* [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description
@ 2020-02-18 15:54 Stefano Garzarella
2020-02-19 11:21 ` Stefan Hajnoczi
2020-03-14 22:02 ` Michael Kerrisk (man-pages)
0 siblings, 2 replies; 3+ messages in thread
From: Stefano Garzarella @ 2020-02-18 15:54 UTC (permalink / raw)
To: mtk.manpages
Cc: Jorgen Hansen, netdev, linux-man, Stefan Hajnoczi, Dexuan Cui
Linux 5.6 added the new well-known VMADDR_CID_LOCAL for
local communication.
This patch explains how to use it and remove the legacy
VMADDR_CID_RESERVED no longer available.
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
v4:
* removed "The" in the "Local communication" section [Stefan]
v3:
* rephrased "Previous versions" part [Jorgen]
v2:
* rephrased "Local communication" description [Stefan]
* added a mention of previous versions that supported
loopback only in the guest [Stefan]
---
man7/vsock.7 | 18 ++++++++++++++++--
1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/man7/vsock.7 b/man7/vsock.7
index c5ffcf07d..fa2c6e17e 100644
--- a/man7/vsock.7
+++ b/man7/vsock.7
@@ -127,8 +127,8 @@ There are several special addresses:
means any address for binding;
.B VMADDR_CID_HYPERVISOR
(0) is reserved for services built into the hypervisor;
-.B VMADDR_CID_RESERVED
-(1) must not be used;
+.B VMADDR_CID_LOCAL
+(1) is the well-known address for local communication (loopback);
.B VMADDR_CID_HOST
(2)
is the well-known address of the host.
@@ -164,6 +164,15 @@ Consider using
.B VMADDR_CID_ANY
when binding instead of getting the local CID with
.BR IOCTL_VM_SOCKETS_GET_LOCAL_CID .
+.SS Local communication
+.B VMADDR_CID_LOCAL
+(1) directs packets to the same host that generated them. This is useful
+for testing applications on a single host and for debugging.
+.PP
+The local CID obtained with
+.BR IOCTL_VM_SOCKETS_GET_LOCAL_CID
+can be used for the same purpose, but it is preferable to use
+.B VMADDR_CID_LOCAL .
.SH ERRORS
.TP
.B EACCES
@@ -222,6 +231,11 @@ are valid.
Support for VMware (VMCI) has been available since Linux 3.9.
KVM (virtio) is supported since Linux 4.8.
Hyper-V is supported since Linux 4.14.
+.PP
+VMADDR_CID_LOCAL is supported since Linux 5.6.
+Local communication in the guest and on the host is available since Linux 5.6.
+Previous versions only supported local communication within a guest
+(not on the host), and only with some transports (VMCI and virtio).
.SH SEE ALSO
.BR bind (2),
.BR connect (2),
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description
2020-02-18 15:54 [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description Stefano Garzarella
@ 2020-02-19 11:21 ` Stefan Hajnoczi
2020-03-14 22:02 ` Michael Kerrisk (man-pages)
1 sibling, 0 replies; 3+ messages in thread
From: Stefan Hajnoczi @ 2020-02-19 11:21 UTC (permalink / raw)
To: Stefano Garzarella
Cc: mtk.manpages, Jorgen Hansen, netdev, linux-man, Dexuan Cui
[-- Attachment #1: Type: text/plain, Size: 846 bytes --]
On Tue, Feb 18, 2020 at 04:54:35PM +0100, Stefano Garzarella wrote:
> Linux 5.6 added the new well-known VMADDR_CID_LOCAL for
> local communication.
>
> This patch explains how to use it and remove the legacy
> VMADDR_CID_RESERVED no longer available.
>
> Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v4:
> * removed "The" in the "Local communication" section [Stefan]
> v3:
> * rephrased "Previous versions" part [Jorgen]
> v2:
> * rephrased "Local communication" description [Stefan]
> * added a mention of previous versions that supported
> loopback only in the guest [Stefan]
> ---
> man7/vsock.7 | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 488 bytes --]
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description
2020-02-18 15:54 [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description Stefano Garzarella
2020-02-19 11:21 ` Stefan Hajnoczi
@ 2020-03-14 22:02 ` Michael Kerrisk (man-pages)
1 sibling, 0 replies; 3+ messages in thread
From: Michael Kerrisk (man-pages) @ 2020-03-14 22:02 UTC (permalink / raw)
To: Stefano Garzarella
Cc: mtk.manpages, Jorgen Hansen, netdev, linux-man, Stefan Hajnoczi,
Dexuan Cui
Hello Stefano,
On 2/18/20 4:54 PM, Stefano Garzarella wrote:
> Linux 5.6 added the new well-known VMADDR_CID_LOCAL for
> local communication.
>
> This patch explains how to use it and remove the legacy
> VMADDR_CID_RESERVED no longer available.
>
> Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
> Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> ---
> v4:
> * removed "The" in the "Local communication" section [Stefan]
> v3:
> * rephrased "Previous versions" part [Jorgen]
> v2:
> * rephrased "Local communication" description [Stefan]
> * added a mention of previous versions that supported
> loopback only in the guest [Stefan]
Thanks. Patch applied.
Cheers,
Michael
> ---
> man7/vsock.7 | 18 ++++++++++++++++--
> 1 file changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/man7/vsock.7 b/man7/vsock.7
> index c5ffcf07d..fa2c6e17e 100644
> --- a/man7/vsock.7
> +++ b/man7/vsock.7
> @@ -127,8 +127,8 @@ There are several special addresses:
> means any address for binding;
> .B VMADDR_CID_HYPERVISOR
> (0) is reserved for services built into the hypervisor;
> -.B VMADDR_CID_RESERVED
> -(1) must not be used;
> +.B VMADDR_CID_LOCAL
> +(1) is the well-known address for local communication (loopback);
> .B VMADDR_CID_HOST
> (2)
> is the well-known address of the host.
> @@ -164,6 +164,15 @@ Consider using
> .B VMADDR_CID_ANY
> when binding instead of getting the local CID with
> .BR IOCTL_VM_SOCKETS_GET_LOCAL_CID .
> +.SS Local communication
> +.B VMADDR_CID_LOCAL
> +(1) directs packets to the same host that generated them. This is useful
> +for testing applications on a single host and for debugging.
> +.PP
> +The local CID obtained with
> +.BR IOCTL_VM_SOCKETS_GET_LOCAL_CID
> +can be used for the same purpose, but it is preferable to use
> +.B VMADDR_CID_LOCAL .
> .SH ERRORS
> .TP
> .B EACCES
> @@ -222,6 +231,11 @@ are valid.
> Support for VMware (VMCI) has been available since Linux 3.9.
> KVM (virtio) is supported since Linux 4.8.
> Hyper-V is supported since Linux 4.14.
> +.PP
> +VMADDR_CID_LOCAL is supported since Linux 5.6.
> +Local communication in the guest and on the host is available since Linux 5.6.
> +Previous versions only supported local communication within a guest
> +(not on the host), and only with some transports (VMCI and virtio).
> .SH SEE ALSO
> .BR bind (2),
> .BR connect (2),
>
--
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2020-03-15 2:23 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-18 15:54 [PATCH v4] vsock.7: add VMADDR_CID_LOCAL description Stefano Garzarella
2020-02-19 11:21 ` Stefan Hajnoczi
2020-03-14 22:02 ` Michael Kerrisk (man-pages)
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).