arch/riscv/kvm/vcpu_sbi_pmu.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2023 Rivos Inc
   4  *
   5  * Authors:
   6  *     Atish Patra <atishp@rivosinc.com>
   7  */
   8
   9 #include <linux/errno.h>
  10 #include <linux/err.h>
  11 #include <linux/kvm_host.h>
  12 #include <asm/csr.h>
  13 #include <asm/sbi.h>
  14 #include <asm/kvm_vcpu_sbi.h>
  15
  16 static int kvm_sbi_ext_pmu_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
  17                                    struct kvm_vcpu_sbi_return *retdata)
  18 {
  19         int ret = 0;
  20         struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
  21         struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
  22         unsigned long funcid = cp->a6;
  23         u64 temp;
  24
  25         if (!kvpmu->init_done) {
  26                 retdata->err_val = SBI_ERR_NOT_SUPPORTED;
  27                 return 0;
  28         }
  29
  30         switch (funcid) {
  31         case SBI_EXT_PMU_NUM_COUNTERS:
  32                 ret = kvm_riscv_vcpu_pmu_num_ctrs(vcpu, retdata);
  33                 break;
  34         case SBI_EXT_PMU_COUNTER_GET_INFO:
  35                 ret = kvm_riscv_vcpu_pmu_ctr_info(vcpu, cp->a0, retdata);
  36                 break;
  37         case SBI_EXT_PMU_COUNTER_CFG_MATCH:
  38 #if defined(CONFIG_32BIT)
  39                 temp = ((uint64_t)cp->a5 << 32) | cp->a4;
  40 #else
  41                 temp = cp->a4;
  42 #endif
  43                 /*
  44                  * This can fail if perf core framework fails to create an event.
  45                  * Forward the error to userspace because it's an error which
  46                  * happened within the host kernel. The other option would be
  47                  * to convert to an SBI error and forward to the guest.
  48                  */
  49                 ret = kvm_riscv_vcpu_pmu_ctr_cfg_match(vcpu, cp->a0, cp->a1,
  50                                                        cp->a2, cp->a3, temp, retdata);
  51                 break;
  52         case SBI_EXT_PMU_COUNTER_START:
  53 #if defined(CONFIG_32BIT)
  54                 temp = ((uint64_t)cp->a4 << 32) | cp->a3;
  55 #else
  56                 temp = cp->a3;
  57 #endif
  58                 ret = kvm_riscv_vcpu_pmu_ctr_start(vcpu, cp->a0, cp->a1, cp->a2,
  59                                                    temp, retdata);
  60                 break;
  61         case SBI_EXT_PMU_COUNTER_STOP:
  62                 ret = kvm_riscv_vcpu_pmu_ctr_stop(vcpu, cp->a0, cp->a1, cp->a2, retdata);
  63                 break;
  64         case SBI_EXT_PMU_COUNTER_FW_READ:
  65                 ret = kvm_riscv_vcpu_pmu_ctr_read(vcpu, cp->a0, retdata);
  66                 break;
  67         default:
  68                 retdata->err_val = SBI_ERR_NOT_SUPPORTED;
  69         }
  70
  71         return ret;
  72 }
  73
  74 static unsigned long kvm_sbi_ext_pmu_probe(struct kvm_vcpu *vcpu)
  75 {
  76         struct kvm_pmu *kvpmu = vcpu_to_pmu(vcpu);
  77
  78         return kvpmu->init_done;
  79 }
  80
  81 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_pmu = {
  82         .extid_start = SBI_EXT_PMU,
  83         .extid_end = SBI_EXT_PMU,
  84         .handler = kvm_sbi_ext_pmu_handler,
  85         .probe = kvm_sbi_ext_pmu_probe,
  86 };