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[PULL 17/28] target/arm: default SVE length to 64 bytes for linux-user
From: |
Alex Bennée |
Subject: |
[PULL 17/28] target/arm: default SVE length to 64 bytes for linux-user |
Date: |
Tue, 17 Mar 2020 17:50:42 +0000 |
The Linux kernel chooses the default of 64 bytes for SVE registers on
the basis that it is the largest size on known hardware that won't
grow the signal frame. We still honour the sve-max-vq property and
userspace can expand the number of lanes by calling PR_SVE_SET_VL.
This should not make any difference to SVE enabled software as the SVE
is of course vector length agnostic.
Signed-off-by: Alex Bennée <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Message-Id: <address@hidden>
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 3623ecefbd9..0909ce86a12 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -195,9 +195,10 @@ static void arm_cpu_reset(CPUState *s)
env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 20, 2, 3);
/* and to the SVE instructions */
env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 16, 2, 3);
- /* with maximum vector length */
- env->vfp.zcr_el[1] = cpu_isar_feature(aa64_sve, cpu) ?
- cpu->sve_max_vq - 1 : 0;
+ /* with reasonable vector length */
+ if (cpu_isar_feature(aa64_sve, cpu)) {
+ env->vfp.zcr_el[1] = MIN(cpu->sve_max_vq - 1, 3);
+ }
/*
* Enable TBI0 and TBI1. While the real kernel only enables TBI0,
* turning on both here will produce smaller code and otherwise
--
2.20.1
- [PULL 14/28] gdbstub: extend GByteArray to read register helpers, (continued)
- [PULL 14/28] gdbstub: extend GByteArray to read register helpers, Alex Bennée, 2020/03/17
- [PULL 23/28] tests/tcg/aarch64: add a gdbstub testcase for SVE registers, Alex Bennée, 2020/03/17
- [PULL 19/28] target/arm: don't bother with id_aa64pfr0_read for USER_ONLY, Alex Bennée, 2020/03/17
- [PULL 27/28] gdbstub: do not split gdb_monitor_write payload, Alex Bennée, 2020/03/17
- [PULL 20/28] tests/tcg/aarch64: userspace system register test, Alex Bennée, 2020/03/17
- [PULL 26/28] gdbstub: change GDBState.last_packet to GByteArray, Alex Bennée, 2020/03/17
- [PULL 18/28] target/arm: generate xml description of our SVE registers, Alex Bennée, 2020/03/17
- [PULL 24/28] tests/tcg/aarch64: add SVE iotcl test, Alex Bennée, 2020/03/17
- [PULL 22/28] tests/guest-debug: add a simple test runner, Alex Bennée, 2020/03/17
- [PULL 21/28] configure: allow user to specify what gdb to use, Alex Bennée, 2020/03/17
- [PULL 17/28] target/arm: default SVE length to 64 bytes for linux-user,
Alex Bennée <=
- [PULL 28/28] gdbstub: Fix single-step issue by confirming 'vContSupported+' feature to gdb, Alex Bennée, 2020/03/17
- Re: [PULL 00/28 for 5.0] testing and gdbstub updates, Peter Maydell, 2020/03/18