acrn-hypervisor/hypervisor/arch/x86/guest/ucode.c

/*
 * Copyright (C) 2018 Intel Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <types.h>
#include <errno.h>
#include <spinlock.h>
#include <cpu.h>
#include <msr.h>
#include <cpuid.h>
#include <ucode.h>
#include <guest_memory.h>
#include <irq.h>
#include <logmsg.h>

#define MICRO_CODE_SIZE_MAX    0x40000U
static uint8_t micro_code[MICRO_CODE_SIZE_MAX];
static spinlock_t micro_code_lock = { .head = 0U, .tail = 0U };

uint64_t get_microcode_version(void)
{
	uint64_t val;
	uint32_t eax, ebx, ecx, edx;

	msr_write(MSR_IA32_BIOS_SIGN_ID, 0U);
	cpuid(CPUID_FEATURES, &eax, &ebx, &ecx, &edx);
	val = msr_read(MSR_IA32_BIOS_SIGN_ID);

	return val;
}

/*
 * According to SDM vol 3 Table 9-7. If data_size field of uCode
 * header is zero, the ucode length is 2000
 */
static inline size_t get_ucode_data_size(const struct ucode_header *uhdr)
{
	return ((uhdr->data_size != 0U) ? uhdr->data_size : 2000U);
}

void acrn_update_ucode(struct acrn_vcpu *vcpu, uint64_t v)
{
	uint64_t gva, fault_addr = 0UL;
	struct ucode_header uhdr;
	size_t data_size;
	int32_t err;
	uint32_t err_code;

	spinlock_obtain(&micro_code_lock);
	gva = v - sizeof(struct ucode_header);

	err_code = 0U;
	err = copy_from_gva(vcpu, &uhdr, gva, sizeof(uhdr), &err_code,
			&fault_addr);
	if (err < 0) {
		if (err == -EFAULT) {
			vcpu_inject_pf(vcpu, fault_addr, err_code);
		}
	} else {
		data_size = get_ucode_data_size(&uhdr) + sizeof(struct ucode_header);
		if (data_size > MICRO_CODE_SIZE_MAX) {
			pr_err("The size of microcode is greater than 0x%x",
					MICRO_CODE_SIZE_MAX);
		} else {
			err_code = 0U;
			err = copy_from_gva(vcpu, micro_code, gva, data_size, &err_code,
					&fault_addr);
			if (err < 0) {
				if (err == -EFAULT) {
					vcpu_inject_pf(vcpu, fault_addr, err_code);
				}
			} else {
				msr_write(MSR_IA32_BIOS_UPDT_TRIG,
					(uint64_t)micro_code + sizeof(struct ucode_header));
				(void)get_microcode_version();
			}
		}
	}
	spinlock_release(&micro_code_lock);
}