[PATCH v3 1/1] target/arm: Trap PMCR when MDCR_EL2.TPMCR is set

[Smail AIDER via <qemu-devel@nongnu.org>]

From: Smail AIDER via <qemu-devel@nongnu.org>

Trap PMCR_EL0 or PMCR accesses to EL2 when MDCR_EL2.TPMCR is set.
Similar to MDCR_EL2.TPM, MDCR_EL2.TPMCR allows trapping EL0 and EL1
accesses to the PMCR register to EL2.

Signed-off-by: Smail AIDER <smail.aider@huawei.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250722131925.2119169-1-smail.aider@huawei.com>
---
 target/arm/cpregs-pmu.c | 33 +++++++++++++++++++++++++--------
 1 file changed, 25 insertions(+), 8 deletions(-)

diff --git a/target/arm/cpregs-pmu.c b/target/arm/cpregs-pmu.c
index 9c4431c18b..13392ddc4c 100644
--- a/target/arm/cpregs-pmu.c
+++ b/target/arm/cpregs-pmu.c
@@ -228,22 +228,27 @@ static bool event_supported(uint16_t number)
     return supported_event_map[number] != UNSUPPORTED_EVENT;
 }
 
-static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
-                                   bool isread)
+static CPAccessResult do_pmreg_access(CPUARMState *env, bool is_pmcr)
 {
     /*
      * Performance monitor registers user accessibility is controlled
-     * by PMUSERENR. MDCR_EL2.TPM and MDCR_EL3.TPM allow configurable
+     * by PMUSERENR. MDCR_EL2.TPM/TPMCR and MDCR_EL3.TPM allow configurable
      * trapping to EL2 or EL3 for other accesses.
      */
     int el = arm_current_el(env);
-    uint64_t mdcr_el2 = arm_mdcr_el2_eff(env);
 
     if (el == 0 && !(env->cp15.c9_pmuserenr & 1)) {
         return CP_ACCESS_TRAP_EL1;
     }
-    if (el < 2 && (mdcr_el2 & MDCR_TPM)) {
-        return CP_ACCESS_TRAP_EL2;
+    if (el < 2) {
+        uint64_t mdcr_el2 = arm_mdcr_el2_eff(env);
+
+        if (mdcr_el2 & MDCR_TPM) {
+            return CP_ACCESS_TRAP_EL2;
+        }
+        if (is_pmcr && (mdcr_el2 & MDCR_TPMCR)) {
+            return CP_ACCESS_TRAP_EL2;
+        }
     }
     if (el < 3 && (env->cp15.mdcr_el3 & MDCR_TPM)) {
         return CP_ACCESS_TRAP_EL3;
@@ -252,6 +257,18 @@ static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
     return CP_ACCESS_OK;
 }
 
+static CPAccessResult pmreg_access(CPUARMState *env, const ARMCPRegInfo *ri,
+                                   bool isread)
+{
+    return do_pmreg_access(env, false);
+}
+
+static CPAccessResult pmreg_access_pmcr(CPUARMState *env, const ARMCPRegInfo *ri,
+                                   bool isread)
+{
+    return do_pmreg_access(env, true);
+}
+
 static CPAccessResult pmreg_access_xevcntr(CPUARMState *env,
                                            const ARMCPRegInfo *ri,
                                            bool isread)
@@ -1187,14 +1204,14 @@ void define_pm_cpregs(ARMCPU *cpu)
             .fgt = FGT_PMCR_EL0,
             .type = ARM_CP_IO | ARM_CP_ALIAS,
             .fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmcr),
-            .accessfn = pmreg_access,
+            .accessfn = pmreg_access_pmcr,
             .readfn = pmcr_read, .raw_readfn = raw_read,
             .writefn = pmcr_write, .raw_writefn = raw_write,
         };
         const ARMCPRegInfo pmcr64 = {
             .name = "PMCR_EL0", .state = ARM_CP_STATE_AA64,
             .opc0 = 3, .opc1 = 3, .crn = 9, .crm = 12, .opc2 = 0,
-            .access = PL0_RW, .accessfn = pmreg_access,
+            .access = PL0_RW, .accessfn = pmreg_access_pmcr,
             .fgt = FGT_PMCR_EL0,
             .type = ARM_CP_IO,
             .fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
-- 
2.34.1