qemu/include/sysemu/hostmem.h
Michal Privoznik 5d9a9a6170 backends/hostmem: Report error when memory size is unaligned
If memory-backend-{file,ram} has a size that's not aligned to
underlying page size it is not only wasteful, but also may lead
to hard to debug behaviour. For instance, in case
memory-backend-file and hugepages, madvise() and mbind() fail.
Rightfully so, page is the smallest unit they can work with. And
even though an error is reported, the root cause it not very
clear:

  qemu-system-x86_64: Couldn't set property 'dump' on 'memory-backend-file': Invalid argument

After this commit:

  qemu-system-x86_64: backend 'memory-backend-file' memory size must be multiple of 2 MiB

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Tested-by: Mario Casquero <mcasquer@redhat.com>
Message-ID: <b5b9f9c6bba07879fb43f3c6f496c69867ae3716.1717584048.git.mprivozn@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-06-08 10:33:38 +02:00

94 lines
2.4 KiB
C

/*
* QEMU Host Memory Backend
*
* Copyright (C) 2013-2014 Red Hat Inc
*
* Authors:
* Igor Mammedov <imammedo@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 SYSEMU_HOSTMEM_H
#define SYSEMU_HOSTMEM_H
#include "sysemu/numa.h"
#include "qapi/qapi-types-machine.h"
#include "qom/object.h"
#include "exec/memory.h"
#include "qemu/bitmap.h"
#include "qemu/thread-context.h"
#define TYPE_MEMORY_BACKEND "memory-backend"
OBJECT_DECLARE_TYPE(HostMemoryBackend, HostMemoryBackendClass,
MEMORY_BACKEND)
/* hostmem-ram.c */
/**
* @TYPE_MEMORY_BACKEND_RAM:
* name of backend that uses mmap on the anonymous RAM
*/
#define TYPE_MEMORY_BACKEND_RAM "memory-backend-ram"
/* hostmem-file.c */
/**
* @TYPE_MEMORY_BACKEND_FILE:
* name of backend that uses mmap on a file descriptor
*/
#define TYPE_MEMORY_BACKEND_FILE "memory-backend-file"
/**
* HostMemoryBackendClass:
* @parent_class: opaque parent class container
*/
struct HostMemoryBackendClass {
ObjectClass parent_class;
/**
* alloc: Allocate memory from backend.
*
* @backend: the #HostMemoryBackend.
* @errp: pointer to Error*, to store an error if it happens.
*
* Return: true on success, else false setting @errp with error.
*/
bool (*alloc)(HostMemoryBackend *backend, Error **errp);
};
/**
* @HostMemoryBackend
*
* @parent: opaque parent object container
* @size: amount of memory backend provides
* @mr: MemoryRegion representing host memory belonging to backend
* @prealloc_threads: number of threads to be used for preallocatining RAM
*/
struct HostMemoryBackend {
/* private */
Object parent;
/* protected */
uint64_t size;
bool merge, dump, use_canonical_path;
bool prealloc, is_mapped, share, reserve;
bool guest_memfd, aligned;
uint32_t prealloc_threads;
ThreadContext *prealloc_context;
DECLARE_BITMAP(host_nodes, MAX_NODES + 1);
HostMemPolicy policy;
MemoryRegion mr;
};
bool host_memory_backend_mr_inited(HostMemoryBackend *backend);
MemoryRegion *host_memory_backend_get_memory(HostMemoryBackend *backend);
void host_memory_backend_set_mapped(HostMemoryBackend *backend, bool mapped);
bool host_memory_backend_is_mapped(HostMemoryBackend *backend);
size_t host_memory_backend_pagesize(HostMemoryBackend *memdev);
char *host_memory_backend_get_name(HostMemoryBackend *backend);
#endif