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Re: [Qemu-devel] [PATCH 0/4] exec: reintroduce MemoryRegion caching
From: |
Auger Eric |
Subject: |
Re: [Qemu-devel] [PATCH 0/4] exec: reintroduce MemoryRegion caching |
Date: |
Wed, 16 May 2018 12:41:35 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 |
Hi Paolo,
On 04/17/2018 04:07 PM, Paolo Bonzini wrote:
> MemoryRegionCache was reverted to "normal" address_space_* operations
> for 2.9, due to lack of support for IOMMUs. This series reinstates
> optimizations, caching only the IOMMU translation but not the IOMMU
> lookup and target AddressSpace translation.
>
> Patches 1 to 3 prepare by introducing a new function
> address_space_translate_iommu (split out of address_space_translate)
> and new header files for declarations shared by regular and "cached"
> address_space_* functions. Patch 4 uses them to introduce both
> the slow path for IOMMU and MMIO cached regions, and the fast path
> for RAM cached regions.
This patch seems to cause a regression with ARM vsmmu + virtio-blk-pci.
Reverting it looks to fix the issue. Otherwise I get:
Program received signal SIGSEGV, Segmentation fault.
address_space_lduw_internal_cached_slow (endian=DEVICE_LITTLE_ENDIAN,
result=0x0, attrs=..., addr=2, cache=0xffffa81110a0) at
/home/augere/UPSTREAM/qemu/memory_ldst.inc.c:242
242 val = lduw_le_p(ptr);
(gdb) where
#0 address_space_lduw_internal_cached_slow (endian=DEVICE_LITTLE_ENDIAN,
result=0x0, attrs=..., addr=2, cache=0xffffa81110a0) at
/home/augere/UPSTREAM/qemu/memory_ldst.inc.c:242
#1 address_space_lduw_le_cached_slow (cache=0xffffa81110a0, address@hidden,
attrs=..., address@hidden, result=0x0) at
/home/augere/UPSTREAM/qemu/memory_ldst.inc.c:273
#2 0x0000000000511c74 in address_space_lduw_le_cached (result=0x0, attrs=...,
addr=2, cache=<optimized out>) at
/home/augere/UPSTREAM/qemu/include/exec/memory_ldst_cached.inc.h:56
#3 lduw_le_phys_cached (addr=2, cache=<optimized out>) at
/home/augere/UPSTREAM/qemu/include/exec/memory_ldst_phys.inc.h:91
#4 virtio_lduw_phys_cached (pa=2, cache=<optimized out>, vdev=<optimized out>)
at /home/augere/UPSTREAM/qemu/include/hw/virtio/virtio-access.h:166
#5 vring_avail_idx (vq=0x1cfe2d0) at
/home/augere/UPSTREAM/qemu/hw/virtio/virtio.c:227
#6 virtio_queue_set_notification (vq=0x1cfe2d0, enable=0) at
/home/augere/UPSTREAM/qemu/hw/virtio/virtio.c:324
#7 0x0000000000511d2c in virtio_queue_set_notification (vq=<optimized out>,
enable=<optimized out>) at /home/augere/UPSTREAM/qemu/hw/virtio/virtio.c:318
#8 0x00000000004aa158 in virtio_blk_handle_vq (s=0x1cf32b0, vq=0x1cfe2d0) at
/home/augere/UPSTREAM/qemu/hw/block/virtio-blk.c:605
#9 0x00000000005113f0 in virtio_queue_notify_aio_vq (vq=0x1cfe2d0) at
/home/augere/UPSTREAM/qemu/hw/virtio/virtio.c:1515
#10 0x000000000087cbf0 in aio_dispatch_handlers (address@hidden) at
util/aio-posix.c:406
#11 0x000000000087d3f8 in aio_dispatch (ctx=0x15300e0) at util/aio-posix.c:437
#12 0x0000000000879f30 in aio_ctx_dispatch (source=<optimized out>,
callback=<optimized out>, user_data=<optimized out>) at util/async.c:261
#13 0x0000ffffbeee97a0 in g_main_context_dispatch () from
/lib64/libglib-2.0.so.0
#14 0x000000000087c678 in glib_pollfds_poll () at util/main-loop.c:215
#15 os_host_main_loop_wait (timeout=<optimized out>) at util/main-loop.c:263
#16 main_loop_wait (address@hidden) at util/main-loop.c:522
#17 0x0000000000423dd8 in main_loop () at vl.c:1943
#18 main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at
vl.c:4675
Investigating further ...
Thanks
Eric
>
> Paolo
>
> Paolo Bonzini (4):
> exec: move memory access declarations to a common header, inline
> *_phys functions
> exec: small changes to flatview_do_translate
> exec: extract address_space_translate_iommu, fix page_mask corner case
> exec: reintroduce MemoryRegion caching
>
> exec.c | 245 ++++++++++++++++++++------
> include/exec/cpu-all.h | 79 ++++-----
> include/exec/memory-internal.h | 3 +
> include/exec/memory.h | 209 ++++++++++------------
> include/exec/memory_ldst.inc.h | 71 ++++++++
> include/exec/memory_ldst_cached.inc.h | 108 ++++++++++++
> include/exec/memory_ldst_phys.inc.h | 147 ++++++++++++++++
> memory.c | 4 +-
> memory_ldst.inc.c | 126 -------------
> 9 files changed, 651 insertions(+), 341 deletions(-)
> create mode 100644 include/exec/memory_ldst.inc.h
> create mode 100644 include/exec/memory_ldst_cached.inc.h
> create mode 100644 include/exec/memory_ldst_phys.inc.h
>
- Re: [Qemu-devel] [PATCH 0/4] exec: reintroduce MemoryRegion caching,
Auger Eric <=