Differential D19495 Diff 69728 sys/amd64/include/vmm_snapshot.h

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sys/amd64/include/vmm_snapshot.h

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				/*-
				* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
				*
				* Copyright (c) 2016 Flavius Anton
				* Copyright (c) 2016 Mihai Tiganus
				* Copyright (c) 2016-2019 Mihai Carabas
				* Copyright (c) 2017-2019 Darius Mihai
				* Copyright (c) 2017-2019 Elena Mihailescu
				* Copyright (c) 2018-2019 Sergiu Weisz
				* All rights reserved.
				* The bhyve-snapshot feature was developed under sponsorships
				* from Matthew Grooms.
				*
				* 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_SNAPSHOT_
				#define _VMM_SNAPSHOT_

				dabUnsubmitted Not Done Inline Actions Perhaps there should be a function to determine the snapshot length rather than leaving it up to someone to interpret this comment and reach in to the struct components to calculate it. dab: Perhaps there should be a function to determine the snapshot length rather than leaving it up…
				darius.mihaim_gmail.comUnsubmitted Not Done Inline Actions There is a function called `vm_get_snapshot_size` - not that you mention it, I realize that the information in the comment should have mentioned "snapshot size" - that computes the size (or length) of the snapshot data darius.mihaim_gmail.com: There is a function called `vm_get_snapshot_size` - not that you mention it, I realize that the…
				dabUnsubmitted Done Inline Actions Ah, missed that. Thanks. dab: Ah, missed that. Thanks.
				#include <sys/errno.h>
				#include <sys/types.h>
				dabUnsubmitted Not Done Inline Actions It looks like this line could be deleted. dab: It looks like this line could be deleted.
				darius.mihaim_gmail.comUnsubmitted Not Done Inline Actions It was left there to point that there wasn't a need for an explicit field. I may remove this line and the comment above if people agree that they shouldn't really be there. darius.mihaim_gmail.com: It was left there to point that there wasn't a need for an explicit field. I may remove this…
				dabUnsubmitted Done Inline Actions Maybe just mention `vm_get_snapshot_size()` in the comment. dab: Maybe just mention `vm_get_snapshot_size()` in the comment.
				#ifndef _KERNEL
				#include <stdbool.h>
				#endif

				struct vmctx;

				enum snapshot_req {
				STRUCT_VMX,
				STRUCT_VIOAPIC,
				STRUCT_VM,
				STRUCT_VLAPIC,
				VM_MEM,
				STRUCT_VHPET,
				STRUCT_VMCX,
				STRUCT_VATPIC,
				STRUCT_VATPIT,
				STRUCT_VPMTMR,
				STRUCT_VRTC,
				};

				struct vm_snapshot_buffer {
				/*
				* R/O for device-specific functions;
				* written by generic snapshot functions.
				*/
				uint8_t *const buf_start;
				const size_t buf_size;

				/*
				* R/W for device-specific functions used to keep track of buffer
				* current position and remaining size.
				*/
				uint8_t *buf;
				size_t buf_rem;

				/*
				* Length of the snapshot is either determined as (buf_size - buf_rem)
				* or (buf - buf_start) -- the second variation returns a signed value
				* so it may not be appropriate.
				*
				* Use vm_get_snapshot_size(meta).
				*/
				};
				dabUnsubmitted Done Inline Actions s/in stead/instead/ dab: s/in stead/instead/

				enum vm_snapshot_op {
				VM_SNAPSHOT_SAVE,
				VM_SNAPSHOT_RESTORE,
				};

				struct vm_snapshot_meta {
				struct vmctx *ctx;
				void *dev_data;
				const char dev_name; / identify userspace devices */
				enum snapshot_req dev_req; /* identify kernel structs */

				struct vm_snapshot_buffer buffer;

				enum vm_snapshot_op op;
				};


				void vm_snapshot_buf_err(const char *bufname, const enum vm_snapshot_op op);
				int vm_snapshot_buf(volatile void *data, size_t data_size,
				struct vm_snapshot_meta *meta);
				size_t vm_get_snapshot_size(struct vm_snapshot_meta *meta);
				int vm_snapshot_guest2host_addr(void **addrp, size_t len, bool restore_null,
				struct vm_snapshot_meta *meta);
				int vm_snapshot_buf_cmp(volatile void *data, size_t data_size,
				struct vm_snapshot_meta *meta);

				#define SNAPSHOT_BUF_OR_LEAVE(DATA, LEN, META, RES, LABEL) \
				do { \
				(RES) = vm_snapshot_buf((DATA), (LEN), (META)); \
				if ((RES) != 0) { \
				vm_snapshot_buf_err(#DATA, (META)->op); \
				goto LABEL; \
				} \
				} while (0)

				#define SNAPSHOT_VAR_OR_LEAVE(DATA, META, RES, LABEL) \
				SNAPSHOT_BUF_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)

				/*
				* Address variables are pointers to guest memory.
				*
				* When RNULL != 0, do not enforce invalid address checks; instead, make the
				* pointer NULL at restore time.
				*/
				#define SNAPSHOT_GUEST2HOST_ADDR_OR_LEAVE(ADDR, LEN, RNULL, META, RES, LABEL) \
				do { \
				(RES) = vm_snapshot_guest2host_addr((void **)&(ADDR), (LEN), (RNULL), \
				(META)); \
				if ((RES) != 0) { \
				if ((RES) == EFAULT) \
				fprintf(stderr, "%s: invalid address: %s\r\n", \
				__func__, #ADDR); \
				goto LABEL; \
				} \
				} while (0)

				/* compare the value in the meta buffer with the data */
				#define SNAPSHOT_BUF_CMP_OR_LEAVE(DATA, LEN, META, RES, LABEL) \
				do { \
				(RES) = vm_snapshot_buf_cmp((DATA), (LEN), (META)); \
				if ((RES) != 0) { \
				vm_snapshot_buf_err(#DATA, (META)->op); \
				goto LABEL; \
				} \
				} while (0)

				#define SNAPSHOT_VAR_CMP_OR_LEAVE(DATA, META, RES, LABEL) \
				SNAPSHOT_BUF_CMP_OR_LEAVE(&(DATA), sizeof(DATA), (META), (RES), LABEL)

				#endif