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

From: Andra Paraschiv <andraprs@amazon.com>
To: netdev <netdev@vger.kernel.org>
Cc: 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>,
	Stefano Garzarella <sgarzare@redhat.com>,
	Stefan Hajnoczi <stefanha@redhat.com>,
	Vitaly Kuznetsov <vkuznets@redhat.com>,
	Andra Paraschiv <andraprs@amazon.com>
Subject: [PATCH net-next v2 1/4] vm_sockets: Include flags field in the vsock address data structure
Date: Fri, 4 Dec 2020 19:02:32 +0200	[thread overview]
Message-ID: <20201204170235.84387-2-andraprs@amazon.com> (raw)
In-Reply-To: <20201204170235.84387-1-andraprs@amazon.com>

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.

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)




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