@@ -223,7 +223,7 @@ Below is the list of TCG VCPU features and their descriptions.
When ``pauth`` is enabled, select the architected QARMA5 algorithm.
Without ``pauth-impdef``, ``pauth-qarma3`` or ``pauth-qarma5`` enabled,
-the architected QARMA5 algorithm is used. The architected QARMA5
+the QEMU impdef algorithm is used. The architected QARMA5
and QARMA3 algorithms have good cryptographic properties, but can
be quite slow to emulate. The impdef algorithm used by QEMU is
non-cryptographic but significantly faster.
@@ -169,7 +169,7 @@ would default to it anyway.
.. code::
- -cpu max,pauth-impdef=on \
+ -cpu max \
-smp 4 \
-accel tcg \
@@ -529,15 +529,15 @@ void arm_cpu_pauth_finalize(ARMCPU *cpu, Error **errp)
return;
}
- if (cpu->prop_pauth_impdef) {
- isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, API, features);
- isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPI, 1);
+ if (cpu->prop_pauth_qarma5) {
+ isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, APA, features);
+ isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPA, 1);
} else if (cpu->prop_pauth_qarma3) {
isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, APA3, features);
isar2 = FIELD_DP64(isar2, ID_AA64ISAR2, GPA3, 1);
- } else { /* default is pauth-qarma5 */
- isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, APA, features);
- isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPA, 1);
+ } else { /* default is pauth-impdef */
+ isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, API, features);
+ isar1 = FIELD_DP64(isar1, ID_AA64ISAR1, GPI, 1);
}
} else if (cpu->prop_pauth_impdef ||
cpu->prop_pauth_qarma3 ||
Pointer authentication on aarch64 is pretty expensive (up to 50% of execution time) when running a virtual machine with tcg and -cpu max (which enables pauth=on). The advice is always: use pauth-impdef=on. Our documentation even mentions it "by default" in docs/system/introduction.rst. Thus, we change the default to use impdef by default. This does not affect kvm or hvf acceleration, since pauth algorithm used is the one from host cpu. This change is retro compatible, in terms of cli, with previous versions, as the semantic of using -cpu max,pauth-impdef=on, and -cpu max,pauth-qarma3=on is preserved. The new option introduced in previous patch and matching old default is -cpu max,pauth-qarma5=on. Signed-off-by: Pierrick Bouvier <pierrick.bouvier@linaro.org> --- docs/system/arm/cpu-features.rst | 2 +- docs/system/introduction.rst | 2 +- target/arm/cpu64.c | 12 ++++++------ 3 files changed, 8 insertions(+), 8 deletions(-)