Mailing List Archive: Only one CPU core detected when booting on UEFI

Only one CPU core detected when booting on UEFI

Dec 16, 2012, 6:07 PM

Post #1 of 9 (4518 views)

Hi Xen developers,

I have been having a problem where only one CPU core is being detected.
I'm using a Lenovo W520 with a UEFI firmware and an Intel Core i7
2720qm (4 real cores, 4 virtual cores). When I boot, I see
"Dom0 has maximum 1 VCPUs", or something similar, scroll by.

In addition, only 10 GB out of my 12 GB of memory is recognized and
ACPI is not working properly (CPU frequency scaling and battery info
are not reported).

This problem has been reported before (for the same laptop too) here:
http://lists.xen.org/archives/html/xen-devel/2012-06/msg00087.html but
unfortunately, the person who sent the message didn't reply with more
information.

Here are the outputs of dmesg with and without Xen:

Without Xen: http://paste.kde.org/626222/raw/
With Xen: http://paste.kde.org/626228/raw/

and some information from xl:

xl vcpu-list: http://paste.kde.org/626234/raw/
xl info: http://paste.kde.org/626240/raw/
xl dmesg: http://paste.kde.org/626246/raw/

This is my first time venturing into Xen territory, so please let me
know if there's any other information needed.

I'm not sure if it helps, but I'd also like to point out that I had a
similar problem with Linux back around July 20, 2011, when I got my
computer. I could work around the issue by booting with "noapic". I'm
not sure which kernel version fixed the issue as I booted with that
option for quite a while. The kernel version, at the time, was 3.0.

I am glad to help in any way I can. I'm excited to get Xen working!
I'm confortable with compiling the kernel or xen if necessary.

Thanks in advance!

Xiao-Long Chen

_______________________________________________
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Only one CPU core detected when booting on UEFI [ In reply to ]

chenxiaolong at cxl

Dec 15, 2012, 11:37 PM

Post #2 of 9 (4463 views)

Permalink

Re: Only one CPU core detected when booting on UEFI [ In reply to ]

JBeulich at suse

Dec 17, 2012, 2:03 AM

Post #3 of 9 (4468 views)

Permalink

>>> On 17.12.12 at 03:07, Xiao-Long Chen <chenxiaolong@cxl.epac.to> wrote:
> Hi Xen developers,
>
> I have been having a problem where only one CPU core is being detected.
> I'm using a Lenovo W520 with a UEFI firmware and an Intel Core i7
> 2720qm (4 real cores, 4 virtual cores). When I boot, I see
> "Dom0 has maximum 1 VCPUs", or something similar, scroll by.
>
> In addition, only 10 GB out of my 12 GB of memory is recognized and
> ACPI is not working properly (CPU frequency scaling and battery info
> are not reported).
>
> This problem has been reported before (for the same laptop too) here:
> http://lists.xen.org/archives/html/xen-devel/2012-06/msg00087.html but
> unfortunately, the person who sent the message didn't reply with more
> information.

And the solution had already been discussed on the list too -
depending on how you do things currently (not judgeable from
the incomplete set of logs you provided), switch to using xen.efi
rather than booting through GrUB2, and/or use a kernel that is
actually EFI-capable (the upstream one continues to require out
of tree patches).

Jan

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Re: Only one CPU core detected when booting on UEFI [ In reply to ]

konrad.wilk at oracle

Dec 21, 2012, 11:59 AM

Post #4 of 9 (4468 views)

Permalink

On Sun, Dec 16, 2012 at 02:37:59AM -0500, Xiao-Long Chen wrote:
> Hi Xen developers,
>
> I have been having a problem where only one CPU core is being detected.
> I'm using a Lenovo W520 with a UEFI firmware and an Intel Core i7
> 2720qm (4 real cores, 4 virtual cores). When I boot, I see
> "Dom0 has maximum 1 VCPUs", or something similar, scroll by.

Ooh.
>
> In addition, only 10 GB out of my 12 GB of memory is recognized and
> ACPI is not working properly (CPU frequency scaling and battery info
> are not reported).
>
> This problem has been reported before (for the same laptop too) here:
> http://lists.xen.org/archives/html/xen-devel/2012-06/msg00087.html but
> unfortunately, the person who sent the message didn't reply with more
> information.
>
> Here are the outputs of dmesg with and without Xen:
>
> Without Xen: http://paste.kde.org/626222/raw/
> With Xen: http://paste.kde.org/626228/raw/

Hm, this:
[ 0.000000] ACPI BIOS Bug: Error: A valid RSDP was not found (20120913/tbxfroot-219)

is a problem. The workaround was mentioned on the mailing list to use
the acpi_rsdp=0xbabfe000

>
> and some information from xl:
>
> xl vcpu-list: http://paste.kde.org/626234/raw/
> xl info: http://paste.kde.org/626240/raw/
> xl dmesg: http://paste.kde.org/626246/raw/

And Xen has the same issue:

(XEN) ACPI Error (tbxfroot-0218): A valid RSDP was not found [20070126]

And it looks to be running in a legacy state - with no calls to EFI.
>
> This is my first time venturing into Xen territory, so please let me
> know if there's any other information needed.

Did you try to boot xen.efi by itself - without using the GRUB loader?
There is a nice writeup of how to do this in docs/misc/efi.markdown.

Also CC-ing Daniel if he has some ideas.
>
> I'm not sure if it helps, but I'd also like to point out that I had a
> similar problem with Linux back around July 20, 2011, when I got my
> computer. I could work around the issue by booting with "noapic". I'm
> not sure which kernel version fixed the issue as I booted with that
> option for quite a while. The kernel version, at the time, was 3.0.
>
> I am glad to help in any way I can. I'm excited to get Xen working!
> I'm confortable with compiling the kernel or xen if necessary.
>
> Thanks in advance!
>
> Xiao-Long Chen
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@lists.xen.org
> http://lists.xen.org/xen-devel
>

_______________________________________________
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http://lists.xen.org/xen-devel

Re: Only one CPU core detected when booting on UEFI [ In reply to ]

chenxiaolong at cxl

Dec 21, 2012, 6:30 PM

Post #5 of 9 (4485 views)

Permalink

Thanks for the reply! I'll respond inline.

On Fri, Dec 21, 2012 at 2:59 PM, Konrad Rzeszutek Wilk <
konrad.wilk@oracle.com> wrote:

> On Sun, Dec 16, 2012 at 02:37:59AM -0500, Xiao-Long Chen wrote:
> > Hi Xen developers,
> >
> > I have been having a problem where only one CPU core is being detected.
> > I'm using a Lenovo W520 with a UEFI firmware and an Intel Core i7
> > 2720qm (4 real cores, 4 virtual cores). When I boot, I see
> > "Dom0 has maximum 1 VCPUs", or something similar, scroll by.
>
> Ooh.

>
> > In addition, only 10 GB out of my 12 GB of memory is recognized and
> > ACPI is not working properly (CPU frequency scaling and battery info
> > are not reported).
> >
> > This problem has been reported before (for the same laptop too) here:
> > http://lists.xen.org/archives/html/xen-devel/2012-06/msg00087.html but
> > unfortunately, the person who sent the message didn't reply with more
> > information.
> >
> > Here are the outputs of dmesg with and without Xen:
> >
> > Without Xen: http://paste.kde.org/626222/raw/
> > With Xen: http://paste.kde.org/626228/raw/
>
> Hm, this:
> [ 0.000000] ACPI BIOS Bug: Error: A valid RSDP was not found
> (20120913/tbxfroot-219)
>
> is a problem. The workaround was mentioned on the mailing list to use
> the acpi_rsdp=0xbabfe000
>

I tried booting with this, but the kernel immediately crashed
(I think). I booted with 'acpi_rsdp=0xbabfe000' and without 'quiet' and
the system hangs while loading the initramfs. I could not see any sort
of response on the system and could not ssh in.

>
> >
> > and some information from xl:
> >
> > xl vcpu-list: http://paste.kde.org/626234/raw/
> > xl info: http://paste.kde.org/626240/raw/
> > xl dmesg: http://paste.kde.org/626246/raw/
>
> And Xen has the same issue:
>
> (XEN) ACPI Error (tbxfroot-0218): A valid RSDP was not found [20070126]
>
> And it looks to be running in a legacy state - with no calls to EFI.
> >
> > This is my first time venturing into Xen territory, so please let me
> > know if there's any other information needed.
>
> Did you try to boot xen.efi by itself - without using the GRUB loader?
> There is a nice writeup of how to do this in docs/misc/efi.markdown.
>

Booting from xen.efi, I see "Dom0 has maximum 8 VCPUs" as expected, but
Linux is still seeing only one core. In addition, my keyboard and mouse
do not work (internal laptop PS/2). I was able to get the dmesg and
'xl dmesg' outputs from ssh though:

dmesg (no xen): http://paste.kde.org/629684/raw/
dmesg (xen.efi): http://paste.kde.org/629690/raw/
xl dmesg: http://paste.kde.org/629696/raw/

The system is incredibly sluggish as when booted with GRUB, but that
may just be due to one core being available.

>
> Also CC-ing Daniel if he has some ideas.
>

Thanks a lot!

Xiao-Long Chen

> >
> > I'm not sure if it helps, but I'd also like to point out that I had a
> > similar problem with Linux back around July 20, 2011, when I got my
> > computer. I could work around the issue by booting with "noapic". I'm
> > not sure which kernel version fixed the issue as I booted with that
> > option for quite a while. The kernel version, at the time, was 3.0.
> >
> > I am glad to help in any way I can. I'm excited to get Xen working!
> > I'm confortable with compiling the kernel or xen if necessary.
> >
> > Thanks in advance!
> >
> > Xiao-Long Chen
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@lists.xen.org
> > http://lists.xen.org/xen-devel
> >
>

Re: Only one CPU core detected when booting on UEFI [ In reply to ]

jajcus at jajcus

Dec 22, 2012, 7:48 AM

Post #6 of 9 (4473 views)

Permalink

Hi,

On Fri, Dec 21, 2012 at 09:30:59PM -0500, Xiao-Long Chen wrote:
> > Hm, this:
> > [ 0.000000] ACPI BIOS Bug: Error: A valid RSDP was not found
> > (20120913/tbxfroot-219)
> >
> > is a problem. The workaround was mentioned on the mailing list to use
> > the acpi_rsdp=0xbabfe000

> I tried booting with this, but the kernel immediately crashed
> (I think). I booted with 'acpi_rsdp=0xbabfe000' and without 'quiet' and
> the system hangs while loading the initramfs. I could not see any sort
> of response on the system and could not ssh in.

I posted the workaround, and it was not 'acpi_rsdp=0xbabfe000',
but 'acpi_rsdp=the-value-xen-reports' (it could be 0xbabfe000 for a
specific machine)

> > Did you try to boot xen.efi by itself - without using the GRUB loader?
> > There is a nice writeup of how to do this in docs/misc/efi.markdown.

GRUB2 still may be used, but only for chain-loading the xen.efi. This
give little gain over booting xen.efi directly from the firmware,
though.

> Booting from xen.efi, I see "Dom0 has maximum 8 VCPUs" as expected,

Now xen can find the ACPI RSDP

> but Linux is still seeing only one core.

That is because Xen doesn't pass all the information obtained via EFI to
the kernel.

> xl dmesg: http://paste.kde.org/629696/raw/

the important part:

> (XEN) ACPI: RSDP BABFE014, 0024 (r2 LENOVO)

Try booting xen.efi and passing 'acpi_rsdp=0xBABFE014' to the kernel via
the kernel command-line.

This should fix other problems with the kernel too, as ACPI is important
for initializing many kernel subsystems.

Greets,
Jacek

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http://lists.xen.org/xen-devel

Re: Only one CPU core detected when booting on UEFI [ In reply to ]

chenxiaolong at cxl

Dec 22, 2012, 10:54 AM

Post #7 of 9 (4492 views)

Permalink

Thanks for the reply!

On Sat, Dec 22, 2012 at 10:48 AM, Jacek Konieczny <jajcus@jajcus.net> wrote:

> Hi,
>
> On Fri, Dec 21, 2012 at 09:30:59PM -0500, Xiao-Long Chen wrote:
> > > Hm, this:
> > > [ 0.000000] ACPI BIOS Bug: Error: A valid RSDP was not found
> > > (20120913/tbxfroot-219)
> > >
> > > is a problem. The workaround was mentioned on the mailing list to use
> > > the acpi_rsdp=0xbabfe000
>
> > I tried booting with this, but the kernel immediately crashed
> > (I think). I booted with 'acpi_rsdp=0xbabfe000' and without 'quiet' and
> > the system hangs while loading the initramfs. I could not see any sort
> > of response on the system and could not ssh in.
>
> I posted the workaround, and it was not 'acpi_rsdp=0xbabfe000',
> but 'acpi_rsdp=the-value-xen-reports' (it could be 0xbabfe000 for a
> specific machine)
>
> > > Did you try to boot xen.efi by itself - without using the GRUB loader?
> > > There is a nice writeup of how to do this in docs/misc/efi.markdown.
>
> GRUB2 still may be used, but only for chain-loading the xen.efi. This
> give little gain over booting xen.efi directly from the firmware,
> though.
>

Good to know. I currently boot xen.efi from the efi shell.

>
> > Booting from xen.efi, I see "Dom0 has maximum 8 VCPUs" as expected,
>
> Now xen can find the ACPI RSDP
>
> > but Linux is still seeing only one core.
>
> That is because Xen doesn't pass all the information obtained via EFI to
> the kernel.
>
> > xl dmesg: http://paste.kde.org/629696/raw/
>
> the important part:
>
> > (XEN) ACPI: RSDP BABFE014, 0024 (r2 LENOVO)
>
> Try booting xen.efi and passing 'acpi_rsdp=0xBABFE014' to the kernel via
> the kernel command-line.
>

I rebooted into xen.efi to make sure that it still reported:

(XEN) ACPI: RSDP BABFE014, 0024 (r2 LENOVO)

then I changed my xen.efi config to this: http://paste.kde.org/629996/raw/
which, unfortunately, still causes the hang.

>
> This should fix other problems with the kernel too, as ACPI is important
> for initializing many kernel subsystems.
>
> Greets,
> Jacek
>

Best regards,
Xiao-Long Chen

Re: Only one CPU core detected when booting on UEFI [ In reply to ]

jajcus at jajcus

Dec 22, 2012, 1:27 PM

Post #8 of 9 (4463 views)

Permalink

On Sat, Dec 22, 2012 at 01:54:07PM -0500, Xiao-Long Chen wrote:

> I rebooted into xen.efi to make sure that it still reported:
>
> (XEN) ACPI: RSDP BABFE014, 0024 (r2 LENOVO)
>
> then I changed my xen.efi config to this: http://paste.kde.org/629996/raw/
> which, unfortunately, still causes the hang.

Have you tried 'acpi_rsdp=0xbabfe014' instead of 'acpi_rsdp=babfe014'?

Do you have the kernel console output from the failed boot with these
settings?

Also, I don't think 'video=vesa:off vga=normal' options make much sense
under EFI and Xen.

Greets,
Jacek

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Re: Only one CPU core detected when booting on UEFI [ In reply to ]

chenxiaolong at cxl

Dec 22, 2012, 5:55 PM

Post #9 of 9 (4468 views)

Permalink

On Sat, Dec 22, 2012 at 4:27 PM, Jacek Konieczny <jajcus@jajcus.net> wrote:

> On Sat, Dec 22, 2012 at 01:54:07PM -0500, Xiao-Long Chen wrote:
>
> > I rebooted into xen.efi to make sure that it still reported:
> >
> > (XEN) ACPI: RSDP BABFE014, 0024 (r2 LENOVO)
> >
> > then I changed my xen.efi config to this:
> http://paste.kde.org/629996/raw/
> > which, unfortunately, still causes the hang.
>
> Have you tried 'acpi_rsdp=0xbabfe014' instead of 'acpi_rsdp=babfe014'?
>
> Do you have the kernel console output from the failed boot with these
> settings?
>

Unfortunately, that doesn't help either. I don't see any output from
the failed boot. Without the acpi_rsdp option, the kernel starts
printing out messages as soon as xen.efi's output is finished
displaying. With acpi_rsdp, the screen clears after xen.efi's messages
scroll by and then nothing happens.

>
> Also, I don't think 'video=vesa:off vga=normal' options make much sense
> under EFI and Xen.
>

Thanks, I took those out. Those were added automatically by the
proprietary NVIDIA drivers and I copied them into the xen.efi config.

Cheers,
Xiao-Long Chen