target/arm: Separate cpu types max-v8 and max-v9

Do not include v9-only features in "max-v8".
Do not include the prohibited v8 features in "max-v9".
In aarch64 tcg mode, define "max" as "max-v9".

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20260827041557.775080-7-richard.henderson@linaro.org
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 12 insertions, 1 deletions

diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index cc42db9e0b..ff02435975 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -230,7 +230,18 @@ to the `Arm Architecture Reference Manual for A-profile architecture
 When a specific named CPU is being emulated, only those features which
 are present in hardware for that CPU are emulated. (If a feature is
 not in the list above then it is not supported, even if the real
-hardware should have it.) The ``max`` CPU enables all features.
+hardware should have it.)
+
+The ``max-v8`` CPU enables all of the listed Armv8-A architecture
+extensions but none of the Armv9-A architecture extensions.
+
+The ``max-v9`` CPU enables all of the listed extensions except for
+those that are prohibited by the Armv9-A architecture: FEAT_AA32EL1,
+FEAT_AA32EL2, FEAT_AA32EL3, and FEAT_DoubleLock.
+
+The ``max`` CPU is an alias for ``max-v9`` under AArch64 TCG emulation,
+an alias for ``max-v8`` under AArch32 TCG emulation, or an alias
+for ``host`` under hardware virtualization.
 
 R-profile CPU architecture support
 ==================================