qemu/hw/dataplane/hostmem.h

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/*
* 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 {
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 */