LXR linux/drivers/firmware/smccc/kvm

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