hw/scsi/vmw_pvscsi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
From: Elazar Leibovich <elazar.leibovich@oracle.com>
When running Ubuntu 3.13.0-65-generic guest, QEMU sometimes crashes
during guest ACPI reset. It crashes on assert(s->rings_info_valid)
in pvscsi_process_io().
Analyzing the crash revealed that it happens when userspace issues
a sync during a reboot syscall.
Below are backtraces we gathered from the guests.
Guest backtrace when issuing PVSCSI_CMD_ADAPTER_RESET:
pci_device_shutdown
device_shutdown
init_pid_ns
init_pid_ns
kernel_power_off
SYSC_reboot
Guest backtrace when issuing PVSCSI_REG_OFFSET_KICK_RW_IO:
scsi_done
scsi_dispatch_cmd
blk_add_timer
scsi_request_fn
elv_rb_add
__blk_run_queue
queue_unplugged
blk_flush_plug_list
blk_finish_plug
ext4_writepages
set_next_entity
do_writepages
__filemap_fdatawrite_range
filemap_write_and_wait_range
ext4_sync_file
ext4_sync_file
do_fsync
sys_fsync
Since QEMU pvscsi should imitate VMware pvscsi device emulation,
we decided to imitate VMware's behavior in this case.
To check VMware behavior, we wrote a kernel module that issues
a reset to the pvscsi device and then issues a kick. We ran it on
VMware ESXi 6.5 and it seems that it simply ignores the kick.
Hence, we decided to ignore the kick as well.
Signed-off-by: Elazar Leibovich <elazar.leibovich@oracle.com>
Signed-off-by: Liran Alon <liran.alon@oracle.com>
---
hw/scsi/vmw_pvscsi.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
index c91352cf46de..b2bb80449bba 100644
--- a/hw/scsi/vmw_pvscsi.c
+++ b/hw/scsi/vmw_pvscsi.c
@@ -719,7 +719,12 @@ pvscsi_process_io(PVSCSIState *s)
PVSCSIRingReqDesc descr;
hwaddr next_descr_pa;
- assert(s->rings_info_valid);
+ if (!s->rings_info_valid) {
+ qemu_log("WARNING: PVSCSI: Cannot process I/O when "
+ "rings are not valid.\n");
+ return;
+ }
+
while ((next_descr_pa = pvscsi_ring_pop_req_descr(&s->rings)) != 0) {
/* Only read after production index verification */
--
2.20.1
Patchew URL: https://patchew.org/QEMU/20200315132634.113632-1-liran.alon@oracle.com/ Hi, This series failed the docker-mingw@fedora build test. Please find the testing commands and their output below. If you have Docker installed, you can probably reproduce it locally. === TEST SCRIPT BEGIN === #! /bin/bash export ARCH=x86_64 make docker-image-fedora V=1 NETWORK=1 time make docker-test-mingw@fedora J=14 NETWORK=1 === TEST SCRIPT END === CC replay/replay.o CC replay/replay-internal.o /tmp/qemu-test/src/hw/scsi/vmw_pvscsi.c: In function 'pvscsi_process_io': /tmp/qemu-test/src/hw/scsi/vmw_pvscsi.c:723:9: error: implicit declaration of function 'qemu_log'; did you mean 'qemu_fork'? [-Werror=implicit-function-declaration] qemu_log("WARNING: PVSCSI: Cannot process I/O when " ^~~~~~~~ qemu_fork /tmp/qemu-test/src/hw/scsi/vmw_pvscsi.c:723:9: error: nested extern declaration of 'qemu_log' [-Werror=nested-externs] cc1: all warnings being treated as errors make: *** [/tmp/qemu-test/src/rules.mak:69: hw/scsi/vmw_pvscsi.o] Error 1 make: *** Waiting for unfinished jobs.... Traceback (most recent call last): File "./tests/docker/docker.py", line 664, in <module> --- raise CalledProcessError(retcode, cmd) subprocess.CalledProcessError: Command '['sudo', '-n', 'docker', 'run', '--label', 'com.qemu.instance.uuid=b60fe0dffe2b447eb06a7f9f46d9f5aa', '-u', '1001', '--security-opt', 'seccomp=unconfined', '--rm', '-e', 'TARGET_LIST=', '-e', 'EXTRA_CONFIGURE_OPTS=', '-e', 'V=', '-e', 'J=14', '-e', 'DEBUG=', '-e', 'SHOW_ENV=', '-e', 'CCACHE_DIR=/var/tmp/ccache', '-v', '/home/patchew/.cache/qemu-docker-ccache:/var/tmp/ccache:z', '-v', '/var/tmp/patchew-tester-tmp-sakg1pkp/src/docker-src.2020-03-15-10.25.38.6677:/var/tmp/qemu:z,ro', 'qemu:fedora', '/var/tmp/qemu/run', 'test-mingw']' returned non-zero exit status 2. filter=--filter=label=com.qemu.instance.uuid=b60fe0dffe2b447eb06a7f9f46d9f5aa make[1]: *** [docker-run] Error 1 make[1]: Leaving directory `/var/tmp/patchew-tester-tmp-sakg1pkp/src' make: *** [docker-run-test-mingw@fedora] Error 2 real 2m8.180s user 0m8.937s The full log is available at http://patchew.org/logs/20200315132634.113632-1-liran.alon@oracle.com/testing.docker-mingw@fedora/?type=message. --- Email generated automatically by Patchew [https://patchew.org/]. Please send your feedback to patchew-devel@redhat.com
On 15/03/20 14:26, Liran Alon wrote: > From: Elazar Leibovich <elazar.leibovich@oracle.com> > > When running Ubuntu 3.13.0-65-generic guest, QEMU sometimes crashes > during guest ACPI reset. It crashes on assert(s->rings_info_valid) > in pvscsi_process_io(). > > Analyzing the crash revealed that it happens when userspace issues > a sync during a reboot syscall. > > Below are backtraces we gathered from the guests. > > Guest backtrace when issuing PVSCSI_CMD_ADAPTER_RESET: > pci_device_shutdown > device_shutdown > init_pid_ns > init_pid_ns > kernel_power_off > SYSC_reboot > > Guest backtrace when issuing PVSCSI_REG_OFFSET_KICK_RW_IO: > scsi_done > scsi_dispatch_cmd > blk_add_timer > scsi_request_fn > elv_rb_add > __blk_run_queue > queue_unplugged > blk_flush_plug_list > blk_finish_plug > ext4_writepages > set_next_entity > do_writepages > __filemap_fdatawrite_range > filemap_write_and_wait_range > ext4_sync_file > ext4_sync_file > do_fsync > sys_fsync > > Since QEMU pvscsi should imitate VMware pvscsi device emulation, > we decided to imitate VMware's behavior in this case. > > To check VMware behavior, we wrote a kernel module that issues > a reset to the pvscsi device and then issues a kick. We ran it on > VMware ESXi 6.5 and it seems that it simply ignores the kick. > Hence, we decided to ignore the kick as well. > > Signed-off-by: Elazar Leibovich <elazar.leibovich@oracle.com> > Signed-off-by: Liran Alon <liran.alon@oracle.com> > --- > hw/scsi/vmw_pvscsi.c | 7 ++++++- > 1 file changed, 6 insertions(+), 1 deletion(-) > > diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c > index c91352cf46de..b2bb80449bba 100644 > --- a/hw/scsi/vmw_pvscsi.c > +++ b/hw/scsi/vmw_pvscsi.c > @@ -719,7 +719,12 @@ pvscsi_process_io(PVSCSIState *s) > PVSCSIRingReqDesc descr; > hwaddr next_descr_pa; > > - assert(s->rings_info_valid); > + if (!s->rings_info_valid) { > + qemu_log("WARNING: PVSCSI: Cannot process I/O when " > + "rings are not valid.\n"); > + return; > + } > + > while ((next_descr_pa = pvscsi_ring_pop_req_descr(&s->rings)) != 0) { > > /* Only read after production index verification */ > Queued, with the qemu_log removed even. Paolo
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