Re: [PATCH] spapr: change default interrupt mode back to 'xics'

[Greg Kurz]

On Tue,  5 Nov 2019 15:17:44 -0600
Lijun Pan <address@hidden> wrote:

> The hugetlbfs hugepage leakage is found under following test procedures:
> 1. configure hugetlbfs to back guest memory with '-mem-path /dev/hugepages'
> 2. hot plug a vcpu and remove it, then quit the guest.
> 3. hugepage leaks found on the host
> 
> git bisect points to the first bad commit: bd94bc064.
> 

Hmmm... Have you investigated some more to understand what's really
happening here ? Is it a problem with QEMU or KVM ? Does it also happen
if you don't use the in-kernel irqchip ?

Please provide more details because reverting to XICS looks like a big
hammer/workaround to me.

> Fixes: bd94bc064 ("spapr: change default interrupt mode to 'dual'")
> Cc: Cédric Le Goater <address@hidden>
> Cc: David Gibson <address@hidden>
> Signed-off-by: Lijun Pan <address@hidden>
> ---
>  hw/ppc/spapr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 94f9d27096..26b064fb6c 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -4437,7 +4437,7 @@ static void spapr_machine_class_init(ObjectClass *oc, 
> void *data)
>      smc->default_caps.caps[SPAPR_CAP_LARGE_DECREMENTER] = SPAPR_CAP_ON;
>      smc->default_caps.caps[SPAPR_CAP_CCF_ASSIST] = SPAPR_CAP_OFF;
>      spapr_caps_add_properties(smc, &error_abort);
> -    smc->irq = &spapr_irq_dual;
> +    smc->irq = &spapr_irq_xics;
>      smc->dr_phb_enabled = true;
>      smc->linux_pci_probe = true;
>      smc->smp_threads_vsmt = true;