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authorXiaoyao Li <xiaoyao.li@intel.com>2024-03-20 03:39:03 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2024-04-23 17:35:25 +0200
commit37662d85b0b7dded0ebdf6747bef6c3bb7ed6a0c (patch)
treeb5d8be3492b7aa7e3df4d1ec71a44180255077fb /backends/hostmem-memfd.c
parentbd3bcf6962b664ca3bf9c60fdcc4534e8e3d0641 (diff)
downloadfocaccia-qemu-37662d85b0b7dded0ebdf6747bef6c3bb7ed6a0c.tar.gz
focaccia-qemu-37662d85b0b7dded0ebdf6747bef6c3bb7ed6a0c.zip
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>
Diffstat (limited to 'backends/hostmem-memfd.c')
-rw-r--r--backends/hostmem-memfd.c1
1 files changed, 1 insertions, 0 deletions
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);
 }