From: James Dingwall <james@dingwall.me.uk>
To: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: xen pci passthrough stops working after xen/x86: fix initial memory balloon target
Date: Fri, 16 Jan 2026 09:27:15 +0000 [thread overview]
Message-ID: <aWoEc7Lxh0zG62S1@dingwall.me.uk> (raw)
In-Reply-To: <aWkqA3u6E1fwB9vj@Mac.lan>
On Thu, Jan 15, 2026 at 06:55:15PM +0100, Roger Pau Monné wrote:
> On Thu, Jan 15, 2026 at 02:50:12PM +0000, James Dingwall wrote:
> > On Thu, Jan 15, 2026 at 01:03:49PM +0100, Roger Pau Monné wrote:
> > > On Thu, Jan 15, 2026 at 11:23:37AM +0000, James Dingwall wrote:
> > > > Hi,
> > > >
> > > > We have encountered a regression with pci passthrough since the
> > > > Ubuntu 6.8.0-91.92 which included this commit:
> > >
> > > Hello,
> > >
> > > Thanks for the report. Could you also send me your kernel Kconfig, to
> > > see which combination of options are you using?
> > >
> >
> Can you confirm that the config used to build the non-working kernel
> also has CONFIG_XEN_UNPOPULATED_ALLOC=y?
The config is the same for both builds and CONFIG_XEN_UNPOPULATED_ALLOC=y
is always set.
> Can you also provide the output of `cat /proc/iomem` for both the
> working and non-working kernels?
non-working Ubuntu-6.8.0-100.100:
00000000-00000fff : Reserved
00001000-0009ffff : System RAM
000a0000-000fffff : Reserved
000f0000-000fffff : System ROM
00100000-2007ffff : System RAM
01000000-025fffff : Kernel code
02600000-033bcfff : Kernel rodata
03400000-0385613f : Kernel data
03d54000-041fffff : Kernel bss
20081000-73b57fff : Unusable memory
76c58000-76d76fff : ACPI Tables
76d77000-76ea0fff : ACPI Non-volatile Storage
77fff000-77ffffff : Unusable memory
80000000-87ffffff : System RAM
88000000-8fffffff : Xen scratch
100000000-103f7ffff : System RAM
4000200000-400021ffff : 0000:01:00.0
4000220000-400023ffff : 0000:01:00.0
4000240000-400025ffff : 0000:01:00.1
4000260000-400027ffff : 0000:01:00.1
working Ubuntu-6.8.0-100.100:
00000000-00000fff : Reserved
00001000-0009ffff : System RAM
000a0000-000fffff : Reserved
000f0000-000fffff : System ROM
00100000-2007ffff : System RAM
01000000-025fffff : Kernel code
02600000-033bcfff : Kernel rodata
03400000-0385613f : Kernel data
03d54000-041fffff : Kernel bss
20081000-73b57fff : Unusable memory
76c58000-76d76fff : ACPI Tables
76d77000-76ea0fff : ACPI Non-volatile Storage
77fff000-77ffffff : Unusable memory
81100000-811fffff : 0000:01:00.1
81100000-811fffff : igb
81200000-812fffff : 0000:01:00.0
81200000-812fffff : igb
81300000-8137ffff : 0000:01:00.1
81380000-813fffff : 0000:01:00.0
81400000-81403fff : 0000:01:00.1
81400000-81403fff : igb
81404000-81407fff : 0000:01:00.0
81404000-81407fff : igb
81500000-815fffff : 0000:03:00.0
81600000-816fffff : 0000:03:00.0
81600000-816fffff : igc
81700000-81703fff : 0000:03:00.0
81700000-81703fff : igc
88000000-8fffffff : Xen scratch
100000000-103f7ffff : System RAM
4000200000-400021ffff : 0000:01:00.0
4000220000-400023ffff : 0000:01:00.0
4000240000-400025ffff : 0000:01:00.1
4000260000-400027ffff : 0000:01:00.1
Just for completeness the working build also reverts "xen/x86: fix initial
memory balloon target" because of a conflict in drivers/xen/balloon.c.
Thanks,
James
next prev parent reply other threads:[~2026-01-16 9:27 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-15 11:23 xen pci passthrough stops working after xen/x86: fix initial memory balloon target James Dingwall
2026-01-15 12:03 ` Roger Pau Monné
2026-01-15 14:50 ` James Dingwall
2026-01-15 17:55 ` Roger Pau Monné
2026-01-16 9:27 ` James Dingwall [this message]
2026-01-16 10:13 ` Roger Pau Monné
2026-01-16 10:34 ` James Dingwall
2026-01-16 11:29 ` Roger Pau Monné
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