[PATCH qemu-server] config: schema: add option to disable hugepages

[PATCH qemu-server] config: schema: add option to disable hugepages

[Maximiliano Sandoval]

Most other options have admit a value for explicitly disabling a feature.

Signed-off-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
---

Notes:
    I 'grep'ed the source and the truthiness of 0 (we do not use
    defined($conf->{hugepages}) anywhere) should keep all existing codepaths as they
    were if the value is not used.
    
    Tested on a PVE VM. Ran:
    
    - qm set 100 --hugepages 0 && qm start 100
    - head /sys/kernel/mm/hugepages/hugepages-*kB/nr_hugepages
    - qm set 100 --hugepages 0 --numa 1 && qm start 100
    - head /sys/kernel/mm/hugepages/hugepages-*kB/nr_hugepages
    
    In both cases the VM stats and no hugepages were used.

 src/PVE/QemuServer.pm | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
index 59a37098..f8b986f5 100644
--- a/src/PVE/QemuServer.pm
+++ b/src/PVE/QemuServer.pm
@@ -438,8 +438,8 @@ EODESC
         description =>
             "Enables hugepages memory.\n\nSets the size of hugepages in MiB. If the value "
             . "is set to 'any' then 1 GiB hugepages will be used if possible, "
-            . "otherwise the size will fall back to 2 MiB.",
-        enum => [qw(any 2 1024)],
+            . "otherwise the size will fall back to 2 MiB. When set to 0, hugepages will not be used.",
+        enum => [qw(any 0 2 1024)],
     },
     keephugepages => {
         optional => 1,
-- 
2.47.3

Re: [PATCH qemu-server] config: schema: add option to disable hugepages

[Maximiliano Sandoval]

Maximiliano Sandoval <m.sandoval@proxmox.com> writes:

> Most other options have admit a value for explicitly disabling a feature.

The `have` should be removed from the commit message.

-- 
Maximiliano

Re: [PATCH qemu-server] config: schema: add option to disable hugepages

[Fabian Grünbichler]

On July 8, 2026 1:48 pm, Maximiliano Sandoval wrote:
> Most other options have admit a value for explicitly disabling a feature.

this is not true, for most options other than booleans disabling means
not setting it?

> 
> Signed-off-by: Maximiliano Sandoval <m.sandoval@proxmox.com>
> ---
> 
> Notes:
>     I 'grep'ed the source and the truthiness of 0 (we do not use
>     defined($conf->{hugepages}) anywhere) should keep all existing codepaths as they
>     were if the value is not used.
>     
>     Tested on a PVE VM. Ran:
>     
>     - qm set 100 --hugepages 0 && qm start 100
>     - head /sys/kernel/mm/hugepages/hugepages-*kB/nr_hugepages
>     - qm set 100 --hugepages 0 --numa 1 && qm start 100
>     - head /sys/kernel/mm/hugepages/hugepages-*kB/nr_hugepages
>     
>     In both cases the VM stats and no hugepages were used.
> 
>  src/PVE/QemuServer.pm | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/src/PVE/QemuServer.pm b/src/PVE/QemuServer.pm
> index 59a37098..f8b986f5 100644
> --- a/src/PVE/QemuServer.pm
> +++ b/src/PVE/QemuServer.pm
> @@ -438,8 +438,8 @@ EODESC
>          description =>
>              "Enables hugepages memory.\n\nSets the size of hugepages in MiB. If the value "
>              . "is set to 'any' then 1 GiB hugepages will be used if possible, "
> -            . "otherwise the size will fall back to 2 MiB.",
> -        enum => [qw(any 2 1024)],
> +            . "otherwise the size will fall back to 2 MiB. When set to 0, hugepages will not be used.",
> +        enum => [qw(any 0 2 1024)],
>      },
>      keephugepages => {
>          optional => 1,
> -- 
> 2.47.3
> 
> 
> 
> 
> 
>