Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Sun 09-12-18 21:46:57, Jiri Kosina wrote: > On Mon, 19 Nov 2018, Michal Hocko wrote: > > > > > > > + It also drops the swap size and > > > > > > available > > > > > > + RAM limit restriction. > > > > > > > > > > Minor nit: I think this should explicitly mention that those two > > > > > things > > > > > are related to bare metal mitigation, to avoid any confusion (as > > > > > otherwise > > > > > the l1tf cmdline parameter is purely about hypervisor mitigations). > > > > > > > > Do you have any specific wording in mind? > > > > > > > > It also drops the swap size and available RAM limit restrictions on both > > > > hypervisor and bare metal. > > > > > > > > Sounds better? > > > > > > > > > With that > > > > > > > > > > Acked-by: Jiri Kosina > > > > > > > > Thanks! > > > > > > Yes, I think that makes it absolutely clear. Thanks, > > > > OK. Here is the incremental diff on top of the patch. I will fold and > > repost later this week. I assume people are still catching up after LPC > > and I do not want to spam them even more. > > Is this queued anywhere in the meantime please? Not yet. Thanks for the reminder. It completely fall of my radar. Thomas, do you want me to resubmit or there are some other changes you would like to see? -- Michal Hocko SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Mon, 19 Nov 2018, Michal Hocko wrote: > > > > > + It also drops the swap size and > > > > > available > > > > > + RAM limit restriction. > > > > > > > > Minor nit: I think this should explicitly mention that those two things > > > > are related to bare metal mitigation, to avoid any confusion (as > > > > otherwise > > > > the l1tf cmdline parameter is purely about hypervisor mitigations). > > > > > > Do you have any specific wording in mind? > > > > > > It also drops the swap size and available RAM limit restrictions on both > > > hypervisor and bare metal. > > > > > > Sounds better? > > > > > > > With that > > > > > > > > Acked-by: Jiri Kosina > > > > > > Thanks! > > > > Yes, I think that makes it absolutely clear. Thanks, > > OK. Here is the incremental diff on top of the patch. I will fold and > repost later this week. I assume people are still catching up after LPC > and I do not want to spam them even more. Is this queued anywhere in the meantime please? Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Mon 19-11-18 14:36:32, Jiri Kosina wrote:
> On Wed, 14 Nov 2018, Michal Hocko wrote:
>
> > > > + It also drops the swap size and
> > > > available
> > > > + RAM limit restriction.
> > >
> > > Minor nit: I think this should explicitly mention that those two things
> > > are related to bare metal mitigation, to avoid any confusion (as
> > > otherwise
> > > the l1tf cmdline parameter is purely about hypervisor mitigations).
> >
> > Do you have any specific wording in mind?
> >
> > It also drops the swap size and available RAM limit restrictions on both
> > hypervisor and bare metal.
> >
> > Sounds better?
> >
> > > With that
> > >
> > > Acked-by: Jiri Kosina
> >
> > Thanks!
>
> Yes, I think that makes it absolutely clear. Thanks,
OK. Here is the incremental diff on top of the patch. I will fold and
repost later this week. I assume people are still catching up after LPC
and I do not want to spam them even more.
diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
index a54f2bd39e77..c5aa4b4a797d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2096,7 +2096,8 @@
Disables hypervisor mitigations and doesn't
emit any warnings.
It also drops the swap size and available
- RAM limit restriction.
+ RAM limit restriction on both hypervisor and
+ bare metal.
Default is 'flush'.
diff --git a/Documentation/admin-guide/l1tf.rst
b/Documentation/admin-guide/l1tf.rst
index b00464a9c09c..2e65e6cb033e 100644
--- a/Documentation/admin-guide/l1tf.rst
+++ b/Documentation/admin-guide/l1tf.rst
@@ -405,7 +405,8 @@ The kernel command line allows to control the L1TF
mitigations at boot
off Disables hypervisor mitigations and doesn't emit any
warnings.
- It also drops the swap size and available RAM limit
restrictions.
+ It also drops the swap size and available RAM limit restrictions
+on both hypervisor and bare metal.
=
--
Michal Hocko
SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Mon 19-11-18 14:36:32, Jiri Kosina wrote:
> On Wed, 14 Nov 2018, Michal Hocko wrote:
>
> > > > + It also drops the swap size and
> > > > available
> > > > + RAM limit restriction.
> > >
> > > Minor nit: I think this should explicitly mention that those two things
> > > are related to bare metal mitigation, to avoid any confusion (as
> > > otherwise
> > > the l1tf cmdline parameter is purely about hypervisor mitigations).
> >
> > Do you have any specific wording in mind?
> >
> > It also drops the swap size and available RAM limit restrictions on both
> > hypervisor and bare metal.
> >
> > Sounds better?
> >
> > > With that
> > >
> > > Acked-by: Jiri Kosina
> >
> > Thanks!
>
> Yes, I think that makes it absolutely clear. Thanks,
OK. Here is the incremental diff on top of the patch. I will fold and
repost later this week. I assume people are still catching up after LPC
and I do not want to spam them even more.
diff --git a/Documentation/admin-guide/kernel-parameters.txt
b/Documentation/admin-guide/kernel-parameters.txt
index a54f2bd39e77..c5aa4b4a797d 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2096,7 +2096,8 @@
Disables hypervisor mitigations and doesn't
emit any warnings.
It also drops the swap size and available
- RAM limit restriction.
+ RAM limit restriction on both hypervisor and
+ bare metal.
Default is 'flush'.
diff --git a/Documentation/admin-guide/l1tf.rst
b/Documentation/admin-guide/l1tf.rst
index b00464a9c09c..2e65e6cb033e 100644
--- a/Documentation/admin-guide/l1tf.rst
+++ b/Documentation/admin-guide/l1tf.rst
@@ -405,7 +405,8 @@ The kernel command line allows to control the L1TF
mitigations at boot
off Disables hypervisor mitigations and doesn't emit any
warnings.
- It also drops the swap size and available RAM limit
restrictions.
+ It also drops the swap size and available RAM limit restrictions
+on both hypervisor and bare metal.
=
--
Michal Hocko
SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Wed, 14 Nov 2018, Michal Hocko wrote: > > > + It also drops the swap size and available > > > + RAM limit restriction. > > > > Minor nit: I think this should explicitly mention that those two things > > are related to bare metal mitigation, to avoid any confusion (as otherwise > > the l1tf cmdline parameter is purely about hypervisor mitigations). > > Do you have any specific wording in mind? > > It also drops the swap size and available RAM limit restrictions on both > hypervisor and bare metal. > > Sounds better? > > > With that > > > > Acked-by: Jiri Kosina > > Thanks! Yes, I think that makes it absolutely clear. Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Wed, 14 Nov 2018, Michal Hocko wrote: > > > + It also drops the swap size and available > > > + RAM limit restriction. > > > > Minor nit: I think this should explicitly mention that those two things > > are related to bare metal mitigation, to avoid any confusion (as otherwise > > the l1tf cmdline parameter is purely about hypervisor mitigations). > > Do you have any specific wording in mind? > > It also drops the swap size and available RAM limit restrictions on both > hypervisor and bare metal. > > Sounds better? > > > With that > > > > Acked-by: Jiri Kosina > > Thanks! Yes, I think that makes it absolutely clear. Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue, Nov 13, 2018 at 07:49:10PM +0100, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. Reviewed-by: Andi Kleen -Andi
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue, Nov 13, 2018 at 07:49:10PM +0100, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. Reviewed-by: Andi Kleen -Andi
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue 13-11-18 20:56:54, Jiri Kosina wrote: > On Tue, 13 Nov 2018, Michal Hocko wrote: > > > From: Michal Hocko > > > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > > whenever the system is deemed affected by L1TF vulnerability. Even > > though the limit is quite high for most deployments it seems to be > > too restrictive for deployments which are willing to live with the > > mitigation disabled. > > > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > > which is clearly out of the limit. > > > > Drop the swap restriction when l1tf=off is specified. It also doesn't > > make much sense to warn about too much memory for the l1tf mitigation > > when it is forcefully disabled by the administrator. > > > > Signed-off-by: Michal Hocko > > --- > > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > > Documentation/admin-guide/l1tf.rst | 5 - > > arch/x86/kernel/cpu/bugs.c | 3 ++- > > arch/x86/mm/init.c | 2 +- > > 4 files changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > b/Documentation/admin-guide/kernel-parameters.txt > > index 81d1d5a74728..a54f2bd39e77 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2095,6 +2095,8 @@ > > off > > Disables hypervisor mitigations and doesn't > > emit any warnings. > > + It also drops the swap size and available > > + RAM limit restriction. > > Minor nit: I think this should explicitly mention that those two things > are related to bare metal mitigation, to avoid any confusion (as otherwise > the l1tf cmdline parameter is purely about hypervisor mitigations). Do you have any specific wording in mind? It also drops the swap size and available RAM limit restrictions on both hypervisor and bare metal. Sounds better? > With that > > Acked-by: Jiri Kosina Thanks! -- Michal Hocko SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue 13-11-18 20:56:54, Jiri Kosina wrote: > On Tue, 13 Nov 2018, Michal Hocko wrote: > > > From: Michal Hocko > > > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > > whenever the system is deemed affected by L1TF vulnerability. Even > > though the limit is quite high for most deployments it seems to be > > too restrictive for deployments which are willing to live with the > > mitigation disabled. > > > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > > which is clearly out of the limit. > > > > Drop the swap restriction when l1tf=off is specified. It also doesn't > > make much sense to warn about too much memory for the l1tf mitigation > > when it is forcefully disabled by the administrator. > > > > Signed-off-by: Michal Hocko > > --- > > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > > Documentation/admin-guide/l1tf.rst | 5 - > > arch/x86/kernel/cpu/bugs.c | 3 ++- > > arch/x86/mm/init.c | 2 +- > > 4 files changed, 9 insertions(+), 3 deletions(-) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > b/Documentation/admin-guide/kernel-parameters.txt > > index 81d1d5a74728..a54f2bd39e77 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2095,6 +2095,8 @@ > > off > > Disables hypervisor mitigations and doesn't > > emit any warnings. > > + It also drops the swap size and available > > + RAM limit restriction. > > Minor nit: I think this should explicitly mention that those two things > are related to bare metal mitigation, to avoid any confusion (as otherwise > the l1tf cmdline parameter is purely about hypervisor mitigations). Do you have any specific wording in mind? It also drops the swap size and available RAM limit restrictions on both hypervisor and bare metal. Sounds better? > With that > > Acked-by: Jiri Kosina Thanks! -- Michal Hocko SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue, 13 Nov 2018, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. > > Signed-off-by: Michal Hocko > --- > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > Documentation/admin-guide/l1tf.rst | 5 - > arch/x86/kernel/cpu/bugs.c | 3 ++- > arch/x86/mm/init.c | 2 +- > 4 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 81d1d5a74728..a54f2bd39e77 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2095,6 +2095,8 @@ > off > Disables hypervisor mitigations and doesn't > emit any warnings. > + It also drops the swap size and available > + RAM limit restriction. Minor nit: I think this should explicitly mention that those two things are related to bare metal mitigation, to avoid any confusion (as otherwise the l1tf cmdline parameter is purely about hypervisor mitigations). With that Acked-by: Jiri Kosina Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On Tue, 13 Nov 2018, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. > > Signed-off-by: Michal Hocko > --- > Documentation/admin-guide/kernel-parameters.txt | 2 ++ > Documentation/admin-guide/l1tf.rst | 5 - > arch/x86/kernel/cpu/bugs.c | 3 ++- > arch/x86/mm/init.c | 2 +- > 4 files changed, 9 insertions(+), 3 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > b/Documentation/admin-guide/kernel-parameters.txt > index 81d1d5a74728..a54f2bd39e77 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -2095,6 +2095,8 @@ > off > Disables hypervisor mitigations and doesn't > emit any warnings. > + It also drops the swap size and available > + RAM limit restriction. Minor nit: I think this should explicitly mention that those two things are related to bare metal mitigation, to avoid any confusion (as otherwise the l1tf cmdline parameter is purely about hypervisor mitigations). With that Acked-by: Jiri Kosina Thanks, -- Jiri Kosina SUSE Labs
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On 18-11-13 19:49:10, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. > > Signed-off-by: Michal Hocko Reviewed-by: Pavel Tatashin
Re: [PATCH] l1tf: drop the swap storage limit restriction when l1tf=off
On 18-11-13 19:49:10, Michal Hocko wrote: > From: Michal Hocko > > Swap storage is restricted to max_swapfile_size (~16TB on x86_64) > whenever the system is deemed affected by L1TF vulnerability. Even > though the limit is quite high for most deployments it seems to be > too restrictive for deployments which are willing to live with the > mitigation disabled. > > We have a customer to deploy 8x 6,4TB PCIe/NVMe SSD swap devices > which is clearly out of the limit. > > Drop the swap restriction when l1tf=off is specified. It also doesn't > make much sense to warn about too much memory for the l1tf mitigation > when it is forcefully disabled by the administrator. > > Signed-off-by: Michal Hocko Reviewed-by: Pavel Tatashin
