[06/11] target/arm: Update MSR access for PAN

Message ID 20191203225333.17055-7-richard.henderson@linaro.org
State New
Headers show
Series
  • target/arm: Implement ARMv8.1-PAN + ARMv8.2-ATS1E1
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Commit Message

Richard Henderson Dec. 3, 2019, 10:53 p.m.
For aarch64, there's a dedicated msr (imm, reg) insn.
For aarch32, this is done via msr to cpsr; and writes
from el0 are ignored.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

---
 target/arm/cpu.h           |  2 ++
 target/arm/helper.c        | 22 ++++++++++++++++++++++
 target/arm/translate-a64.c | 14 ++++++++++++++
 target/arm/translate.c     |  4 ++++
 4 files changed, 42 insertions(+)

-- 
2.17.1

Comments

Peter Maydell Dec. 6, 2019, 7:10 p.m. | #1
On Tue, 3 Dec 2019 at 22:53, Richard Henderson
<richard.henderson@linaro.org> wrote:
>

> For aarch64, there's a dedicated msr (imm, reg) insn.

> For aarch32, this is done via msr to cpsr; and writes

> from el0 are ignored.

>

> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

> ---

>  target/arm/cpu.h           |  2 ++

>  target/arm/helper.c        | 22 ++++++++++++++++++++++

>  target/arm/translate-a64.c | 14 ++++++++++++++

>  target/arm/translate.c     |  4 ++++

>  4 files changed, 42 insertions(+)

>

> diff --git a/target/arm/cpu.h b/target/arm/cpu.h

> index 170dd5b124..f0e61bf34f 100644

> --- a/target/arm/cpu.h

> +++ b/target/arm/cpu.h

> @@ -1159,6 +1159,7 @@ void pmu_init(ARMCPU *cpu);

>   * We will need to move AArch32 SS somewhere else at that point.

>   */

>  #define CPSR_RESERVED (1U << 21)

> +#define CPSR_PAN (1U << 22)

>  #define CPSR_J (1U << 24)

>  #define CPSR_IT_0_1 (3U << 25)

>  #define CPSR_Q (1U << 27)

> @@ -1225,6 +1226,7 @@ void pmu_init(ARMCPU *cpu);

>  #define PSTATE_BTYPE (3U << 10)

>  #define PSTATE_IL (1U << 20)

>  #define PSTATE_SS (1U << 21)

> +#define PSTATE_PAN (1U << 22)

>  #define PSTATE_V (1U << 28)

>  #define PSTATE_C (1U << 29)

>  #define PSTATE_Z (1U << 30)

> diff --git a/target/arm/helper.c b/target/arm/helper.c

> index 4e3fe00316..512be5c644 100644

> --- a/target/arm/helper.c

> +++ b/target/arm/helper.c

> @@ -4112,6 +4112,17 @@ static void aa64_daif_write(CPUARMState *env, const ARMCPRegInfo *ri,

>      env->daif = value & PSTATE_DAIF;

>  }

>

> +static uint64_t aa64_pan_read(CPUARMState *env, const ARMCPRegInfo *ri)

> +{

> +    return env->pstate & PSTATE_PAN;

> +}

> +

> +static void aa64_pan_write(CPUARMState *env, const ARMCPRegInfo *ri,

> +                           uint64_t value)

> +{

> +    env->pstate = (env->pstate & ~PSTATE_PAN) | (value & PSTATE_PAN);

> +}

> +

>  static CPAccessResult aa64_cacheop_access(CPUARMState *env,

>                                            const ARMCPRegInfo *ri,

>                                            bool isread)

> @@ -7405,6 +7416,17 @@ void register_cp_regs_for_features(ARMCPU *cpu)

>          define_arm_cp_regs(cpu, lor_reginfo);

>      }

>

> +    if (cpu_isar_feature(aa64_pan, cpu)) {

> +        static const ARMCPRegInfo pan_reginfo[] = {

> +            { .name = "PAN", .state = ARM_CP_STATE_AA64,

> +              .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 3,

> +              .type = ARM_CP_NO_RAW, .access = PL1_RW,

> +              .readfn = aa64_pan_read, .writefn = aa64_pan_write, },

> +            REGINFO_SENTINEL

> +        };


Same remarks about regdef as for UAO.

> +        define_arm_cp_regs(cpu, pan_reginfo);

> +    }

> +

>      if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {

>          static const ARMCPRegInfo vhe_reginfo[] = {

>              { .name = "CONTEXTIDR_EL2", .state = ARM_CP_STATE_AA64,

> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c

> index b5c7bc2d76..7f5a68106b 100644

> --- a/target/arm/translate-a64.c

> +++ b/target/arm/translate-a64.c

> @@ -1601,6 +1601,20 @@ static void handle_msr_i(DisasContext *s, uint32_t insn,

>          s->base.is_jmp = DISAS_NEXT;

>          break;

>

> +    case 0x04: /* PAN */

> +        if (!dc_isar_feature(aa64_pan, s) || s->current_el == 0) {

> +            goto do_unallocated;

> +        }

> +        if (crm & 1) {

> +            set_pstate_bits(PSTATE_PAN);

> +        } else {

> +            clear_pstate_bits(PSTATE_PAN);

> +        }

> +        t1 = tcg_const_i32(s->current_el);

> +        gen_helper_rebuild_hflags_a64(cpu_env, t1);

> +        tcg_temp_free_i32(t1);

> +        break;


and same question about whether we need to break the TB here.

> +

>      case 0x05: /* SPSel */

>          if (s->current_el == 0) {

>              goto do_unallocated;

> diff --git a/target/arm/translate.c b/target/arm/translate.c

> index 47a374b53d..98e6072dd4 100644

> --- a/target/arm/translate.c

> +++ b/target/arm/translate.c

> @@ -2785,6 +2785,10 @@ static int gen_set_psr(DisasContext *s, uint32_t mask, int spsr, TCGv_i32 t0)

>          tcg_gen_or_i32(tmp, tmp, t0);

>          store_cpu_field(tmp, spsr);

>      } else {

> +        /* Data writes to CPSR.PAN using an MSR insn at EL0 are ignored.  */

> +        if (IS_USER(s)) {

> +            mask &= ~CPSR_PAN;

> +        }


I think we should also ignore the write if the PAN feature
isn't present (see remark on earlier patch).

>          gen_set_cpsr(t0, mask);

>      }

>      tcg_temp_free_i32(t0);

> --

> 2.17.1




thanks
-- PMM

Patch

diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index 170dd5b124..f0e61bf34f 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1159,6 +1159,7 @@  void pmu_init(ARMCPU *cpu);
  * We will need to move AArch32 SS somewhere else at that point.
  */
 #define CPSR_RESERVED (1U << 21)
+#define CPSR_PAN (1U << 22)
 #define CPSR_J (1U << 24)
 #define CPSR_IT_0_1 (3U << 25)
 #define CPSR_Q (1U << 27)
@@ -1225,6 +1226,7 @@  void pmu_init(ARMCPU *cpu);
 #define PSTATE_BTYPE (3U << 10)
 #define PSTATE_IL (1U << 20)
 #define PSTATE_SS (1U << 21)
+#define PSTATE_PAN (1U << 22)
 #define PSTATE_V (1U << 28)
 #define PSTATE_C (1U << 29)
 #define PSTATE_Z (1U << 30)
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 4e3fe00316..512be5c644 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -4112,6 +4112,17 @@  static void aa64_daif_write(CPUARMState *env, const ARMCPRegInfo *ri,
     env->daif = value & PSTATE_DAIF;
 }
 
+static uint64_t aa64_pan_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+    return env->pstate & PSTATE_PAN;
+}
+
+static void aa64_pan_write(CPUARMState *env, const ARMCPRegInfo *ri,
+                           uint64_t value)
+{
+    env->pstate = (env->pstate & ~PSTATE_PAN) | (value & PSTATE_PAN);
+}
+
 static CPAccessResult aa64_cacheop_access(CPUARMState *env,
                                           const ARMCPRegInfo *ri,
                                           bool isread)
@@ -7405,6 +7416,17 @@  void register_cp_regs_for_features(ARMCPU *cpu)
         define_arm_cp_regs(cpu, lor_reginfo);
     }
 
+    if (cpu_isar_feature(aa64_pan, cpu)) {
+        static const ARMCPRegInfo pan_reginfo[] = {
+            { .name = "PAN", .state = ARM_CP_STATE_AA64,
+              .opc0 = 3, .opc1 = 0, .crn = 4, .crm = 2, .opc2 = 3,
+              .type = ARM_CP_NO_RAW, .access = PL1_RW,
+              .readfn = aa64_pan_read, .writefn = aa64_pan_write, },
+            REGINFO_SENTINEL
+        };
+        define_arm_cp_regs(cpu, pan_reginfo);
+    }
+
     if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {
         static const ARMCPRegInfo vhe_reginfo[] = {
             { .name = "CONTEXTIDR_EL2", .state = ARM_CP_STATE_AA64,
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index b5c7bc2d76..7f5a68106b 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1601,6 +1601,20 @@  static void handle_msr_i(DisasContext *s, uint32_t insn,
         s->base.is_jmp = DISAS_NEXT;
         break;
 
+    case 0x04: /* PAN */
+        if (!dc_isar_feature(aa64_pan, s) || s->current_el == 0) {
+            goto do_unallocated;
+        }
+        if (crm & 1) {
+            set_pstate_bits(PSTATE_PAN);
+        } else {
+            clear_pstate_bits(PSTATE_PAN);
+        }
+        t1 = tcg_const_i32(s->current_el);
+        gen_helper_rebuild_hflags_a64(cpu_env, t1);
+        tcg_temp_free_i32(t1);
+        break;
+
     case 0x05: /* SPSel */
         if (s->current_el == 0) {
             goto do_unallocated;
diff --git a/target/arm/translate.c b/target/arm/translate.c
index 47a374b53d..98e6072dd4 100644
--- a/target/arm/translate.c
+++ b/target/arm/translate.c
@@ -2785,6 +2785,10 @@  static int gen_set_psr(DisasContext *s, uint32_t mask, int spsr, TCGv_i32 t0)
         tcg_gen_or_i32(tmp, tmp, t0);
         store_cpu_field(tmp, spsr);
     } else {
+        /* Data writes to CPSR.PAN using an MSR insn at EL0 are ignored.  */
+        if (IS_USER(s)) {
+            mask &= ~CPSR_PAN;
+        }
         gen_set_cpsr(t0, mask);
     }
     tcg_temp_free_i32(t0);