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

From: "Paraschiv, Andra-Irina" <andraprs@amazon.com>
To: Stefano Garzarella <sgarzare@redhat.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 21:25:41 +0200	[thread overview]
Message-ID: <5c98dbc3-ecba-a579-8ada-48697367964c@amazon.com> (raw)
In-Reply-To: <20201207095905.q7rczeh54n2zy7fo@steredhat>

On 07/12/2020 11:59, Stefano Garzarella wrote:
>
> 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 :-)

Yup, I've seen both ways. I'd rather keep the changelog in the commit 
message, for further reference after merge, in the commits.

>
> Anyway the patch LGTM:
>
> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

Thank you.

Andra

>
>>
>> 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.
>>
>

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.