| Message ID | 20210825200953.1684541-1-philmd@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RFC] hw/virtio: Do not access vring cache if queue is not ready | expand |
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; >
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 :/
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
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;
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(-)