Re: [PATCH hyperv-next v4 09/16] Drivers: hv: Check message and event pages for non-NULL before iounmap()

[Tianyu Lan]

On Tue, Jul 15, 2025 at 6:16 AM Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx> wrote:
>
> It might happen that some hyp SynIC pages aren't allocated.
>
> Check for that and only then call iounmap().
>
> Signed-off-by: Roman Kisel <romank@xxxxxxxxxxxxxxxxxxx>
> ---
>  drivers/hv/hv.c | 12 ++++++++----
>  1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
> index 820711e954d1..a8669843c56e 100644
> --- a/drivers/hv/hv.c
> +++ b/drivers/hv/hv.c
> @@ -367,8 +367,10 @@ void hv_synic_disable_regs(unsigned int cpu)
>          */
>         simp.simp_enabled = 0;
>         if (ms_hyperv.paravisor_present || hv_root_partition()) {
> -               iounmap(hv_cpu->hyp_synic_message_page);
> -               hv_cpu->hyp_synic_message_page = NULL;
> +               if (hv_cpu->hyp_synic_message_page) {
> +                       iounmap(hv_cpu->hyp_synic_message_page);
> +                       hv_cpu->hyp_synic_message_page = NULL;
> +               }
>         } else {
>                 simp.base_simp_gpa = 0;
>         }
> @@ -379,8 +381,10 @@ void hv_synic_disable_regs(unsigned int cpu)
>         siefp.siefp_enabled = 0;
>
>         if (ms_hyperv.paravisor_present || hv_root_partition()) {
> -               iounmap(hv_cpu->hyp_synic_event_page);
> -               hv_cpu->hyp_synic_event_page = NULL;
> +               if (hv_cpu->hyp_synic_event_page) {
> +                       iounmap(hv_cpu->hyp_synic_event_page);
> +                       hv_cpu->hyp_synic_event_page = NULL;
> +               }
>         } else {
>                 siefp.base_siefp_gpa = 0;
>         }
> --
> 2.43.0
>
>

Reviewed-by: Tianyu Lan <tiala@xxxxxxxxxxxxx>
-- 
Thanks
Tianyu Lan