On 11/22/2022 1:26 AM, Klaus Jensen wrote: > On Nov 21 16:04, Keith Busch wrote: >> [cc'ing Klaus] >> >> On Mon, Nov 21, 2022 at 03:49:45PM -0700, Jonathan Derrick wrote: >>> On 11/21/2022 3:34 PM, Jonathan Derrick wrote: >>>> On 11/21/2022 1:55 PM, Keith Busch wrote: >>>>> On Thu, Nov 17, 2022 at 02:22:10PM -0700, Jonathan Derrick wrote: >>>>>> I seem to have isolated the error mechanism for older kernels, but 6.2.0-rc2 >>>>>> reliably segfaults my QEMU instance (something else to look into) and I don't >>>>>> have any 'real' hardware to test this on at the moment. It looks like several >>>>>> passthru commands are able to enqueue prior/during/after resetting/connecting. >>>>> >>>>> I'm not seeing any problem with the latest nvme-qemu after several dozen >>>>> iterations of this test case. In that environment, the formats and >>>>> resets complete practically synchronously with the call, so everything >>>>> proceeds quickly. Is there anything special I need to change? >>>>> >>>> I can still repro this with nvme-fixes tag, so I'll have to dig into it myself >>> Here's a backtrace: >>> >>> Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault. >>> [Switching to Thread 0x7ffff7554400 (LWP 531154)] >>> 0x000055555597a9d5 in nvme_ctrl (req=0x7fffec892780) at ../hw/nvme/nvme.h:539 >>> 540 return sq->ctrl; >>> (gdb) backtrace >>> #0 0x000055555597a9d5 in nvme_ctrl (req=0x7fffec892780) at ../hw/nvme/nvme.h:539 >>> #1 0x0000555555994360 in nvme_format_bh (opaque=0x5555579dd000) at ../hw/nvme/ctrl.c:5852 >> >> Thanks, looks like a race between the admin queue format's bottom half, >> and the controller reset tearing down that queue. I'll work with Klaus >> on that qemu side (looks like a well placed qemu_bh_cancel() should do >> it). >> > > Yuck. Bug located and quelched I think. > > Jonathan, please try > > https://lore.kernel.org/qemu-devel/20221122081348.49963-2-its@xxxxxxxxxxxxx/ > > This fixes the qemu crash, but I still see a "nvme still not live after > 42 seconds!" resulting from the test. I'm seeing A LOT of invalid > submission queue doorbell writes: > > pci_nvme_ub_db_wr_invalid_sq in nvme_process_db: submission queue doorbell write for nonexistent queue, sqid=0, ignoring > > Tested on a 6.1-rc4. Good change, just defers it a bit for me: Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault. [Switching to Thread 0x7ffff7554400 (LWP 559269)] 0x000055555598922e in nvme_enqueue_req_completion (cq=0x0, req=0x7fffec141310) at ../hw/nvme/ctrl.c:1390 1390 assert(cq->cqid == req->sq->cqid); (gdb) backtrace #0 0x000055555598922e in nvme_enqueue_req_completion (cq=0x0, req=0x7fffec141310) at ../hw/nvme/ctrl.c:1390 #1 0x000055555598a7a7 in nvme_misc_cb (opaque=0x7fffec141310, ret=0) at ../hw/nvme/ctrl.c:2002 #2 0x000055555599448a in nvme_do_format (iocb=0x55555770ccd0) at ../hw/nvme/ctrl.c:5891 #3 0x00005555559942a9 in nvme_format_ns_cb (opaque=0x55555770ccd0, ret=0) at ../hw/nvme/ctrl.c:5828 #4 0x0000555555dda018 in blk_aio_complete (acb=0x7fffec1fccd0) at ../block/block-backend.c:1501 #5 0x0000555555dda2fc in blk_aio_write_entry (opaque=0x7fffec1fccd0) at ../block/block-backend.c:1568 #6 0x0000555555f506b9 in coroutine_trampoline (i0=-331119632, i1=32767) at ../util/coroutine-ucontext.c:177 #7 0x00007ffff77c84e0 in __start_context () at ../sysdeps/unix/sysv/linux/x86_64/__start_context.S:91 #8 0x00007ffff4ff2bd0 in () #9 0x0000000000000000 in ()
