diff mbox series

[v5,08/17] KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig

Message ID 20220721055728.718573-9-kaleshsingh@google.com (mailing list archive)
State New, archived
Headers show
Series KVM nVHE Hypervisor stack unwinder | expand

Commit Message

Kalesh Singh July 21, 2022, 5:57 a.m. UTC
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 <kaleshsingh@google.com>
---

Changes in v5:
  - Make PROTECTED_NVHE_STACKTRACE depend on NVHE_EL2_DEBUG, per Marc

 arch/arm64/kvm/Kconfig | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

Comments

Fuad Tabba July 21, 2022, 9:57 a.m. UTC | #1
Hi Kalesh,

On Thu, Jul 21, 2022 at 6:57 AM Kalesh Singh <kaleshsingh@google.com> 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 <kaleshsingh@google.com>
> ---

Just wanted to point out that I have specifically tested this as well,
enabling PROTECTED_NVHE_STACKTRACE but not NVHE_EL2_DEBUG. Works as
expected.

Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>

Cheers,
/fuad


>
> 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
> --
> 2.37.0.170.g444d1eabd0-goog
>
diff mbox series

Patch

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