Thread (37 messages) 37 messages, 4 authors, 2022-07-27

Re: [PATCH v6 12/17] KVM: arm64: Add PROTECTED_NVHE_STACKTRACE Kconfig

From: Marc Zyngier <maz@kernel.org>
Date: 2022-07-26 10:00:35
Also in: kvmarm, lkml

On Tue, 26 Jul 2022 08:37:45 +0100,
Kalesh Singh [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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 <redacted>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
---

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.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help