From 37662d85b0b7dded0ebdf6747bef6c3bb7ed6a0c Mon Sep 17 00:00:00 2001 From: Xiaoyao Li Date: Wed, 20 Mar 2024 03:39:03 -0500 Subject: [PATCH] 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 Reviewed-by: David Hildenbrand Message-ID: <20240320083945.991426-8-michael.roth@amd.com> Signed-off-by: Paolo Bonzini --- backends/hostmem-file.c | 1 + backends/hostmem-memfd.c | 1 + backends/hostmem-ram.c | 1 + backends/hostmem.c | 1 + hw/core/machine.c | 5 +++++ include/hw/boards.h | 2 ++ include/sysemu/hostmem.h | 1 + 7 files changed, 12 insertions(+) diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c index ac3e433cbd..3c69db7946 100644 --- a/backends/hostmem-file.c +++ b/backends/hostmem-file.c @@ -85,6 +85,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) ram_flags |= fb->readonly ? RAM_READONLY_FD : 0; ram_flags |= fb->rom == ON_OFF_AUTO_ON ? RAM_READONLY : 0; ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; + ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0; ram_flags |= fb->is_pmem ? RAM_PMEM : 0; ram_flags |= RAM_NAMED_FILE; return memory_region_init_ram_from_file(&backend->mr, OBJECT(backend), name, diff --git a/backends/hostmem-memfd.c b/backends/hostmem-memfd.c index 3923ea9364..745ead0034 100644 --- a/backends/hostmem-memfd.c +++ b/backends/hostmem-memfd.c @@ -55,6 +55,7 @@ memfd_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; + ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0; return memory_region_init_ram_from_fd(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, fd, 0, errp); } diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c index d121249f0f..f7d81af783 100644 --- a/backends/hostmem-ram.c +++ b/backends/hostmem-ram.c @@ -30,6 +30,7 @@ ram_backend_memory_alloc(HostMemoryBackend *backend, Error **errp) name = host_memory_backend_get_name(backend); ram_flags = backend->share ? RAM_SHARED : 0; ram_flags |= backend->reserve ? 0 : RAM_NORESERVE; + ram_flags |= backend->guest_memfd ? RAM_GUEST_MEMFD : 0; return memory_region_init_ram_flags_nomigrate(&backend->mr, OBJECT(backend), name, backend->size, ram_flags, errp); diff --git a/backends/hostmem.c b/backends/hostmem.c index 81a72ce40b..eb9682b4a8 100644 --- a/backends/hostmem.c +++ b/backends/hostmem.c @@ -277,6 +277,7 @@ static void host_memory_backend_init(Object *obj) /* TODO: convert access to globals to compat properties */ backend->merge = machine_mem_merge(machine); backend->dump = machine_dump_guest_core(machine); + backend->guest_memfd = machine_require_guest_memfd(machine); backend->reserve = true; backend->prealloc_threads = machine->smp.cpus; } diff --git a/hw/core/machine.c b/hw/core/machine.c index a92bec2314..582c2df37a 100644 --- a/hw/core/machine.c +++ b/hw/core/machine.c @@ -1201,6 +1201,11 @@ bool machine_mem_merge(MachineState *machine) return machine->mem_merge; } +bool machine_require_guest_memfd(MachineState *machine) +{ + return machine->require_guest_memfd; +} + static char *cpu_slot_to_string(const CPUArchId *cpu) { GString *s = g_string_new(NULL); diff --git a/include/hw/boards.h b/include/hw/boards.h index 50e0cf4278..69c1ba45cf 100644 --- a/include/hw/boards.h +++ b/include/hw/boards.h @@ -36,6 +36,7 @@ bool machine_usb(MachineState *machine); int machine_phandle_start(MachineState *machine); bool machine_dump_guest_core(MachineState *machine); bool machine_mem_merge(MachineState *machine); +bool machine_require_guest_memfd(MachineState *machine); HotpluggableCPUList *machine_query_hotpluggable_cpus(MachineState *machine); void machine_set_cpu_numa_node(MachineState *machine, const CpuInstanceProperties *props, @@ -370,6 +371,7 @@ struct MachineState { char *dt_compatible; bool dump_guest_core; bool mem_merge; + bool require_guest_memfd; bool usb; bool usb_disabled; char *firmware; diff --git a/include/sysemu/hostmem.h b/include/sysemu/hostmem.h index 0e411aaa29..04b884bf42 100644 --- a/include/sysemu/hostmem.h +++ b/include/sysemu/hostmem.h @@ -74,6 +74,7 @@ struct HostMemoryBackend { 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);