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/sbi.h>
  14 #include <asm/kvm_vcpu_sbi.h>
  15
  16 static int kvm_sbi_ext_base_handler(struct kvm_vcpu *vcpu, struct kvm_run *run,
  17                                     struct kvm_vcpu_sbi_return *retdata)
  18 {
  19         struct kvm_cpu_context *cp = &vcpu->arch.guest_context;
  20         const struct kvm_vcpu_sbi_extension *sbi_ext;
  21         unsigned long *out_val = &retdata->out_val;
  22
  23         switch (cp->a6) {
  24         case SBI_EXT_BASE_GET_SPEC_VERSION:
  25                 *out_val = (KVM_SBI_VERSION_MAJOR <<
  26                             SBI_SPEC_VERSION_MAJOR_SHIFT) |
  27                             KVM_SBI_VERSION_MINOR;
  28                 break;
  29         case SBI_EXT_BASE_GET_IMP_ID:
  30                 *out_val = KVM_SBI_IMPID;
  31                 break;
  32         case SBI_EXT_BASE_GET_IMP_VERSION:
  33                 *out_val = LINUX_VERSION_CODE;
  34                 break;
  35         case SBI_EXT_BASE_PROBE_EXT:
  36                 if ((cp->a0 >= SBI_EXT_EXPERIMENTAL_START &&
  37                      cp->a0 <= SBI_EXT_EXPERIMENTAL_END) ||
  38                     (cp->a0 >= SBI_EXT_VENDOR_START &&
  39                      cp->a0 <= SBI_EXT_VENDOR_END)) {
  40                         /*
  41                          * For experimental/vendor extensions
  42                          * forward it to the userspace
  43                          */
  44                         kvm_riscv_vcpu_sbi_forward(vcpu, run);
  45                         retdata->uexit = true;
  46                 } else {
  47                         sbi_ext = kvm_vcpu_sbi_find_ext(vcpu, cp->a0);
  48                         *out_val = sbi_ext && sbi_ext->probe ?
  49                                            sbi_ext->probe(vcpu) : !!sbi_ext;
  50                 }
  51                 break;
  52         case SBI_EXT_BASE_GET_MVENDORID:
  53                 *out_val = vcpu->arch.mvendorid;
  54                 break;
  55         case SBI_EXT_BASE_GET_MARCHID:
  56                 *out_val = vcpu->arch.marchid;
  57                 break;
  58         case SBI_EXT_BASE_GET_MIMPID:
  59                 *out_val = vcpu->arch.mimpid;
  60                 break;
  61         default:
  62                 retdata->err_val = SBI_ERR_NOT_SUPPORTED;
  63                 break;
  64         }
  65
  66         return 0;
  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                                        struct kvm_vcpu_sbi_return *retdata)
  78 {
  79         /*
  80          * Both SBI experimental and vendor extensions are
  81          * unconditionally forwarded to userspace.
  82          */
  83         kvm_riscv_vcpu_sbi_forward(vcpu, run);
  84         retdata->uexit = true;
  85         return 0;
  86 }
  87
  88 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_experimental = {
  89         .extid_start = SBI_EXT_EXPERIMENTAL_START,
  90         .extid_end = SBI_EXT_EXPERIMENTAL_END,
  91         .handler = kvm_sbi_ext_forward_handler,
  92 };
  93
  94 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_vendor = {
  95         .extid_start = SBI_EXT_VENDOR_START,
  96         .extid_end = SBI_EXT_VENDOR_END,
  97         .handler = kvm_sbi_ext_forward_handler,
  98 };