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

[Stefano Garzarella <sgarzare@redhat.com>]

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,
Stefano

>
>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/20201211103241.17751-1-andraprs@amazon.com/
>
>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/20201204170235.84387-1-andraprs@amazon.com/
>
>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/20201201152505.19445-1-andraprs@amazon.com/
>
>---
>
>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)
>
>
>
>
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