Commit 2e97a0c0 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'x86_misc_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull misc x86 updates from Borislav Petkov:
 "The pile which we cannot find the proper topic for so we stick it in
  x86/misc:

   - Add support for decoding instructions which do MMIO accesses in
     order to use it in SEV and TDX guests

   - An include fix and reorg to allow for removing set_fs in UML later"

* tag 'x86_misc_for_v5.17_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mtrr: Remove the mtrr_bp_init() stub
  x86/sev-es: Use insn_decode_mmio() for MMIO implementation
  x86/insn-eval: Introduce insn_decode_mmio()
  x86/insn-eval: Introduce insn_get_modrm_reg_ptr()
  x86/insn-eval: Handle insn_get_opcode() failure
parents 4a692ae3 4d5cff69

arch/x86/include/asm/insn-eval.h

+13 −0
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ bool insn_has_rep_prefix(struct insn *insn); 
void __user *insn_get_addr_ref(struct insn *insn, struct pt_regs *regs);

int insn_get_modrm_rm_off(struct insn *insn, struct pt_regs *regs);

int insn_get_modrm_reg_off(struct insn *insn, struct pt_regs *regs);

unsigned long *insn_get_modrm_reg_ptr(struct insn *insn, struct pt_regs *regs);

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

int insn_get_code_seg_params(struct pt_regs *regs);

int insn_get_effective_ip(struct pt_regs *regs, unsigned long *ip);
@@ -29,4 +30,16 @@ int insn_fetch_from_user_inatomic(struct pt_regs *regs, 
bool insn_decode_from_regs(struct insn *insn, struct pt_regs *regs,

			   unsigned char buf[MAX_INSN_SIZE], int buf_size);



enum mmio_type {

	MMIO_DECODE_FAILED,

	MMIO_WRITE,

	MMIO_WRITE_IMM,

	MMIO_READ,

	MMIO_READ_ZERO_EXTEND,

	MMIO_READ_SIGN_EXTEND,

	MMIO_MOVS,

};



enum mmio_type insn_decode_mmio(struct insn *insn, int *bytes);



#endif /* _ASM_X86_INSN_EVAL_H */

arch/x86/include/asm/mtrr.h

+1 −7
Original line number Diff line number Diff line
@@ -24,8 +24,8 @@ 
#define _ASM_X86_MTRR_H



#include <uapi/asm/mtrr.h>

#include <asm/memtype.h>



void mtrr_bp_init(void);



/*

 * The following functions are for use by other drivers that cannot use
@@ -43,7 +43,6 @@ extern int mtrr_del(int reg, unsigned long base, unsigned long size); 
extern int mtrr_del_page(int reg, unsigned long base, unsigned long size);

extern void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi);

extern void mtrr_ap_init(void);

extern void mtrr_bp_init(void);

extern void set_mtrr_aps_delayed_init(void);

extern void mtrr_aps_init(void);

extern void mtrr_bp_restore(void);
@@ -84,11 +83,6 @@ static inline int mtrr_trim_uncached_memory(unsigned long end_pfn) 
static inline void mtrr_centaur_report_mcr(int mcr, u32 lo, u32 hi)

{

}

static inline void mtrr_bp_init(void)

{

	pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel.");

}



#define mtrr_ap_init() do {} while (0)

#define set_mtrr_aps_delayed_init() do {} while (0)

#define mtrr_aps_init() do {} while (0)

arch/x86/kernel/setup.c

+6 −1
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <asm/kasan.h>

#include <asm/kaslr.h>

#include <asm/mce.h>

#include <asm/memtype.h>

#include <asm/mtrr.h>

#include <asm/realmode.h>

#include <asm/olpc_ofw.h>
@@ -967,7 +968,11 @@ void __init setup_arch(char **cmdline_p) 
	max_pfn = e820__end_of_ram_pfn();



	/* update e820 for memory not covered by WB MTRRs */

	if (IS_ENABLED(CONFIG_MTRR))

		mtrr_bp_init();

	else

		pat_disable("PAT support disabled because CONFIG_MTRR is disabled in the kernel.");



	if (mtrr_trim_uncached_memory(max_pfn))

		max_pfn = e820__end_of_ram_pfn();

arch/x86/kernel/sev.c

+41 −131
Original line number Diff line number Diff line
@@ -792,22 +792,6 @@ static void __init vc_early_forward_exception(struct es_em_ctxt *ctxt) 
	do_early_exception(ctxt->regs, trapnr);

}



static long *vc_insn_get_reg(struct es_em_ctxt *ctxt)

{

	long *reg_array;

	int offset;



	reg_array = (long *)ctxt->regs;

	offset    = insn_get_modrm_reg_off(&ctxt->insn, ctxt->regs);



	if (offset < 0)

		return NULL;



	offset /= sizeof(long);



	return reg_array + offset;

}



static long *vc_insn_get_rm(struct es_em_ctxt *ctxt)

{

	long *reg_array;
@@ -855,76 +839,6 @@ static enum es_result vc_do_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt, 
	return sev_es_ghcb_hv_call(ghcb, true, ctxt, exit_code, exit_info_1, exit_info_2);

}



static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,

						 struct es_em_ctxt *ctxt)

{

	struct insn *insn = &ctxt->insn;

	unsigned int bytes = 0;

	enum es_result ret;

	int sign_byte;

	long *reg_data;



	switch (insn->opcode.bytes[1]) {

		/* MMIO Read w/ zero-extension */

	case 0xb6:

		bytes = 1;

		fallthrough;

	case 0xb7:

		if (!bytes)

			bytes = 2;



		ret = vc_do_mmio(ghcb, ctxt, bytes, true);

		if (ret)

			break;



		/* Zero extend based on operand size */

		reg_data = vc_insn_get_reg(ctxt);

		if (!reg_data)

			return ES_DECODE_FAILED;



		memset(reg_data, 0, insn->opnd_bytes);



		memcpy(reg_data, ghcb->shared_buffer, bytes);

		break;



		/* MMIO Read w/ sign-extension */

	case 0xbe:

		bytes = 1;

		fallthrough;

	case 0xbf:

		if (!bytes)

			bytes = 2;



		ret = vc_do_mmio(ghcb, ctxt, bytes, true);

		if (ret)

			break;



		/* Sign extend based on operand size */

		reg_data = vc_insn_get_reg(ctxt);

		if (!reg_data)

			return ES_DECODE_FAILED;



		if (bytes == 1) {

			u8 *val = (u8 *)ghcb->shared_buffer;



			sign_byte = (*val & 0x80) ? 0xff : 0x00;

		} else {

			u16 *val = (u16 *)ghcb->shared_buffer;



			sign_byte = (*val & 0x8000) ? 0xff : 0x00;

		}

		memset(reg_data, sign_byte, insn->opnd_bytes);



		memcpy(reg_data, ghcb->shared_buffer, bytes);

		break;



	default:

		ret = ES_UNSUPPORTED;

	}



	return ret;

}



/*

 * The MOVS instruction has two memory operands, which raises the

 * problem that it is not known whether the access to the source or the
@@ -992,83 +906,79 @@ static enum es_result vc_handle_mmio_movs(struct es_em_ctxt *ctxt, 
		return ES_RETRY;

}



static enum es_result vc_handle_mmio(struct ghcb *ghcb,

				     struct es_em_ctxt *ctxt)

static enum es_result vc_handle_mmio(struct ghcb *ghcb, struct es_em_ctxt *ctxt)

{

	struct insn *insn = &ctxt->insn;

	unsigned int bytes = 0;

	enum mmio_type mmio;

	enum es_result ret;

	u8 sign_byte;

	long *reg_data;



	switch (insn->opcode.bytes[0]) {

	/* MMIO Write */

	case 0x88:

		bytes = 1;

		fallthrough;

	case 0x89:

		if (!bytes)

			bytes = insn->opnd_bytes;

	mmio = insn_decode_mmio(insn, &bytes);

	if (mmio == MMIO_DECODE_FAILED)

		return ES_DECODE_FAILED;



		reg_data = vc_insn_get_reg(ctxt);

	if (mmio != MMIO_WRITE_IMM && mmio != MMIO_MOVS) {

		reg_data = insn_get_modrm_reg_ptr(insn, ctxt->regs);

		if (!reg_data)

			return ES_DECODE_FAILED;

	}



	switch (mmio) {

	case MMIO_WRITE:

		memcpy(ghcb->shared_buffer, reg_data, bytes);



		ret = vc_do_mmio(ghcb, ctxt, bytes, false);

		break;



	case 0xc6:

		bytes = 1;

		fallthrough;

	case 0xc7:

		if (!bytes)

			bytes = insn->opnd_bytes;



	case MMIO_WRITE_IMM:

		memcpy(ghcb->shared_buffer, insn->immediate1.bytes, bytes);



		ret = vc_do_mmio(ghcb, ctxt, bytes, false);

		break;



		/* MMIO Read */

	case 0x8a:

		bytes = 1;

		fallthrough;

	case 0x8b:

		if (!bytes)

			bytes = insn->opnd_bytes;



	case MMIO_READ:

		ret = vc_do_mmio(ghcb, ctxt, bytes, true);

		if (ret)

			break;



		reg_data = vc_insn_get_reg(ctxt);

		if (!reg_data)

			return ES_DECODE_FAILED;



		/* Zero-extend for 32-bit operation */

		if (bytes == 4)

			*reg_data = 0;



		memcpy(reg_data, ghcb->shared_buffer, bytes);

		break;

	case MMIO_READ_ZERO_EXTEND:

		ret = vc_do_mmio(ghcb, ctxt, bytes, true);

		if (ret)

			break;



		/* MOVS instruction */

	case 0xa4:

		bytes = 1;

		fallthrough;

	case 0xa5:

		if (!bytes)

			bytes = insn->opnd_bytes;

		/* Zero extend based on operand size */

		memset(reg_data, 0, insn->opnd_bytes);

		memcpy(reg_data, ghcb->shared_buffer, bytes);

		break;

	case MMIO_READ_SIGN_EXTEND:

		ret = vc_do_mmio(ghcb, ctxt, bytes, true);

		if (ret)

			break;



		ret = vc_handle_mmio_movs(ctxt, bytes);

		if (bytes == 1) {

			u8 *val = (u8 *)ghcb->shared_buffer;



			sign_byte = (*val & 0x80) ? 0xff : 0x00;

		} else {

			u16 *val = (u16 *)ghcb->shared_buffer;



			sign_byte = (*val & 0x8000) ? 0xff : 0x00;

		}



		/* Sign extend based on operand size */

		memset(reg_data, sign_byte, insn->opnd_bytes);

		memcpy(reg_data, ghcb->shared_buffer, bytes);

		break;

		/* Two-Byte Opcodes */

	case 0x0f:

		ret = vc_handle_mmio_twobyte_ops(ghcb, ctxt);

	case MMIO_MOVS:

		ret = vc_handle_mmio_movs(ctxt, bytes);

		break;

	default:

		ret = ES_UNSUPPORTED;

		break;

	}



	return ret;

arch/x86/kvm/mmu/spte.c

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
#include "spte.h"



#include <asm/e820/api.h>

#include <asm/memtype.h>

#include <asm/vmx.h>



static bool __read_mostly enable_mmio_caching = true;