Add a flag to the DeviceState, which is set/checked when we call an accessor associated with the device's IO MRs. This should prevent a device's MMIO handler from using DMA apis to access it's own MMIO regions.
Signed-off-by: Alexander Bulekov <[email protected]> --- include/hw/qdev-core.h | 1 + softmmu/memory.c | 15 +++++++++++++++ softmmu/trace-events | 1 + 3 files changed, 17 insertions(+) diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h index 20d3066595..7b93b017c5 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -193,6 +193,7 @@ struct DeviceState { int instance_id_alias; int alias_required_for_version; ResettableState reset; + int engaged_in_io; }; struct DeviceListener { diff --git a/softmmu/memory.c b/softmmu/memory.c index 7340e19ff5..229c63a68d 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
