kern/55397: Xen pvh instance: zpool create on xbd* devices panics

[kardel%netbsd.org@localhost]

>Number:         55397
>Category:       kern
>Synopsis:       Xen pvh instance: zpool create on xbd* devices panics
>Confidential:   no
>Severity:       serious
>Priority:       high
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Fri Jun 19 08:50:00 +0000 2020
>Originator:     Frank Kardel
>Release:        NetBSD 9.99.65
>Organization:
	
>Environment:
	
	
System: NetBSD abstest2 9.99.65 NetBSD 9.99.65 (GENERIC) #2: Tue Jun 9 01:58:38 CEST 2020 kardel@Andromeda:/src/NetBSD/cur/src/obj.amd64/sys/arch/amd64/compile/GENERIC amd64
Architecture: x86_64
Machine: amd64
>Description:
	Attempting to
		zpool create data mirror xbd1 xbd2
	on a xen pvh instance panics like this:
	  [ 451.7783806] panic: kernel diagnostic assertion "(req->req_bp->b_flags & B_PHYS) != 0" failed: file "/src/NetBSD/cur/src/sys/arch/xen/xen/xbd_xenbus.c", line 1373
	  [ 451.7783806] cpu0: Begin traceback...
	  [ 451.7783806] vpanic() at netbsd:vpanic+0x152
	  [ 451.7783806] __x86_indirect_thunk_rax() at netbsd:__x86_indirect_thunk_rax
	  [ 451.7783806] xbd_diskstart() at netbsd:xbd_diskstart+0x7c2
	  [ 451.7783806] dk_start() at netbsd:dk_start+0xef
	  [ 451.7783806] spec_strategy() at netbsd:spec_strategy+0x9f
	  [ 451.7783806] VOP_STRATEGY() at netbsd:VOP_STRATEGY+0x3c
	  [ 451.7783806] zio_vdev_io_start() at zfs:zio_vdev_io_start+0x192
	  [ 451.7783806] zio_execute() at zfs:zio_execute+0xe3
	  [ 451.7783806] zio_nowait() at zfs:zio_nowait+0x5c
	  [ 451.7783806] vdev_mirror_io_start() at zfs:vdev_mirror_io_start+0x157
	  [ 451.7783806] zio_vdev_io_start() at zfs:zio_vdev_io_start+0x192
	  [ 451.7783806] zio_execute() at zfs:zio_execute+0xe3
	  [ 451.7783806] zio_nowait() at zfs:zio_nowait+0x5c
	  [ 451.7783806] vdev_mirror_io_start() at zfs:vdev_mirror_io_start+0x157
	  [ 451.7783806] zio_vdev_io_start() at zfs:zio_vdev_io_start+0x33f
	  [ 451.7783806] zio_execute() at zfs:zio_execute+0xe3
	  [ 451.7783806] task_executor() at solaris:task_executor+0x67
	  [ 451.7783806] threadpool_thread() at netbsd:threadpool_thread+0x19e
	  [ 451.7783806] cpu0: End traceback...
	  [ 451.7783806] rebooting..

>How-To-Repeat:
	perform "zpool create pool mirror xbd? xbd?" on a pvh xen instance with
	appropriate disks.
>Fix:
	?

>Unformatted: