Re: [PATCH net-next v2 1/4] vm_sockets: Include flags field in the vsock address data structure

From: Stefano Garzarella <sgarzare@redhat.com>
To: Andra Paraschiv <andraprs@amazon.com>
Cc: netdev <netdev@vger.kernel.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	"David S . Miller" <davem@davemloft.net>,
	David Duncan <davdunc@amazon.com>,
	Dexuan Cui <decui@microsoft.com>, Alexander Graf <graf@amazon.de>,
	Jorgen Hansen <jhansen@vmware.com>,
	Jakub Kicinski <kuba@kernel.org>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>
Subject: Re: [PATCH net-next v2 1/4] vm_sockets: Include flags field in the vsock address data structure
Date: Mon, 7 Dec 2020 10:59:05 +0100	[thread overview]
Message-ID: <20201207095905.q7rczeh54n2zy7fo@steredhat> (raw)
In-Reply-To: <20201204170235.84387-2-andraprs@amazon.com>

On Fri, Dec 04, 2020 at 07:02:32PM +0200, Andra Paraschiv wrote:
>vsock enables communication between virtual machines and the host they
>are running on. With the multi transport support (guest->host and
>host->guest), nested VMs can also use vsock channels for communication.
>
>In addition to this, by default, all the vsock packets are forwarded to
>the host, if no host->guest transport is loaded. This behavior can be
>implicitly used for enabling vsock communication between sibling VMs.
>
>Add a flags field in the vsock address data structure that can be used
>to explicitly mark the vsock connection as being targeted for a certain
>type of communication. This way, can distinguish between different use
>cases such as nested VMs and sibling VMs.
>
>Use the already available "svm_reserved1" field and mark it as a flags
>field instead. This field can be set when initializing the vsock address
>variable used for the connect() call.
>
>Changelog
>
>v1 -> v2
>
>* Update the field name to "svm_flags".
>* Split the current patch in 2 patches.

Usually the changelog goes after the 3 dashes, but I'm not sure there is 
a strict rule :-)

Anyway the patch LGTM:

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

>
>Signed-off-by: Andra Paraschiv <andraprs@amazon.com>
>---
> include/uapi/linux/vm_sockets.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/include/uapi/linux/vm_sockets.h b/include/uapi/linux/vm_sockets.h
>index fd0ed7221645d..46735376a57a8 100644
>--- a/include/uapi/linux/vm_sockets.h
>+++ b/include/uapi/linux/vm_sockets.h
>@@ -145,7 +145,7 @@
>
> struct sockaddr_vm {
> 	__kernel_sa_family_t svm_family;
>-	unsigned short svm_reserved1;
>+	unsigned short svm_flags;
> 	unsigned int svm_port;
> 	unsigned int svm_cid;
> 	unsigned char svm_zero[sizeof(struct sockaddr) -
>-- 
>2.20.1 (Apple Git-117)
>
>
>
>
>Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
>