /* Do not allow more than one simultanous access to a device's IO Regions
*/
+ if (mr->owner &&
+ !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) {
+ dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE);
+ if (dev->engaged_in_io) {
+ trace_memory_region_reentrant_io(get_cpu_index(), mr, addr, size);
+ return MEMTX_ERROR;
+ }
+ dev->engaged_in_io = true;
+ }
+
/* FIXME: support unaligned access? */
access_size = MAX(MIN(size, access_size_max), access_size_min);
access_mask = MAKE_64BIT_MASK(0, access_size * 8);
@@ -555,6 +567,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_mask, attrs);
}
}
+ if (dev) {
+ dev->engaged_in_io = false;
+ }
return r;
}
diff --git a/softmmu/trace-events b/softmmu/trace-events
index 9c88887b3c..d7228316db 100644
--- a/softmmu/trace-events
+++ b/softmmu/trace-events
@@ -13,6 +13,7 @@ memory_region_ops_read(int cpu_index, void *mr, uint64_t
addr, uint64_t value, u
memory_region_ops_write(int cpu_index, void *mr, uint64_t addr, uint64_t
value, unsigned size, const char *name) "cpu %d mr %p addr 0x%"PRIx64" value
0x%"PRIx64" size %u name '%s'"
memory_region_subpage_read(int cpu_index, void *mr, uint64_t offset, uint64_t
value, unsigned size) "cpu %d mr %p offset 0x%"PRIx64" value 0x%"PRIx64" size
%u"
memory_region_subpage_write(int cpu_index, void *mr, uint64_t offset, uint64_t
value, unsigned size) "cpu %d mr %p offset 0x%"PRIx64" value 0x%"PRIx64" size
%u"
+memory_region_reentrant_io(int cpu_index, void *mr, uint64_t offset, unsigned
size) "cpu %d mr %p offset 0x%"PRIx64" size %u"
memory_region_ram_device_read(int cpu_index, void *mr, uint64_t addr, uint64_t
value, unsigned size) "cpu %d mr %p addr 0x%"PRIx64" value 0x%"PRIx64" size %u"
memory_region_ram_device_write(int cpu_index, void *mr, uint64_t addr,
uint64_t value, unsigned size) "cpu %d mr %p addr 0x%"PRIx64" value 0x%"PRIx64"
size %u"
memory_region_sync_dirty(const char *mr, const char *listener, int global) "mr
'%s' listener '%s' synced (global=%d)"
--
2.33.0
- [PATCH v2 3/3] memory: fix bh-initiated dma-reentracy issues, (continued)
Re: [PATCH v2 1/3] memory: Track whether a Device is engaged in IO, David Hildenbrand, 2022/05/30
[PATCH v2 2/3] memory: fix PIO/MMIO-initiated dma-reentracy issues,
Alexander Bulekov <=