* [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready
@ 2021-08-25 20:09 Philippe Mathieu-Daudé
2021-08-25 20:36 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 4+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-08-25 20:09 UTC (permalink / raw)
To: qemu-devel
Cc: Michael S. Tsirkin, Jason Wang, Li Qiang, Qiuhao Li,
Alexander Bulekov, Stefan Hajnoczi, Paolo Bonzini,
Philippe Mathieu-Daudé,
Cheolwoo Myung
Do not intent to access the vring MemoryRegion cache if
the queue is not ready (no vring available).
This fixes issue #301:
qemu-system-i386: include/exec/memory_ldst_cached.h.inc:77: void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint16_t, MemTxAttrs, MemTxResult *):
Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
(gdb) bt
#1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
#4 0x0000555558f2a122 in address_space_stw_le_cached (cache=0x61300010bb70, addr=516, val=0, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:77
#5 0x0000555558f2964c in stw_le_phys_cached (cache=0x61300010bb70, addr=516, val=0) at include/exec/memory_ldst_phys.h.inc:109
#6 0x0000555558f28da8 in virtio_stw_phys_cached (vdev=0x62d00004e680, cache=0x61300010bb70, pa=516, value=0) at include/hw/virtio/virtio-access.h:196
#7 0x0000555558f287dc in vring_set_avail_event (vq=0x7fff5d23e800, val=0) at hw/virtio/virtio.c:428
#8 0x0000555558efabb7 in virtio_queue_split_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:437
#9 0x0000555558ef9f3c in virtio_queue_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:498
#10 0x0000555558c94786 in virtio_blk_handle_vq (s=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/virtio-blk.c:795
#11 0x0000555558cb96c2 in virtio_blk_data_plane_handle_output (vdev=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/dataplane/virtio-blk.c:165
#12 0x0000555558f35937 in virtio_queue_notify_aio_vq (vq=0x7fff5d23e800) at hw/virtio/virtio.c:2323
#13 0x0000555558f264b3 in virtio_queue_host_notifier_aio_read (n=0x7fff5d23e87c) at hw/virtio/virtio.c:3532
#14 0x0000555559a9cd3e in aio_dispatch_handler (ctx=0x613000063000, node=0x60d000008f40) at util/aio-posix.c:329
#15 0x0000555559a963ae in aio_dispatch_handlers (ctx=0x613000063000) at util/aio-posix.c:372
#16 0x0000555559a95f82 in aio_dispatch (ctx=0x613000063000) at util/aio-posix.c:382
and #302:
qemu-system-i386: include/exec/memory_ldst_cached.h.inc:30: uint16_t address_space_lduw_le_cached(MemoryRegionCache *, hwaddr, MemTxAttrs, MemTxResult *):
Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
0x00007ffff4d312a2 in raise () from /lib64/libc.so.6
(gdb) bt
#1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
#4 0x0000555558f2b8ec in address_space_lduw_le_cached (cache=0x61300010a7c0, addr=134, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:30
#5 0x0000555558f2ac6b in lduw_le_phys_cached (cache=0x61300010a7c0, addr=134) at include/exec/memory_ldst_phys.h.inc:67
#6 0x0000555558f2a3cd in virtio_lduw_phys_cached (vdev=0x62d00003a680, cache=0x61300010a7c0, pa=134) at include/hw/virtio/virtio-access.h:166
#7 0x0000555558f300ea in vring_avail_ring (vq=0x7fffdd55d8a0, i=65) at hw/virtio/virtio.c:326
#8 0x0000555558f33b10 in vring_get_used_event (vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:332
#9 0x0000555558f33677 in virtio_split_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2471
#10 0x0000555558f1859f in virtio_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2523
#11 0x0000555558f188cc in virtio_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2565
#12 0x0000555557c2bd52 in virtio_input_handle_sts (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/input/virtio-input.c:100
#13 0x0000555558f16df7 in virtio_queue_notify (vdev=0x62d00003a680, n=1) at hw/virtio/virtio.c:2363
#14 0x00005555583f45c0 in virtio_pci_notify_write (opaque=0x62d000032400, addr=7, val=0, size=1) at hw/virtio/virtio-pci.c:1369
#15 0x0000555558b80b04 in memory_region_write_accessor (mr=0x62d000033190, addr=7, value=0x7fffffff8eb0, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:492
Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/301
BugLink: https://bugs.launchpad.net/qemu/+bug/1910941
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/302
BugLink: https://bugs.launchpad.net/qemu/+bug/1913510
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
Could be more readable to use virtio_queue_ready()
RFC because I have no clue about this hot path code,
I simply looked at the backtraces.
---
hw/virtio/virtio.c | 82 +++++++++++++++++++++++++++++++++++++---------
1 file changed, 66 insertions(+), 16 deletions(-)
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 874377f37a7..be1ec9e05ef 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -289,26 +289,38 @@ static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
/* Called within rcu_read_lock(). */
static inline uint16_t vring_avail_flags(VirtQueue *vq)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingAvail, flags);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
+ if (unlikely(!vq->vring.avail)) {
+ return 0;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return 0;
}
+ pa = offsetof(VRingAvail, flags);
return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
}
/* Called within rcu_read_lock(). */
static inline uint16_t vring_avail_idx(VirtQueue *vq)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingAvail, idx);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
+ if (unlikely(!vq->vring.avail)) {
+ return 0;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return 0;
}
+ pa = offsetof(VRingAvail, idx);
vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
return vq->shadow_avail_idx;
}
@@ -316,13 +328,19 @@ static inline uint16_t vring_avail_idx(VirtQueue *vq)
/* Called within rcu_read_lock(). */
static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingAvail, ring[i]);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
+ if (unlikely(!vq->vring.avail)) {
+ return 0;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return 0;
}
+ pa = offsetof(VRingAvail, ring[i]);
return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
}
@@ -336,13 +354,19 @@ static inline uint16_t vring_get_used_event(VirtQueue *vq)
static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
int i)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingUsed, ring[i]);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
+ if (unlikely(!vq->vring.avail)) {
+ return;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return;
}
+ pa = offsetof(VRingUsed, ring[i]);
virtio_tswap32s(vq->vdev, &uelem->id);
virtio_tswap32s(vq->vdev, &uelem->len);
address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem));
@@ -352,23 +376,35 @@ static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
/* Called within rcu_read_lock(). */
static uint16_t vring_used_idx(VirtQueue *vq)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingUsed, idx);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
+ if (unlikely(!vq->vring.avail)) {
+ return 0;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return 0;
}
+ pa = offsetof(VRingUsed, idx);
return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
}
/* Called within rcu_read_lock(). */
static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- hwaddr pa = offsetof(VRingUsed, idx);
+ VRingMemoryRegionCaches *caches;
+ if (unlikely(!vq->vring.avail)) {
+ return;
+ }
+
+ caches = vring_get_region_caches(vq);
if (caches) {
+ hwaddr pa = offsetof(VRingUsed, idx);
+
virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
address_space_cache_invalidate(&caches->used, pa, sizeof(val));
}
@@ -379,17 +415,22 @@ static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
/* Called within rcu_read_lock(). */
static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask)
{
- VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
- VirtIODevice *vdev = vq->vdev;
- hwaddr pa = offsetof(VRingUsed, flags);
+ VRingMemoryRegionCaches *caches;
+ hwaddr pa;
uint16_t flags;
+ if (unlikely(!vq->vring.avail)) {
+ return;
+ }
+
+ caches = vring_get_region_caches(vq);
if (!caches) {
return;
}
+ pa = offsetof(VRingUsed, flags);
flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
- virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask);
+ virtio_stw_phys_cached(vq->vdev, &caches->used, pa, flags | mask);
address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
}
@@ -401,6 +442,10 @@ static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask)
hwaddr pa = offsetof(VRingUsed, flags);
uint16_t flags;
+ if (unlikely(!vq->vring.avail)) {
+ return;
+ }
+
if (!caches) {
return;
}
@@ -415,10 +460,15 @@ static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val)
{
VRingMemoryRegionCaches *caches;
hwaddr pa;
+
if (!vq->notification) {
return;
}
+ if (unlikely(!vq->vring.avail)) {
+ return;
+ }
+
caches = vring_get_region_caches(vq);
if (!caches) {
return;
--
2.31.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready
2021-08-25 20:09 [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready Philippe Mathieu-Daudé
@ 2021-08-25 20:36 ` Philippe Mathieu-Daudé
2021-08-25 22:50 ` Philippe Mathieu-Daudé
0 siblings, 1 reply; 4+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-08-25 20:36 UTC (permalink / raw)
To: qemu-devel
Cc: Michael S. Tsirkin, Jason Wang, Li Qiang, Qiuhao Li,
Alexander Bulekov, Stefan Hajnoczi, Paolo Bonzini,
Cheolwoo Myung
On 8/25/21 10:09 PM, Philippe Mathieu-Daudé wrote:
> Do not intent to access the vring MemoryRegion cache if
> the queue is not ready (no vring available).
>
> This fixes issue #301:
>
> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:77: void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint16_t, MemTxAttrs, MemTxResult *):
> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
> (gdb) bt
> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
> #4 0x0000555558f2a122 in address_space_stw_le_cached (cache=0x61300010bb70, addr=516, val=0, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:77
> #5 0x0000555558f2964c in stw_le_phys_cached (cache=0x61300010bb70, addr=516, val=0) at include/exec/memory_ldst_phys.h.inc:109
> #6 0x0000555558f28da8 in virtio_stw_phys_cached (vdev=0x62d00004e680, cache=0x61300010bb70, pa=516, value=0) at include/hw/virtio/virtio-access.h:196
> #7 0x0000555558f287dc in vring_set_avail_event (vq=0x7fff5d23e800, val=0) at hw/virtio/virtio.c:428
> #8 0x0000555558efabb7 in virtio_queue_split_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:437
> #9 0x0000555558ef9f3c in virtio_queue_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:498
> #10 0x0000555558c94786 in virtio_blk_handle_vq (s=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/virtio-blk.c:795
> #11 0x0000555558cb96c2 in virtio_blk_data_plane_handle_output (vdev=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/dataplane/virtio-blk.c:165
> #12 0x0000555558f35937 in virtio_queue_notify_aio_vq (vq=0x7fff5d23e800) at hw/virtio/virtio.c:2323
> #13 0x0000555558f264b3 in virtio_queue_host_notifier_aio_read (n=0x7fff5d23e87c) at hw/virtio/virtio.c:3532
> #14 0x0000555559a9cd3e in aio_dispatch_handler (ctx=0x613000063000, node=0x60d000008f40) at util/aio-posix.c:329
> #15 0x0000555559a963ae in aio_dispatch_handlers (ctx=0x613000063000) at util/aio-posix.c:372
> #16 0x0000555559a95f82 in aio_dispatch (ctx=0x613000063000) at util/aio-posix.c:382
>
> and #302:
>
> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:30: uint16_t address_space_lduw_le_cached(MemoryRegionCache *, hwaddr, MemTxAttrs, MemTxResult *):
> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
> 0x00007ffff4d312a2 in raise () from /lib64/libc.so.6
> (gdb) bt
> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
> #4 0x0000555558f2b8ec in address_space_lduw_le_cached (cache=0x61300010a7c0, addr=134, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:30
> #5 0x0000555558f2ac6b in lduw_le_phys_cached (cache=0x61300010a7c0, addr=134) at include/exec/memory_ldst_phys.h.inc:67
> #6 0x0000555558f2a3cd in virtio_lduw_phys_cached (vdev=0x62d00003a680, cache=0x61300010a7c0, pa=134) at include/hw/virtio/virtio-access.h:166
> #7 0x0000555558f300ea in vring_avail_ring (vq=0x7fffdd55d8a0, i=65) at hw/virtio/virtio.c:326
> #8 0x0000555558f33b10 in vring_get_used_event (vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:332
> #9 0x0000555558f33677 in virtio_split_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2471
> #10 0x0000555558f1859f in virtio_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2523
> #11 0x0000555558f188cc in virtio_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2565
> #12 0x0000555557c2bd52 in virtio_input_handle_sts (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/input/virtio-input.c:100
> #13 0x0000555558f16df7 in virtio_queue_notify (vdev=0x62d00003a680, n=1) at hw/virtio/virtio.c:2363
> #14 0x00005555583f45c0 in virtio_pci_notify_write (opaque=0x62d000032400, addr=7, val=0, size=1) at hw/virtio/virtio-pci.c:1369
> #15 0x0000555558b80b04 in memory_region_write_accessor (mr=0x62d000033190, addr=7, value=0x7fffffff8eb0, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:492
>
> Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
> Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/301
> BugLink: https://bugs.launchpad.net/qemu/+bug/1910941
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/302
> BugLink: https://bugs.launchpad.net/qemu/+bug/1913510
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
> Could be more readable to use virtio_queue_ready()
>
> RFC because I have no clue about this hot path code,
> I simply looked at the backtraces.
> ---
> hw/virtio/virtio.c | 82 +++++++++++++++++++++++++++++++++++++---------
> 1 file changed, 66 insertions(+), 16 deletions(-)
>
> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 874377f37a7..be1ec9e05ef 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -289,26 +289,38 @@ static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
> /* Called within rcu_read_lock(). */
> static inline uint16_t vring_avail_flags(VirtQueue *vq)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingAvail, flags);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
>
> + if (unlikely(!vq->vring.avail)) {
> + return 0;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return 0;
> }
>
> + pa = offsetof(VRingAvail, flags);
> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> }
>
> /* Called within rcu_read_lock(). */
> static inline uint16_t vring_avail_idx(VirtQueue *vq)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingAvail, idx);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
>
> + if (unlikely(!vq->vring.avail)) {
> + return 0;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return 0;
> }
>
> + pa = offsetof(VRingAvail, idx);
> vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> return vq->shadow_avail_idx;
> }
> @@ -316,13 +328,19 @@ static inline uint16_t vring_avail_idx(VirtQueue *vq)
> /* Called within rcu_read_lock(). */
> static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingAvail, ring[i]);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
>
> + if (unlikely(!vq->vring.avail)) {
> + return 0;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return 0;
> }
>
> + pa = offsetof(VRingAvail, ring[i]);
> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> }
Self-NAck.
While the previous part could be OK, what follows is crap (checking
avail instead of used) so please disregard this patch.
> @@ -336,13 +354,19 @@ static inline uint16_t vring_get_used_event(VirtQueue *vq)
> static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
> int i)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingUsed, ring[i]);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
>
> + if (unlikely(!vq->vring.avail)) {
> + return;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return;
> }
>
> + pa = offsetof(VRingUsed, ring[i]);
> virtio_tswap32s(vq->vdev, &uelem->id);
> virtio_tswap32s(vq->vdev, &uelem->len);
> address_space_write_cached(&caches->used, pa, uelem, sizeof(VRingUsedElem));
> @@ -352,23 +376,35 @@ static inline void vring_used_write(VirtQueue *vq, VRingUsedElem *uelem,
> /* Called within rcu_read_lock(). */
> static uint16_t vring_used_idx(VirtQueue *vq)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingUsed, idx);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
>
> + if (unlikely(!vq->vring.avail)) {
> + return 0;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return 0;
> }
>
> + pa = offsetof(VRingUsed, idx);
> return virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
> }
>
> /* Called within rcu_read_lock(). */
> static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - hwaddr pa = offsetof(VRingUsed, idx);
> + VRingMemoryRegionCaches *caches;
>
> + if (unlikely(!vq->vring.avail)) {
> + return;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (caches) {
> + hwaddr pa = offsetof(VRingUsed, idx);
> +
> virtio_stw_phys_cached(vq->vdev, &caches->used, pa, val);
> address_space_cache_invalidate(&caches->used, pa, sizeof(val));
> }
> @@ -379,17 +415,22 @@ static inline void vring_used_idx_set(VirtQueue *vq, uint16_t val)
> /* Called within rcu_read_lock(). */
> static inline void vring_used_flags_set_bit(VirtQueue *vq, int mask)
> {
> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> - VirtIODevice *vdev = vq->vdev;
> - hwaddr pa = offsetof(VRingUsed, flags);
> + VRingMemoryRegionCaches *caches;
> + hwaddr pa;
> uint16_t flags;
>
> + if (unlikely(!vq->vring.avail)) {
> + return;
> + }
> +
> + caches = vring_get_region_caches(vq);
> if (!caches) {
> return;
> }
>
> + pa = offsetof(VRingUsed, flags);
> flags = virtio_lduw_phys_cached(vq->vdev, &caches->used, pa);
> - virtio_stw_phys_cached(vdev, &caches->used, pa, flags | mask);
> + virtio_stw_phys_cached(vq->vdev, &caches->used, pa, flags | mask);
> address_space_cache_invalidate(&caches->used, pa, sizeof(flags));
> }
>
> @@ -401,6 +442,10 @@ static inline void vring_used_flags_unset_bit(VirtQueue *vq, int mask)
> hwaddr pa = offsetof(VRingUsed, flags);
> uint16_t flags;
>
> + if (unlikely(!vq->vring.avail)) {
> + return;
> + }
> +
> if (!caches) {
> return;
> }
> @@ -415,10 +460,15 @@ static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val)
> {
> VRingMemoryRegionCaches *caches;
> hwaddr pa;
> +
> if (!vq->notification) {
> return;
> }
>
> + if (unlikely(!vq->vring.avail)) {
> + return;
> + }
> +
> caches = vring_get_region_caches(vq);
> if (!caches) {
> return;
>
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready
2021-08-25 20:36 ` Philippe Mathieu-Daudé
@ 2021-08-25 22:50 ` Philippe Mathieu-Daudé
2021-08-26 7:45 ` Stefan Hajnoczi
0 siblings, 1 reply; 4+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-08-25 22:50 UTC (permalink / raw)
To: qemu-devel
Cc: Michael S. Tsirkin, Jason Wang, Li Qiang, Qiuhao Li,
Alexander Bulekov, Stefan Hajnoczi, Paolo Bonzini,
Cheolwoo Myung
On 8/25/21 10:36 PM, Philippe Mathieu-Daudé wrote:
> On 8/25/21 10:09 PM, Philippe Mathieu-Daudé wrote:
>> Do not intent to access the vring MemoryRegion cache if
>> the queue is not ready (no vring available).
>>
>> This fixes issue #301:
>>
>> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:77: void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint16_t, MemTxAttrs, MemTxResult *):
>> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
>> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
>> (gdb) bt
>> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
>> #4 0x0000555558f2a122 in address_space_stw_le_cached (cache=0x61300010bb70, addr=516, val=0, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:77
>> #5 0x0000555558f2964c in stw_le_phys_cached (cache=0x61300010bb70, addr=516, val=0) at include/exec/memory_ldst_phys.h.inc:109
>> #6 0x0000555558f28da8 in virtio_stw_phys_cached (vdev=0x62d00004e680, cache=0x61300010bb70, pa=516, value=0) at include/hw/virtio/virtio-access.h:196
>> #7 0x0000555558f287dc in vring_set_avail_event (vq=0x7fff5d23e800, val=0) at hw/virtio/virtio.c:428
>> #8 0x0000555558efabb7 in virtio_queue_split_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:437
>> #9 0x0000555558ef9f3c in virtio_queue_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:498
>> #10 0x0000555558c94786 in virtio_blk_handle_vq (s=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/virtio-blk.c:795
>> #11 0x0000555558cb96c2 in virtio_blk_data_plane_handle_output (vdev=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/dataplane/virtio-blk.c:165
>> #12 0x0000555558f35937 in virtio_queue_notify_aio_vq (vq=0x7fff5d23e800) at hw/virtio/virtio.c:2323
>> #13 0x0000555558f264b3 in virtio_queue_host_notifier_aio_read (n=0x7fff5d23e87c) at hw/virtio/virtio.c:3532
>> #14 0x0000555559a9cd3e in aio_dispatch_handler (ctx=0x613000063000, node=0x60d000008f40) at util/aio-posix.c:329
>> #15 0x0000555559a963ae in aio_dispatch_handlers (ctx=0x613000063000) at util/aio-posix.c:372
>> #16 0x0000555559a95f82 in aio_dispatch (ctx=0x613000063000) at util/aio-posix.c:382
>>
>> and #302:
>>
>> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:30: uint16_t address_space_lduw_le_cached(MemoryRegionCache *, hwaddr, MemTxAttrs, MemTxResult *):
>> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
>> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
>> 0x00007ffff4d312a2 in raise () from /lib64/libc.so.6
>> (gdb) bt
>> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
>> #4 0x0000555558f2b8ec in address_space_lduw_le_cached (cache=0x61300010a7c0, addr=134, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:30
>> #5 0x0000555558f2ac6b in lduw_le_phys_cached (cache=0x61300010a7c0, addr=134) at include/exec/memory_ldst_phys.h.inc:67
>> #6 0x0000555558f2a3cd in virtio_lduw_phys_cached (vdev=0x62d00003a680, cache=0x61300010a7c0, pa=134) at include/hw/virtio/virtio-access.h:166
>> #7 0x0000555558f300ea in vring_avail_ring (vq=0x7fffdd55d8a0, i=65) at hw/virtio/virtio.c:326
>> #8 0x0000555558f33b10 in vring_get_used_event (vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:332
>> #9 0x0000555558f33677 in virtio_split_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2471
>> #10 0x0000555558f1859f in virtio_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2523
>> #11 0x0000555558f188cc in virtio_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2565
>> #12 0x0000555557c2bd52 in virtio_input_handle_sts (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/input/virtio-input.c:100
>> #13 0x0000555558f16df7 in virtio_queue_notify (vdev=0x62d00003a680, n=1) at hw/virtio/virtio.c:2363
>> #14 0x00005555583f45c0 in virtio_pci_notify_write (opaque=0x62d000032400, addr=7, val=0, size=1) at hw/virtio/virtio-pci.c:1369
>> #15 0x0000555558b80b04 in memory_region_write_accessor (mr=0x62d000033190, addr=7, value=0x7fffffff8eb0, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:492
>>
>> Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
>> Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
>> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/301
>> BugLink: https://bugs.launchpad.net/qemu/+bug/1910941
>> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/302
>> BugLink: https://bugs.launchpad.net/qemu/+bug/1913510
>> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
>> ---
>> Could be more readable to use virtio_queue_ready()
>>
>> RFC because I have no clue about this hot path code,
>> I simply looked at the backtraces.
>> ---
>> hw/virtio/virtio.c | 82 +++++++++++++++++++++++++++++++++++++---------
>> 1 file changed, 66 insertions(+), 16 deletions(-)
>>
>> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
>> index 874377f37a7..be1ec9e05ef 100644
>> --- a/hw/virtio/virtio.c
>> +++ b/hw/virtio/virtio.c
>> @@ -289,26 +289,38 @@ static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
>> /* Called within rcu_read_lock(). */
>> static inline uint16_t vring_avail_flags(VirtQueue *vq)
>> {
>> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
>> - hwaddr pa = offsetof(VRingAvail, flags);
>> + VRingMemoryRegionCaches *caches;
>> + hwaddr pa;
>>
>> + if (unlikely(!vq->vring.avail)) {
>> + return 0;
>> + }
>> +
>> + caches = vring_get_region_caches(vq);
>> if (!caches) {
>> return 0;
>> }
>>
>> + pa = offsetof(VRingAvail, flags);
>> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
>> }
>>
>> /* Called within rcu_read_lock(). */
>> static inline uint16_t vring_avail_idx(VirtQueue *vq)
>> {
>> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
>> - hwaddr pa = offsetof(VRingAvail, idx);
>> + VRingMemoryRegionCaches *caches;
>> + hwaddr pa;
>>
>> + if (unlikely(!vq->vring.avail)) {
>> + return 0;
>> + }
>> +
>> + caches = vring_get_region_caches(vq);
>> if (!caches) {
>> return 0;
>> }
>>
>> + pa = offsetof(VRingAvail, idx);
>> vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
>> return vq->shadow_avail_idx;
>> }
>> @@ -316,13 +328,19 @@ static inline uint16_t vring_avail_idx(VirtQueue *vq)
>> /* Called within rcu_read_lock(). */
>> static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
>> {
>> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
>> - hwaddr pa = offsetof(VRingAvail, ring[i]);
>> + VRingMemoryRegionCaches *caches;
>> + hwaddr pa;
>>
>> + if (unlikely(!vq->vring.avail)) {
>> + return 0;
>> + }
>> +
>> + caches = vring_get_region_caches(vq);
>> if (!caches) {
>> return 0;
>> }
>>
>> + pa = offsetof(VRingAvail, ring[i]);
>> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
>> }
>
> Self-NAck.
>
> While the previous part could be OK, what follows is crap (checking
> avail instead of used) so please disregard this patch.
Previous part is also crap :/
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready
2021-08-25 22:50 ` Philippe Mathieu-Daudé
@ 2021-08-26 7:45 ` Stefan Hajnoczi
0 siblings, 0 replies; 4+ messages in thread
From: Stefan Hajnoczi @ 2021-08-26 7:45 UTC (permalink / raw)
To: Philippe Mathieu-Daudé
Cc: Michael S. Tsirkin, Jason Wang, Li Qiang, qemu-devel, Qiuhao Li,
Alexander Bulekov, Paolo Bonzini, Cheolwoo Myung
[-- Attachment #1: Type: text/plain, Size: 7971 bytes --]
On Thu, Aug 26, 2021 at 12:50:34AM +0200, Philippe Mathieu-Daudé wrote:
> On 8/25/21 10:36 PM, Philippe Mathieu-Daudé wrote:
> > On 8/25/21 10:09 PM, Philippe Mathieu-Daudé wrote:
> >> Do not intent to access the vring MemoryRegion cache if
> >> the queue is not ready (no vring available).
> >>
> >> This fixes issue #301:
> >>
> >> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:77: void address_space_stw_le_cached(MemoryRegionCache *, hwaddr, uint16_t, MemTxAttrs, MemTxResult *):
> >> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
> >> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
> >> (gdb) bt
> >> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
> >> #4 0x0000555558f2a122 in address_space_stw_le_cached (cache=0x61300010bb70, addr=516, val=0, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:77
> >> #5 0x0000555558f2964c in stw_le_phys_cached (cache=0x61300010bb70, addr=516, val=0) at include/exec/memory_ldst_phys.h.inc:109
> >> #6 0x0000555558f28da8 in virtio_stw_phys_cached (vdev=0x62d00004e680, cache=0x61300010bb70, pa=516, value=0) at include/hw/virtio/virtio-access.h:196
> >> #7 0x0000555558f287dc in vring_set_avail_event (vq=0x7fff5d23e800, val=0) at hw/virtio/virtio.c:428
> >> #8 0x0000555558efabb7 in virtio_queue_split_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:437
> >> #9 0x0000555558ef9f3c in virtio_queue_set_notification (vq=0x7fff5d23e800, enable=1) at hw/virtio/virtio.c:498
> >> #10 0x0000555558c94786 in virtio_blk_handle_vq (s=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/virtio-blk.c:795
> >> #11 0x0000555558cb96c2 in virtio_blk_data_plane_handle_output (vdev=0x62d00004e680, vq=0x7fff5d23e800) at hw/block/dataplane/virtio-blk.c:165
> >> #12 0x0000555558f35937 in virtio_queue_notify_aio_vq (vq=0x7fff5d23e800) at hw/virtio/virtio.c:2323
> >> #13 0x0000555558f264b3 in virtio_queue_host_notifier_aio_read (n=0x7fff5d23e87c) at hw/virtio/virtio.c:3532
> >> #14 0x0000555559a9cd3e in aio_dispatch_handler (ctx=0x613000063000, node=0x60d000008f40) at util/aio-posix.c:329
> >> #15 0x0000555559a963ae in aio_dispatch_handlers (ctx=0x613000063000) at util/aio-posix.c:372
> >> #16 0x0000555559a95f82 in aio_dispatch (ctx=0x613000063000) at util/aio-posix.c:382
> >>
> >> and #302:
> >>
> >> qemu-system-i386: include/exec/memory_ldst_cached.h.inc:30: uint16_t address_space_lduw_le_cached(MemoryRegionCache *, hwaddr, MemTxAttrs, MemTxResult *):
> >> Assertion `addr < cache->len && 2 <= cache->len - addr' failed.
> >> Thread 1 "qemu-system-i38" received signal SIGABRT, Aborted.
> >> 0x00007ffff4d312a2 in raise () from /lib64/libc.so.6
> >> (gdb) bt
> >> #1 0x00007ffff4d1a8a4 in abort () at /lib64/libc.so.6
> >> #4 0x0000555558f2b8ec in address_space_lduw_le_cached (cache=0x61300010a7c0, addr=134, attrs=..., result=0x0) at include/exec/memory_ldst_cached.h.inc:30
> >> #5 0x0000555558f2ac6b in lduw_le_phys_cached (cache=0x61300010a7c0, addr=134) at include/exec/memory_ldst_phys.h.inc:67
> >> #6 0x0000555558f2a3cd in virtio_lduw_phys_cached (vdev=0x62d00003a680, cache=0x61300010a7c0, pa=134) at include/hw/virtio/virtio-access.h:166
> >> #7 0x0000555558f300ea in vring_avail_ring (vq=0x7fffdd55d8a0, i=65) at hw/virtio/virtio.c:326
> >> #8 0x0000555558f33b10 in vring_get_used_event (vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:332
> >> #9 0x0000555558f33677 in virtio_split_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2471
> >> #10 0x0000555558f1859f in virtio_should_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2523
> >> #11 0x0000555558f188cc in virtio_notify (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/virtio/virtio.c:2565
> >> #12 0x0000555557c2bd52 in virtio_input_handle_sts (vdev=0x62d00003a680, vq=0x7fffdd55d8a0) at hw/input/virtio-input.c:100
> >> #13 0x0000555558f16df7 in virtio_queue_notify (vdev=0x62d00003a680, n=1) at hw/virtio/virtio.c:2363
> >> #14 0x00005555583f45c0 in virtio_pci_notify_write (opaque=0x62d000032400, addr=7, val=0, size=1) at hw/virtio/virtio-pci.c:1369
> >> #15 0x0000555558b80b04 in memory_region_write_accessor (mr=0x62d000033190, addr=7, value=0x7fffffff8eb0, size=1, shift=0, mask=255, attrs=...) at softmmu/memory.c:492
> >>
> >> Reported-by: Cheolwoo Myung <cwmyung@snu.ac.kr>
> >> Reported-by: Qiuhao Li <Qiuhao.Li@outlook.com>
> >> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/301
> >> BugLink: https://bugs.launchpad.net/qemu/+bug/1910941
> >> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/302
> >> BugLink: https://bugs.launchpad.net/qemu/+bug/1913510
> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> >> ---
> >> Could be more readable to use virtio_queue_ready()
> >>
> >> RFC because I have no clue about this hot path code,
> >> I simply looked at the backtraces.
> >> ---
> >> hw/virtio/virtio.c | 82 +++++++++++++++++++++++++++++++++++++---------
> >> 1 file changed, 66 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> >> index 874377f37a7..be1ec9e05ef 100644
> >> --- a/hw/virtio/virtio.c
> >> +++ b/hw/virtio/virtio.c
> >> @@ -289,26 +289,38 @@ static VRingMemoryRegionCaches *vring_get_region_caches(struct VirtQueue *vq)
> >> /* Called within rcu_read_lock(). */
> >> static inline uint16_t vring_avail_flags(VirtQueue *vq)
> >> {
> >> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> >> - hwaddr pa = offsetof(VRingAvail, flags);
> >> + VRingMemoryRegionCaches *caches;
> >> + hwaddr pa;
> >>
> >> + if (unlikely(!vq->vring.avail)) {
> >> + return 0;
> >> + }
> >> +
> >> + caches = vring_get_region_caches(vq);
> >> if (!caches) {
> >> return 0;
> >> }
> >>
> >> + pa = offsetof(VRingAvail, flags);
> >> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> >> }
> >>
> >> /* Called within rcu_read_lock(). */
> >> static inline uint16_t vring_avail_idx(VirtQueue *vq)
> >> {
> >> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> >> - hwaddr pa = offsetof(VRingAvail, idx);
> >> + VRingMemoryRegionCaches *caches;
> >> + hwaddr pa;
> >>
> >> + if (unlikely(!vq->vring.avail)) {
> >> + return 0;
> >> + }
> >> +
> >> + caches = vring_get_region_caches(vq);
> >> if (!caches) {
> >> return 0;
> >> }
> >>
> >> + pa = offsetof(VRingAvail, idx);
> >> vq->shadow_avail_idx = virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> >> return vq->shadow_avail_idx;
> >> }
> >> @@ -316,13 +328,19 @@ static inline uint16_t vring_avail_idx(VirtQueue *vq)
> >> /* Called within rcu_read_lock(). */
> >> static inline uint16_t vring_avail_ring(VirtQueue *vq, int i)
> >> {
> >> - VRingMemoryRegionCaches *caches = vring_get_region_caches(vq);
> >> - hwaddr pa = offsetof(VRingAvail, ring[i]);
> >> + VRingMemoryRegionCaches *caches;
> >> + hwaddr pa;
> >>
> >> + if (unlikely(!vq->vring.avail)) {
> >> + return 0;
> >> + }
> >> +
> >> + caches = vring_get_region_caches(vq);
> >> if (!caches) {
> >> return 0;
> >> }
> >>
> >> + pa = offsetof(VRingAvail, ring[i]);
> >> return virtio_lduw_phys_cached(vq->vdev, &caches->avail, pa);
> >> }
> >
> > Self-NAck.
> >
> > While the previous part could be OK, what follows is crap (checking
> > avail instead of used) so please disregard this patch.
>
> Previous part is also crap :/
The topic reminds me of:
commit abdd16f4681cc4d6bf84990227b5c9b98e869ccd
Author: Stefan Hajnoczi <stefanha@redhat.com>
Date: Fri Feb 7 10:46:19 2020 +0000
virtio: gracefully handle invalid region caches
Stefan
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^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-08-25 20:09 [RFC PATCH] hw/virtio: Do not access vring cache if queue is not ready Philippe Mathieu-Daudé
2021-08-25 20:36 ` Philippe Mathieu-Daudé
2021-08-25 22:50 ` Philippe Mathieu-Daudé
2021-08-26 7:45 ` Stefan Hajnoczi
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