* [PATCH v5 0/4] memory: prevent dma-reentracy issues
@ 2023-01-26 5:25 Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 1/4] " Alexander Bulekov
` (4 more replies)
0 siblings, 5 replies; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:25 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
These patches aim to solve two types of DMA-reentrancy issues:
1.) mmio -> dma -> mmio case
To solve this, we track whether the device is engaged in io by
checking/setting a reentrancy-guard within APIs used for MMIO access.
2.) bh -> dma write -> mmio case
This case is trickier, since we dont have a generic way to associate a
bh with the underlying Device/DeviceState. Thus, this version allows a
device to associate a reentrancy-guard with a bh, when creating it.
(Instead of calling qemu_bh_new, you call qemu_bh_new_guarded)
I replaced most of the qemu_bh_new invocations with the guarded analog,
except for the ones where the DeviceState was not trivially accessible
v4-> v5:
- Add corresponding checkpatch checks
- Save/restore reentrancy-flag when entering/exiting BHs
- Improve documentation
- Check object_dynamic_cast return value
v3 -> v4: Instead of changing all of the DMA APIs, instead add an
optional reentrancy guard to the BH API.
v2 -> v3: Bite the bullet and modify the DMA APIs, rather than
attempting to guess DeviceStates in BHs.
Alexander Bulekov (4):
memory: prevent dma-reentracy issues
async: Add an optional reentrancy guard to the BH API
checkpatch: add qemu_bh_new/aio_bh_new checks
hw: replace most qemu_bh_new calls with qemu_bh_new_guarded
docs/devel/multiple-iothreads.txt | 7 +++++++
hw/9pfs/xen-9p-backend.c | 4 +++-
hw/block/dataplane/virtio-blk.c | 3 ++-
hw/block/dataplane/xen-block.c | 5 +++--
hw/block/virtio-blk.c | 5 +++--
hw/char/virtio-serial-bus.c | 3 ++-
hw/display/qxl.c | 9 ++++++---
hw/display/virtio-gpu.c | 6 ++++--
hw/ide/ahci.c | 3 ++-
hw/ide/core.c | 3 ++-
hw/misc/imx_rngc.c | 6 ++++--
hw/misc/macio/mac_dbdma.c | 2 +-
hw/net/virtio-net.c | 3 ++-
hw/nvme/ctrl.c | 6 ++++--
hw/scsi/mptsas.c | 3 ++-
hw/scsi/scsi-bus.c | 3 ++-
hw/scsi/vmw_pvscsi.c | 3 ++-
hw/usb/dev-uas.c | 3 ++-
hw/usb/hcd-dwc2.c | 3 ++-
hw/usb/hcd-ehci.c | 3 ++-
hw/usb/hcd-uhci.c | 2 +-
hw/usb/host-libusb.c | 6 ++++--
hw/usb/redirect.c | 6 ++++--
hw/usb/xen-usb.c | 3 ++-
hw/virtio/virtio-balloon.c | 5 +++--
hw/virtio/virtio-crypto.c | 3 ++-
include/block/aio.h | 18 ++++++++++++++++--
include/hw/qdev-core.h | 7 +++++++
include/qemu/main-loop.h | 7 +++++--
scripts/checkpatch.pl | 8 ++++++++
softmmu/memory.c | 17 +++++++++++++++++
softmmu/trace-events | 1 +
tests/unit/ptimer-test-stubs.c | 3 ++-
util/async.c | 18 +++++++++++++++++-
util/main-loop.c | 5 +++--
util/trace-events | 1 +
36 files changed, 150 insertions(+), 43 deletions(-)
--
2.39.0
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v5 1/4] memory: prevent dma-reentracy issues
2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
@ 2023-01-26 5:25 ` Alexander Bulekov
2023-01-26 20:54 ` Peter Xu
2023-01-26 5:25 ` [PATCH v5 2/4] async: Add an optional reentrancy guard to the BH API Alexander Bulekov
` (3 subsequent siblings)
4 siblings, 1 reply; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:25 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA.
This flag is set/checked prior to calling a device's MemoryRegion
handlers, and set when device code initiates DMA. The purpose of this
flag is to prevent two types of DMA-based reentrancy issues:
1.) mmio -> dma -> mmio case
2.) bh -> dma write -> mmio case
These issues have led to problems such as stack-exhaustion and
use-after-frees.
Summary of the problem from Peter Maydell:
https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
include/hw/qdev-core.h | 7 +++++++
softmmu/memory.c | 17 +++++++++++++++++
softmmu/trace-events | 1 +
3 files changed, 25 insertions(+)
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 35fddb19a6..8858195262 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 e05332d07f..daffb48493 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -533,6 +533,7 @@ 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) {
@@ -542,6 +543,19 @@ 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) {
+ if (dev->mem_reentrancy_guard.engaged_in_io) {
+ trace_memory_region_reentrant_io(get_cpu_index(), mr, addr, size);
+ return MEMTX_ERROR;
+ }
+ 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 +570,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_mask, attrs);
}
}
+ if (dev) {
+ dev->mem_reentrancy_guard.engaged_in_io = false;
+ }
return r;
}
diff --git a/softmmu/trace-events b/softmmu/trace-events
index 22606dc27b..62d04ea9a7 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)"
--
2.39.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v5 2/4] async: Add an optional reentrancy guard to the BH API
2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 1/4] " Alexander Bulekov
@ 2023-01-26 5:25 ` Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks Alexander Bulekov
` (2 subsequent siblings)
4 siblings, 0 replies; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:25 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen, Fam Zheng, Kevin Wolf,
Hanna Reitz, open list:Block I/O path
Devices can pass their MemoryReentrancyGuard (from their DeviceState),
when creating new BHes. Then, the async API will toggle the guard
before/after calling the BH call-back. This prevents bh->mmio reentrancy
issues.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
docs/devel/multiple-iothreads.txt | 7 +++++++
include/block/aio.h | 18 ++++++++++++++++--
include/qemu/main-loop.h | 7 +++++--
tests/unit/ptimer-test-stubs.c | 3 ++-
util/async.c | 18 +++++++++++++++++-
util/main-loop.c | 5 +++--
util/trace-events | 1 +
7 files changed, 51 insertions(+), 8 deletions(-)
diff --git a/docs/devel/multiple-iothreads.txt b/docs/devel/multiple-iothreads.txt
index 343120f2ef..a3e949f6b3 100644
--- a/docs/devel/multiple-iothreads.txt
+++ b/docs/devel/multiple-iothreads.txt
@@ -61,6 +61,7 @@ There are several old APIs that use the main loop AioContext:
* LEGACY qemu_aio_set_event_notifier() - monitor an event notifier
* LEGACY timer_new_ms() - create a timer
* LEGACY qemu_bh_new() - create a BH
+ * LEGACY qemu_bh_new_guarded() - create a BH with a device re-entrancy guard
* LEGACY qemu_aio_wait() - run an event loop iteration
Since they implicitly work on the main loop they cannot be used in code that
@@ -72,8 +73,14 @@ Instead, use the AioContext functions directly (see include/block/aio.h):
* aio_set_event_notifier() - monitor an event notifier
* aio_timer_new() - create a timer
* aio_bh_new() - create a BH
+ * aio_bh_new_guarded() - create a BH with a device re-entrancy guard
* aio_poll() - run an event loop iteration
+The qemu_bh_new_guarded/aio_bh_new_guarded APIs accept a "MemReentrancyGuard"
+argument, which is used to check for and prevent re-entrancy problems. For
+BHs associated with devices, the reentrancy-guard is contained in the
+corresponding DeviceState and named "mem_reentrancy_guard".
+
The AioContext can be obtained from the IOThread using
iothread_get_aio_context() or for the main loop using qemu_get_aio_context().
Code that takes an AioContext argument works both in IOThreads or the main
diff --git a/include/block/aio.h b/include/block/aio.h
index 0f65a3cc9e..94d661ff7e 100644
--- a/include/block/aio.h
+++ b/include/block/aio.h
@@ -23,6 +23,8 @@
#include "qemu/thread.h"
#include "qemu/timer.h"
#include "block/graph-lock.h"
+#include "hw/qdev-core.h"
+
typedef struct BlockAIOCB BlockAIOCB;
typedef void BlockCompletionFunc(void *opaque, int ret);
@@ -332,9 +334,11 @@ void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
* is opaque and must be allocated prior to its use.
*
* @name: A human-readable identifier for debugging purposes.
+ * @reentrancy_guard: A guard set when entering a cb to prevent
+ * device-reentrancy issues
*/
QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
- const char *name);
+ const char *name, MemReentrancyGuard *reentrancy_guard);
/**
* aio_bh_new: Allocate a new bottom half structure
@@ -343,7 +347,17 @@ QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
* string.
*/
#define aio_bh_new(ctx, cb, opaque) \
- aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)))
+ aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)), NULL)
+
+/**
+ * aio_bh_new_guarded: Allocate a new bottom half structure with a
+ * reentrancy_guard
+ *
+ * A convenience wrapper for aio_bh_new_full() that uses the cb as the name
+ * string.
+ */
+#define aio_bh_new_guarded(ctx, cb, opaque, guard) \
+ aio_bh_new_full((ctx), (cb), (opaque), (stringify(cb)), guard)
/**
* aio_notify: Force processing of pending events.
diff --git a/include/qemu/main-loop.h b/include/qemu/main-loop.h
index c25f390696..84d1ce57f0 100644
--- a/include/qemu/main-loop.h
+++ b/include/qemu/main-loop.h
@@ -389,9 +389,12 @@ void qemu_cond_timedwait_iothread(QemuCond *cond, int ms);
void qemu_fd_register(int fd);
+#define qemu_bh_new_guarded(cb, opaque, guard) \
+ qemu_bh_new_full((cb), (opaque), (stringify(cb)), guard)
#define qemu_bh_new(cb, opaque) \
- qemu_bh_new_full((cb), (opaque), (stringify(cb)))
-QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name);
+ qemu_bh_new_full((cb), (opaque), (stringify(cb)), NULL)
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name,
+ MemReentrancyGuard *reentrancy_guard);
void qemu_bh_schedule_idle(QEMUBH *bh);
enum {
diff --git a/tests/unit/ptimer-test-stubs.c b/tests/unit/ptimer-test-stubs.c
index f5e75a96b6..24d5413f9d 100644
--- a/tests/unit/ptimer-test-stubs.c
+++ b/tests/unit/ptimer-test-stubs.c
@@ -107,7 +107,8 @@ int64_t qemu_clock_deadline_ns_all(QEMUClockType type, int attr_mask)
return deadline;
}
-QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name,
+ MemReentrancyGuard *reentrancy_guard)
{
QEMUBH *bh = g_new(QEMUBH, 1);
diff --git a/util/async.c b/util/async.c
index 14d63b3091..dae77c0d7e 100644
--- a/util/async.c
+++ b/util/async.c
@@ -65,6 +65,7 @@ struct QEMUBH {
void *opaque;
QSLIST_ENTRY(QEMUBH) next;
unsigned flags;
+ MemReentrancyGuard *reentrancy_guard;
};
/* Called concurrently from any thread */
@@ -133,7 +134,7 @@ void aio_bh_schedule_oneshot_full(AioContext *ctx, QEMUBHFunc *cb,
}
QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
- const char *name)
+ const char *name, MemReentrancyGuard *reentrancy_guard)
{
QEMUBH *bh;
bh = g_new(QEMUBH, 1);
@@ -142,13 +143,28 @@ QEMUBH *aio_bh_new_full(AioContext *ctx, QEMUBHFunc *cb, void *opaque,
.cb = cb,
.opaque = opaque,
.name = name,
+ .reentrancy_guard = reentrancy_guard,
};
return bh;
}
void aio_bh_call(QEMUBH *bh)
{
+ bool last_engaged_in_io = false;
+
+ if (bh->reentrancy_guard) {
+ last_engaged_in_io = bh->reentrancy_guard->engaged_in_io;
+ if (bh->reentrancy_guard->engaged_in_io) {
+ trace_reentrant_aio(bh->ctx, bh->name);
+ }
+ bh->reentrancy_guard->engaged_in_io = true;
+ }
+
bh->cb(bh->opaque);
+
+ if (bh->reentrancy_guard) {
+ bh->reentrancy_guard->engaged_in_io = last_engaged_in_io;
+ }
}
/* Multiple occurrences of aio_bh_poll cannot be called concurrently. */
diff --git a/util/main-loop.c b/util/main-loop.c
index 58f776a8c9..07d2e2040a 100644
--- a/util/main-loop.c
+++ b/util/main-loop.c
@@ -617,9 +617,10 @@ void main_loop_wait(int nonblocking)
/* Functions to operate on the main QEMU AioContext. */
-QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name)
+QEMUBH *qemu_bh_new_full(QEMUBHFunc *cb, void *opaque, const char *name, MemReentrancyGuard *reentrancy_guard)
{
- return aio_bh_new_full(qemu_aio_context, cb, opaque, name);
+ return aio_bh_new_full(qemu_aio_context, cb, opaque, name,
+ reentrancy_guard);
}
/*
diff --git a/util/trace-events b/util/trace-events
index c8f53d7d9f..dc3b1eb3bf 100644
--- a/util/trace-events
+++ b/util/trace-events
@@ -11,6 +11,7 @@ poll_remove(void *ctx, void *node, int fd) "ctx %p node %p fd %d"
# async.c
aio_co_schedule(void *ctx, void *co) "ctx %p co %p"
aio_co_schedule_bh_cb(void *ctx, void *co) "ctx %p co %p"
+reentrant_aio(void *ctx, const char *name) "ctx %p name %s"
# thread-pool.c
thread_pool_submit(void *pool, void *req, void *opaque) "pool %p req %p opaque %p"
--
2.39.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks
2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 1/4] " Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 2/4] async: Add an optional reentrancy guard to the BH API Alexander Bulekov
@ 2023-01-26 5:25 ` Alexander Bulekov
2023-01-26 14:57 ` Stefan Hajnoczi
2023-01-26 5:25 ` [PATCH v5 4/4] hw: replace most qemu_bh_new calls with qemu_bh_new_guarded Alexander Bulekov
2023-01-26 16:18 ` [PATCH v5 0/4] memory: prevent dma-reentracy issues Darren Kenny
4 siblings, 1 reply; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:25 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
Advise authors to use the _guarded versions of the APIs, instead.
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
scripts/checkpatch.pl | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 6ecabfb2b5..61bb4b0a19 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2865,6 +2865,14 @@ sub process {
if ($line =~ /\bsignal\s*\(/ && !($line =~ /SIG_(?:IGN|DFL)/)) {
ERROR("use sigaction to establish signal handlers; signal is not portable\n" . $herecurr);
}
+# recommend qemu_bh_new_guarded instead of qemu_bh_new
+ if ($line =~ /\bqemu_bh_new\s*\(/) {
+ ERROR("use qemu_bh_new_guarded() instead of qemu_bh_new() to avoid reentrancy problems\n" . $herecurr);
+ }
+# recommend aio_bh_new_guarded instead of aio_bh_new
+ if ($line =~ /\baio_bh_new\s*\(/) {
+ ERROR("use aio_bh_new_guarded() instead of aio_bh_new() to avoid reentrancy problems\n" . $herecurr);
+ }
# check for module_init(), use category-specific init macros explicitly please
if ($line =~ /^module_init\s*\(/) {
ERROR("please use block_init(), type_init() etc. instead of module_init()\n" . $herecurr);
--
2.39.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [PATCH v5 4/4] hw: replace most qemu_bh_new calls with qemu_bh_new_guarded
2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
` (2 preceding siblings ...)
2023-01-26 5:25 ` [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks Alexander Bulekov
@ 2023-01-26 5:25 ` Alexander Bulekov
2023-01-26 16:18 ` [PATCH v5 0/4] memory: prevent dma-reentracy issues Darren Kenny
4 siblings, 0 replies; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:25 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen, Stefano Stabellini,
Anthony Perard, Paul Durrant, Kevin Wolf, Hanna Reitz, Amit Shah,
Marc-André Lureau, John Snow, Peter Maydell,
Mark Cave-Ayland, Keith Busch, Klaus Jensen, Fam Zheng,
Dmitry Fleytman, Gonglei (Arei),
open list:X86 Xen CPUs, open list:virtio-blk,
open list:i.MX31 (kzm), open list:Old World (g3beige)
This protects devices from bh->mmio reentrancy issues.
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
hw/9pfs/xen-9p-backend.c | 4 +++-
hw/block/dataplane/virtio-blk.c | 3 ++-
hw/block/dataplane/xen-block.c | 5 +++--
hw/block/virtio-blk.c | 5 +++--
hw/char/virtio-serial-bus.c | 3 ++-
hw/display/qxl.c | 9 ++++++---
hw/display/virtio-gpu.c | 6 ++++--
hw/ide/ahci.c | 3 ++-
hw/ide/core.c | 3 ++-
hw/misc/imx_rngc.c | 6 ++++--
hw/misc/macio/mac_dbdma.c | 2 +-
hw/net/virtio-net.c | 3 ++-
hw/nvme/ctrl.c | 6 ++++--
hw/scsi/mptsas.c | 3 ++-
hw/scsi/scsi-bus.c | 3 ++-
hw/scsi/vmw_pvscsi.c | 3 ++-
hw/usb/dev-uas.c | 3 ++-
hw/usb/hcd-dwc2.c | 3 ++-
hw/usb/hcd-ehci.c | 3 ++-
hw/usb/hcd-uhci.c | 2 +-
hw/usb/host-libusb.c | 6 ++++--
hw/usb/redirect.c | 6 ++++--
hw/usb/xen-usb.c | 3 ++-
hw/virtio/virtio-balloon.c | 5 +++--
hw/virtio/virtio-crypto.c | 3 ++-
25 files changed, 66 insertions(+), 35 deletions(-)
diff --git a/hw/9pfs/xen-9p-backend.c b/hw/9pfs/xen-9p-backend.c
index 65c4979c3c..f077c1b255 100644
--- a/hw/9pfs/xen-9p-backend.c
+++ b/hw/9pfs/xen-9p-backend.c
@@ -441,7 +441,9 @@ static int xen_9pfs_connect(struct XenLegacyDevice *xendev)
xen_9pdev->rings[i].ring.out = xen_9pdev->rings[i].data +
XEN_FLEX_RING_SIZE(ring_order);
- xen_9pdev->rings[i].bh = qemu_bh_new(xen_9pfs_bh, &xen_9pdev->rings[i]);
+ xen_9pdev->rings[i].bh = qemu_bh_new_guarded(xen_9pfs_bh,
+ &xen_9pdev->rings[i],
+ &DEVICE(xen_9pdev)->mem_reentrancy_guard);
xen_9pdev->rings[i].out_cons = 0;
xen_9pdev->rings[i].out_size = 0;
xen_9pdev->rings[i].inprogress = false;
diff --git a/hw/block/dataplane/virtio-blk.c b/hw/block/dataplane/virtio-blk.c
index 26f965cabc..191a8c90aa 100644
--- a/hw/block/dataplane/virtio-blk.c
+++ b/hw/block/dataplane/virtio-blk.c
@@ -127,7 +127,8 @@ bool virtio_blk_data_plane_create(VirtIODevice *vdev, VirtIOBlkConf *conf,
} else {
s->ctx = qemu_get_aio_context();
}
- s->bh = aio_bh_new(s->ctx, notify_guest_bh, s);
+ s->bh = aio_bh_new_guarded(s->ctx, notify_guest_bh, s,
+ &DEVICE(s)->mem_reentrancy_guard);
s->batch_notify_vqs = bitmap_new(conf->num_queues);
*dataplane = s;
diff --git a/hw/block/dataplane/xen-block.c b/hw/block/dataplane/xen-block.c
index 2785b9e849..e31806b317 100644
--- a/hw/block/dataplane/xen-block.c
+++ b/hw/block/dataplane/xen-block.c
@@ -632,8 +632,9 @@ XenBlockDataPlane *xen_block_dataplane_create(XenDevice *xendev,
} else {
dataplane->ctx = qemu_get_aio_context();
}
- dataplane->bh = aio_bh_new(dataplane->ctx, xen_block_dataplane_bh,
- dataplane);
+ dataplane->bh = aio_bh_new_guarded(dataplane->ctx, xen_block_dataplane_bh,
+ dataplane,
+ &DEVICE(xendev)->mem_reentrancy_guard);
return dataplane;
}
diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
index f717550fdc..e9f516e633 100644
--- a/hw/block/virtio-blk.c
+++ b/hw/block/virtio-blk.c
@@ -866,8 +866,9 @@ static void virtio_blk_dma_restart_cb(void *opaque, bool running,
* requests will be processed while starting the data plane.
*/
if (!s->bh && !virtio_bus_ioeventfd_enabled(bus)) {
- s->bh = aio_bh_new(blk_get_aio_context(s->conf.conf.blk),
- virtio_blk_dma_restart_bh, s);
+ s->bh = aio_bh_new_guarded(blk_get_aio_context(s->conf.conf.blk),
+ virtio_blk_dma_restart_bh, s,
+ &DEVICE(s)->mem_reentrancy_guard);
blk_inc_in_flight(s->conf.conf.blk);
qemu_bh_schedule(s->bh);
}
diff --git a/hw/char/virtio-serial-bus.c b/hw/char/virtio-serial-bus.c
index 7d4601cb5d..dd619f0731 100644
--- a/hw/char/virtio-serial-bus.c
+++ b/hw/char/virtio-serial-bus.c
@@ -985,7 +985,8 @@ static void virtser_port_device_realize(DeviceState *dev, Error **errp)
return;
}
- port->bh = qemu_bh_new(flush_queued_data_bh, port);
+ port->bh = qemu_bh_new_guarded(flush_queued_data_bh, port,
+ &dev->mem_reentrancy_guard);
port->elem = NULL;
}
diff --git a/hw/display/qxl.c b/hw/display/qxl.c
index 6772849dec..67efa3c3ef 100644
--- a/hw/display/qxl.c
+++ b/hw/display/qxl.c
@@ -2223,11 +2223,14 @@ static void qxl_realize_common(PCIQXLDevice *qxl, Error **errp)
qemu_add_vm_change_state_handler(qxl_vm_change_state_handler, qxl);
- qxl->update_irq = qemu_bh_new(qxl_update_irq_bh, qxl);
+ qxl->update_irq = qemu_bh_new_guarded(qxl_update_irq_bh, qxl,
+ &DEVICE(qxl)->mem_reentrancy_guard);
qxl_reset_state(qxl);
- qxl->update_area_bh = qemu_bh_new(qxl_render_update_area_bh, qxl);
- qxl->ssd.cursor_bh = qemu_bh_new(qemu_spice_cursor_refresh_bh, &qxl->ssd);
+ qxl->update_area_bh = qemu_bh_new_guarded(qxl_render_update_area_bh, qxl,
+ &DEVICE(qxl)->mem_reentrancy_guard);
+ qxl->ssd.cursor_bh = qemu_bh_new_guarded(qemu_spice_cursor_refresh_bh, &qxl->ssd,
+ &DEVICE(qxl)->mem_reentrancy_guard);
}
static void qxl_realize_primary(PCIDevice *dev, Error **errp)
diff --git a/hw/display/virtio-gpu.c b/hw/display/virtio-gpu.c
index 5e15c79b94..66ac9b6cc5 100644
--- a/hw/display/virtio-gpu.c
+++ b/hw/display/virtio-gpu.c
@@ -1339,8 +1339,10 @@ void virtio_gpu_device_realize(DeviceState *qdev, Error **errp)
g->ctrl_vq = virtio_get_queue(vdev, 0);
g->cursor_vq = virtio_get_queue(vdev, 1);
- g->ctrl_bh = qemu_bh_new(virtio_gpu_ctrl_bh, g);
- g->cursor_bh = qemu_bh_new(virtio_gpu_cursor_bh, g);
+ g->ctrl_bh = qemu_bh_new_guarded(virtio_gpu_ctrl_bh, g,
+ &qdev->mem_reentrancy_guard);
+ g->cursor_bh = qemu_bh_new_guarded(virtio_gpu_cursor_bh, g,
+ &qdev->mem_reentrancy_guard);
QTAILQ_INIT(&g->reslist);
QTAILQ_INIT(&g->cmdq);
QTAILQ_INIT(&g->fenceq);
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c
index 7ce001cacd..37091150cb 100644
--- a/hw/ide/ahci.c
+++ b/hw/ide/ahci.c
@@ -1508,7 +1508,8 @@ static void ahci_cmd_done(const IDEDMA *dma)
ahci_write_fis_d2h(ad);
if (ad->port_regs.cmd_issue && !ad->check_bh) {
- ad->check_bh = qemu_bh_new(ahci_check_cmd_bh, ad);
+ ad->check_bh = qemu_bh_new_guarded(ahci_check_cmd_bh, ad,
+ &DEVICE(ad)->mem_reentrancy_guard);
qemu_bh_schedule(ad->check_bh);
}
}
diff --git a/hw/ide/core.c b/hw/ide/core.c
index 5d1039378f..8c8d1a8ec2 100644
--- a/hw/ide/core.c
+++ b/hw/ide/core.c
@@ -519,7 +519,8 @@ BlockAIOCB *ide_issue_trim(
iocb = blk_aio_get(&trim_aiocb_info, s->blk, cb, cb_opaque);
iocb->s = s;
- iocb->bh = qemu_bh_new(ide_trim_bh_cb, iocb);
+ iocb->bh = qemu_bh_new_guarded(ide_trim_bh_cb, iocb,
+ &DEVICE(s)->mem_reentrancy_guard);
iocb->ret = 0;
iocb->qiov = qiov;
iocb->i = -1;
diff --git a/hw/misc/imx_rngc.c b/hw/misc/imx_rngc.c
index 632c03779c..082c6980ad 100644
--- a/hw/misc/imx_rngc.c
+++ b/hw/misc/imx_rngc.c
@@ -228,8 +228,10 @@ static void imx_rngc_realize(DeviceState *dev, Error **errp)
sysbus_init_mmio(sbd, &s->iomem);
sysbus_init_irq(sbd, &s->irq);
- s->self_test_bh = qemu_bh_new(imx_rngc_self_test, s);
- s->seed_bh = qemu_bh_new(imx_rngc_seed, s);
+ s->self_test_bh = qemu_bh_new_guarded(imx_rngc_self_test, s,
+ &dev->mem_reentrancy_guard);
+ s->seed_bh = qemu_bh_new_guarded(imx_rngc_seed, s,
+ &dev->mem_reentrancy_guard);
}
static void imx_rngc_reset(DeviceState *dev)
diff --git a/hw/misc/macio/mac_dbdma.c b/hw/misc/macio/mac_dbdma.c
index efcc02609f..cc7e02203d 100644
--- a/hw/misc/macio/mac_dbdma.c
+++ b/hw/misc/macio/mac_dbdma.c
@@ -914,7 +914,7 @@ static void mac_dbdma_realize(DeviceState *dev, Error **errp)
{
DBDMAState *s = MAC_DBDMA(dev);
- s->bh = qemu_bh_new(DBDMA_run_bh, s);
+ s->bh = qemu_bh_new_guarded(DBDMA_run_bh, s, &dev->mem_reentrancy_guard);
}
static void mac_dbdma_class_init(ObjectClass *oc, void *data)
diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
index 3ae909041a..a170c724de 100644
--- a/hw/net/virtio-net.c
+++ b/hw/net/virtio-net.c
@@ -2885,7 +2885,8 @@ static void virtio_net_add_queue(VirtIONet *n, int index)
n->vqs[index].tx_vq =
virtio_add_queue(vdev, n->net_conf.tx_queue_size,
virtio_net_handle_tx_bh);
- n->vqs[index].tx_bh = qemu_bh_new(virtio_net_tx_bh, &n->vqs[index]);
+ n->vqs[index].tx_bh = qemu_bh_new_guarded(virtio_net_tx_bh, &n->vqs[index],
+ &DEVICE(vdev)->mem_reentrancy_guard);
}
n->vqs[index].tx_waiting = 0;
diff --git a/hw/nvme/ctrl.c b/hw/nvme/ctrl.c
index f25cc2c235..dcb250e772 100644
--- a/hw/nvme/ctrl.c
+++ b/hw/nvme/ctrl.c
@@ -4318,7 +4318,8 @@ static void nvme_init_sq(NvmeSQueue *sq, NvmeCtrl *n, uint64_t dma_addr,
QTAILQ_INSERT_TAIL(&(sq->req_list), &sq->io_req[i], entry);
}
- sq->bh = qemu_bh_new(nvme_process_sq, sq);
+ sq->bh = qemu_bh_new_guarded(nvme_process_sq, sq,
+ &DEVICE(sq->ctrl)->mem_reentrancy_guard);
if (n->dbbuf_enabled) {
sq->db_addr = n->dbbuf_dbs + (sqid << 3);
@@ -4708,7 +4709,8 @@ static void nvme_init_cq(NvmeCQueue *cq, NvmeCtrl *n, uint64_t dma_addr,
}
}
n->cq[cqid] = cq;
- cq->bh = qemu_bh_new(nvme_post_cqes, cq);
+ cq->bh = qemu_bh_new_guarded(nvme_post_cqes, cq,
+ &DEVICE(cq->ctrl)->mem_reentrancy_guard);
}
static uint16_t nvme_create_cq(NvmeCtrl *n, NvmeRequest *req)
diff --git a/hw/scsi/mptsas.c b/hw/scsi/mptsas.c
index c485da792c..3de288b454 100644
--- a/hw/scsi/mptsas.c
+++ b/hw/scsi/mptsas.c
@@ -1322,7 +1322,8 @@ static void mptsas_scsi_realize(PCIDevice *dev, Error **errp)
}
s->max_devices = MPTSAS_NUM_PORTS;
- s->request_bh = qemu_bh_new(mptsas_fetch_requests, s);
+ s->request_bh = qemu_bh_new_guarded(mptsas_fetch_requests, s,
+ &DEVICE(dev)->mem_reentrancy_guard);
scsi_bus_init(&s->bus, sizeof(s->bus), &dev->qdev, &mptsas_scsi_info);
}
diff --git a/hw/scsi/scsi-bus.c b/hw/scsi/scsi-bus.c
index ceceafb2cd..e5c9f7a53d 100644
--- a/hw/scsi/scsi-bus.c
+++ b/hw/scsi/scsi-bus.c
@@ -193,7 +193,8 @@ static void scsi_dma_restart_cb(void *opaque, bool running, RunState state)
AioContext *ctx = blk_get_aio_context(s->conf.blk);
/* The reference is dropped in scsi_dma_restart_bh.*/
object_ref(OBJECT(s));
- s->bh = aio_bh_new(ctx, scsi_dma_restart_bh, s);
+ s->bh = aio_bh_new_guarded(ctx, scsi_dma_restart_bh, s,
+ &DEVICE(s)->mem_reentrancy_guard);
qemu_bh_schedule(s->bh);
}
}
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index fa76696855..4de34536e9 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -1184,7 +1184,8 @@ pvscsi_realizefn(PCIDevice *pci_dev, Error **errp)
pcie_endpoint_cap_init(pci_dev, PVSCSI_EXP_EP_OFFSET);
}
- s->completion_worker = qemu_bh_new(pvscsi_process_completion_queue, s);
+ s->completion_worker = qemu_bh_new_guarded(pvscsi_process_completion_queue, s,
+ &DEVICE(pci_dev)->mem_reentrancy_guard);
scsi_bus_init(&s->bus, sizeof(s->bus), DEVICE(pci_dev), &pvscsi_scsi_info);
/* override default SCSI bus hotplug-handler, with pvscsi's one */
diff --git a/hw/usb/dev-uas.c b/hw/usb/dev-uas.c
index 88f99c05d5..f013ded91e 100644
--- a/hw/usb/dev-uas.c
+++ b/hw/usb/dev-uas.c
@@ -937,7 +937,8 @@ static void usb_uas_realize(USBDevice *dev, Error **errp)
QTAILQ_INIT(&uas->results);
QTAILQ_INIT(&uas->requests);
- uas->status_bh = qemu_bh_new(usb_uas_send_status_bh, uas);
+ uas->status_bh = qemu_bh_new_guarded(usb_uas_send_status_bh, uas,
+ &d->mem_reentrancy_guard);
dev->flags |= (1 << USB_DEV_FLAG_IS_SCSI_STORAGE);
scsi_bus_init(&uas->bus, sizeof(uas->bus), DEVICE(dev), &usb_uas_scsi_info);
diff --git a/hw/usb/hcd-dwc2.c b/hw/usb/hcd-dwc2.c
index 8755e9cbb0..a0c4e782b2 100644
--- a/hw/usb/hcd-dwc2.c
+++ b/hw/usb/hcd-dwc2.c
@@ -1364,7 +1364,8 @@ static void dwc2_realize(DeviceState *dev, Error **errp)
s->fi = USB_FRMINTVL - 1;
s->eof_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, dwc2_frame_boundary, s);
s->frame_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, dwc2_work_timer, s);
- s->async_bh = qemu_bh_new(dwc2_work_bh, s);
+ s->async_bh = qemu_bh_new_guarded(dwc2_work_bh, s,
+ &dev->mem_reentrancy_guard);
sysbus_init_irq(sbd, &s->irq);
}
diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index d4da8dcb8d..c930c60921 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -2533,7 +2533,8 @@ void usb_ehci_realize(EHCIState *s, DeviceState *dev, Error **errp)
}
s->frame_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ehci_work_timer, s);
- s->async_bh = qemu_bh_new(ehci_work_bh, s);
+ s->async_bh = qemu_bh_new_guarded(ehci_work_bh, s,
+ &dev->mem_reentrancy_guard);
s->device = dev;
s->vmstate = qemu_add_vm_change_state_handler(usb_ehci_vm_state_change, s);
diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index 30ae0104bb..bdc891f57a 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -1193,7 +1193,7 @@ void usb_uhci_common_realize(PCIDevice *dev, Error **errp)
USB_SPEED_MASK_LOW | USB_SPEED_MASK_FULL);
}
}
- s->bh = qemu_bh_new(uhci_bh, s);
+ s->bh = qemu_bh_new_guarded(uhci_bh, s, &DEVICE(dev)->mem_reentrancy_guard);
s->frame_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, uhci_frame_timer, s);
s->num_ports_vmstate = NB_PORTS;
QTAILQ_INIT(&s->queues);
diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
index 176868d345..f500db85ab 100644
--- a/hw/usb/host-libusb.c
+++ b/hw/usb/host-libusb.c
@@ -1141,7 +1141,8 @@ static void usb_host_nodev_bh(void *opaque)
static void usb_host_nodev(USBHostDevice *s)
{
if (!s->bh_nodev) {
- s->bh_nodev = qemu_bh_new(usb_host_nodev_bh, s);
+ s->bh_nodev = qemu_bh_new_guarded(usb_host_nodev_bh, s,
+ &DEVICE(s)->mem_reentrancy_guard);
}
qemu_bh_schedule(s->bh_nodev);
}
@@ -1739,7 +1740,8 @@ static int usb_host_post_load(void *opaque, int version_id)
USBHostDevice *dev = opaque;
if (!dev->bh_postld) {
- dev->bh_postld = qemu_bh_new(usb_host_post_load_bh, dev);
+ dev->bh_postld = qemu_bh_new_guarded(usb_host_post_load_bh, dev,
+ &DEVICE(dev)->mem_reentrancy_guard);
}
qemu_bh_schedule(dev->bh_postld);
dev->bh_postld_pending = true;
diff --git a/hw/usb/redirect.c b/hw/usb/redirect.c
index fd7df599bc..39fbaaab16 100644
--- a/hw/usb/redirect.c
+++ b/hw/usb/redirect.c
@@ -1441,8 +1441,10 @@ static void usbredir_realize(USBDevice *udev, Error **errp)
}
}
- dev->chardev_close_bh = qemu_bh_new(usbredir_chardev_close_bh, dev);
- dev->device_reject_bh = qemu_bh_new(usbredir_device_reject_bh, dev);
+ dev->chardev_close_bh = qemu_bh_new_guarded(usbredir_chardev_close_bh, dev,
+ &DEVICE(dev)->mem_reentrancy_guard);
+ dev->device_reject_bh = qemu_bh_new_guarded(usbredir_device_reject_bh, dev,
+ &DEVICE(dev)->mem_reentrancy_guard);
dev->attach_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL, usbredir_do_attach, dev);
packet_id_queue_init(&dev->cancelled, dev, "cancelled");
diff --git a/hw/usb/xen-usb.c b/hw/usb/xen-usb.c
index 0f7369e7ed..dec91294ad 100644
--- a/hw/usb/xen-usb.c
+++ b/hw/usb/xen-usb.c
@@ -1021,7 +1021,8 @@ static void usbback_alloc(struct XenLegacyDevice *xendev)
QTAILQ_INIT(&usbif->req_free_q);
QSIMPLEQ_INIT(&usbif->hotplug_q);
- usbif->bh = qemu_bh_new(usbback_bh, usbif);
+ usbif->bh = qemu_bh_new_guarded(usbback_bh, usbif,
+ &DEVICE(xendev)->mem_reentrancy_guard);
}
static int usbback_free(struct XenLegacyDevice *xendev)
diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c
index 746f07c4d2..309cebacc6 100644
--- a/hw/virtio/virtio-balloon.c
+++ b/hw/virtio/virtio-balloon.c
@@ -908,8 +908,9 @@ static void virtio_balloon_device_realize(DeviceState *dev, Error **errp)
precopy_add_notifier(&s->free_page_hint_notify);
object_ref(OBJECT(s->iothread));
- s->free_page_bh = aio_bh_new(iothread_get_aio_context(s->iothread),
- virtio_ballloon_get_free_page_hints, s);
+ s->free_page_bh = aio_bh_new_guarded(iothread_get_aio_context(s->iothread),
+ virtio_ballloon_get_free_page_hints, s,
+ &DEVICE(s)->mem_reentrancy_guard);
}
if (virtio_has_feature(s->host_features, VIRTIO_BALLOON_F_REPORTING)) {
diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
index 516425e26a..4c95f1096e 100644
--- a/hw/virtio/virtio-crypto.c
+++ b/hw/virtio/virtio-crypto.c
@@ -1050,7 +1050,8 @@ static void virtio_crypto_device_realize(DeviceState *dev, Error **errp)
vcrypto->vqs[i].dataq =
virtio_add_queue(vdev, 1024, virtio_crypto_handle_dataq_bh);
vcrypto->vqs[i].dataq_bh =
- qemu_bh_new(virtio_crypto_dataq_bh, &vcrypto->vqs[i]);
+ qemu_bh_new_guarded(virtio_crypto_dataq_bh, &vcrypto->vqs[i],
+ &dev->mem_reentrancy_guard);
vcrypto->vqs[i].vcrypto = vcrypto;
}
--
2.39.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
* Re: [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks
2023-01-26 5:25 ` [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks Alexander Bulekov
@ 2023-01-26 14:57 ` Stefan Hajnoczi
0 siblings, 0 replies; 9+ messages in thread
From: Stefan Hajnoczi @ 2023-01-26 14:57 UTC (permalink / raw)
To: Alexander Bulekov
Cc: qemu-devel, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
[-- Attachment #1: Type: text/plain, Size: 1234 bytes --]
On Thu, Jan 26, 2023 at 12:25:57AM -0500, Alexander Bulekov wrote:
> Advise authors to use the _guarded versions of the APIs, instead.
>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
> ---
> scripts/checkpatch.pl | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
> index 6ecabfb2b5..61bb4b0a19 100755
> --- a/scripts/checkpatch.pl
> +++ b/scripts/checkpatch.pl
> @@ -2865,6 +2865,14 @@ sub process {
> if ($line =~ /\bsignal\s*\(/ && !($line =~ /SIG_(?:IGN|DFL)/)) {
> ERROR("use sigaction to establish signal handlers; signal is not portable\n" . $herecurr);
> }
> +# recommend qemu_bh_new_guarded instead of qemu_bh_new
> + if ($line =~ /\bqemu_bh_new\s*\(/) {
> + ERROR("use qemu_bh_new_guarded() instead of qemu_bh_new() to avoid reentrancy problems\n" . $herecurr);
> + }
> +# recommend aio_bh_new_guarded instead of aio_bh_new
> + if ($line =~ /\baio_bh_new\s*\(/) {
> + ERROR("use aio_bh_new_guarded() instead of aio_bh_new() to avoid reentrancy problems\n" . $herecurr);
> + }
These checks should be limited to source code in hw/. Other directories
can use BHs without MemReentrancyGuard.
Stefan
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^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v5 0/4] memory: prevent dma-reentracy issues
2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
` (3 preceding siblings ...)
2023-01-26 5:25 ` [PATCH v5 4/4] hw: replace most qemu_bh_new calls with qemu_bh_new_guarded Alexander Bulekov
@ 2023-01-26 16:18 ` Darren Kenny
4 siblings, 0 replies; 9+ messages in thread
From: Darren Kenny @ 2023-01-26 16:18 UTC (permalink / raw)
To: Alexander Bulekov, qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Bin Meng, Paolo Bonzini, Michael S . Tsirkin,
Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
Hi Alex,
From my perspective, I'm happy with the changes made, so from me at
least:
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Thanks,
Darren.
On Thursday, 2023-01-26 at 00:25:54 -05, Alexander Bulekov wrote:
> These patches aim to solve two types of DMA-reentrancy issues:
>
> 1.) mmio -> dma -> mmio case
> To solve this, we track whether the device is engaged in io by
> checking/setting a reentrancy-guard within APIs used for MMIO access.
>
> 2.) bh -> dma write -> mmio case
> This case is trickier, since we dont have a generic way to associate a
> bh with the underlying Device/DeviceState. Thus, this version allows a
> device to associate a reentrancy-guard with a bh, when creating it.
> (Instead of calling qemu_bh_new, you call qemu_bh_new_guarded)
>
> I replaced most of the qemu_bh_new invocations with the guarded analog,
> except for the ones where the DeviceState was not trivially accessible
>
> v4-> v5:
> - Add corresponding checkpatch checks
> - Save/restore reentrancy-flag when entering/exiting BHs
> - Improve documentation
> - Check object_dynamic_cast return value
>
> v3 -> v4: Instead of changing all of the DMA APIs, instead add an
> optional reentrancy guard to the BH API.
>
> v2 -> v3: Bite the bullet and modify the DMA APIs, rather than
> attempting to guess DeviceStates in BHs.
>
> Alexander Bulekov (4):
> memory: prevent dma-reentracy issues
> async: Add an optional reentrancy guard to the BH API
> checkpatch: add qemu_bh_new/aio_bh_new checks
> hw: replace most qemu_bh_new calls with qemu_bh_new_guarded
>
> docs/devel/multiple-iothreads.txt | 7 +++++++
> hw/9pfs/xen-9p-backend.c | 4 +++-
> hw/block/dataplane/virtio-blk.c | 3 ++-
> hw/block/dataplane/xen-block.c | 5 +++--
> hw/block/virtio-blk.c | 5 +++--
> hw/char/virtio-serial-bus.c | 3 ++-
> hw/display/qxl.c | 9 ++++++---
> hw/display/virtio-gpu.c | 6 ++++--
> hw/ide/ahci.c | 3 ++-
> hw/ide/core.c | 3 ++-
> hw/misc/imx_rngc.c | 6 ++++--
> hw/misc/macio/mac_dbdma.c | 2 +-
> hw/net/virtio-net.c | 3 ++-
> hw/nvme/ctrl.c | 6 ++++--
> hw/scsi/mptsas.c | 3 ++-
> hw/scsi/scsi-bus.c | 3 ++-
> hw/scsi/vmw_pvscsi.c | 3 ++-
> hw/usb/dev-uas.c | 3 ++-
> hw/usb/hcd-dwc2.c | 3 ++-
> hw/usb/hcd-ehci.c | 3 ++-
> hw/usb/hcd-uhci.c | 2 +-
> hw/usb/host-libusb.c | 6 ++++--
> hw/usb/redirect.c | 6 ++++--
> hw/usb/xen-usb.c | 3 ++-
> hw/virtio/virtio-balloon.c | 5 +++--
> hw/virtio/virtio-crypto.c | 3 ++-
> include/block/aio.h | 18 ++++++++++++++++--
> include/hw/qdev-core.h | 7 +++++++
> include/qemu/main-loop.h | 7 +++++--
> scripts/checkpatch.pl | 8 ++++++++
> softmmu/memory.c | 17 +++++++++++++++++
> softmmu/trace-events | 1 +
> tests/unit/ptimer-test-stubs.c | 3 ++-
> util/async.c | 18 +++++++++++++++++-
> util/main-loop.c | 5 +++--
> util/trace-events | 1 +
> 36 files changed, 150 insertions(+), 43 deletions(-)
>
> --
> 2.39.0
^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: [PATCH v5 1/4] memory: prevent dma-reentracy issues
2023-01-26 5:25 ` [PATCH v5 1/4] " Alexander Bulekov
@ 2023-01-26 20:54 ` Peter Xu
0 siblings, 0 replies; 9+ messages in thread
From: Peter Xu @ 2023-01-26 20:54 UTC (permalink / raw)
To: Alexander Bulekov
Cc: qemu-devel, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
On Thu, Jan 26, 2023 at 12:25:55AM -0500, Alexander Bulekov wrote:
> Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA.
> This flag is set/checked prior to calling a device's MemoryRegion
> handlers, and set when device code initiates DMA. The purpose of this
> flag is to prevent two types of DMA-based reentrancy issues:
>
> 1.) mmio -> dma -> mmio case
> 2.) bh -> dma write -> mmio case
>
> These issues have led to problems such as stack-exhaustion and
> use-after-frees.
>
> Summary of the problem from Peter Maydell:
> https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827
>
> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
> Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
Acked-by: Peter Xu <peterx@redhat.com>
--
Peter Xu
^ permalink raw reply [flat|nested] 9+ messages in thread
* [PATCH v5 1/4] memory: prevent dma-reentracy issues
2023-01-26 5:24 Alexander Bulekov
@ 2023-01-26 5:24 ` Alexander Bulekov
0 siblings, 0 replies; 9+ messages in thread
From: Alexander Bulekov @ 2023-01-26 5:24 UTC (permalink / raw)
To: qemu-devel
Cc: Alexander Bulekov, Stefan Hajnoczi, Philippe Mathieu-Daudé,
Mauro Matteo Cascella, Peter Xu, Jason Wang, David Hildenbrand,
Gerd Hoffmann, Thomas Huth, Laurent Vivier, Bandan Das,
Edgar E . Iglesias, Darren Kenny, Bin Meng, Paolo Bonzini,
Michael S . Tsirkin, Marcel Apfelbaum, Daniel P . Berrangé,
Eduardo Habkost, Jon Maloy, Siqi Chen
Add a flag to the DeviceState, when a device is engaged in PIO/MMIO/DMA.
This flag is set/checked prior to calling a device's MemoryRegion
handlers, and set when device code initiates DMA. The purpose of this
flag is to prevent two types of DMA-based reentrancy issues:
1.) mmio -> dma -> mmio case
2.) bh -> dma write -> mmio case
These issues have led to problems such as stack-exhaustion and
use-after-frees.
Summary of the problem from Peter Maydell:
https://lore.kernel.org/qemu-devel/CAFEAcA_23vc7hE3iaM-JVA6W38LK4hJoWae5KcknhPRD5fPBZA@mail.gmail.com
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/62
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/540
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/541
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/556
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/557
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/827
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Alexander Bulekov <alxndr@bu.edu>
---
include/hw/qdev-core.h | 7 +++++++
softmmu/memory.c | 17 +++++++++++++++++
softmmu/trace-events | 1 +
3 files changed, 25 insertions(+)
diff --git a/include/hw/qdev-core.h b/include/hw/qdev-core.h
index 35fddb19a6..8858195262 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 e05332d07f..daffb48493 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -533,6 +533,7 @@ 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) {
@@ -542,6 +543,19 @@ 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) {
+ if (dev->mem_reentrancy_guard.engaged_in_io) {
+ trace_memory_region_reentrant_io(get_cpu_index(), mr, addr, size);
+ return MEMTX_ERROR;
+ }
+ 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 +570,9 @@ static MemTxResult access_with_adjusted_size(hwaddr addr,
access_mask, attrs);
}
}
+ if (dev) {
+ dev->mem_reentrancy_guard.engaged_in_io = false;
+ }
return r;
}
diff --git a/softmmu/trace-events b/softmmu/trace-events
index 22606dc27b..62d04ea9a7 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)"
--
2.39.0
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2023-01-26 20:55 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
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2023-01-26 5:25 [PATCH v5 0/4] memory: prevent dma-reentracy issues Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 1/4] " Alexander Bulekov
2023-01-26 20:54 ` Peter Xu
2023-01-26 5:25 ` [PATCH v5 2/4] async: Add an optional reentrancy guard to the BH API Alexander Bulekov
2023-01-26 5:25 ` [PATCH v5 3/4] checkpatch: add qemu_bh_new/aio_bh_new checks Alexander Bulekov
2023-01-26 14:57 ` Stefan Hajnoczi
2023-01-26 5:25 ` [PATCH v5 4/4] hw: replace most qemu_bh_new calls with qemu_bh_new_guarded Alexander Bulekov
2023-01-26 16:18 ` [PATCH v5 0/4] memory: prevent dma-reentracy issues Darren Kenny
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2023-01-26 5:24 Alexander Bulekov
2023-01-26 5:24 ` [PATCH v5 1/4] " Alexander Bulekov
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