[Qemu-devel] [PULL 07/49] target/arm: Add PAuth active bit to tbflags

[Peter Maydell <peter.maydell@linaro.org>]

From: Richard Henderson <richard.henderson@linaro.org>

There are 5 bits of state that could be added, but to save
space within tbflags, add only a single enable bit.
Helpers will determine the rest of the state at runtime.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190108223129.5570-4-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 target/arm/cpu.h           |  1 +
 target/arm/translate.h     |  2 ++
 target/arm/helper.c        | 19 +++++++++++++++++++
 target/arm/translate-a64.c |  1 +
 4 files changed, 23 insertions(+)

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 843d5936ead..9ad7b2d11ed 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -3014,6 +3014,7 @@ FIELD(TBFLAG_A64, TBI0, 0, 1)
 FIELD(TBFLAG_A64, TBI1, 1, 1)
 FIELD(TBFLAG_A64, SVEEXC_EL, 2, 2)
 FIELD(TBFLAG_A64, ZCR_LEN, 4, 4)
+FIELD(TBFLAG_A64, PAUTH_ACTIVE, 8, 1)
 
 static inline bool bswap_code(bool sctlr_b)
 {
diff --git a/target/arm/translate.h b/target/arm/translate.h
index 1550aa8bc7f..d8a8bb4e9c0 100644
--- a/target/arm/translate.h
+++ b/target/arm/translate.h
@@ -68,6 +68,8 @@ typedef struct DisasContext {
     bool is_ldex;
     /* True if a single-step exception will be taken to the current EL */
     bool ss_same_el;
+    /* True if v8.3-PAuth is active.  */
+    bool pauth_active;
     /* Bottom two bits of XScale c15_cpar coprocessor access control reg */
     int c15_cpar;
     /* TCG op of the current insn_start.  */
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 9bf8fbd8f9b..caea722c9b8 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -12983,6 +12983,25 @@ void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc,
             flags = FIELD_DP32(flags, TBFLAG_A64, SVEEXC_EL, sve_el);
             flags = FIELD_DP32(flags, TBFLAG_A64, ZCR_LEN, zcr_len);
         }
+
+        if (cpu_isar_feature(aa64_pauth, cpu)) {
+            /*
+             * In order to save space in flags, we record only whether
+             * pauth is "inactive", meaning all insns are implemented as
+             * a nop, or "active" when some action must be performed.
+             * The decision of which action to take is left to a helper.
+             */
+            uint64_t sctlr;
+            if (current_el == 0) {
+                /* FIXME: ARMv8.1-VHE S2 translation regime.  */
+                sctlr = env->cp15.sctlr_el[1];
+            } else {
+                sctlr = env->cp15.sctlr_el[current_el];
+            }
+            if (sctlr & (SCTLR_EnIA | SCTLR_EnIB | SCTLR_EnDA | SCTLR_EnDB)) {
+                flags = FIELD_DP32(flags, TBFLAG_A64, PAUTH_ACTIVE, 1);
+            }
+        }
     } else {
         *pc = env->regs[15];
         flags = FIELD_DP32(flags, TBFLAG_A32, THUMB, env->thumb);
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b7b6ab63716..37a57af7150 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -13409,6 +13409,7 @@ static void aarch64_tr_init_disas_context(DisasContextBase *dcbase,
     dc->fp_excp_el = FIELD_EX32(tb_flags, TBFLAG_ANY, FPEXC_EL);
     dc->sve_excp_el = FIELD_EX32(tb_flags, TBFLAG_A64, SVEEXC_EL);
     dc->sve_len = (FIELD_EX32(tb_flags, TBFLAG_A64, ZCR_LEN) + 1) * 16;
+    dc->pauth_active = FIELD_EX32(tb_flags, TBFLAG_A64, PAUTH_ACTIVE);
     dc->vec_len = 0;
     dc->vec_stride = 0;
     dc->cp_regs = arm_cpu->cp_regs;
-- 
2.20.1