nvproxy: unmap nvidia-uvm from sentry when FD is closed

PiperOrigin-RevId: 875885672

Author: nixprime

pkg/sentry/devices/nvproxy/uvm.go

@@ -83,6 +83,7 @@ type uvmFD struct {
 
 // Release implements vfs.FileDescriptionImpl.Release.
 func (fd *uvmFD) Release(context.Context) {
+	fd.memmapFile.pfm.UnmapAll()
 	fdnotifier.RemoveFD(fd.hostFD)
 	fd.queue.Notify(waiter.EventHUp)
 	unix.Close(int(fd.hostFD))