Linux Virtualization - Nov 2019 - [PATCH net-next 2/6] vsock: add VMADDR_CID_LOCAL definition

> From: Stefano Garzarella [mailto:sgarzare at redhat.com]
> Sent: Tuesday, November 19, 2019 12:01 PM
> 
> The VMADDR_CID_RESERVED (1) was used by VMCI, but now it is not
> used anymore, so we can reuse it for local communication
> (loopback) adding the new well-know CID: VMADDR_CID_LOCAL.
> 
> Cc: Jorgen Hansen <jhansen at vmware.com>
> Signed-off-by: Stefano Garzarella <sgarzare at redhat.com>
> ---
>  include/uapi/linux/vm_sockets.h | 8 +++++---
>  net/vmw_vsock/vmci_transport.c  | 2 +-
>  2 files changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/include/uapi/linux/vm_sockets.h
> b/include/uapi/linux/vm_sockets.h
> index 68d57c5e99bc..fd0ed7221645 100644
> --- a/include/uapi/linux/vm_sockets.h
> +++ b/include/uapi/linux/vm_sockets.h
> @@ -99,11 +99,13 @@
> 
>  #define VMADDR_CID_HYPERVISOR 0
> 
> -/* This CID is specific to VMCI and can be considered reserved (even VMCI
> - * doesn't use it anymore, it's a legacy value from an older
release).
> +/* Use this as the destination CID in an address when referring to the
> + * local communication (loopback).
> + * (This was VMADDR_CID_RESERVED, but even VMCI doesn't use it
> anymore,
> + * it was a legacy value from an older release).
>   */
> 
> -#define VMADDR_CID_RESERVED 1
> +#define VMADDR_CID_LOCAL 1
> 
>  /* Use this as the destination CID in an address when referring to the
host
>   * (any process other than the hypervisor).  VMCI relies on it being 2,
but
> diff --git a/net/vmw_vsock/vmci_transport.c
> b/net/vmw_vsock/vmci_transport.c
> index 644d32e43d23..4b8b1150a738 100644
> --- a/net/vmw_vsock/vmci_transport.c
> +++ b/net/vmw_vsock/vmci_transport.c
> @@ -648,7 +648,7 @@ static int vmci_transport_recv_dgram_cb(void *data,
> struct vmci_datagram *dg)
>  static bool vmci_transport_stream_allow(u32 cid, u32 port)
>  {
>  	static const u32 non_socket_contexts[] = {
> -		VMADDR_CID_RESERVED,
> +		VMADDR_CID_LOCAL,
>  	};
>  	int i;
> 
> --
> 2.21.0
Reviewed-by: Jorgen Hansen <jhansen at vmware.com>