arch/riscv/kvm/vcpu_sbi_base.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2021 Western Digital Corporation or its affiliates.
   4  *
   5  * Authors:
   6  *     Atish Patra <atish.patra@wdc.com>
   7  */
   8
   9 #include <linux/errno.h>
  10 #include <linux/err.h>
  11 #include <linux/kvm_host.h>
  12 #include <linux/version.h>
  13 #include <asm/csr.h>
  14 #include <asm/sbi.h>
  15 #include <asm/kvm_vcpu_timer.h>
  16 #include <asm/kvm_vcpu_sbi.h>
  17
  18 static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
  19                                     unsigned long *out_val,
  20                                     struct kvm_cpu_trap *trap, bool *exit)
  21 {
  22         int ret = 0;
  23         struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
  24         struct sbiret ecall_ret;
  25
  26         switch (cp->a6) {
  27         case SBI_EXT_BASE_GET_SPEC_VERSION:
  28                 *out_val = (KVM_SBI_VERSION_MAJOR <<
  29                             SBI_SPEC_VERSION_MAJOR_SHIFT) |
  30                             KVM_SBI_VERSION_MINOR;
  31                 break;
  32         case SBI_EXT_BASE_GET_IMP_ID:
  33                 *out_val = KVM_SBI_IMPID;
  34                 break;
  35         case SBI_EXT_BASE_GET_IMP_VERSION:
  36                 *out_val = LINUX_VERSION_CODE;
  37                 break;
  38         case SBI_EXT_BASE_PROBE_EXT:
  39                 if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
  40                      cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
  41                     (cp->a0 >= SBI_EXT_VENDOR_START &&
  42                      cp->a0 <= SBI_EXT_VENDOR_END)) {
  43                         /*
  44                          * For experimental/vendor extensions
  45                          * forward it to the userspace
  46                          */
  47                         kvm_riscv_vcpu_sbi_forward(vcpu, run);
  48                         *exit = true;
  49                 } else
  50                         *out_val = kvm_vcpu_sbi_find_ext(cp->a0) ? 1 : 0;
  51                 break;
  52         case SBI_EXT_BASE_GET_MVENDORID:
  53         case SBI_EXT_BASE_GET_MARCHID:
  54         case SBI_EXT_BASE_GET_MIMPID:
  55                 ecall_ret = sbi_ecall(SBI_EXT_BASE, cp->a6, 0, 0, 0, 0, 0, 0);
  56                 if (!ecall_ret.error)
  57                         *out_val = ecall_ret.value;
  58                 /*TODO: We are unnecessarily converting the error twice */
  59                 ret = sbi_err_map_linux_errno(ecall_ret.error);
  60                 break;
  61         default:
  62                 ret = -EOPNOTSUPP;
  63                 break;
  64         }
  65
  66         return ret;
  67 }
  68
  69 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_base = {
  70         .extid_start = SBI_EXT_BASE,
  71         .extid_end = SBI_EXT_BASE,
  72         .handler = kvm_sbi_ext_base_handler,
  73 };
  74
  75 static int kvm_sbi_ext_forward_handler(struct kvm_vcpu *vcpu,
  76                                         struct kvm_run *run,
  77                                         unsigned long *out_val,
  78                                         struct kvm_cpu_trap *utrap,
  79                                         bool *exit)
  80 {
  81         /*
  82          * Both SBI experimental and vendor extensions are
  83          * unconditionally forwarded to userspace.
  84          */
  85         kvm_riscv_vcpu_sbi_forward(vcpu, run);
  86         *exit = true;
  87         return 0;
  88 }
  89
  90 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental = {
  91         .extid_start = SBI_EXT_EXPERIMENTAL_START,
  92         .extid_end = SBI_EXT_EXPERIMENTAL_END,
  93         .handler = kvm_sbi_ext_forward_handler,
  94 };
  95
  96 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor = {
  97         .extid_start = SBI_EXT_VENDOR_START,
  98         .extid_end = SBI_EXT_VENDOR_END,
  99         .handler = kvm_sbi_ext_forward_handler,
 100 };