From 8a40fe5f1bf3837ae3f9961efe1d51e7214f2664 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Fri, 28 Aug 2020 10:02:47 +0100 Subject: [PATCH] target/arm: Rearrange {sve,fp}_check_access assert We want to ensure that access is checked by the time we ask for a specific fp/vector register. We want to ensure that we do not emit two lots of code to raise an exception. But sometimes it's difficult to cleanly organize the code such that we never pass through sve_check_access exactly once. Allow multiple calls so long as the result is true, that is, no exception to be raised. Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell Message-id: 20200815013145.539409-5-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/translate-a64.c | 27 ++++++++++++++++----------- target/arm/translate.h | 1 + 2 files changed, 17 insertions(+), 11 deletions(-) diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c index 0fc5e12fab..115dc946e7 100644 --- a/target/arm/translate-a64.c +++ b/target/arm/translate-a64.c @@ -1156,18 +1156,18 @@ static void do_vec_ld(DisasContext *s, int destidx, int element, * unallocated-encoding checks (otherwise the syndrome information * for the resulting exception will be incorrect). */ -static inline bool fp_access_check(DisasContext *s) +static bool fp_access_check(DisasContext *s) { - assert(!s->fp_access_checked); - s->fp_access_checked = true; + if (s->fp_excp_el) { + assert(!s->fp_access_checked); + s->fp_access_checked = true; - if (!s->fp_excp_el) { - return true; + gen_exception_insn(s, s->pc_curr, EXCP_UDEF, + syn_fp_access_trap(1, 0xe, false), s->fp_excp_el); + return false; } - - gen_exception_insn(s, s->pc_curr, EXCP_UDEF, - syn_fp_access_trap(1, 0xe, false), s->fp_excp_el); - return false; + s->fp_access_checked = true; + return true; } /* Check that SVE access is enabled. If it is, return true. @@ -1176,10 +1176,14 @@ static inline bool fp_access_check(DisasContext *s) bool sve_access_check(DisasContext *s) { if (s->sve_excp_el) { - gen_exception_insn(s, s->pc_curr, EXCP_UDEF, syn_sve_access_trap(), - s->sve_excp_el); + assert(!s->sve_access_checked); + s->sve_access_checked = true; + + gen_exception_insn(s, s->pc_curr, EXCP_UDEF, + syn_sve_access_trap(), s->sve_excp_el); return false; } + s->sve_access_checked = true; return fp_access_check(s); } @@ -14529,6 +14533,7 @@ static void disas_a64_insn(CPUARMState *env, DisasContext *s) s->base.pc_next += 4; s->fp_access_checked = false; + s->sve_access_checked = false; if (dc_isar_feature(aa64_bti, s)) { if (s->base.num_insns == 1) { diff --git a/target/arm/translate.h b/target/arm/translate.h index 6d6d4c0f42..423b0e08df 100644 --- a/target/arm/translate.h +++ b/target/arm/translate.h @@ -64,6 +64,7 @@ typedef struct DisasContext { * that it is set at the point where we actually touch the FP regs. */ bool fp_access_checked; + bool sve_access_checked; /* ARMv8 single-step state (this is distinct from the QEMU gdbstub * single-step support). */