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authorJean-Philippe Brucker <jean-philippe@linaro.org>2023-12-19 17:57:50 +0000
committerPeter Maydell <peter.maydell@linaro.org>2023-12-19 18:03:32 +0000
commit6980c31dec42b6daebf7fec13b2d39ed87bb4766 (patch)
treedbfdf02c08ac122563872341018cbf1a52098e0d /target/arm/helper.c
parent47eac5d4237f217a09313a807b5ebb2ab784e0f7 (diff)
target/arm/helper: Propagate MDCR_EL2.HPMN into PMCR_EL0.N
MDCR_EL2.HPMN allows an hypervisor to limit the number of PMU counters available to EL1 and EL0 (to keep the others to itself). QEMU already implements this split correctly, except for PMCR_EL0.N reads: the number of counters read by EL1 or EL0 should be the one configured in MDCR_EL2.HPMN. Cc: qemu-stable@nongnu.org Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Message-id: 20231215144652.4193815-2-jean-philippe@linaro.org Reviewed-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Diffstat (limited to 'target/arm/helper.c')
-rw-r--r--target/arm/helper.c22
1 files changed, 20 insertions, 2 deletions
diff --git a/target/arm/helper.c b/target/arm/helper.c
index 436a43a4b7..fc546df5c7 100644
--- a/target/arm/helper.c
+++ b/target/arm/helper.c
@@ -1475,6 +1475,22 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri,
pmu_op_finish(env);
}
+static uint64_t pmcr_read(CPUARMState *env, const ARMCPRegInfo *ri)
+{
+ uint64_t pmcr = env->cp15.c9_pmcr;
+
+ /*
+ * If EL2 is implemented and enabled for the current security state, reads
+ * of PMCR.N from EL1 or EL0 return the value of MDCR_EL2.HPMN or HDCR.HPMN.
+ */
+ if (arm_current_el(env) <= 1 && arm_is_el2_enabled(env)) {
+ pmcr &= ~PMCRN_MASK;
+ pmcr |= (env->cp15.mdcr_el2 & MDCR_HPMN) << PMCRN_SHIFT;
+ }
+
+ return pmcr;
+}
+
static void pmswinc_write(CPUARMState *env, const ARMCPRegInfo *ri,
uint64_t value)
{
@@ -7158,8 +7174,9 @@ static void define_pmu_regs(ARMCPU *cpu)
.fgt = FGT_PMCR_EL0,
.type = ARM_CP_IO | ARM_CP_ALIAS,
.fieldoffset = offsetoflow32(CPUARMState, cp15.c9_pmcr),
- .accessfn = pmreg_access, .writefn = pmcr_write,
- .raw_writefn = raw_write,
+ .accessfn = pmreg_access,
+ .readfn = pmcr_read, .raw_readfn = raw_read,
+ .writefn = pmcr_write, .raw_writefn = raw_write,
};
ARMCPRegInfo pmcr64 = {
.name = "PMCR_EL0", .state = ARM_CP_STATE_AA64,
@@ -7169,6 +7186,7 @@ static void define_pmu_regs(ARMCPU *cpu)
.type = ARM_CP_IO,
.fieldoffset = offsetof(CPUARMState, cp15.c9_pmcr),
.resetvalue = cpu->isar.reset_pmcr_el0,
+ .readfn = pmcr_read, .raw_readfn = raw_read,
.writefn = pmcr_write, .raw_writefn = raw_write,
};