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authorRichard Henderson <richard.henderson@linaro.org>2021-01-11 13:57:39 -1000
committerPeter Maydell <peter.maydell@linaro.org>2021-01-19 14:38:51 +0000
commiteb94284d0812b4e7c11c5d075b584100ac1c1b9a (patch)
treead205638a5b69b2bfce54899472934b4179db904 /docs/system/arm
parent283fc52ade85eb50141f3b8b85f82b07d016cb17 (diff)
downloadqemu-eb94284d0812b4e7c11c5d075b584100ac1c1b9a.zip
target/arm: Add cpu properties to control pauth
The crypto overhead of emulating pauth can be significant for some workloads. Add two boolean properties that allows the feature to be turned off, on with the architected algorithm, or on with an implementation defined algorithm. We need two intermediate booleans to control the state while parsing properties lest we clobber ID_AA64ISAR1 into an invalid intermediate state. Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-id: 20210111235740.462469-3-richard.henderson@linaro.org [PMM: fixed docs typo, tweaked text to clarify that the impdef algorithm is specific to QEMU] Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'docs/system/arm')
-rw-r--r--docs/system/arm/cpu-features.rst21
1 files changed, 21 insertions, 0 deletions
diff --git a/docs/system/arm/cpu-features.rst b/docs/system/arm/cpu-features.rst
index 35196a6b75..c455442eaf 100644
--- a/docs/system/arm/cpu-features.rst
+++ b/docs/system/arm/cpu-features.rst
@@ -211,6 +211,27 @@ the list of KVM VCPU features and their descriptions.
influence the guest scheduler behavior and/or be
exposed to the guest userspace.
+TCG VCPU Features
+=================
+
+TCG VCPU features are CPU features that are specific to TCG.
+Below is the list of TCG VCPU features and their descriptions.
+
+ pauth Enable or disable `FEAT_Pauth`, pointer
+ authentication. By default, the feature is
+ enabled with `-cpu max`.
+
+ pauth-impdef When `FEAT_Pauth` is enabled, either the
+ *impdef* (Implementation Defined) algorithm
+ is enabled or the *architected* QARMA algorithm
+ is enabled. By default the impdef algorithm
+ is disabled, and QARMA is enabled.
+
+ The architected QARMA algorithm has good
+ cryptographic properties, but can be quite slow
+ to emulate. The impdef algorithm used by QEMU
+ is non-cryptographic but significantly faster.
+
SVE CPU Properties
==================