[PULL 05/21] target/arm: Enable FEAT_CSV2_3 for -cpu max

Maintainers: Paolo Bonzini <pbonzini@redhat.com>, Peter Maydell <peter.maydell@linaro.org>, Arnaud Minier <arnaud.minier@telecom-paris.fr>, "Inès Varhol" <ines.varhol@telecom-paris.fr>, Tyrone Ting <kfting@nuvoton.com>, Hao Wu <wuhaotsh@google.com>, Radoslaw Biernacki <rad@semihalf.com>, Leif Lindholm <quic_llindhol@quicinc.com>, Marcin Juszkiewicz <marcin.juszkiewicz@linaro.org>, "Marc-André Lureau" <marcandre.lureau@redhat.com>, Luc Michel <luc@lmichel.fr>, Damien Hedde <damien.hedde@dahe.fr>, Eduardo Habkost <eduardo@habkost.net>, Marcel Apfelbaum <marcel.apfelbaum@gmail.com>, "Philippe Mathieu-Daudé" <philmd@linaro.org>, Yanan Wang <wangyanan55@huawei.com>, Alistair Francis <alistair@alistair23.me>, "Edgar E. Iglesias" <edgar.iglesias@gmail.com>, Alexander Graf <agraf@csgraf.de>, Cleber Rosa <crosa@redhat.com>, Wainer dos Santos Moschetta <wainersm@redhat.com>, Beraldo Leal <bleal@redhat.com>, Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>, Thomas Huth <thuth@redhat.com>, Laurent Vivier <lvivier@redhat.com>
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[PULL 05/21] target/arm: Enable FEAT_CSV2_3 for -cpu max
Posted by Peter Maydell 1 year ago
FEAT_CSV2_3 adds a mechanism to identify if hardware cannot disclose
information about whether branch targets and branch history trained
in one hardware described context can control speculative execution
in a different hardware context.

There is no branch prediction in TCG, so we don't need to do anything
to be compliant with this.  Upadte the '-cpu max' ID registers to
advertise the feature.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-id: 20240418152004.2106516-3-peter.maydell@linaro.org
---
 docs/system/arm/emulation.rst | 1 +
 target/arm/tcg/cpu64.c        | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 5fdc64a944f..d70b66f7530 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -32,6 +32,7 @@ the following architecture extensions:
 - FEAT_CSV2_1p1 (Cache speculation variant 2, version 1.1)
 - FEAT_CSV2_1p2 (Cache speculation variant 2, version 1.2)
 - FEAT_CSV2_2 (Cache speculation variant 2, version 2)
+- FEAT_CSV2_3 (Cache speculation variant 2, version 3)
 - FEAT_CSV3 (Cache speculation variant 3)
 - FEAT_DGH (Data gathering hint)
 - FEAT_DIT (Data Independent Timing instructions)
diff --git a/target/arm/tcg/cpu64.c b/target/arm/tcg/cpu64.c
index 62c4663512b..8ad05c53e8d 100644
--- a/target/arm/tcg/cpu64.c
+++ b/target/arm/tcg/cpu64.c
@@ -1159,7 +1159,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64PFR0, SVE, 1);
     t = FIELD_DP64(t, ID_AA64PFR0, SEL2, 1);      /* FEAT_SEL2 */
     t = FIELD_DP64(t, ID_AA64PFR0, DIT, 1);       /* FEAT_DIT */
-    t = FIELD_DP64(t, ID_AA64PFR0, CSV2, 2);      /* FEAT_CSV2_2 */
+    t = FIELD_DP64(t, ID_AA64PFR0, CSV2, 3);      /* FEAT_CSV2_3 */
     t = FIELD_DP64(t, ID_AA64PFR0, CSV3, 1);      /* FEAT_CSV3 */
     cpu->isar.id_aa64pfr0 = t;
 
@@ -1174,7 +1174,7 @@ void aarch64_max_tcg_initfn(Object *obj)
     t = FIELD_DP64(t, ID_AA64PFR1, MTE, 3);       /* FEAT_MTE3 */
     t = FIELD_DP64(t, ID_AA64PFR1, RAS_FRAC, 0);  /* FEAT_RASv1p1 + FEAT_DoubleFault */
     t = FIELD_DP64(t, ID_AA64PFR1, SME, 1);       /* FEAT_SME */
-    t = FIELD_DP64(t, ID_AA64PFR1, CSV2_FRAC, 0); /* FEAT_CSV2_2 */
+    t = FIELD_DP64(t, ID_AA64PFR1, CSV2_FRAC, 0); /* FEAT_CSV2_3 */
     t = FIELD_DP64(t, ID_AA64PFR1, NMI, 1);       /* FEAT_NMI */
     cpu->isar.id_aa64pfr1 = t;
 
-- 
2.34.1