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[PATCH v4 11/21] target/arm: default SVE length to 64 bytes for linux-us
From: |
Alex Bennée |
Subject: |
[PATCH v4 11/21] target/arm: default SVE length to 64 bytes for linux-user |
Date: |
Fri, 20 Dec 2019 12:04:28 +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>
---
v2
- tweak zcr_el[1] instead
---
target/arm/cpu.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index dd51adac059..2d2e786245b 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -199,9 +199,9 @@ static void arm_cpu_reset(CPUState *s)
/* and to the SVE instructions */
env->cp15.cpacr_el1 = deposit64(env->cp15.cpacr_el1, 16, 2, 3);
env->cp15.cptr_el[3] |= CPTR_EZ;
- /* with maximum vector length */
+ /* with reasonable vector length */
env->vfp.zcr_el[1] = cpu_isar_feature(aa64_sve, cpu) ?
- cpu->sve_max_vq - 1 : 0;
+ MIN(cpu->sve_max_vq - 1, 3) : 0;
env->vfp.zcr_el[2] = env->vfp.zcr_el[1];
env->vfp.zcr_el[3] = env->vfp.zcr_el[1];
/*
--
2.20.1
- [PATCH v4 04/21] gdbstub: move mem_buf to GDBState and use GByteArray, (continued)
- [PATCH v4 04/21] gdbstub: move mem_buf to GDBState and use GByteArray, Alex Bennée, 2019/12/20
- [PATCH v4 06/21] target/arm: use gdb_get_reg helpers, Alex Bennée, 2019/12/20
- [PATCH v4 02/21] gdbstub: stop passing GDBState * around and use global, Alex Bennée, 2019/12/20
- [PATCH v4 07/21] target/m68k: use gdb_get_reg helpers, Alex Bennée, 2019/12/20
- [PATCH v4 10/21] target/arm: explicitly encode regnum in our XML, Alex Bennée, 2019/12/20
- [PATCH v4 09/21] target/arm: prepare for multiple dynamic XMLs, Alex Bennée, 2019/12/20
- [PATCH v4 17/21] tests/tcg/aarch64: add a gdbstub testcase for SVE registers, Alex Bennée, 2019/12/20
- [PATCH v4 16/21] tests/guest-debug: add a simple test runner, Alex Bennée, 2019/12/20
- [PATCH v4 08/21] gdbstub: extend GByteArray to read register helpers, Alex Bennée, 2019/12/20
- [PATCH v4 18/21] tests/tcg/aarch64: add SVE iotcl test, Alex Bennée, 2019/12/20
- [PATCH v4 11/21] target/arm: default SVE length to 64 bytes for linux-user,
Alex Bennée <=
- [PATCH v4 12/21] target/arm: generate xml description of our SVE registers, Alex Bennée, 2019/12/20
- [PATCH v4 15/21] tests/tcg/aarch64: userspace system register test, Alex Bennée, 2019/12/20
- [PATCH v4 14/21] target/arm: don't bother with id_aa64pfr0_read for USER_ONLY, Alex Bennée, 2019/12/20
- [PATCH v4 13/21] tests/tcg: add a configure compiler check for ARMv8.1 and SVE, Alex Bennée, 2019/12/20
- [PATCH v4 19/21] tests/tcg/aarch64: add test-sve-ioctl guest-debug test, Alex Bennée, 2019/12/20
- [PATCH v4 21/21] gdbstub: do not split gdb_monitor_write payload, Alex Bennée, 2019/12/20
- [PATCH v4 20/21] gdbstub: change GDBState.last_packet to GByteArray, Alex Bennée, 2019/12/20