drivers/firmware/smccc/kvm_guest.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 #define pr_fmt(fmt) "smccc: KVM: " fmt
   4
   5 #include <linux/arm-smccc.h>
   6 #include <linux/bitmap.h>
   7 #include <linux/cache.h>
   8 #include <linux/kernel.h>
   9 #include <linux/string.h>
  10
  11 #include <asm/hypervisor.h>
  12
  13 static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };
  14
  15 void __init kvm_init_hyp_services(void)
  16 {
  17         struct arm_smccc_res res;
  18         u32 val[4];
  19
  20         if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
  21                 return;
  22
  23         arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
  24         if (res.a0 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_0 ||
  25             res.a1 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_1 ||
  26             res.a2 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_2 ||
  27             res.a3 != ARM_SMCCC_VENDOR_HYP_UID_KVM_REG_3)
  28                 return;
  29
  30         memset(&res, 0, sizeof(res));
  31         arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);
  32
  33         val[0] = lower_32_bits(res.a0);
  34         val[1] = lower_32_bits(res.a1);
  35         val[2] = lower_32_bits(res.a2);
  36         val[3] = lower_32_bits(res.a3);
  37
  38         bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);
  39
  40         pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",
  41                  res.a3, res.a2, res.a1, res.a0);
  42
  43         kvm_arch_init_hyp_services();
  44 }
  45
  46 bool kvm_arm_hyp_service_available(u32 func_id)
  47 {
  48         if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)
  49                 return false;
  50
  51         return test_bit(func_id, __kvm_arm_hyp_services);
  52 }
  53 EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);