These prctl set the Streaming SVE vector length, which may
be completely different from the Normal SVE vector length.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
linux-user/aarch64/target_prctl.h | 48 +++++++++++++++++++++++++++++++
linux-user/syscall.c | 16 +++++++++++
2 files changed, 64 insertions(+)
diff --git a/linux-user/aarch64/target_prctl.h
b/linux-user/aarch64/target_prctl.h
index 40481e6663..f8f8f88992 100644
--- a/linux-user/aarch64/target_prctl.h
+++ b/linux-user/aarch64/target_prctl.h
@@ -10,6 +10,7 @@ static abi_long do_prctl_sve_get_vl(CPUArchState *env)
{
ARMCPU *cpu = env_archcpu(env);
if (cpu_isar_feature(aa64_sve, cpu)) {
+ /* PSTATE.SM is always unset on syscall entry. */
return sve_vq(env) * 16;
}
return -TARGET_EINVAL;
@@ -27,6 +28,7 @@ static abi_long do_prctl_sve_set_vl(CPUArchState *env,
abi_long arg2)
&& arg2 >= 0 && arg2 <= 512 * 16 && !(arg2 & 15)) {
uint32_t vq, old_vq;
+ /* PSTATE.SM is always unset on syscall entry. */
old_vq = sve_vq(env);
/*
@@ -49,6 +51,52 @@ static abi_long do_prctl_sve_set_vl(CPUArchState *env,
abi_long arg2)
}
#define do_prctl_sve_set_vl do_prctl_sve_set_vl
+static abi_long do_prctl_sme_get_vl(CPUArchState *env)
+{
+ ARMCPU *cpu = env_archcpu(env);
+ if (cpu_isar_feature(aa64_sme, cpu)) {
+ return sme_vq(env) * 16;
+ }
+ return -TARGET_EINVAL;
+}
+#define do_prctl_sme_get_vl do_prctl_sme_get_vl
+
+static abi_long do_prctl_sme_set_vl(CPUArchState *env, abi_long arg2)
+{
+ /*
+ * We cannot support either PR_SME_SET_VL_ONEXEC or PR_SME_VL_INHERIT.
+ * Note the kernel definition of sve_vl_valid allows for VQ=512,
+ * i.e. VL=8192, even though the architectural maximum is VQ=16.
+ */
+ if (cpu_isar_feature(aa64_sme, env_archcpu(env))
+ && arg2 >= 0 && arg2 <= 512 * 16 && !(arg2 & 15)) {
+ int vq, old_vq;
+
+ old_vq = sme_vq(env);
+
+ /*
+ * Bound the value of vq, so that we know that it fits into
+ * the 4-bit field in SMCR_EL1. Because PSTATE.SM is cleared
+ * on syscall entry, we are not modifying the current SVE
+ * vector length.
+ */
+ vq = MAX(arg2 / 16, 1);
+ vq = MIN(vq, 16);
+ env->vfp.smcr_el[1] =
+ FIELD_DP64(env->vfp.smcr_el[1], SMCR, LEN, vq - 1);
+ vq = sme_vq(env);
+
+ if (old_vq != vq) {
+ /* PSTATE.ZA state is cleared on any change to VQ. */
+ env->svcr = FIELD_DP64(env->svcr, SVCR, ZA, 0);
+ arm_rebuild_hflags(env);
+ }
+ return vq * 16;
+ }
+ return -TARGET_EINVAL;
+}
+#define do_prctl_sme_set_vl do_prctl_sme_set_vl
+
static abi_long do_prctl_reset_keys(CPUArchState *env, abi_long arg2)
{
ARMCPU *cpu = env_archcpu(env);
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index a7f41ef0ac..e8d6e20b85 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6346,6 +6346,12 @@ abi_long do_arch_prctl(CPUX86State *env, int code,
abi_ulong addr)
#ifndef PR_SET_SYSCALL_USER_DISPATCH
# define PR_SET_SYSCALL_USER_DISPATCH 59
#endif
+#ifndef PR_SME_SET_VL
+# define PR_SME_SET_VL 63
+# define PR_SME_GET_VL 64
+# define PR_SME_VL_LEN_MASK 0xffff
+# define PR_SME_VL_INHERIT (1 << 17)
+#endif
#include "target_prctl.h"
@@ -6386,6 +6392,12 @@ static abi_long do_prctl_inval1(CPUArchState *env,
abi_long arg2)
#ifndef do_prctl_set_unalign
#define do_prctl_set_unalign do_prctl_inval1
#endif
+#ifndef do_prctl_sme_get_vl
+#define do_prctl_sme_get_vl do_prctl_inval0
+#endif
+#ifndef do_prctl_sme_set_vl
+#define do_prctl_sme_set_vl do_prctl_inval1
+#endif
static abi_long do_prctl(CPUArchState *env, abi_long option, abi_long arg2,
abi_long arg3, abi_long arg4, abi_long arg5)
@@ -6437,6 +6449,10 @@ static abi_long do_prctl(CPUArchState *env, abi_long
option, abi_long arg2,
return do_prctl_sve_get_vl(env);
case PR_SVE_SET_VL:
return do_prctl_sve_set_vl(env, arg2);
+ case PR_SME_GET_VL:
+ return do_prctl_sme_get_vl(env);
+ case PR_SME_SET_VL:
+ return do_prctl_sme_set_vl(env, arg2);
case PR_PAC_RESET_KEYS:
if (arg3 || arg4 || arg5) {
return -TARGET_EINVAL;
--
2.34.1
