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// SPDX-License-Identifier: GPL-2.0-only
/*
* AMD Memory Encryption Support
*
* Copyright (C) 2019 SUSE
*
* Author: Joerg Roedel <jroedel@suse.de>
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/sev-es.h>
#include <asm/insn-eval.h>
#include <asm/fpu/internal.h>
#include <asm/processor.h>
#include <asm/trap_pf.h>
#include <asm/trapnr.h>
#include <asm/svm.h>
static inline u64 sev_es_rd_ghcb_msr(void)
{
return __rdmsr(MSR_AMD64_SEV_ES_GHCB);
}
static inline void sev_es_wr_ghcb_msr(u64 val)
{
u32 low, high;
low = (u32)(val);
high = (u32)(val >> 32);
native_wrmsr(MSR_AMD64_SEV_ES_GHCB, low, high);
}
static int vc_fetch_insn_kernel(struct es_em_ctxt *ctxt,
unsigned char *buffer)
{
return copy_from_kernel_nofault(buffer, (unsigned char *)ctxt->regs->ip, MAX_INSN_SIZE);
}
static enum es_result vc_decode_insn(struct es_em_ctxt *ctxt)
{
char buffer[MAX_INSN_SIZE];
enum es_result ret;
int res;
res = vc_fetch_insn_kernel(ctxt, buffer);
if (unlikely(res == -EFAULT)) {
ctxt->fi.vector = X86_TRAP_PF;
ctxt->fi.error_code = 0;
ctxt->fi.cr2 = ctxt->regs->ip;
return ES_EXCEPTION;
}
insn_init(&ctxt->insn, buffer, MAX_INSN_SIZE - res, 1);
insn_get_length(&ctxt->insn);
ret = ctxt->insn.immediate.got ? ES_OK : ES_DECODE_FAILED;
return ret;
}
static enum es_result vc_write_mem(struct es_em_ctxt *ctxt,
char *dst, char *buf, size_t size)
{
unsigned long error_code = X86_PF_PROT | X86_PF_WRITE;
char __user *target = (char __user *)dst;
u64 d8;
u32 d4;
u16 d2;
u8 d1;
switch (size) {
case 1:
memcpy(&d1, buf, 1);
if (put_user(d1, target))
goto fault;
break;
case 2:
memcpy(&d2, buf, 2);
if (put_user(d2, target))
goto fault;
break;
case 4:
memcpy(&d4, buf, 4);
if (put_user(d4, target))
goto fault;
break;
case 8:
memcpy(&d8, buf, 8);
if (put_user(d8, target))
goto fault;
break;
default:
WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
return ES_UNSUPPORTED;
}
return ES_OK;
fault:
if (user_mode(ctxt->regs))
error_code |= X86_PF_USER;
ctxt->fi.vector = X86_TRAP_PF;
ctxt->fi.error_code = error_code;
ctxt->fi.cr2 = (unsigned long)dst;
return ES_EXCEPTION;
}
static enum es_result vc_read_mem(struct es_em_ctxt *ctxt,
char *src, char *buf, size_t size)
{
unsigned long error_code = X86_PF_PROT;
char __user *s = (char __user *)src;
u64 d8;
u32 d4;
u16 d2;
u8 d1;
switch (size) {
case 1:
if (get_user(d1, s))
goto fault;
memcpy(buf, &d1, 1);
break;
case 2:
if (get_user(d2, s))
goto fault;
memcpy(buf, &d2, 2);
break;
case 4:
if (get_user(d4, s))
goto fault;
memcpy(buf, &d4, 4);
break;
case 8:
if (get_user(d8, s))
goto fault;
memcpy(buf, &d8, 8);
break;
default:
WARN_ONCE(1, "%s: Invalid size: %zu\n", __func__, size);
return ES_UNSUPPORTED;
}
return ES_OK;
fault:
if (user_mode(ctxt->regs))
error_code |= X86_PF_USER;
ctxt->fi.vector = X86_TRAP_PF;
ctxt->fi.error_code = error_code;
ctxt->fi.cr2 = (unsigned long)src;
return ES_EXCEPTION;
}
/* Include code shared with pre-decompression boot stage */
#include "sev-es-shared.c"
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