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>
		
			
				
	
	
		
			59 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			59 lines
		
	
	
		
			1.5 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * QEMU Host Memory Backend
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 *
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 * Copyright (C) 2013-2014 Red Hat Inc
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 *
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 * Authors:
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 *   Igor Mammedov <imammedo@redhat.com>
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 *
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 * This work is licensed under the terms of the GNU GPL, version 2 or later.
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 * See the COPYING file in the top-level directory.
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 */
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#include "qemu/osdep.h"
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#include "sysemu/hostmem.h"
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#include "qapi/error.h"
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#include "qemu/module.h"
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#include "qom/object_interfaces.h"
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static bool
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ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
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{
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    g_autofree char *name = NULL;
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    uint32_t ram_flags;
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    if (!backend->size) {
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        error_setg(errp, "can't create backend with size 0");
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        return false;
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    }
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    name = host_memory_backend_get_name(backend);
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    ram_flags = backend->share ? RAM_SHARED : 0;
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    ram_flags |= backend->reserve ? 0 : RAM_NORESERVE;
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    ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0;
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    return memory_region_init_ram_flags_nomigrate(&backend->mr, OBJECT(backend),
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                                                  name, backend->size,
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                                                  ram_flags, errp);
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}
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static void
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ram_backend_class_init(ObjectClass *oc, void *data)
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{
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    HostMemoryBackendClass *bc = MEMORY_BACKEND_CLASS(oc);
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    bc->alloc = ram_backend_memory_alloc;
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}
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static const TypeInfo ram_backend_info = {
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    .name = TYPE_MEMORY_BACKEND_RAM,
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    .parent = TYPE_MEMORY_BACKEND,
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    .class_init = ram_backend_class_init,
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};
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static void register_types(void)
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{
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    type_register_static(&ram_backend_info);
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}
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type_init(register_types);
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