freebsd-dev/sys/amd64/include/vmm_instruction_emul.h
John Baldwin 5f8754c077 Add a new variant of the GLA2GPA ioctl for use by the debug server.
Unlike the existing GLA2GPA ioctl, GLA2GPA_NOFAULT does not modify
the guest.  In particular, it does not inject any faults or modify
PTEs in the guest when performing an address space translation.

This is used by bhyve's debug server to read and write memory for
the remote debugger.

Reviewed by:	grehan
MFC after:	1 month
Differential Revision:	https://reviews.freebsd.org/D14075
2018-02-26 19:19:05 +00:00

126 lines
4.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2012 NetApp, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY NETAPP, INC ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL NETAPP, INC OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _VMM_INSTRUCTION_EMUL_H_
#define _VMM_INSTRUCTION_EMUL_H_
#include <sys/mman.h>
/*
* Callback functions to read and write memory regions.
*/
typedef int (*mem_region_read_t)(void *vm, int cpuid, uint64_t gpa,
uint64_t *rval, int rsize, void *arg);
typedef int (*mem_region_write_t)(void *vm, int cpuid, uint64_t gpa,
uint64_t wval, int wsize, void *arg);
/*
* Emulate the decoded 'vie' instruction.
*
* The callbacks 'mrr' and 'mrw' emulate reads and writes to the memory region
* containing 'gpa'. 'mrarg' is an opaque argument that is passed into the
* callback functions.
*
* 'void *vm' should be 'struct vm *' when called from kernel context and
* 'struct vmctx *' when called from user context.
* s
*/
int vmm_emulate_instruction(void *vm, int cpuid, uint64_t gpa, struct vie *vie,
struct vm_guest_paging *paging, mem_region_read_t mrr,
mem_region_write_t mrw, void *mrarg);
int vie_update_register(void *vm, int vcpuid, enum vm_reg_name reg,
uint64_t val, int size);
/*
* Returns 1 if an alignment check exception should be injected and 0 otherwise.
*/
int vie_alignment_check(int cpl, int operand_size, uint64_t cr0,
uint64_t rflags, uint64_t gla);
/* Returns 1 if the 'gla' is not canonical and 0 otherwise. */
int vie_canonical_check(enum vm_cpu_mode cpu_mode, uint64_t gla);
uint64_t vie_size2mask(int size);
int vie_calculate_gla(enum vm_cpu_mode cpu_mode, enum vm_reg_name seg,
struct seg_desc *desc, uint64_t off, int length, int addrsize, int prot,
uint64_t *gla);
#ifdef _KERNEL
/*
* APIs to fetch and decode the instruction from nested page fault handler.
*
* 'vie' must be initialized before calling 'vmm_fetch_instruction()'
*/
int vmm_fetch_instruction(struct vm *vm, int cpuid,
struct vm_guest_paging *guest_paging,
uint64_t rip, int inst_length, struct vie *vie,
int *is_fault);
/*
* Translate the guest linear address 'gla' to a guest physical address.
*
* retval is_fault Interpretation
* 0 0 'gpa' contains result of the translation
* 0 1 An exception was injected into the guest
* EFAULT N/A An unrecoverable hypervisor error occurred
*/
int vm_gla2gpa(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
uint64_t gla, int prot, uint64_t *gpa, int *is_fault);
/*
* Like vm_gla2gpa, but no exceptions are injected into the guest and
* PTEs are not changed.
*/
int vm_gla2gpa_nofault(struct vm *vm, int vcpuid, struct vm_guest_paging *paging,
uint64_t gla, int prot, uint64_t *gpa, int *is_fault);
void vie_init(struct vie *vie, const char *inst_bytes, int inst_length);
/*
* Decode the instruction fetched into 'vie' so it can be emulated.
*
* 'gla' is the guest linear address provided by the hardware assist
* that caused the nested page table fault. It is used to verify that
* the software instruction decoding is in agreement with the hardware.
*
* Some hardware assists do not provide the 'gla' to the hypervisor.
* To skip the 'gla' verification for this or any other reason pass
* in VIE_INVALID_GLA instead.
*/
#define VIE_INVALID_GLA (1UL << 63) /* a non-canonical address */
int vmm_decode_instruction(struct vm *vm, int cpuid, uint64_t gla,
enum vm_cpu_mode cpu_mode, int csd, struct vie *vie);
#endif /* _KERNEL */
#endif /* _VMM_INSTRUCTION_EMUL_H_ */