Also known as 'vmchannel', a transport mechanism is needed for
communication between the host userspace and guest userspace for
achieving things like making clipboard copy/paste work seamlessly across
the host and guest, locking the guest screen in case the vnc session to
the guest is closed and so on. This can be used in offline cases as
well, for example with libguestfs to probe which file systems the guest
uses, the apps installed, etc.
Virtio-serial is just the transport protocol that will enable such
applications to be written. It has two parts: (a) device emulation in
qemu that presents a virtio-pci device to the guest and (b) a guest
driver that presents a char device interface to userspace applications.
Signed-off-by: Dominick Grift <dominick.grift@gmail.com>
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