On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
<[email protected]> wrote:
>
> On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > Hi Greg, hi Thomas,
> >
> > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > 4.14.63, default setting.
>
> For 4.4, I would be amazed if anything was there, the backport was done
> only to handle the local user issue, not the "full" protection. So
> please try 4.9 or 4.14.
Thanks for quick reply. Right, just checked. the patch for create the
sysfs entry is missing.
>
> How about 4.17 and 4.18, do those trees work properly for you?
I guess it's the same.
>
> > Tried stable/master branch 31130a16d459 ("Merge tag
> > 'for-linus-4.19-rc1-tag' of
> > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > It's the same there.
>
> Ah, so we are bug compatible, good :)
I will try test stable master a bit more to gather the full log.
>
> > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > boot, 4.4.148 boot fine.
> > The call trace seem irq related, is it known bug?
>
> You are not giving us much to go on here sorry. We need full details,
> and also please cc: lkml and the other developers who worked on this.
> THomas is on vacation this week.
Now, add more developers to cc, also lkml.
I have the config and boot dmesg attached for default setting.
>
> thanks,
>
> greg k-h
Thanks,
--
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens
On Thu, Aug 16, 2018 at 06:28:59PM +0200, Jinpu Wang wrote:
> On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
> <[email protected]> wrote:
> >
> > On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > > Hi Greg, hi Thomas,
> > >
> > > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > > 4.14.63, default setting.
> >
> > For 4.4, I would be amazed if anything was there, the backport was done
> > only to handle the local user issue, not the "full" protection. So
> > please try 4.9 or 4.14.
> Thanks for quick reply. Right, just checked. the patch for create the
> sysfs entry is missing.
What patch is that? What is the git commit id that we missed?
> > How about 4.17 and 4.18, do those trees work properly for you?
> I guess it's the same.
> >
> > > Tried stable/master branch 31130a16d459 ("Merge tag
> > > 'for-linus-4.19-rc1-tag' of
> > > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > > It's the same there.
> >
> > Ah, so we are bug compatible, good :)
> I will try test stable master a bit more to gather the full log.
> >
> > > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > > boot, 4.4.148 boot fine.
> > > The call trace seem irq related, is it known bug?
> >
> > You are not giving us much to go on here sorry. We need full details,
> > and also please cc: lkml and the other developers who worked on this.
> > THomas is on vacation this week.
> Now, add more developers to cc, also lkml.
>
> I have the config and boot dmesg attached for default setting.
I see no error in your boot log, what exactly are you worried about?
confused,
greg k-h
On Thu, Aug 16, 2018 at 6:39 PM Greg Kroah-Hartman
<[email protected]> wrote:
>
> On Thu, Aug 16, 2018 at 06:28:59PM +0200, Jinpu Wang wrote:
> > On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
> > <[email protected]> wrote:
> > >
> > > On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > > > Hi Greg, hi Thomas,
> > > >
> > > > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > > > 4.14.63, default setting.
> > >
> > > For 4.4, I would be amazed if anything was there, the backport was done
> > > only to handle the local user issue, not the "full" protection. So
> > > please try 4.9 or 4.14.
> > Thanks for quick reply. Right, just checked. the patch for create the
> > sysfs entry is missing.
>
> What patch is that? What is the git commit id that we missed?
>
> > > How about 4.17 and 4.18, do those trees work properly for you?
> > I guess it's the same.
> > >
> > > > Tried stable/master branch 31130a16d459 ("Merge tag
> > > > 'for-linus-4.19-rc1-tag' of
> > > > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > > > It's the same there.
> > >
> > > Ah, so we are bug compatible, good :)
> > I will try test stable master a bit more to gather the full log.
> > >
> > > > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > > > boot, 4.4.148 boot fine.
> > > > The call trace seem irq related, is it known bug?
> > >
> > > You are not giving us much to go on here sorry. We need full details,
> > > and also please cc: lkml and the other developers who worked on this.
> > > THomas is on vacation this week.
> > Now, add more developers to cc, also lkml.
> >
> > I have the config and boot dmesg attached for default setting.
>
> I see no error in your boot log, what exactly are you worried about?
2 problems here:
1 According to https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html
I expect /sys/devices/system/cpu/smt/, but it's not.
2 kernel 4.14.63 panic when I boot with 'nosmt' or 'l1tf=full', I
attached the picture here again,
I will try to get the full log tomorrow, also test with linus tree.
>
> confused,
>
> greg k-h
Thanks
--
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens
On Thu, Aug 16, 2018 at 6:48 PM Jinpu Wang <[email protected]> wrote:
>
> On Thu, Aug 16, 2018 at 6:39 PM Greg Kroah-Hartman
> <[email protected]> wrote:
> >
> > On Thu, Aug 16, 2018 at 06:28:59PM +0200, Jinpu Wang wrote:
> > > On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
> > > <[email protected]> wrote:
> > > >
> > > > On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > > > > Hi Greg, hi Thomas,
> > > > >
> > > > > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > > > > 4.14.63, default setting.
> > > >
> > > > For 4.4, I would be amazed if anything was there, the backport was done
> > > > only to handle the local user issue, not the "full" protection. So
> > > > please try 4.9 or 4.14.
> > > Thanks for quick reply. Right, just checked. the patch for create the
> > > sysfs entry is missing.
> >
> > What patch is that? What is the git commit id that we missed?
> >
> > > > How about 4.17 and 4.18, do those trees work properly for you?
> > > I guess it's the same.
> > > >
> > > > > Tried stable/master branch 31130a16d459 ("Merge tag
> > > > > 'for-linus-4.19-rc1-tag' of
> > > > > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > > > > It's the same there.
> > > >
> > > > Ah, so we are bug compatible, good :)
> > > I will try test stable master a bit more to gather the full log.
> > > >
> > > > > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > > > > boot, 4.4.148 boot fine.
> > > > > The call trace seem irq related, is it known bug?
> > > >
> > > > You are not giving us much to go on here sorry. We need full details,
> > > > and also please cc: lkml and the other developers who worked on this.
> > > > THomas is on vacation this week.
> > > Now, add more developers to cc, also lkml.
> > >
> > > I have the config and boot dmesg attached for default setting.
> >
> > I see no error in your boot log, what exactly are you worried about?
> 2 problems here:
> 1 According to https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html
> I expect /sys/devices/system/cpu/smt/, but it's not.
> 2 kernel 4.14.63 panic when I boot with 'nosmt' or 'l1tf=full', I
> attached the picture here again,
> I will try to get the full log tomorrow, also test with linus tree.
> >
> > confused,
> >
> > greg k-h
>
> Thanks
I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
but I did explicitly enable CONFIG_HOTPLUG_CPU.
That's why the smt dir is missing, and kernel panic when I boot with
'nosmt' or 'l1tf=full' probably also other combination.
With CONFIG_HOTPLUG_CPU=y, it works fine so far.
Thanks,
--
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens
On Fri, Aug 17, 2018 at 02:39:00PM +0200, Jinpu Wang wrote:
> On Thu, Aug 16, 2018 at 6:48 PM Jinpu Wang <[email protected]> wrote:
> >
> > On Thu, Aug 16, 2018 at 6:39 PM Greg Kroah-Hartman
> > <[email protected]> wrote:
> > >
> > > On Thu, Aug 16, 2018 at 06:28:59PM +0200, Jinpu Wang wrote:
> > > > On Thu, Aug 16, 2018 at 5:51 PM Greg Kroah-Hartman
> > > > <[email protected]> wrote:
> > > > >
> > > > > On Thu, Aug 16, 2018 at 05:43:23PM +0200, Jinpu Wang wrote:
> > > > > > Hi Greg, hi Thomas,
> > > > > >
> > > > > > I noticed /sys/devices/system/cpu/smt dir is missing on 4.4.148 and
> > > > > > 4.14.63, default setting.
> > > > >
> > > > > For 4.4, I would be amazed if anything was there, the backport was done
> > > > > only to handle the local user issue, not the "full" protection. So
> > > > > please try 4.9 or 4.14.
> > > > Thanks for quick reply. Right, just checked. the patch for create the
> > > > sysfs entry is missing.
> > >
> > > What patch is that? What is the git commit id that we missed?
> > >
> > > > > How about 4.17 and 4.18, do those trees work properly for you?
> > > > I guess it's the same.
> > > > >
> > > > > > Tried stable/master branch 31130a16d459 ("Merge tag
> > > > > > 'for-linus-4.19-rc1-tag' of
> > > > > > git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip")
> > > > > > It's the same there.
> > > > >
> > > > > Ah, so we are bug compatible, good :)
> > > > I will try test stable master a bit more to gather the full log.
> > > > >
> > > > > > When boot with 'nosmt' kernel paramter kernel 4.14.63 panic during
> > > > > > boot, 4.4.148 boot fine.
> > > > > > The call trace seem irq related, is it known bug?
> > > > >
> > > > > You are not giving us much to go on here sorry. We need full details,
> > > > > and also please cc: lkml and the other developers who worked on this.
> > > > > THomas is on vacation this week.
> > > > Now, add more developers to cc, also lkml.
> > > >
> > > > I have the config and boot dmesg attached for default setting.
> > >
> > > I see no error in your boot log, what exactly are you worried about?
> > 2 problems here:
> > 1 According to https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html
> > I expect /sys/devices/system/cpu/smt/, but it's not.
> > 2 kernel 4.14.63 panic when I boot with 'nosmt' or 'l1tf=full', I
> > attached the picture here again,
> > I will try to get the full log tomorrow, also test with linus tree.
> > >
> > > confused,
> > >
> > > greg k-h
> >
> > Thanks
> I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
> but I did explicitly enable CONFIG_HOTPLUG_CPU.
>
> That's why the smt dir is missing, and kernel panic when I boot with
> 'nosmt' or 'l1tf=full' probably also other combination.
>
> With CONFIG_HOTPLUG_CPU=y, it works fine so far.
So do we need a new configuration dependancy here to resolve this
problem? Why is this not an issue in Linus's tree?
confused,
greg k-h
On Fri, 17 Aug 2018, Greg Kroah-Hartman wrote:
> On Fri, Aug 17, 2018 at 02:39:00PM +0200, Jinpu Wang wrote:
> >
> > I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
> > but I did explicitly enable CONFIG_HOTPLUG_CPU.
> >
> > That's why the smt dir is missing, and kernel panic when I boot with
> > 'nosmt' or 'l1tf=full' probably also other combination.
> >
> > With CONFIG_HOTPLUG_CPU=y, it works fine so far.
>
> So do we need a new configuration dependancy here to resolve this
> problem? Why is this not an issue in Linus's tree?
That's probably the same problem on Linus tree. Have not tested it yet
though. I'll have a look.
Thanks,
tglx
On Sat, Aug 18, 2018 at 2:50 PM Thomas Gleixner <[email protected]> wrote:
>
> On Fri, 17 Aug 2018, Greg Kroah-Hartman wrote:
> > On Fri, Aug 17, 2018 at 02:39:00PM +0200, Jinpu Wang wrote:
> > >
> > > I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
> > > but I did explicitly enable CONFIG_HOTPLUG_CPU.
> > >
> > > That's why the smt dir is missing, and kernel panic when I boot with
> > > 'nosmt' or 'l1tf=full' probably also other combination.
> > >
> > > With CONFIG_HOTPLUG_CPU=y, it works fine so far.
> >
> > So do we need a new configuration dependancy here to resolve this
> > problem? Why is this not an issue in Linus's tree?
>
> That's probably the same problem on Linus tree. Have not tested it yet
> though. I'll have a look.
>
> Thanks,
>
> tglx
>
Yeah, it's the same problem on Linus tree.
Probably makes sense to do the following, I can sent a formal patch if
you think it's right thing to do:
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b0312f8..8a52f0b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -188,7 +188,7 @@ config X86
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_USER_RETURN_NOTIFIER
- select HOTPLUG_SMT if SMP
+ select HOTPLUG_SMT if SMP && HOTPLUG_CPU
select IRQ_FORCED_THREADING
select NEED_SG_DMA_LENGTH
select PCI_LOCKLESS_CONFIG
--
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens
On Mon, 20 Aug 2018, Jinpu Wang wrote:
> On Sat, Aug 18, 2018 at 2:50 PM Thomas Gleixner <[email protected]> wrote:
> >
> > On Fri, 17 Aug 2018, Greg Kroah-Hartman wrote:
> > > On Fri, Aug 17, 2018 at 02:39:00PM +0200, Jinpu Wang wrote:
> > > >
> > > > I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
> > > > but I did explicitly enable CONFIG_HOTPLUG_CPU.
> > > >
> > > > That's why the smt dir is missing, and kernel panic when I boot with
> > > > 'nosmt' or 'l1tf=full' probably also other combination.
> > > >
> > > > With CONFIG_HOTPLUG_CPU=y, it works fine so far.
> > >
> > > So do we need a new configuration dependancy here to resolve this
> > > problem? Why is this not an issue in Linus's tree?
> >
> > That's probably the same problem on Linus tree. Have not tested it yet
> > though. I'll have a look.
> >
> > Thanks,
> >
> > tglx
> >
> Yeah, it's the same problem on Linus tree.
>
> Probably makes sense to do the following, I can sent a formal patch if
> you think it's right thing to do:
>
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index b0312f8..8a52f0b 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -188,7 +188,7 @@ config X86
> select HAVE_SYSCALL_TRACEPOINTS
> select HAVE_UNSTABLE_SCHED_CLOCK
> select HAVE_USER_RETURN_NOTIFIER
> - select HOTPLUG_SMT if SMP
> + select HOTPLUG_SMT if SMP && HOTPLUG_CPU
That works, but we might as well force 'select HOTPLUG_CPU if SMP' so the
L1TF mitigations are functional. Sigh....
Thanks,
tglx
On Mon, Aug 20, 2018 at 3:02 PM Thomas Gleixner <[email protected]> wrote:
>
> On Mon, 20 Aug 2018, Jinpu Wang wrote:
>
> > On Sat, Aug 18, 2018 at 2:50 PM Thomas Gleixner <[email protected]> wrote:
> > >
> > > On Fri, 17 Aug 2018, Greg Kroah-Hartman wrote:
> > > > On Fri, Aug 17, 2018 at 02:39:00PM +0200, Jinpu Wang wrote:
> > > > >
> > > > > I found the problem, CONFIG_HOTPLUG_SMT is enable due to CONFIG_SMP,
> > > > > but I did explicitly enable CONFIG_HOTPLUG_CPU.
> > > > >
> > > > > That's why the smt dir is missing, and kernel panic when I boot with
> > > > > 'nosmt' or 'l1tf=full' probably also other combination.
> > > > >
> > > > > With CONFIG_HOTPLUG_CPU=y, it works fine so far.
> > > >
> > > > So do we need a new configuration dependancy here to resolve this
> > > > problem? Why is this not an issue in Linus's tree?
> > >
> > > That's probably the same problem on Linus tree. Have not tested it yet
> > > though. I'll have a look.
> > >
> > > Thanks,
> > >
> > > tglx
> > >
> > Yeah, it's the same problem on Linus tree.
> >
> > Probably makes sense to do the following, I can sent a formal patch if
> > you think it's right thing to do:
> >
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index b0312f8..8a52f0b 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -188,7 +188,7 @@ config X86
> > select HAVE_SYSCALL_TRACEPOINTS
> > select HAVE_UNSTABLE_SCHED_CLOCK
> > select HAVE_USER_RETURN_NOTIFIER
> > - select HOTPLUG_SMT if SMP
> > + select HOTPLUG_SMT if SMP && HOTPLUG_CPU
>
> That works, but we might as well force 'select HOTPLUG_CPU if SMP' so the
> L1TF mitigations are functional. Sigh....
>
> Thanks,
>
> tglx
right, sth like?
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b0312f8..5852948 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -188,7 +188,8 @@ config X86
select HAVE_SYSCALL_TRACEPOINTS
select HAVE_UNSTABLE_SCHED_CLOCK
select HAVE_USER_RETURN_NOTIFIER
- select HOTPLUG_SMT if SMP
+ select HOTPLUG_CPU if SMP
+ select HOTPLUG_SMT if SMP && HOTPLUG_CPU
select IRQ_FORCED_THREADING
select NEED_SG_DMA_LENGTH
select PCI_LOCKLESS_CONFIG
--
Thanks,
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens
On Mon, 20 Aug 2018, Jinpu Wang wrote:
> On Mon, Aug 20, 2018 at 3:02 PM Thomas Gleixner <[email protected]> wrote:
> > That works, but we might as well force 'select HOTPLUG_CPU if SMP' so the
> > L1TF mitigations are functional. Sigh....
> >
> > Thanks,
> >
> > tglx
> right, sth like?
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index b0312f8..5852948 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -188,7 +188,8 @@ config X86
> select HAVE_SYSCALL_TRACEPOINTS
> select HAVE_UNSTABLE_SCHED_CLOCK
> select HAVE_USER_RETURN_NOTIFIER
> - select HOTPLUG_SMT if SMP
> + select HOTPLUG_CPU if SMP
> + select HOTPLUG_SMT if SMP && HOTPLUG_CPU
The && HOTPLUG is pretty pointless now.
On Mon, Aug 20, 2018 at 4:47 PM Thomas Gleixner <[email protected]> wrote:
>
> On Mon, 20 Aug 2018, Jinpu Wang wrote:
> > On Mon, Aug 20, 2018 at 3:02 PM Thomas Gleixner <[email protected]> wrote:
> > > That works, but we might as well force 'select HOTPLUG_CPU if SMP' so the
> > > L1TF mitigations are functional. Sigh....
> > >
> > > Thanks,
> > >
> > > tglx
> > right, sth like?
> > diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> > index b0312f8..5852948 100644
> > --- a/arch/x86/Kconfig
> > +++ b/arch/x86/Kconfig
> > @@ -188,7 +188,8 @@ config X86
> > select HAVE_SYSCALL_TRACEPOINTS
> > select HAVE_UNSTABLE_SCHED_CLOCK
> > select HAVE_USER_RETURN_NOTIFIER
> > - select HOTPLUG_SMT if SMP
> > + select HOTPLUG_CPU if SMP
> > + select HOTPLUG_SMT if SMP && HOTPLUG_CPU
>
> The && HOTPLUG is pretty pointless now.
Hmm, so this way?
+ select HOTPLUG_CPU if SMP
+ select HOTPLUG_SMT if HOTPLUG_CPU
thanks!
--
Jack Wang
Linux Kernel Developer
ProfitBricks GmbH
Greifswalder Str. 207
D - 10405 Berlin
Tel: +49 30 577 008 042
Fax: +49 30 577 008 299
Email: [email protected]
URL: https://www.profitbricks.de
Sitz der Gesellschaft: Berlin
Registergericht: Amtsgericht Charlottenburg, HRB 125506 B
Geschäftsführer: Achim Weiss, Matthias Steinberg, Christoph Steffens