From: Atish Patra <atishp@rivosinc.com>
To: linux-kernel@vger.kernel.org
Cc: Atish Patra <atishp@rivosinc.com>,
Anup Patel <anup@brainfault.org>,
Andrew Jones <ajones@ventanamicro.com>,
Atish Patra <atishp@atishpatra.org>, Guo Ren <guoren@kernel.org>,
kvm-riscv@lists.infradead.org, kvm@vger.kernel.org,
linux-riscv@lists.infradead.org,
Mark Rutland <mark.rutland@arm.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Sergey Matyukevich <sergey.matyukevich@syntacore.com>,
Eric Lin <eric.lin@sifive.com>, Will Deacon <will@kernel.org>
Subject: [PATCH v2 09/11] RISC-V: KVM: Implement trap & emulate for hpmcounters
Date: Thu, 15 Dec 2022 09:00:44 -0800 [thread overview]
Message-ID: <20221215170046.2010255-10-atishp@rivosinc.com> (raw)
In-Reply-To: <20221215170046.2010255-1-atishp@rivosinc.com>
As the KVM guests only see the virtual PMU counters, all hpmcounter
access should trap and KVM emulates the read access on behalf of guests.
Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
arch/riscv/include/asm/kvm_vcpu_pmu.h | 16 ++++++++++
arch/riscv/kvm/vcpu_insn.c | 4 ++-
arch/riscv/kvm/vcpu_pmu.c | 44 ++++++++++++++++++++++++++-
3 files changed, 62 insertions(+), 2 deletions(-)
diff --git a/arch/riscv/include/asm/kvm_vcpu_pmu.h b/arch/riscv/include/asm/kvm_vcpu_pmu.h
index 6a8c0f7..7a9a8e6 100644
--- a/arch/riscv/include/asm/kvm_vcpu_pmu.h
+++ b/arch/riscv/include/asm/kvm_vcpu_pmu.h
@@ -43,6 +43,19 @@ struct kvm_pmu {
#define vcpu_to_pmu(vcpu) (&(vcpu)->arch.pmu)
#define pmu_to_vcpu(pmu) (container_of((pmu), struct kvm_vcpu, arch.pmu))
+#if defined(CONFIG_32BIT)
+#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
+{ .base = CSR_CYCLEH, .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm }, \
+{ .base = CSR_CYCLE, .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm },
+#else
+#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
+{ .base = CSR_CYCLE, .count = 31, .func = kvm_riscv_vcpu_pmu_read_hpm },
+#endif
+
+int kvm_riscv_vcpu_pmu_read_hpm(struct kvm_vcpu *vcpu, unsigned int csr_num,
+ unsigned long *val, unsigned long new_val,
+ unsigned long wr_mask);
+
int kvm_riscv_vcpu_pmu_num_ctrs(struct kvm_vcpu *vcpu, struct kvm_vcpu_sbi_ext_data *edata);
int kvm_riscv_vcpu_pmu_ctr_info(struct kvm_vcpu *vcpu, unsigned long cidx,
struct kvm_vcpu_sbi_ext_data *edata);
@@ -65,6 +78,9 @@ void kvm_riscv_vcpu_pmu_reset(struct kvm_vcpu *vcpu);
#else
struct kvm_pmu {
};
+#define KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS \
+{ .base = 0, .count = 0, .func = NULL },
+
static inline int kvm_riscv_vcpu_pmu_init(struct kvm_vcpu *vcpu)
{
diff --git a/arch/riscv/kvm/vcpu_insn.c b/arch/riscv/kvm/vcpu_insn.c
index 1ff2649..f689337 100644
--- a/arch/riscv/kvm/vcpu_insn.c
+++ b/arch/riscv/kvm/vcpu_insn.c
@@ -213,7 +213,9 @@ struct csr_func {
unsigned long wr_mask);
};
-static const struct csr_func csr_funcs[] = {};
+static const struct csr_func csr_funcs[] = {
+ KVM_RISCV_VCPU_HPMCOUNTER_CSR_FUNCS
+};
/**
* kvm_riscv_vcpu_csr_return -- Handle CSR read/write after user space
diff --git a/arch/riscv/kvm/vcpu_pmu.c b/arch/riscv/kvm/vcpu_pmu.c
index 0f0748f1..53c4163 100644
--- a/arch/riscv/kvm/vcpu_pmu.c
+++ b/arch/riscv/kvm/vcpu_pmu.c
@@ -17,6 +17,43 @@
#define kvm_pmu_num_counters(pmu) ((pmu)->num_hw_ctrs + (pmu)->num_fw_ctrs)
+static int pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
+ unsigned long *out_val)
+{
+ struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
+ struct kvm_pmc *pmc;
+ u64 enabled, running;
+
+ pmc = &kvpmu->pmc[cidx];
+ if (!pmc->perf_event)
+ return -EINVAL;
+
+ pmc->counter_val += perf_event_read_value(pmc->perf_event, &enabled, &running);
+ *out_val = pmc->counter_val;
+
+ return 0;
+}
+
+int kvm_riscv_vcpu_pmu_read_hpm(struct kvm_vcpu *vcpu, unsigned int csr_num,
+ unsigned long *val, unsigned long new_val,
+ unsigned long wr_mask)
+{
+ struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
+ int cidx, ret = KVM_INSN_CONTINUE_NEXT_SEPC;
+
+ if (!kvpmu || !kvpmu->init_done)
+ return KVM_INSN_EXIT_TO_USER_SPACE;
+
+ if (wr_mask)
+ return KVM_INSN_ILLEGAL_TRAP;
+ cidx = csr_num - CSR_CYCLE;
+
+ if (pmu_ctr_read(vcpu, cidx, val) < 0)
+ return KVM_INSN_EXIT_TO_USER_SPACE;
+
+ return ret;
+}
+
int kvm_riscv_vcpu_pmu_num_ctrs(struct kvm_vcpu *vcpu, struct kvm_vcpu_sbi_ext_data *edata)
{
struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
@@ -69,7 +106,12 @@ int kvm_riscv_vcpu_pmu_ctr_cfg_match(struct kvm_vcpu *vcpu, unsigned long ctr_ba
int kvm_riscv_vcpu_pmu_ctr_read(struct kvm_vcpu *vcpu, unsigned long cidx,
struct kvm_vcpu_sbi_ext_data *edata)
{
- /* TODO */
+ int ret;
+
+ ret = pmu_ctr_read(vcpu, cidx, &edata->out_val);
+ if (ret == -EINVAL)
+ edata->err_val = SBI_ERR_INVALID_PARAM;
+
return 0;
}
--
2.25.1
next prev parent reply other threads:[~2022-12-15 17:02 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-12-15 17:00 [PATCH v2 00/11] KVM perf support Atish Patra
2022-12-15 17:00 ` [PATCH v2 01/11] RISC-V: Define helper functions expose hpm counter width and count Atish Patra
2023-01-12 10:06 ` Andrew Jones
2023-01-12 18:18 ` Atish Kumar Patra
2023-01-13 7:22 ` Andrew Jones
2023-01-24 20:41 ` Atish Patra
2022-12-15 17:00 ` [PATCH v2 02/11] RISC-V: KVM: Define a probe function for SBI extension data structures Atish Patra
2023-01-12 10:21 ` Andrew Jones
2023-01-12 18:19 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 03/11] RISC-V: KVM: Return correct code for hsm stop function Atish Patra
2023-01-12 10:28 ` Andrew Jones
2023-01-12 18:25 ` Atish Kumar Patra
2023-01-13 7:25 ` Andrew Jones
2022-12-15 17:00 ` [PATCH v2 04/11] RISC-V: KVM: Modify SBI extension handler to return SBI error code Atish Patra
2023-01-12 11:04 ` Andrew Jones
2023-01-12 18:47 ` Atish Kumar Patra
2023-01-13 7:42 ` Andrew Jones
2022-12-15 17:00 ` [PATCH v2 05/11] RISC-V: KVM: Improve privilege mode filtering for perf Atish Patra
2022-12-15 20:17 ` Conor Dooley
2022-12-15 21:10 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 06/11] RISC-V: KVM: Add skeleton support " Atish Patra
2023-01-12 15:10 ` Andrew Jones
2023-01-12 18:09 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 07/11] RISC-V: KVM: Add SBI PMU extension support Atish Patra
2023-01-12 15:29 ` Andrew Jones
2023-01-12 18:04 ` Atish Kumar Patra
2022-12-15 17:00 ` [PATCH v2 08/11] RISC-V: KVM: Disable all hpmcounter access for VS/VU mode Atish Patra
2023-01-12 15:47 ` Andrew Jones
2022-12-15 17:00 ` Atish Patra [this message]
2023-01-13 11:47 ` [PATCH v2 09/11] RISC-V: KVM: Implement trap & emulate for hpmcounters Andrew Jones
2022-12-15 17:00 ` [PATCH v2 10/11] RISC-V: KVM: Implement perf support without sampling Atish Patra
2023-01-13 11:45 ` Andrew Jones
2023-01-23 7:23 ` Andrew Jones
2023-01-26 0:50 ` Atish Patra
2022-12-15 17:00 ` [PATCH v2 11/11] RISC-V: KVM: Implement firmware events Atish Patra
2023-01-13 12:08 ` Andrew Jones
2023-01-26 3:08 ` Atish Patra
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