This can be used to disable stacktrace for the protected KVM
nVHE hypervisor, in order to save on the associated memory usage.
This option is disabled by default, since protected KVM is not widely
used on platforms other than Android currently.
Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Fuad Tabba <[email protected]>
Tested-by: Fuad Tabba <[email protected]>
---
Changes in v6:
- Add Fuad’s Reviewed-by and Tested-by tags
Changes in v5:
- Make PROTECTED_NVHE_STACKTRACE depend on NVHE_EL2_DEBUG, per Marc
arch/arm64/kvm/Kconfig | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
index 8a5fbbf084df..09c995869916 100644
--- a/arch/arm64/kvm/Kconfig
+++ b/arch/arm64/kvm/Kconfig
@@ -46,6 +46,21 @@ menuconfig KVM
If unsure, say N.
+config PROTECTED_NVHE_STACKTRACE
+ bool "Protected KVM hypervisor stacktraces"
+ depends on NVHE_EL2_DEBUG
+ default n
+ help
+ Say Y here to enable pKVM hypervisor stacktraces on hyp_panic()
+
+ If you are not using protected nVHE (pKVM), say N.
+
+ If using protected nVHE mode, but cannot afford the associated
+ memory cost (less than 0.75 page per CPU) of pKVM stacktraces,
+ say N.
+
+ If unsure, say N.
+
config NVHE_EL2_DEBUG
bool "Debug mode for non-VHE EL2 object"
depends on KVM
--
2.37.1.359.gd136c6c3e2-goog
On Tue, 26 Jul 2022 08:37:45 +0100,
Kalesh Singh <[email protected]> wrote:
>
> This can be used to disable stacktrace for the protected KVM
> nVHE hypervisor, in order to save on the associated memory usage.
>
> This option is disabled by default, since protected KVM is not widely
> used on platforms other than Android currently.
>
> Signed-off-by: Kalesh Singh <[email protected]>
> Reviewed-by: Fuad Tabba <[email protected]>
> Tested-by: Fuad Tabba <[email protected]>
> ---
>
> Changes in v6:
> - Add Fuad’s Reviewed-by and Tested-by tags
>
> Changes in v5:
> - Make PROTECTED_NVHE_STACKTRACE depend on NVHE_EL2_DEBUG, per Marc
>
> arch/arm64/kvm/Kconfig | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> index 8a5fbbf084df..09c995869916 100644
> --- a/arch/arm64/kvm/Kconfig
> +++ b/arch/arm64/kvm/Kconfig
> @@ -46,6 +46,21 @@ menuconfig KVM
>
> If unsure, say N.
>
> +config PROTECTED_NVHE_STACKTRACE
> + bool "Protected KVM hypervisor stacktraces"
> + depends on NVHE_EL2_DEBUG
> + default n
> + help
> + Say Y here to enable pKVM hypervisor stacktraces on hyp_panic()
> +
> + If you are not using protected nVHE (pKVM), say N.
> +
> + If using protected nVHE mode, but cannot afford the associated
> + memory cost (less than 0.75 page per CPU) of pKVM stacktraces,
> + say N.
> +
> + If unsure, say N.
> +
> config NVHE_EL2_DEBUG
> bool "Debug mode for non-VHE EL2 object"
> depends on KVM
Having NVHE_EL2_DEBUG after PROTECTED_NVHE_STACKTRACE is pretty odd
when you use 'make menuconfig', as the new option appears out of
sequence.
I'll move it around, no need to respin for this.
Thanks,
M.
--
Without deviation from the norm, progress is not possible.
On Tue, Jul 26, 2022 at 3:00 AM Marc Zyngier <[email protected]> wrote:
>
> On Tue, 26 Jul 2022 08:37:45 +0100,
> Kalesh Singh <[email protected]> wrote:
> >
> > This can be used to disable stacktrace for the protected KVM
> > nVHE hypervisor, in order to save on the associated memory usage.
> >
> > This option is disabled by default, since protected KVM is not widely
> > used on platforms other than Android currently.
> >
> > Signed-off-by: Kalesh Singh <[email protected]>
> > Reviewed-by: Fuad Tabba <[email protected]>
> > Tested-by: Fuad Tabba <[email protected]>
> > ---
> >
> > Changes in v6:
> > - Add Fuad’s Reviewed-by and Tested-by tags
> >
> > Changes in v5:
> > - Make PROTECTED_NVHE_STACKTRACE depend on NVHE_EL2_DEBUG, per Marc
> >
> > arch/arm64/kvm/Kconfig | 15 +++++++++++++++
> > 1 file changed, 15 insertions(+)
> >
> > diff --git a/arch/arm64/kvm/Kconfig b/arch/arm64/kvm/Kconfig
> > index 8a5fbbf084df..09c995869916 100644
> > --- a/arch/arm64/kvm/Kconfig
> > +++ b/arch/arm64/kvm/Kconfig
> > @@ -46,6 +46,21 @@ menuconfig KVM
> >
> > If unsure, say N.
> >
> > +config PROTECTED_NVHE_STACKTRACE
> > + bool "Protected KVM hypervisor stacktraces"
> > + depends on NVHE_EL2_DEBUG
> > + default n
> > + help
> > + Say Y here to enable pKVM hypervisor stacktraces on hyp_panic()
> > +
> > + If you are not using protected nVHE (pKVM), say N.
> > +
> > + If using protected nVHE mode, but cannot afford the associated
> > + memory cost (less than 0.75 page per CPU) of pKVM stacktraces,
> > + say N.
> > +
> > + If unsure, say N.
> > +
> > config NVHE_EL2_DEBUG
> > bool "Debug mode for non-VHE EL2 object"
> > depends on KVM
>
> Having NVHE_EL2_DEBUG after PROTECTED_NVHE_STACKTRACE is pretty odd
> when you use 'make menuconfig', as the new option appears out of
> sequence.
Ahh good catch. Should have moved it when the dependency got changed.
>
> I'll move it around, no need to respin for this.
>
Thanks Marc.
> Thanks,
>
> M.
>
> --
> Without deviation from the norm, progress is not possible.