[PATCH 2/3] RISC-V: KVM: Update firmware counters for various events

From: Atish Patra
Date: Thu Dec 12 2024 - 15:57:21 EST


SBI PMU specification defines few firmware counters which can be
used by the guests to collect the statstics about various traps
occurred in the host.

Update these counters whenever a corresponding trap is taken

Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
---
arch/riscv/kvm/vcpu_exit.c | 31 +++++++++++++++++++++++++++----
1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_exit.c b/arch/riscv/kvm/vcpu_exit.c
index c9f8b2094554..acdcd619797e 100644
--- a/arch/riscv/kvm/vcpu_exit.c
+++ b/arch/riscv/kvm/vcpu_exit.c
@@ -165,6 +165,17 @@ void kvm_riscv_vcpu_trap_redirect(struct kvm_vcpu *vcpu,
vcpu->arch.guest_context.sstatus |= SR_SPP;
}

+static inline int vcpu_redirect(struct kvm_vcpu *vcpu, struct kvm_cpu_trap *trap)
+{
+ int ret = -EFAULT;
+
+ if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
+ kvm_riscv_vcpu_trap_redirect(vcpu, trap);
+ ret = 1;
+ }
+ return ret;
+}
+
/*
* Return > 0 to return to guest, < 0 on error, 0 (and set exit_reason) on
* proper exit to userspace.
@@ -183,15 +194,27 @@ int kvm_riscv_vcpu_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
run->exit_reason = KVM_EXIT_UNKNOWN;
switch (trap->scause) {
case EXC_INST_ILLEGAL:
+ kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ILLEGAL_INSN);
+ ret = vcpu_redirect(vcpu, trap);
+ break;
case EXC_LOAD_MISALIGNED:
+ kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_LOAD);
+ ret = vcpu_redirect(vcpu, trap);
+ break;
case EXC_STORE_MISALIGNED:
+ kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_MISALIGNED_STORE);
+ ret = vcpu_redirect(vcpu, trap);
+ break;
case EXC_LOAD_ACCESS:
+ kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_LOAD);
+ ret = vcpu_redirect(vcpu, trap);
+ break;
case EXC_STORE_ACCESS:
+ kvm_riscv_vcpu_pmu_incr_fw(vcpu, SBI_PMU_FW_ACCESS_STORE);
+ ret = vcpu_redirect(vcpu, trap);
+ break;
case EXC_INST_ACCESS:
- if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV) {
- kvm_riscv_vcpu_trap_redirect(vcpu, trap);
- ret = 1;
- }
+ ret = vcpu_redirect(vcpu, trap);
break;
case EXC_VIRTUAL_INST_FAULT:
if (vcpu->arch.guest_context.hstatus & HSTATUS_SPV)

--
2.34.1