target/riscv: Mask out upper sscofpmf bits during validation

As per the ISA definition, the upper 8 bits in hpmevent are defined
by Sscofpmf for privilege mode filtering and overflow bits while the
lower 56 bits are desginated for platform specific hpmevent values.
For the reset case, mhpmevent value should have zero in lower 56 bits.
Software may set the OF bit to indicate disable interrupt.

Ensure that correct value is checked after masking while clearing the
event encodings.

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Atish Patra <atishp@rivosinc.com>
Message-ID: <20250206-pmu_minor_fixes-v2-2-1bb0f4aeb8b4@rivosinc.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

diff --git a/target/riscv/pmu.c b/target/riscv/pmu.c
index cf713663ee56f87d426a80ecdb597a351b33bb2f..0408f96e6af8a5258178931540200fc0ebb11df7 100644 (file)
--- a/target/riscv/pmu.c
+++ b/target/riscv/pmu.c
@@ -390,7 +390,7 @@ int riscv_pmu_update_event_map(CPURISCVState *env, uint64_t value,
      * Expected mhpmevent value is zero for reset case. Remove the current
      * mapping.
      */
-    if (!value) {
+    if (!(value & MHPMEVENT_IDX_MASK)) {
         g_hash_table_foreach_remove(cpu->pmu_event_ctr_map,
                                     pmu_remove_event_map,
                                     GUINT_TO_POINTER(ctr_idx));