[PATCH v5 15/22] RISC-V: KVM: Improve firmware counter read function

[Atish Patra]

Rename the function to indicate that it is meant for firmware
counter read. While at it, add a range sanity check for it as
well.

Signed-off-by: Atish Patra <ati...@rivosinc.com>
---
 arch/riscv/include/asm/kvm_vcpu_pmu.h | 2 +-
 arch/riscv/kvm/vcpu_pmu.c             | 7 ++++++-
 arch/riscv/kvm/vcpu_sbi_pmu.c         | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h 
b/arch/riscv/include/asm/kvm_vcpu_pmu.h
index 55861b5d3382..fa0f535bbbf0 100644
--- a/arch/riscv/include/asm/kvm_vcpu_pmu.h
+++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h
@@ -89,7 +89,7 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, 
unsigned long ctr_ba
                                     unsigned long ctr_mask, unsigned long 
flags,
                                     unsigned long eidx, u64 evtdata,
                                     struct kvm_vcpu_sbi_return *retdata);
-int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
+int kvm_riscv_vcpu_pmu_fw_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
                                struct kvm_vcpu_sbi_return *retdata);
 int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu *vcpu, unsigned long 
cidx,
                                      struct kvm_vcpu_sbi_return *retdata);
diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index ff326152eeff..94efa88d054d 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -235,6 +235,11 @@ static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned 
long cidx,
        u64 enabled, running;
        int fevent_code;
 
+       if (cidx >= kvm_pmu_num_counters(kvpmu) || cidx == 1) {
+               pr_warn("Invalid counter id [%ld] during read\n", cidx);
+               return -EINVAL;
+       }
+
        pmc = &kvpmu->pmc[cidx];
 
        if (pmc->cinfo.type == SBI_PMU_CTR_TYPE_FW) {
@@ -747,7 +752,7 @@ int kvm_riscv_vcpu_pmu_fw_ctr_read_hi(struct kvm_vcpu 
*vcpu, unsigned long cidx,
        return 0;
 }
 
-int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
+int kvm_riscv_vcpu_pmu_fw_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
                                struct kvm_vcpu_sbi_return *retdata)
 {
        int ret;
diff --git a/arch/riscv/kvm/vcpu_sbi_pmu.c b/arch/riscv/kvm/vcpu_sbi_pmu.c
index cf111de51bdb..e4be34e03e83 100644
--- a/arch/riscv/kvm/vcpu_sbi_pmu.c
+++ b/arch/riscv/kvm/vcpu_sbi_pmu.c
@@ -62,7 +62,7 @@ static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, 
struct kvm_run *run,
                ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2, 
retdata);
                break;
        case SBI_EXT_PMU_COUNTER_FW_READ:
-               ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, retdata);
+               ret = kvm_riscv_vcpu_pmu_fw_ctr_read(vcpu, cp->a0, retdata);
                break;
        case SBI_EXT_PMU_COUNTER_FW_READ_HI:
                if (IS_ENABLED(CONFIG_32BIT))
-- 
2.34.1