diff options
| -rw-r--r-- | include/exec/memory.h | 5 | ||||
| -rw-r--r-- | include/hw/qdev-core.h | 7 | ||||
| -rw-r--r-- | softmmu/memory.c | 16 |
3 files changed, 28 insertions, 0 deletions
diff --git a/include/exec/memory.h b/include/exec/memory.h index 15ade918ba..e45ce6061f 100644 --- a/include/exec/memory.h +++ b/include/exec/memory.h @@ -767,6 +767,8 @@ struct MemoryRegion { bool is_iommu; RAMBlock *ram_block; Object *owner; + /* owner as TYPE_DEVICE. Used for re-entrancy checks in MR access hotpath */ + DeviceState *dev; const MemoryRegionOps *ops; void *opaque; @@ -791,6 +793,9 @@ 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/include/hw/qdev-core.h b/include/hw/qdev-core.h index bd50ad5ee1..7623703943 100644 --- a/include/hw/qdev-core.h +++ b/include/hw/qdev-core.h @@ -162,6 +162,10 @@ struct NamedClockList { QLIST_ENTRY(NamedClockList) node; }; +typedef struct { + bool engaged_in_io; +} MemReentrancyGuard; + /** * DeviceState: * @realized: Indicates whether the device has been fully constructed. @@ -194,6 +198,9 @@ struct DeviceState { int alias_required_for_version; ResettableState reset; GSList *unplug_blockers; + + /* Is the device currently in mmio/pio/dma? Used to prevent re-entrancy */ + MemReentrancyGuard mem_reentrancy_guard; }; struct DeviceListener { diff --git a/softmmu/memory.c b/softmmu/memory.c index b1a6cae6f5..b7b3386e9d 100644 --- a/softmmu/memory.c +++ b/softmmu/memory.c @@ -542,6 +542,18 @@ static MemTxResult access_with_adjusted_size(hwaddr addr, access_size_max = 4; } + /* Do not allow more than one simultaneous access to a device's IO Regions */ + if (mr->dev && !mr->disable_reentrancy_guard && + !mr->ram_device && !mr->ram && !mr->rom_device && !mr->readonly) { + if (mr->dev->mem_reentrancy_guard.engaged_in_io) { + warn_report_once("Blocked re-entrant IO on MemoryRegion: " + "%s at addr: 0x%" HWADDR_PRIX, + memory_region_name(mr), addr); + return MEMTX_ACCESS_ERROR; + } + mr->dev->mem_reentrancy_guard.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); @@ -556,6 +568,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr, access_mask, attrs); } } + if (mr->dev) { + mr->dev->mem_reentrancy_guard.engaged_in_io = false; + } return r; } @@ -1170,6 +1185,7 @@ static void memory_region_do_init(MemoryRegion *mr, } mr->name = g_strdup(name); mr->owner = owner; + mr->dev = (DeviceState *) object_dynamic_cast(mr->owner, TYPE_DEVICE); mr->ram_block = NULL; if (name) { |