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torvalds
GitHub Repository: torvalds/linux
 Path: blob/master/arch/x86/boot/compressed/sev-handle-vc.c
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// SPDX-License-Identifier: GPL-2.0

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#include "misc.h"

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#include "sev.h"

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#include <linux/kernel.h>

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#include <linux/string.h>

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#include <asm/insn.h>

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#include <asm/pgtable_types.h>

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#include <asm/ptrace.h>

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#include <asm/sev.h>

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#include <asm/trapnr.h>

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#include <asm/trap_pf.h>

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#include <asm/fpu/xcr.h>

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#define __BOOT_COMPRESSED

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/* Basic instruction decoding support needed */

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#include "../../lib/inat.c"

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#include "../../lib/insn.c"

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/*

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 * Copy a version of this function here - insn-eval.c can't be used in

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 * pre-decompression code.

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 */

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bool insn_has_rep_prefix(struct insn *insn)

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{

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	insn_byte_t p;

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	int i;

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	insn_get_prefixes(insn);

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	for_each_insn_prefix(insn, i, p) {

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		if (p == 0xf2 || p == 0xf3)

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			return true;

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	}

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	return false;

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}

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enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)

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{

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	char buffer[MAX_INSN_SIZE];

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	int ret;

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	memcpy(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);

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	ret = insn_decode(&ctxt->insn, buffer, MAX_INSN_SIZE, INSN_MODE_64);

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	if (ret < 0)

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		return ES_DECODE_FAILED;

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	return ES_OK;

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}

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extern void sev_insn_decode_init(void) __alias(inat_init_tables);

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/*

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 * Only a dummy for insn_get_seg_base() - Early boot-code is 64bit only and

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 * doesn't use segments.

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 */

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static unsigned long insn_get_seg_base(struct pt_regs *regs, int seg_reg_idx)

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{

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	return 0UL;

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}

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static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,

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				   void *dst, char *buf, size_t size)

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{

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	memcpy(dst, buf, size);

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	return ES_OK;

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}

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static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,

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				  void *src, char *buf, size_t size)

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{

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	memcpy(buf, src, size);

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	return ES_OK;

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}

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static enum es_result vc_ioio_check(struct es_em_ctxt *ctxt, u16 port, size_t size)

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{

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	return ES_OK;

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}

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static bool fault_in_kernel_space(unsigned long address)

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{

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	return false;

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}

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#define sev_printk(fmt, ...)

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#include "../../coco/sev/vc-shared.c"

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void do_boot_stage2_vc(struct pt_regs *regs, unsigned long exit_code)

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{

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	struct es_em_ctxt ctxt;

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	enum es_result result;

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	if (!boot_ghcb && !early_setup_ghcb())

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		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);

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	vc_ghcb_invalidate(boot_ghcb);

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	result = vc_init_em_ctxt(&ctxt, regs, exit_code);

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	if (result != ES_OK)

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		goto finish;

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	result = vc_check_opcode_bytes(&ctxt, exit_code);

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	if (result != ES_OK)

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		goto finish;

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	switch (exit_code) {

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	case SVM_EXIT_RDTSC:

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	case SVM_EXIT_RDTSCP:

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		result = vc_handle_rdtsc(boot_ghcb, &ctxt, exit_code);

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		break;

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	case SVM_EXIT_IOIO:

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		result = vc_handle_ioio(boot_ghcb, &ctxt);

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		break;

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	case SVM_EXIT_CPUID:

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		result = vc_handle_cpuid(boot_ghcb, &ctxt);

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		break;

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	default:

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		result = ES_UNSUPPORTED;

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		break;

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	}

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finish:

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	if (result == ES_OK)

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		vc_finish_insn(&ctxt);

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	else if (result != ES_RETRY)

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		sev_es_terminate(SEV_TERM_SET_GEN, GHCB_SEV_ES_GEN_REQ);

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}

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