diff mbox

docs: Specify VCPU hotplug procedure for HVMlite guests

Message ID 1454515899-1787-1-git-send-email-boris.ostrovsky@oracle.com
State New, archived
Headers show

Commit Message

Boris Ostrovsky Feb. 3, 2016, 4:11 p.m. UTC
HVMlite VCPUs can be added and removed by toggling 'availability'
value of VCPU's xenstore entry.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---

I am not sure this is really needed since it's no different from how we
do hotplug for PV or HVM/qemu-trad guests.

I may have been a bit too grandiose by describing yesterday's patch as
"add CPU hotplug support". It was really enabling existing functionality.

 docs/misc/hvmlite.markdown | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Wei Liu Feb. 3, 2016, 4:20 p.m. UTC | #1
On Wed, Feb 03, 2016 at 11:11:39AM -0500, Boris Ostrovsky wrote:
> HVMlite VCPUs can be added and removed by toggling 'availability'
> value of VCPU's xenstore entry.
> 
> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
> ---
> 
> I am not sure this is really needed since it's no different from how we
> do hotplug for PV or HVM/qemu-trad guests.
> 

There is no harm to have more document. Not everyone who wants to
implement PVH support is familiar with PV and / or want to look at Linux
and libxl code (for various reasons). ;-)

Wei.

> I may have been a bit too grandiose by describing yesterday's patch as
> "add CPU hotplug support". It was really enabling existing functionality.
> 
>  docs/misc/hvmlite.markdown | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/docs/misc/hvmlite.markdown b/docs/misc/hvmlite.markdown
> index c1b75c6..1a2e866 100644
> --- a/docs/misc/hvmlite.markdown
> +++ b/docs/misc/hvmlite.markdown
> @@ -80,3 +80,8 @@ are used in order to bring up secondary vCPUs:
>   * `VCPUOP_down` is used to bring down a vCPU.
>  
>   * `VCPUOP_is_up` is used to scan the number of available vCPUs.
> +
> +## VCPU hotplug ##
> +
> +VCPUs can be hot-plugged or hot-removed by writing "online" or "offline" to
> +xenstore's /local/domain/<domain_id>/cpu/<vcpu_id>/availability entry
> -- 
> 2.1.0
>
diff mbox

Patch

diff --git a/docs/misc/hvmlite.markdown b/docs/misc/hvmlite.markdown
index c1b75c6..1a2e866 100644
--- a/docs/misc/hvmlite.markdown
+++ b/docs/misc/hvmlite.markdown
@@ -80,3 +80,8 @@  are used in order to bring up secondary vCPUs:
  * `VCPUOP_down` is used to bring down a vCPU.
 
  * `VCPUOP_is_up` is used to scan the number of available vCPUs.
+
+## VCPU hotplug ##
+
+VCPUs can be hot-plugged or hot-removed by writing "online" or "offline" to
+xenstore's /local/domain/<domain_id>/cpu/<vcpu_id>/availability entry