FEAT_FGT also implements an extra trap bit in the MDCR_EL2 and MDCR_EL3 registers: bit TDCC enables trapping of use of the Debug Comms Channel registers OSDTRRX_EL1, OSDTRTX_EL1, MDCCSR_EL0, MDCCINT_EL0, DBGDTR_EL0, DBGDTRRX_EL0 and DBGDTRTX_EL0 (and their AArch32 equivalents). This trapping is independent of whether fine-grained traps are enabled or not.
Implement these extra traps. (We don't implement DBGDTR_EL0, DBGDTRRX_EL0 and DBGDTRTX_EL0.) Signed-off-by: Peter Maydell <peter.mayd...@linaro.org> Reviewed-by: Richard Henderson <richard.hender...@linaro.org> Tested-by: Fuad Tabba <ta...@google.com> Message-id: 20230130182459.3309057-23-peter.mayd...@linaro.org Message-id: 20230127175507.2895013-23-peter.mayd...@linaro.org --- target/arm/debug_helper.c | 35 +++++++++++++++++++++++++++++++---- 1 file changed, 31 insertions(+), 4 deletions(-) diff --git a/target/arm/debug_helper.c b/target/arm/debug_helper.c index b106746b0e1..3c671c88c1a 100644 --- a/target/arm/debug_helper.c +++ b/target/arm/debug_helper.c @@ -599,6 +599,33 @@ static CPAccessResult access_tda(CPUARMState *env, const ARMCPRegInfo *ri, return CP_ACCESS_OK; } +/* + * Check for traps to Debug Comms Channel registers. If FEAT_FGT + * is implemented then these are controlled by MDCR_EL2.TDCC for + * EL2 and MDCR_EL3.TDCC for EL3. They are also controlled by + * the general debug access trap bits MDCR_EL2.TDA and MDCR_EL3.TDA. + */ +static CPAccessResult access_tdcc(CPUARMState *env, const ARMCPRegInfo *ri, + bool isread) +{ + int el = arm_current_el(env); + uint64_t mdcr_el2 = arm_mdcr_el2_eff(env); + bool mdcr_el2_tda = (mdcr_el2 & MDCR_TDA) || (mdcr_el2 & MDCR_TDE) || + (arm_hcr_el2_eff(env) & HCR_TGE); + bool mdcr_el2_tdcc = cpu_isar_feature(aa64_fgt, env_archcpu(env)) && + (mdcr_el2 & MDCR_TDCC); + bool mdcr_el3_tdcc = cpu_isar_feature(aa64_fgt, env_archcpu(env)) && + (env->cp15.mdcr_el3 & MDCR_TDCC); + + if (el < 2 && (mdcr_el2_tda || mdcr_el2_tdcc)) { + return CP_ACCESS_TRAP_EL2; + } + if (el < 3 && ((env->cp15.mdcr_el3 & MDCR_TDA) || mdcr_el3_tdcc)) { + return CP_ACCESS_TRAP_EL3; + } + return CP_ACCESS_OK; +} + static void oslar_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { @@ -681,7 +708,7 @@ static const ARMCPRegInfo debug_cp_reginfo[] = { */ { .name = "MDCCSR_EL0", .state = ARM_CP_STATE_AA64, .opc0 = 2, .opc1 = 3, .crn = 0, .crm = 1, .opc2 = 0, - .access = PL0_R, .accessfn = access_tda, + .access = PL0_R, .accessfn = access_tdcc, .type = ARM_CP_CONST, .resetvalue = 0 }, /* * OSDTRRX_EL1/OSDTRTX_EL1 are used for save and restore of DBGDTRRX_EL0. @@ -689,11 +716,11 @@ static const ARMCPRegInfo debug_cp_reginfo[] = { */ { .name = "OSDTRRX_EL1", .state = ARM_CP_STATE_BOTH, .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = 0, .opc2 = 2, - .access = PL1_RW, .accessfn = access_tda, + .access = PL1_RW, .accessfn = access_tdcc, .type = ARM_CP_CONST, .resetvalue = 0 }, { .name = "OSDTRTX_EL1", .state = ARM_CP_STATE_BOTH, .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = 3, .opc2 = 2, - .access = PL1_RW, .accessfn = access_tda, + .access = PL1_RW, .accessfn = access_tdcc, .type = ARM_CP_CONST, .resetvalue = 0 }, /* * OSECCR_EL1 provides a mechanism for an operating system @@ -757,7 +784,7 @@ static const ARMCPRegInfo debug_cp_reginfo[] = { */ { .name = "MDCCINT_EL1", .state = ARM_CP_STATE_BOTH, .cp = 14, .opc0 = 2, .opc1 = 0, .crn = 0, .crm = 2, .opc2 = 0, - .access = PL1_RW, .accessfn = access_tda, + .access = PL1_RW, .accessfn = access_tdcc, .type = ARM_CP_NOP }, /* * Dummy DBGCLAIM registers. -- 2.34.1