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13423063c7
The KVM/arm64 uses SMCCC to detect hypervisor presence. That code is private, and it follows the SMCCC specification. Other existing and emerging hypervisor guest implementations can and should use that standard approach as well. Factor out a common infrastructure that the guests can use, update KVM to employ the new API. The central notion of the SMCCC method is the UUID of the hypervisor, and the new API follows that. No functional changes. Validated with a KVM/arm64 guest. Signed-off-by: Roman Kisel <romank@linux.microsoft.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Michael Kelley <mhklinux@outlook.com> Link: https://lore.kernel.org/r/20250428210742.435282-2-romank@linux.microsoft.com Signed-off-by: Wei Liu <wei.liu@kernel.org> Message-ID: <20250428210742.435282-2-romank@linux.microsoft.com>
102 lines
2.5 KiB
C
102 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2020 Arm Limited
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*/
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#define pr_fmt(fmt) "smccc: " fmt
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#include <linux/cache.h>
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#include <linux/init.h>
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#include <linux/arm-smccc.h>
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#include <linux/kernel.h>
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#include <linux/platform_device.h>
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#include <asm/archrandom.h>
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static u32 smccc_version = ARM_SMCCC_VERSION_1_0;
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static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE;
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bool __ro_after_init smccc_trng_available = false;
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s32 __ro_after_init smccc_soc_id_version = SMCCC_RET_NOT_SUPPORTED;
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s32 __ro_after_init smccc_soc_id_revision = SMCCC_RET_NOT_SUPPORTED;
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void __init arm_smccc_version_init(u32 version, enum arm_smccc_conduit conduit)
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{
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struct arm_smccc_res res;
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smccc_version = version;
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smccc_conduit = conduit;
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smccc_trng_available = smccc_probe_trng();
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if ((smccc_version >= ARM_SMCCC_VERSION_1_2) &&
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(smccc_conduit != SMCCC_CONDUIT_NONE)) {
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arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
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ARM_SMCCC_ARCH_SOC_ID, &res);
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if ((s32)res.a0 >= 0) {
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arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 0, &res);
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smccc_soc_id_version = (s32)res.a0;
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arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_SOC_ID, 1, &res);
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smccc_soc_id_revision = (s32)res.a0;
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}
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}
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}
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enum arm_smccc_conduit arm_smccc_1_1_get_conduit(void)
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{
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if (smccc_version < ARM_SMCCC_VERSION_1_1)
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return SMCCC_CONDUIT_NONE;
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return smccc_conduit;
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}
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EXPORT_SYMBOL_GPL(arm_smccc_1_1_get_conduit);
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u32 arm_smccc_get_version(void)
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{
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return smccc_version;
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}
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EXPORT_SYMBOL_GPL(arm_smccc_get_version);
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s32 arm_smccc_get_soc_id_version(void)
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{
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return smccc_soc_id_version;
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}
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s32 arm_smccc_get_soc_id_revision(void)
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{
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return smccc_soc_id_revision;
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}
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EXPORT_SYMBOL_GPL(arm_smccc_get_soc_id_revision);
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bool arm_smccc_hypervisor_has_uuid(const uuid_t *hyp_uuid)
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{
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struct arm_smccc_res res = {};
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uuid_t uuid;
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if (arm_smccc_1_1_get_conduit() != SMCCC_CONDUIT_HVC)
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return false;
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arm_smccc_1_1_hvc(ARM_SMCCC_VENDOR_HYP_CALL_UID_FUNC_ID, &res);
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if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
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return false;
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uuid = smccc_res_to_uuid(res.a0, res.a1, res.a2, res.a3);
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return uuid_equal(&uuid, hyp_uuid);
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}
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EXPORT_SYMBOL_GPL(arm_smccc_hypervisor_has_uuid);
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static int __init smccc_devices_init(void)
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{
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struct platform_device *pdev;
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if (smccc_trng_available) {
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pdev = platform_device_register_simple("smccc_trng", -1,
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NULL, 0);
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if (IS_ERR(pdev))
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pr_err("smccc_trng: could not register device: %ld\n",
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PTR_ERR(pdev));
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}
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return 0;
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}
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device_initcall(smccc_devices_init);
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