Re: External USB disks not recognized with v6.1.8 when using Xen

[Christian Kujau]

On Wed, 1 Feb 2023, Juergen Gross wrote:
> On 31.01.23 23:50, Christian Kujau wrote:
> > [Leaving the full quote below for reference and adding more appropriate
> > people.]
> > 
> > After a far too long round of git-bisect I narrowed it down to:
> > 
> >    c1c59538337ab6d45700cb4a1c9725e67f59bc6e is the first bad commit
> > 
> >      x86/pat: Fix pat_x_mtrr_type() for MTRR disabled case
> >      commit 90b926e68f500844dff16b5bcea178dc55cf580a upstream.
> > 
> > And indeed, reverting this single commit from v6.1.8 (stable) makes the
> > disks appear again.
> 
> I have problems understanding the behavior.
> 
> Assuming the cited error messages
> 
>   ioremap error for 0xf2520000-0xf2530000, requested 0x2, got 0x0
> 
> are related to the issue, this would mean that the ioremap() caller
> requested _PAGE_CACHE_MODE_UC_MINUS (type 0x2) and got _PAGE_CACHE_MODE_WB
> (type 0x0).
> 
> The patch you have reverted is modifying behavior only if the _input_ type
> is _PAGE_CACHE_MODE_WB.

This also happens on mainline, not only in stable. Reverting this patch 
from 6.2-rc6 makes the disks appear again.

Christian.

> Anyone having an idea what could be wrong here?
> 
> 
> Juergen
> 
> > 
> > TL;DR: with v6.1.8 in Xen Dom0 mode (i.e. the Xen host itself) the
> > external disk enclosure attached via USB is not being recognized. When
> > booted *without* Xen, the disks show up just fine.
> > 
> > Details with dmesg and lsusb outputs:
> >    https://nerdbynature.de/bits/usb_v6.1.8/
> > 
> > Thanks Thorsten for the localmodconfig hint, I've tried that before, but
> > the thing just did not want to boot, so I manually cut down on options,
> > but it's still ~12 minutes per compile, ccache helped a bit in the end.
> > 
> > Thanks for reading,
> > Christian.
> > 
> > On Mon, 30 Jan 2023, Linux kernel regression tracking (#adding) wrote:
> > 
> > > [TLDR: I'm adding this report to the list of tracked Linux kernel
> > > regressions; the text you find below is based on a few templates
> > > paragraphs you might have encountered already in similar form.
> > > See link in footer if these mails annoy you.]
> > > 
> > > On 30.01.23 04:46, Christian Kujau wrote:
> > > > [CC stable as I only tested the stable tree for now]
> > > > 
> > > > I'm running a current Alpine Linux with linux-edge-6.1.8-r0 installed on
> > > > a
> > > > Lenovo Thinkpad L540 where an external disk enclosure with two disks is
> > > > attached via USB. The Alpine Linux kernel appears to track Linux stable
> > > > and is more or less vanilla. Also, the machine boots into Xen 4.17.0 and
> > > > then starts a few headless VMs, nothing too exotic here.
> > > > 
> > > > But when updating from Linux 6.1.1 to 6.1.8, the disks from the external
> > > > enclosure did not show up. Unplug, replug, no dice, and this is 100%
> > > > reproducable. dmesg has new these lines now:
> > > > 
> > > > +ioremap error for 0xf2520000-0xf2530000, requested 0x2, got 0x0
> > > > +ioremap error for 0xf2520000-0xf2530000, requested 0x2, got 0x0
> > > > +xhci_hcd 0000:00:14.0: init 0000:00:14.0 fail, -14
> > > > +ioremap error for 0xfed1f000-0xfed20000, requested 0x2, got 0x0
> > > > +iTCO_wdt iTCO_wdt.1.auto: ioremap failed for resource [mem
> > > > 0xfed1f410-0xfed1f414]
> > > > 
> > > > I'm not sure if the ioremap error is related here (booted with
> > > > early_ioremap_debug but then dmesg was filled with WARNINGS for both
> > > > versions, so I disabled it again), but that xhci_hcd error looks
> > > > suspicious.
> > > > 
> > > > Curiously 6.1.8 works just fine when NOT booted via Xen. I booted into
> > > > Xen + vanilla 6.1.8 now and was able to reproduce this issue. Xen +
> > > > vanilla 6.1.1 works fine.
> > > 
> > > Thanks for the report. To be sure the issue doesn't fall through the
> > > cracks unnoticed, I'm adding it to regzbot, the Linux kernel regression
> > > tracking bot:
> > > 
> > > #regzbot ^introduced v6.1.1..v6.1.8
> > > #regzbot title xen/usb(?): External USB disks not recognized anymore
> > > under Xen
> > > #regzbot ignore-activity
> > > 
> > > This isn't a regression? This issue or a fix for it are already
> > > discussed somewhere else? It was fixed already? You want to clarify when
> > > the regression started to happen? Or point out I got the title or
> > > something else totally wrong? Then just reply and tell me -- ideally
> > > while also telling regzbot about it, as explained by the page listed in
> > > the footer of this mail.
> > > 
> > > Developers: When fixing the issue, remember to add 'Link:' tags pointing
> > > to the report (the parent of this mail). See page linked in footer for
> > > details.
> > > 
> > > >  From v6.1.1 to v6.1.8 there's only one commit in drivers/xen, but 54
> > > > commits in drivers/usb. Compiling takes time because the distribution
> > > > kernel has almost everything enabled and I still need to cut down
> > > > enabled
> > > > options to be able to attempt a git biset in a reasonable time,
> > > 
> > > FWIW, I'm working on a text for the kernel docs that will use
> > > "localmodconfig" to trim down the configs automatically. Maybe it's
> > > helpful for you, here is a draft:
> > > 
> > > https://www.leemhuis.info/files/misc/How%20to%20quickly%20build%20a%20Linux%20kernel%20%E2%80%94%20The%20Linux%20Kernel%20documentation.html
> > > 
> > > > but I
> > > > still wanted to report this, maybe someone has an idea about this.
> > > > 
> > > > Full dmesg and lshw outputs: https://nerdbynature.de/bits/usb_v6.1.8/
> > > > 
> > > > Thanks,
> > > > Christian.
> > > > 
> > > > PS: I found this workaround on the interwebs[0] to force the USB ports
> > > > of that machine to USB 2.0 and then the missing disks magically appear:
> > > > 
> > > > $ lspci -nn | grep -i usb
> > > > 00:14.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series
> > > > Chipset Family USB xHCI [8086:8c31] (rev 05)  <=== !!!
> > > > 00:1a.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series
> > > > Chipset Family USB EHCI #2 [8086:8c2d] (rev 05)
> > > > 00:1d.0 USB controller [0c03]: Intel Corporation 8 Series/C220 Series
> > > > Chipset Family USB EHCI #1 [8086:8c26] (rev 05)
> > > > 
> > > > $ setpci -H1 -d 8086:8c31 d8.l=0
> > > > $ setpci -H1 -d 8086:8c31 d0.l=0
> > > > 
> > > > $ dmesg
> > > > usb 1-1.3: new full-speed USB device number 3 using ehci-pci
> > > > usb 2-1.3: new high-speed USB device number 3 using ehci-pci
> > > > usb 1-1.3: New USB device found, idVendor=138a, idProduct=0011,
> > > > bcdDevice=0.78
> > > > usb 1-1.3: New USB device strings: Mfr=0, Product=0, SerialNumber=1
> > > > usb 1-1.3: SerialNumber: aa32bf84ed47
> > > > usb 1-1.5: new full-speed USB device number 4 using ehci-pci
> > > > usb 2-1.3: New USB device found, idVendor=1e91, idProduct=a3a8,
> > > > bcdDevice=2.07
> > > > usb 2-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=5
> > > > usb 2-1.3: Product: Elite Pro Dual
> > > > usb 2-1.3: Manufacturer: OWC
> > > > usb 2-1.3: SerialNumber: RANDOM__1E359879645F
> > > > usb 2-1.3: UAS is ignored for this device, using usb-storage instead
> > > > usb-storage 2-1.3:1.0: USB Mass Storage device detected
> > > > usb-storage 2-1.3:1.0: Quirks match for vid 1e91 pid a3a8: 800000
> > > > scsi host5: usb-storage 2-1.3:1.0
> > > > usb 1-1.5: New USB device found, idVendor=8087, idProduct=07dc,
> > > > bcdDevice=0.01
> > > > usb 1-1.5: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> > > > Bluetooth: hci0: Legacy ROM 2.5 revision 8.0 build 1 week 45 2013
> > > > Bluetooth: hci0: Intel Bluetooth firmware file:
> > > > intel/ibt-hw-37.7.10-fw-1.80.1.2d.d.bseq
> > > > usb 1-1.6: new high-speed USB device number 5 using ehci-pci
> > > > usb 1-1.6: New USB device found, idVendor=04f2, idProduct=b398,
> > > > bcdDevice=39.98
> > > > usb 1-1.6: New USB device strings: Mfr=1, Product=2, SerialNumber=0
> > > > usb 1-1.6: Product: Integrated Camera
> > > > usb 1-1.6: Manufacturer: Vimicro corp.
> > > > Bluetooth: hci0: Intel BT fw patch 0x2a completed & activated
> > > > scsi 5:0:0:0: Direct-Access     ElitePro Dual U3FW-1      0207 PQ: 0
> > > > ANSI: 6
> > > > scsi 5:0:0:1: Direct-Access     ElitePro Dual U3FW-2      0207 PQ: 0
> > > > ANSI: 6
> > > > sd 5:0:0:0: [sdc] Very big device. Trying to use READ CAPACITY(16).
> > > > sd 5:0:0:0: [sdc] 7814037168 512-byte logical blocks: (4.00 TB/3.64 TiB)
> > > > sd 5:0:0:1: [sdd] Very big device. Trying to use READ CAPACITY(16).
> > > > sd 5:0:0:1: [sdd] 7814037168 512-byte logical blocks: (4.00 TB/3.64 TiB)
> > > > sd 5:0:0:1: [sdd] Write Protect is off
> > > > sd 5:0:0:1: [sdd] Mode Sense: 47 00 10 08
> > > > sd 5:0:0:0: [sdc] Write Protect is off
> > > > sd 5:0:0:0: [sdc] Mode Sense: 47 00 10 08
> > > > sd 5:0:0:0: [sdc] No Caching mode page found
> > > > sd 5:0:0:0: [sdc] Assuming drive cache: write through
> > > > sd 5:0:0:1: [sdd] No Caching mode page found
> > > > sd 5:0:0:1: [sdd] Assuming drive cache: write through
> > > > sd 5:0:0:0: [sdc] Attached SCSI disk
> > > > sd 5:0:0:1: [sdd] Attached SCSI disk
> > > > 
> > > > $ lsblk /dev/sd[cd]
> > > > NAME MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
> > > > sdc    8:32   0  3.6T  0 disk
> > > > sdd    8:48   0  3.6T  0 disk
> > > > 
> > > > 
> > > > [0] https://superuser.com/a/875863/218574
> > > 
> > > Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> > > --
> > > Everything you wanna know about Linux kernel regression tracking:
> > > https://linux-regtracking.leemhuis.info/about/#tldr
> > > That page also explains what to do if mails like this annoy you.
> > > 
> > 
> 
> 

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