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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/drivers/firmware/smccc/kvm_guest.c
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// SPDX-License-Identifier: GPL-2.0

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#define pr_fmt(fmt) "smccc: KVM: " fmt

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#include <linux/arm-smccc.h>

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#include <linux/bitmap.h>

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#include <linux/cache.h>

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#include <linux/kernel.h>

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#include <linux/memblock.h>

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#include <linux/string.h>

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#include <uapi/linux/psci.h>

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#include <asm/hypervisor.h>

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static DECLARE_BITMAP(__kvm_arm_hyp_services, ARM_SMCCC_KVM_NUM_FUNCS) __ro_after_init = { };

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void __init kvm_init_hyp_services(void)

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{

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	uuid_t kvm_uuid = ARM_SMCCC_VENDOR_HYP_UID_KVM;

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	struct arm_smccc_res res;

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	u32 val[4];

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	if (!arm_smccc_hypervisor_has_uuid(&kvm_uuid))

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		return;

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	memset(&res, 0, sizeof(res));

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	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_FEATURES_FUNC_ID, &res);

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	val[0] = lower_32_bits(res.a0);

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	val[1] = lower_32_bits(res.a1);

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	val[2] = lower_32_bits(res.a2);

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	val[3] = lower_32_bits(res.a3);

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	bitmap_from_arr32(__kvm_arm_hyp_services, val, ARM_SMCCC_KVM_NUM_FUNCS);

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	pr_info("hypervisor services detected (0x%08lx 0x%08lx 0x%08lx 0x%08lx)\n",

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		 res.a3, res.a2, res.a1, res.a0);

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	kvm_arch_init_hyp_services();

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}

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bool kvm_arm_hyp_service_available(u32 func_id)

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{

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	if (func_id >= ARM_SMCCC_KVM_NUM_FUNCS)

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		return false;

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	return test_bit(func_id, __kvm_arm_hyp_services);

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}

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EXPORT_SYMBOL_GPL(kvm_arm_hyp_service_available);

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#ifdef CONFIG_ARM64

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void  __init kvm_arm_target_impl_cpu_init(void)

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{

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	int i;

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	u32 ver;

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	u64 max_cpus;

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	struct arm_smccc_res res;

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	struct target_impl_cpu *target;

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	if (!kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_VER) ||

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	    !kvm_arm_hyp_service_available(ARM_SMCCC_KVM_FUNC_DISCOVER_IMPL_CPUS))

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		return;

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	arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_VER_FUNC_ID,

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			     0, &res);

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	if (res.a0 != SMCCC_RET_SUCCESS)

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		return;

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	/* Version info is in lower 32 bits and is in SMMCCC_VERSION format */

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	ver = lower_32_bits(res.a1);

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	if (PSCI_VERSION_MAJOR(ver) != 1) {

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		pr_warn("Unsupported target CPU implementation version v%d.%d\n",

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			PSCI_VERSION_MAJOR(ver), PSCI_VERSION_MINOR(ver));

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		return;

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	}

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	if (!res.a2) {

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		pr_warn("No target implementation CPUs specified\n");

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		return;

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	}

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	max_cpus = res.a2;

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	target = memblock_alloc(sizeof(*target) * max_cpus,  __alignof__(*target));

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	if (!target) {

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		pr_warn("Not enough memory for struct target_impl_cpu\n");

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		return;

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	}

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	for (i = 0; i < max_cpus; i++) {

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		arm_smccc_1_1_invoke(ARM_SMCCC_VENDOR_HYP_KVM_DISCOVER_IMPL_CPUS_FUNC_ID,

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				     i, 0, 0, &res);

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		if (res.a0 != SMCCC_RET_SUCCESS) {

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			pr_warn("Discovering target implementation CPUs failed\n");

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			goto mem_free;

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		}

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		target[i].midr = res.a1;

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		target[i].revidr = res.a2;

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		target[i].aidr = res.a3;

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	}

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	if (!cpu_errata_set_target_impl(max_cpus, target)) {

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		pr_warn("Failed to set target implementation CPUs\n");

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		goto mem_free;

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	}

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	pr_info("Number of target implementation CPUs is %lld\n", max_cpus);

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	return;

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mem_free:

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	memblock_free(target, sizeof(*target) * max_cpus);

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}

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#endif

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