[qemu.git] / include / hw / virtio / dataplane / hostmem.h

/*
 * Thread-safe guest to host memory mapping
 *
 * Copyright 2012 Red Hat, Inc. and/or its affiliates
 *
 * Authors:
 *   Stefan Hajnoczi <stefanha@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2 or later.
 * See the COPYING file in the top-level directory.
 *
 */

#ifndef HOSTMEM_H
#define HOSTMEM_H

#include "exec/memory.h"
#include "qemu/thread.h"

typedef struct {
    MemoryRegion *mr;
    void *host_addr;
    hwaddr guest_addr;
    uint64_t size;
    bool readonly;
} HostMemRegion;

typedef struct {
    /* The listener is invoked when regions change and a new list of regions is
     * built up completely before they are installed.
     */
    MemoryListener listener;
    HostMemRegion *new_regions;
    size_t num_new_regions;

    /* Current regions are accessed from multiple threads either to lookup
     * addresses or to install a new list of regions.  The lock protects the
     * pointer and the regions.
     */
    QemuMutex current_regions_lock;
    HostMemRegion *current_regions;
    size_t num_current_regions;
} HostMem;

void hostmem_init(HostMem *hostmem);
void hostmem_finalize(HostMem *hostmem);

/**
 * Map a guest physical address to a pointer
 *
 * Note that there is map/unmap mechanism here.  The caller must ensure that
 * mapped memory is no longer used across events like hot memory unplug.  This
 * can be done with other mechanisms like bdrv_drain_all() that quiesce
 * in-flight I/O.
 */
void *hostmem_lookup(HostMem *hostmem, hwaddr phys, hwaddr len, bool is_write);

#endif /* HOSTMEM_H */
Commit	Line	Data
185ecf40 SH	1	/*
	2	* Thread-safe guest to host memory mapping
	3	*
	4	* Copyright 2012 Red Hat, Inc. and/or its affiliates
	5	*
	6	* Authors:
	7	* Stefan Hajnoczi <stefanha@redhat.com>
	8	*
	9	* This work is licensed under the terms of the GNU GPL, version 2 or later.
	10	* See the COPYING file in the top-level directory.
	11	*
	12	*/
	13
	14	#ifndef HOSTMEM_H
	15	#define HOSTMEM_H
	16
	17	#include "exec/memory.h"
	18	#include "qemu/thread.h"
	19
	20	typedef struct {
dfde4e6e	21	MemoryRegion *mr;
185ecf40 SH	22	void *host_addr;
	23	hwaddr guest_addr;
	24	uint64_t size;
	25	bool readonly;
	26	} HostMemRegion;
	27
	28	typedef struct {
	29	/* The listener is invoked when regions change and a new list of regions is
	30	* built up completely before they are installed.
	31	*/
	32	MemoryListener listener;
	33	HostMemRegion *new_regions;
	34	size_t num_new_regions;
	35
	36	/* Current regions are accessed from multiple threads either to lookup
	37	* addresses or to install a new list of regions. The lock protects the
	38	* pointer and the regions.
	39	*/
	40	QemuMutex current_regions_lock;
	41	HostMemRegion *current_regions;
	42	size_t num_current_regions;
	43	} HostMem;
	44
	45	void hostmem_init(HostMem *hostmem);
	46	void hostmem_finalize(HostMem *hostmem);
	47
	48	/**
	49	* Map a guest physical address to a pointer
	50	*
	51	* Note that there is map/unmap mechanism here. The caller must ensure that
	52	* mapped memory is no longer used across events like hot memory unplug. This
	53	* can be done with other mechanisms like bdrv_drain_all() that quiesce
	54	* in-flight I/O.
	55	*/
	56	void hostmem_lookup(HostMem hostmem, hwaddr phys, hwaddr len, bool is_write);
	57
	58	#endif /* HOSTMEM_H */