qemu/include/sysemu/hostmem.h
Xiaoyao Li 37662d85b0 HostMem: Add mechanism to opt in kvm guest memfd via MachineState
Add a new member "guest_memfd" to memory backends. When it's set
to true, it enables RAM_GUEST_MEMFD in ram_flags, thus private kvm
guest_memfd will be allocated during RAMBlock allocation.

Memory backend's @guest_memfd is wired with @require_guest_memfd
field of MachineState. It avoid looking up the machine in phymem.c.

MachineState::require_guest_memfd is supposed to be set by any VMs
that requires KVM guest memfd as private memory, e.g., TDX VM.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-ID: <20240320083945.991426-8-michael.roth@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-23 17:35:25 +02:00

95 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;
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