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 <cwmy...@snu.ac.kr> >> Reported-by: Qiuhao Li <qiuhao...@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 <phi...@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 :/
