* [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing
@ 2021-01-28 4:45 Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate Rebecca Cran
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Rebecca Cran @ 2021-01-28 4:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Rebecca Cran, Richard Henderson
Add support for FEAT_DIT. DIT (Data Independent Timing) is a required
feature for ARMv8.4.
Changes from v2 to v3:
o Fixed PSTATE_SS patch:
- Reverted the singlestep removal.
- Fixed saving cpsr into spsr.
o Added DIT to the max 32-bit CPU.
Rebecca Cran (4):
target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate.
target/arm: Add support for FEAT_DIT, Data Independent Timing
target/arm: Set ID_AA64PFR0.DIT and ID_PFR0.DIT to 1 for "max" AA64
CPU
target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU
target/arm/cpu.c | 4 ++++
target/arm/cpu.h | 12 ++++++++++
target/arm/cpu64.c | 5 ++++
target/arm/helper-a64.c | 2 +-
target/arm/helper.c | 24 +++++++++++++++++++-
target/arm/internals.h | 6 +++++
target/arm/op_helper.c | 9 +-------
target/arm/translate-a64.c | 12 ++++++++++
8 files changed, 64 insertions(+), 10 deletions(-)
--
2.26.2
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate.
2021-01-28 4:45 [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
@ 2021-01-28 4:45 ` Rebecca Cran
2021-01-28 5:00 ` Richard Henderson
2021-01-28 4:45 ` [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Rebecca Cran @ 2021-01-28 4:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Rebecca Cran, Richard Henderson
cpsr has been treated as being the same as spsr, but it isn't.
Since PSTATE_SS isn't in cpsr, remove it and move it into env->pstate.
Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
---
target/arm/helper-a64.c | 2 +-
target/arm/helper.c | 2 +-
target/arm/op_helper.c | 9 +--------
3 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index c426c23d2c4e..a6b162049806 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -1001,7 +1001,7 @@ void HELPER(exception_return)(CPUARMState *env, uint64_t new_pc)
mask = aarch32_cpsr_valid_mask(env->features, &env_archcpu(env)->isar);
cpsr_write(env, spsr, mask, CPSRWriteRaw);
if (!arm_singlestep_active(env)) {
- env->uncached_cpsr &= ~PSTATE_SS;
+ env->pstate &= ~PSTATE_SS;
}
aarch64_sync_64_to_32(env);
diff --git a/target/arm/helper.c b/target/arm/helper.c
index d2ead3fcbdbd..7b7e72ba878c 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -9402,7 +9402,7 @@ static void take_aarch32_exception(CPUARMState *env, int new_mode,
* For exceptions taken to AArch32 we must clear the SS bit in both
* PSTATE and in the old-state value we save to SPSR_<mode>, so zero it now.
*/
- env->uncached_cpsr &= ~PSTATE_SS;
+ env->pstate &= ~PSTATE_SS;
env->spsr = cpsr_read(env);
/* Clear IT bits. */
env->condexec_bits = 0;
diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c
index 5e0f123043b5..65cb37d088f8 100644
--- a/target/arm/op_helper.c
+++ b/target/arm/op_helper.c
@@ -389,14 +389,7 @@ void HELPER(exception_bkpt_insn)(CPUARMState *env, uint32_t syndrome)
uint32_t HELPER(cpsr_read)(CPUARMState *env)
{
- /*
- * We store the ARMv8 PSTATE.SS bit in env->uncached_cpsr.
- * This is convenient for populating SPSR_ELx, but must be
- * hidden from aarch32 mode, where it is not visible.
- *
- * TODO: ARMv8.4-DIT -- need to move SS somewhere else.
- */
- return cpsr_read(env) & ~(CPSR_EXEC | PSTATE_SS);
+ return cpsr_read(env) & ~CPSR_EXEC;
}
void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)
--
2.26.2
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing
2021-01-28 4:45 [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate Rebecca Cran
@ 2021-01-28 4:45 ` Rebecca Cran
2021-01-28 5:06 ` Richard Henderson
2021-01-28 4:45 ` [PATCH v3 3/4] target/arm: Set ID_AA64PFR0.DIT and ID_PFR0.DIT to 1 for "max" AA64 CPU Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU Rebecca Cran
3 siblings, 1 reply; 10+ messages in thread
From: Rebecca Cran @ 2021-01-28 4:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Rebecca Cran, Richard Henderson
Add support for FEAT_DIT. DIT (Data Independent Timing) is a required
feature for ARMv8.4. Since virtual machine execution is largely
nondeterministic and TCG is outside of the security domain, it's
implemented as a NOP.
Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
target/arm/cpu.h | 12 +++++++++++
target/arm/helper.c | 22 ++++++++++++++++++++
target/arm/internals.h | 6 ++++++
target/arm/translate-a64.c | 12 +++++++++++
4 files changed, 52 insertions(+)
diff --git a/target/arm/cpu.h b/target/arm/cpu.h
index df0d6778330f..56b1053dfdec 100644
--- a/target/arm/cpu.h
+++ b/target/arm/cpu.h
@@ -1242,6 +1242,7 @@ void pmu_init(ARMCPU *cpu);
#define CPSR_IT_2_7 (0xfc00U)
#define CPSR_GE (0xfU << 16)
#define CPSR_IL (1U << 20)
+#define CPSR_DIT (1U << 21)
#define CPSR_PAN (1U << 22)
#define CPSR_J (1U << 24)
#define CPSR_IT_0_1 (3U << 25)
@@ -1309,6 +1310,7 @@ void pmu_init(ARMCPU *cpu);
#define PSTATE_SS (1U << 21)
#define PSTATE_PAN (1U << 22)
#define PSTATE_UAO (1U << 23)
+#define PSTATE_DIT (1U << 24)
#define PSTATE_TCO (1U << 25)
#define PSTATE_V (1U << 28)
#define PSTATE_C (1U << 29)
@@ -3875,6 +3877,11 @@ static inline bool isar_feature_aa32_tts2uxn(const ARMISARegisters *id)
return FIELD_EX32(id->id_mmfr4, ID_MMFR4, XNX) != 0;
}
+static inline bool isar_feature_aa32_dit(const ARMISARegisters *id)
+{
+ return FIELD_EX32(id->id_pfr0, ID_PFR0, DIT) != 0;
+}
+
/*
* 64-bit feature tests via id registers.
*/
@@ -4119,6 +4126,11 @@ static inline bool isar_feature_aa64_tts2uxn(const ARMISARegisters *id)
return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, XNX) != 0;
}
+static inline bool isar_feature_aa64_dit(const ARMISARegisters *id)
+{
+ return FIELD_EX64(id->id_aa64pfr0, ID_AA64PFR0, DIT) != 0;
+}
+
/*
* Feature tests for "does this exist in either 32-bit or 64-bit?"
*/
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 7b7e72ba878c..435208121e9f 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -4419,6 +4419,24 @@ static const ARMCPRegInfo uao_reginfo = {
.readfn = aa64_uao_read, .writefn = aa64_uao_write
};
+static uint64_t aa64_dit_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+ return env->pstate & PSTATE_DIT;
+}
+
+static void aa64_dit_write(CPUARMState *env, const ARMCPRegInfo *ri,
+ uint64_t value)
+{
+ env->pstate = (env->pstate & ~PSTATE_DIT) | (value & PSTATE_DIT);
+}
+
+static const ARMCPRegInfo dit_reginfo = {
+ .name = "DIT", .state = ARM_CP_STATE_AA64,
+ .opc0 = 3, .opc1 = 3, .crn = 4, .crm = 2, .opc2 = 5,
+ .type = ARM_CP_NO_RAW, .access = PL0_RW,
+ .readfn = aa64_dit_read, .writefn = aa64_dit_write
+};
+
static CPAccessResult aa64_cacheop_poc_access(CPUARMState *env,
const ARMCPRegInfo *ri,
bool isread)
@@ -8203,6 +8221,10 @@ void register_cp_regs_for_features(ARMCPU *cpu)
define_one_arm_cp_reg(cpu, &uao_reginfo);
}
+ if (cpu_isar_feature(aa64_dit, cpu)) {
+ define_one_arm_cp_reg(cpu, &dit_reginfo);
+ }
+
if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {
define_arm_cp_regs(cpu, vhe_reginfo);
}
diff --git a/target/arm/internals.h b/target/arm/internals.h
index 853fa88fd616..3d11e42d8e1b 100644
--- a/target/arm/internals.h
+++ b/target/arm/internals.h
@@ -1222,6 +1222,9 @@ static inline uint32_t aarch32_cpsr_valid_mask(uint64_t features,
if (isar_feature_aa32_pan(id)) {
valid |= CPSR_PAN;
}
+ if (isar_feature_aa32_dit(id)) {
+ valid |= CPSR_DIT;
+ }
return valid;
}
@@ -1240,6 +1243,9 @@ static inline uint32_t aarch64_pstate_valid_mask(const ARMISARegisters *id)
if (isar_feature_aa64_uao(id)) {
valid |= PSTATE_UAO;
}
+ if (isar_feature_aa64_dit(id)) {
+ valid |= PSTATE_DIT;
+ }
if (isar_feature_aa64_mte(id)) {
valid |= PSTATE_TCO;
}
diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
index ffc060e5d70c..1c4b8d02f3b8 100644
--- a/target/arm/translate-a64.c
+++ b/target/arm/translate-a64.c
@@ -1700,6 +1700,18 @@ static void handle_msr_i(DisasContext *s, uint32_t insn,
tcg_temp_free_i32(t1);
break;
+ case 0x1a: /* DIT */
+ if (!dc_isar_feature(aa64_dit, s)) {
+ goto do_unallocated;
+ }
+ if (crm & 1) {
+ set_pstate_bits(PSTATE_DIT);
+ } else {
+ clear_pstate_bits(PSTATE_DIT);
+ }
+ /* There's no need to rebuild hflags because DIT is a nop */
+ break;
+
case 0x1e: /* DAIFSet */
t1 = tcg_const_i32(crm);
gen_helper_msr_i_daifset(cpu_env, t1);
--
2.26.2
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v3 3/4] target/arm: Set ID_AA64PFR0.DIT and ID_PFR0.DIT to 1 for "max" AA64 CPU
2021-01-28 4:45 [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
@ 2021-01-28 4:45 ` Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU Rebecca Cran
3 siblings, 0 replies; 10+ messages in thread
From: Rebecca Cran @ 2021-01-28 4:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Rebecca Cran, Richard Henderson
Enable FEAT_DIT for the "max" AARCH64 CPU.
Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
---
target/arm/cpu64.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/target/arm/cpu64.c b/target/arm/cpu64.c
index 5e851028c592..9a5cfd4fc632 100644
--- a/target/arm/cpu64.c
+++ b/target/arm/cpu64.c
@@ -666,6 +666,7 @@ static void aarch64_max_initfn(Object *obj)
t = FIELD_DP64(t, ID_AA64PFR0, FP, 1);
t = FIELD_DP64(t, ID_AA64PFR0, ADVSIMD, 1);
t = FIELD_DP64(t, ID_AA64PFR0, SEL2, 1);
+ t = FIELD_DP64(t, ID_AA64PFR0, DIT, 1);
cpu->isar.id_aa64pfr0 = t;
t = cpu->isar.id_aa64pfr1;
@@ -715,6 +716,10 @@ static void aarch64_max_initfn(Object *obj)
u = FIELD_DP32(u, ID_ISAR6, SPECRES, 1);
cpu->isar.id_isar6 = u;
+ u = cpu->isar.id_pfr0;
+ u = FIELD_DP32(u, ID_PFR0, DIT, 1);
+ cpu->isar.id_pfr0 = u;
+
u = cpu->isar.id_mmfr3;
u = FIELD_DP32(u, ID_MMFR3, PAN, 2); /* ATS1E1 */
cpu->isar.id_mmfr3 = u;
--
2.26.2
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU
2021-01-28 4:45 [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
` (2 preceding siblings ...)
2021-01-28 4:45 ` [PATCH v3 3/4] target/arm: Set ID_AA64PFR0.DIT and ID_PFR0.DIT to 1 for "max" AA64 CPU Rebecca Cran
@ 2021-01-28 4:45 ` Rebecca Cran
2021-01-28 5:07 ` Richard Henderson
3 siblings, 1 reply; 10+ messages in thread
From: Rebecca Cran @ 2021-01-28 4:45 UTC (permalink / raw)
To: qemu-devel; +Cc: Peter Maydell, Rebecca Cran, Richard Henderson
Enable FEAT_DIT for the "max" 32-bit CPU.
Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
---
target/arm/cpu.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/target/arm/cpu.c b/target/arm/cpu.c
index 40142ac141e5..c98f44624423 100644
--- a/target/arm/cpu.c
+++ b/target/arm/cpu.c
@@ -2197,6 +2197,10 @@ static void arm_max_initfn(Object *obj)
t = FIELD_DP32(t, ID_MMFR4, CNP, 1); /* TTCNP */
t = FIELD_DP32(t, ID_MMFR4, XNX, 1); /* TTS2UXN */
cpu->isar.id_mmfr4 = t;
+
+ t = cpu->isar.id_pfr0;
+ t = FIELD_DP32(t, ID_PFR0, DIT, 1);
+ cpu->isar.id_pfr0 = t;
}
#endif
}
--
2.26.2
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate.
2021-01-28 4:45 ` [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate Rebecca Cran
@ 2021-01-28 5:00 ` Richard Henderson
0 siblings, 0 replies; 10+ messages in thread
From: Richard Henderson @ 2021-01-28 5:00 UTC (permalink / raw)
To: Rebecca Cran, qemu-devel; +Cc: Peter Maydell
On 1/27/21 6:45 PM, Rebecca Cran wrote:
> cpsr has been treated as being the same as spsr, but it isn't.
> Since PSTATE_SS isn't in cpsr, remove it and move it into env->pstate.
>
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
> ---
> target/arm/helper-a64.c | 2 +-
> target/arm/helper.c | 2 +-
> target/arm/op_helper.c | 9 +--------
> 3 files changed, 3 insertions(+), 10 deletions(-)
Missing a change to cpu_get_tb_cpu_state to remove pstate_for_ss and simply use
env->pstate.
r~
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing
2021-01-28 4:45 ` [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
@ 2021-01-28 5:06 ` Richard Henderson
2021-02-02 22:21 ` Rebecca Cran
0 siblings, 1 reply; 10+ messages in thread
From: Richard Henderson @ 2021-01-28 5:06 UTC (permalink / raw)
To: Rebecca Cran, qemu-devel; +Cc: Peter Maydell
On 1/27/21 6:45 PM, Rebecca Cran wrote:
> Add support for FEAT_DIT. DIT (Data Independent Timing) is a required
> feature for ARMv8.4. Since virtual machine execution is largely
> nondeterministic and TCG is outside of the security domain, it's
> implemented as a NOP.
>
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This misses the convert from AA32 CPSR to AA64 SPSR on exception entry (and
vice-versa on return).
In particular: CPSR.DIT (bit 21) -> SPSR_EL1.DIT (bit 24), and merging
PSTATE.SS into SPSR_EL1.SS (bit 21).
r~
> ---
> target/arm/cpu.h | 12 +++++++++++
> target/arm/helper.c | 22 ++++++++++++++++++++
> target/arm/internals.h | 6 ++++++
> target/arm/translate-a64.c | 12 +++++++++++
> 4 files changed, 52 insertions(+)
>
> diff --git a/target/arm/cpu.h b/target/arm/cpu.h
> index df0d6778330f..56b1053dfdec 100644
> --- a/target/arm/cpu.h
> +++ b/target/arm/cpu.h
> @@ -1242,6 +1242,7 @@ void pmu_init(ARMCPU *cpu);
> #define CPSR_IT_2_7 (0xfc00U)
> #define CPSR_GE (0xfU << 16)
> #define CPSR_IL (1U << 20)
> +#define CPSR_DIT (1U << 21)
> #define CPSR_PAN (1U << 22)
> #define CPSR_J (1U << 24)
> #define CPSR_IT_0_1 (3U << 25)
> @@ -1309,6 +1310,7 @@ void pmu_init(ARMCPU *cpu);
> #define PSTATE_SS (1U << 21)
> #define PSTATE_PAN (1U << 22)
> #define PSTATE_UAO (1U << 23)
> +#define PSTATE_DIT (1U << 24)
> #define PSTATE_TCO (1U << 25)
> #define PSTATE_V (1U << 28)
> #define PSTATE_C (1U << 29)
> @@ -3875,6 +3877,11 @@ static inline bool isar_feature_aa32_tts2uxn(const ARMISARegisters *id)
> return FIELD_EX32(id->id_mmfr4, ID_MMFR4, XNX) != 0;
> }
>
> +static inline bool isar_feature_aa32_dit(const ARMISARegisters *id)
> +{
> + return FIELD_EX32(id->id_pfr0, ID_PFR0, DIT) != 0;
> +}
> +
> /*
> * 64-bit feature tests via id registers.
> */
> @@ -4119,6 +4126,11 @@ static inline bool isar_feature_aa64_tts2uxn(const ARMISARegisters *id)
> return FIELD_EX64(id->id_aa64mmfr1, ID_AA64MMFR1, XNX) != 0;
> }
>
> +static inline bool isar_feature_aa64_dit(const ARMISARegisters *id)
> +{
> + return FIELD_EX64(id->id_aa64pfr0, ID_AA64PFR0, DIT) != 0;
> +}
> +
> /*
> * Feature tests for "does this exist in either 32-bit or 64-bit?"
> */
> diff --git a/target/arm/helper.c b/target/arm/helper.c
> index 7b7e72ba878c..435208121e9f 100644
> --- a/target/arm/helper.c
> +++ b/target/arm/helper.c
> @@ -4419,6 +4419,24 @@ static const ARMCPRegInfo uao_reginfo = {
> .readfn = aa64_uao_read, .writefn = aa64_uao_write
> };
>
> +static uint64_t aa64_dit_read(CPUARMState *env, const ARMCPRegInfo *ri)
> +{
> + return env->pstate & PSTATE_DIT;
> +}
> +
> +static void aa64_dit_write(CPUARMState *env, const ARMCPRegInfo *ri,
> + uint64_t value)
> +{
> + env->pstate = (env->pstate & ~PSTATE_DIT) | (value & PSTATE_DIT);
> +}
> +
> +static const ARMCPRegInfo dit_reginfo = {
> + .name = "DIT", .state = ARM_CP_STATE_AA64,
> + .opc0 = 3, .opc1 = 3, .crn = 4, .crm = 2, .opc2 = 5,
> + .type = ARM_CP_NO_RAW, .access = PL0_RW,
> + .readfn = aa64_dit_read, .writefn = aa64_dit_write
> +};
> +
> static CPAccessResult aa64_cacheop_poc_access(CPUARMState *env,
> const ARMCPRegInfo *ri,
> bool isread)
> @@ -8203,6 +8221,10 @@ void register_cp_regs_for_features(ARMCPU *cpu)
> define_one_arm_cp_reg(cpu, &uao_reginfo);
> }
>
> + if (cpu_isar_feature(aa64_dit, cpu)) {
> + define_one_arm_cp_reg(cpu, &dit_reginfo);
> + }
> +
> if (arm_feature(env, ARM_FEATURE_EL2) && cpu_isar_feature(aa64_vh, cpu)) {
> define_arm_cp_regs(cpu, vhe_reginfo);
> }
> diff --git a/target/arm/internals.h b/target/arm/internals.h
> index 853fa88fd616..3d11e42d8e1b 100644
> --- a/target/arm/internals.h
> +++ b/target/arm/internals.h
> @@ -1222,6 +1222,9 @@ static inline uint32_t aarch32_cpsr_valid_mask(uint64_t features,
> if (isar_feature_aa32_pan(id)) {
> valid |= CPSR_PAN;
> }
> + if (isar_feature_aa32_dit(id)) {
> + valid |= CPSR_DIT;
> + }
>
> return valid;
> }
> @@ -1240,6 +1243,9 @@ static inline uint32_t aarch64_pstate_valid_mask(const ARMISARegisters *id)
> if (isar_feature_aa64_uao(id)) {
> valid |= PSTATE_UAO;
> }
> + if (isar_feature_aa64_dit(id)) {
> + valid |= PSTATE_DIT;
> + }
> if (isar_feature_aa64_mte(id)) {
> valid |= PSTATE_TCO;
> }
> diff --git a/target/arm/translate-a64.c b/target/arm/translate-a64.c
> index ffc060e5d70c..1c4b8d02f3b8 100644
> --- a/target/arm/translate-a64.c
> +++ b/target/arm/translate-a64.c
> @@ -1700,6 +1700,18 @@ static void handle_msr_i(DisasContext *s, uint32_t insn,
> tcg_temp_free_i32(t1);
> break;
>
> + case 0x1a: /* DIT */
> + if (!dc_isar_feature(aa64_dit, s)) {
> + goto do_unallocated;
> + }
> + if (crm & 1) {
> + set_pstate_bits(PSTATE_DIT);
> + } else {
> + clear_pstate_bits(PSTATE_DIT);
> + }
> + /* There's no need to rebuild hflags because DIT is a nop */
> + break;
> +
> case 0x1e: /* DAIFSet */
> t1 = tcg_const_i32(crm);
> gen_helper_msr_i_daifset(cpu_env, t1);
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU
2021-01-28 4:45 ` [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU Rebecca Cran
@ 2021-01-28 5:07 ` Richard Henderson
0 siblings, 0 replies; 10+ messages in thread
From: Richard Henderson @ 2021-01-28 5:07 UTC (permalink / raw)
To: Rebecca Cran, qemu-devel; +Cc: Peter Maydell
On 1/27/21 6:45 PM, Rebecca Cran wrote:
> Enable FEAT_DIT for the "max" 32-bit CPU.
>
> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
> ---
> target/arm/cpu.c | 4 ++++
> 1 file changed, 4 insertions(+)
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing
2021-01-28 5:06 ` Richard Henderson
@ 2021-02-02 22:21 ` Rebecca Cran
2021-02-03 0:11 ` Richard Henderson
0 siblings, 1 reply; 10+ messages in thread
From: Rebecca Cran @ 2021-02-02 22:21 UTC (permalink / raw)
To: Richard Henderson, qemu-devel; +Cc: Peter Maydell
On 1/27/21 10:06 PM, Richard Henderson wrote:
> On 1/27/21 6:45 PM, Rebecca Cran wrote:
>> Add support for FEAT_DIT. DIT (Data Independent Timing) is a required
>> feature for ARMv8.4. Since virtual machine execution is largely
>> nondeterministic and TCG is outside of the security domain, it's
>> implemented as a NOP.
>>
>> Signed-off-by: Rebecca Cran <rebecca@nuviainc.com>
>> Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
>
>
> This misses the convert from AA32 CPSR to AA64 SPSR on exception entry (and
> vice-versa on return).
>
> In particular: CPSR.DIT (bit 21) -> SPSR_EL1.DIT (bit 24), and merging
> PSTATE.SS into SPSR_EL1.SS (bit 21).
Thanks. I _think_ I'm understanding it better now. Would the following
work? I don't see where I need to map PSTATE.SS into SPSR_EL1.SS though,
because isn't that handled automatically since PSTATE maps onto SPSR?
diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
index a6b162049806..c1ff24d42f32 100644
--- a/target/arm/helper-a64.c
+++ b/target/arm/helper-a64.c
@@ -1003,6 +1003,11 @@ void HELPER(exception_return)(CPUARMState *env,
uint64_t new_pc)
if (!arm_singlestep_active(env)) {
env->pstate &= ~PSTATE_SS;
}
+
+ if (spsr & PSTATE_DIT) {
+ env->uncached_cpsr |= CPSR_DIT;
+ }
+
aarch64_sync_64_to_32(env);
if (spsr & CPSR_T) {
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 54ac1f476940..1ecfd63d8f70 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -9426,6 +9426,12 @@ static void take_aarch32_exception(CPUARMState
*env, int new_mode,
*/
env->pstate &= ~PSTATE_SS;
env->spsr = cpsr_read(env);
+
+ if (env->uncached_cpsr & CPSR_DIT) {
+ env->spsr |= PSTATE_DIT;
+ env->spsr &= ~PSTATE_SS;
+ }
+
/* Clear IT bits. */
env->condexec_bits = 0;
/* Switch to the new mode, and to the correct instruction set. */
@@ -9905,6 +9911,11 @@ static void arm_cpu_do_interrupt_aarch64(CPUState
*cs)
old_mode = cpsr_read(env);
env->elr_el[new_el] = env->regs[15];
+ if (old_mode & CPSR_DIT) {
+ old_mode |= PSTATE_DIT;
+ old_mode &= ~PSTATE_SS;
+ }
+
aarch64_sync_32_to_64(env);
env->condexec_bits = 0;
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing
2021-02-02 22:21 ` Rebecca Cran
@ 2021-02-03 0:11 ` Richard Henderson
0 siblings, 0 replies; 10+ messages in thread
From: Richard Henderson @ 2021-02-03 0:11 UTC (permalink / raw)
To: Rebecca Cran, qemu-devel; +Cc: Peter Maydell
On 2/2/21 12:21 PM, Rebecca Cran wrote:
> On 1/27/21 10:06 PM, Richard Henderson wrote:
>> In particular: CPSR.DIT (bit 21) -> SPSR_EL1.DIT (bit 24), and merging
>> PSTATE.SS into SPSR_EL1.SS (bit 21).
>
> Thanks. I _think_ I'm understanding it better now. Would the following work? I
> don't see where I need to map PSTATE.SS into SPSR_EL1.SS though, because isn't
> that handled automatically since PSTATE maps onto SPSR?
>
>
> diff --git a/target/arm/helper-a64.c b/target/arm/helper-a64.c
> index a6b162049806..c1ff24d42f32 100644
> --- a/target/arm/helper-a64.c
> +++ b/target/arm/helper-a64.c
> @@ -1003,6 +1003,11 @@ void HELPER(exception_return)(CPUARMState *env, uint64_t
> new_pc)
> if (!arm_singlestep_active(env)) {
> env->pstate &= ~PSTATE_SS;
> }
> +
> + if (spsr & PSTATE_DIT) {
> + env->uncached_cpsr |= CPSR_DIT;
> + }
This is missing the restore of PSTATE_SS for when singlestep *is* active.
> @@ -9426,6 +9426,12 @@ static void take_aarch32_exception(CPUARMState *env, int
> new_mode,
> */
> env->pstate &= ~PSTATE_SS;
> env->spsr = cpsr_read(env);
> +
> + if (env->uncached_cpsr & CPSR_DIT) {
> + env->spsr |= PSTATE_DIT;
> + env->spsr &= ~PSTATE_SS;
> + }
This one is incorrect because we're not storing to SPSR_ELx format, but SPSR
(the aa32 version), which has DIT at bit 21.
> @@ -9905,6 +9911,11 @@ static void arm_cpu_do_interrupt_aarch64(CPUState *cs)
> old_mode = cpsr_read(env);
> env->elr_el[new_el] = env->regs[15];
>
> + if (old_mode & CPSR_DIT) {
> + old_mode |= PSTATE_DIT;
> + old_mode &= ~PSTATE_SS;
This line would be clearer using CPSR_DIT. I don't see PSTATE_SS being added
to old_mode. Is that somewhere else, or simply missing context here?
I think it would be clearer to add some new helpers. Naming is always
difficult, but how about:
static uint32_t cpsr_read_for_spsr_elx(CPUARMState *env)
{
uint32_t ret = cpsr_read(env);
/* Move DIT to the correct location for SPSR_ELx */
if (ret & CPSR_DIT) {
ret &= ~CPSR_DIT;
ret |= PSTATE_DIT;
}
/* Merge PSTATE.SS into SPSR_ELx */
ret |= env->pstate & PSTATE_SS;
return ret;
}
static void cpsr_write_from_spsr_elx(CPUARMState *env,
uint32_t val)
{
uint32_t mask;
/* Save SPSR_ELx.SS into PSTATE. */
env->pstate = (env->pstate & ~PSTATE_SS) | (val & PSTATE_SS);
val &= ~PSTATE_SS;
/* Move DIT to the correct location for CPSR */
if (val & PSTATE_DIT) {
val &= ~PSTATE_DIT;
val |= CPSR_DIT;
}
mask = aarch32_cpsr_valid_mask(env->features, \
&env_archcpu(env)->isar);
cpsr_write(env, val, mask, CPSRWriteRaw);
}
r~
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2021-02-03 0:12 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-01-28 4:45 [PATCH v3 0/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 1/4] target/arm: Remove PSTATE_SS from cpsr and move it into env->pstate Rebecca Cran
2021-01-28 5:00 ` Richard Henderson
2021-01-28 4:45 ` [PATCH v3 2/4] target/arm: Add support for FEAT_DIT, Data Independent Timing Rebecca Cran
2021-01-28 5:06 ` Richard Henderson
2021-02-02 22:21 ` Rebecca Cran
2021-02-03 0:11 ` Richard Henderson
2021-01-28 4:45 ` [PATCH v3 3/4] target/arm: Set ID_AA64PFR0.DIT and ID_PFR0.DIT to 1 for "max" AA64 CPU Rebecca Cran
2021-01-28 4:45 ` [PATCH v3 4/4] target/arm: Set ID_PFR0.DIT to 1 for "max" 32-bit CPU Rebecca Cran
2021-01-28 5:07 ` Richard Henderson
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