Subject: Re: [PATCH net-next v4 0/5] vsock: Add flags field in the vsock address

From: "Paraschiv, Andra-Irina" <[email-masked]>
Date: Mon, 14 Dec 2020 20:19:36 +0200

On 14/12/2020 19:09, Stefano Garzarella wrote:
>
> On Mon, Dec 14, 2020 at 06:11:17PM +0200, Andra Paraschiv wrote:
>> vsock enables communication between virtual machines and the host 
>> they are
>> running on. Nested VMs can be setup to use vsock channels, as the multi
>> transport support has been available in the mainline since the v5.5 
>> Linux kernel
>> has been released.
>>
>> Implicitly, if no host->guest vsock transport is loaded, all the 
>> vsock packets
>> are forwarded to the host. This behavior can be used to setup 
>> communication
>> channels between sibling VMs that are running on the same host. One 
>> example can
>> be the vsock channels that can be established within AWS Nitro Enclaves
>> (see Documentation/virt/ne_overview.rst).
>>
>> To be able to explicitly mark a connection as being used for a 
>> certain use case,
>> add a flags field in the vsock address data structure. The value of 
>> the flags
>> field is taken into consideration when the vsock transport is 
>> assigned. This way
>> can distinguish between different use cases, such as nested VMs / local
>> communication and sibling VMs.
>>
>> The flags field can be set in the user space application connect 
>> logic. On the
>> listen path, the field can be set in the kernel space logic.
>
> I reviewed and tested all the patches, great job!
>

Thanks for checking it out.

Andra

>
>>
>> Thank you.
>>
>> Andra
>>
>> ---
>>
>> Patch Series Changelog
>>
>> The patch series is built on top of v5.10.
>>
>> GitHub repo branch for the latest version of the patch series:
>>
>> * https://github.com/andraprs/linux/tree/vsock-flag-sibling-comm-v4
>>
>> v3 -> v4
>>
>> * Rebase on top of v5.10.
>> * Add check for supported flag values.
>> * Update the "svm_flags" field to be 1 byte instead of 2 bytes.
>> * v3: 
>> https://lore.kernel.org/lkml/[email-masked]/
>>
>> v2 -> v3
>>
>> * Rebase on top of v5.10-rc7.
>> * Add "svm_flags" as a new field, not reusing "svm_reserved1".
>> * Update comments to mention when the "VMADDR_FLAG_TO_HOST" flag is 
>> set in the
>>  connect and listen paths.
>> * Update bitwise check logic to not compare result to the flag value.
>> * v2: 
>> https://lore.kernel.org/lkml/[email-masked]/
>>
>> v1 -> v2
>>
>> * Update the vsock flag naming to "VMADDR_FLAG_TO_HOST".
>> * Use bitwise operators to setup and check the vsock flag.
>> * Set the vsock flag on the receive path in the vsock transport 
>> assignment
>>  logic.
>> * Merge the checks for the g2h transport assignment in one "if" block.
>> * v1: 
>> https://lore.kernel.org/lkml/[email-masked]/
>>
>> ---
>>
>> Andra Paraschiv (5):
>>  vm_sockets: Add flags field in the vsock address data structure
>>  vm_sockets: Add VMADDR_FLAG_TO_HOST vsock flag
>>  vsock_addr: Check for supported flag values
>>  af_vsock: Set VMADDR_FLAG_TO_HOST flag on the receive path
>>  af_vsock: Assign the vsock transport considering the vsock address
>>    flags
>>
>> include/uapi/linux/vm_sockets.h | 26 +++++++++++++++++++++++++-
>> net/vmw_vsock/af_vsock.c        | 21 +++++++++++++++++++--
>> net/vmw_vsock/vsock_addr.c      |  4 +++-
>> 3 files changed, 47 insertions(+), 4 deletions(-)
>>
>> -- 
>> 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.