Re: [PATCH v2 04/17] iommu/hyperv: don't setup IRQ remapping when running as root

From: Vitaly Kuznetsov
Date: Thu Nov 12 2020 - 10:27:24 EST


Wei Liu <wei.liu@xxxxxxxxxx> writes:

> The IOMMU code needs more work. We're sure for now the IRQ remapping
> hooks are not applicable when Linux is the root.

Super-nitpick: I would suggest we always say 'root partition' as 'root'
has a 'slightly different' meaning in Linux and this commit message may
sound confusing to an unprepared reader.

>
> Signed-off-by: Wei Liu <wei.liu@xxxxxxxxxx>
> Acked-by: Joerg Roedel <jroedel@xxxxxxx>
> ---
> drivers/iommu/hyperv-iommu.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/iommu/hyperv-iommu.c b/drivers/iommu/hyperv-iommu.c
> index e09e2d734c57..8d3ce3add57d 100644
> --- a/drivers/iommu/hyperv-iommu.c
> +++ b/drivers/iommu/hyperv-iommu.c
> @@ -20,6 +20,7 @@
> #include <asm/io_apic.h>
> #include <asm/irq_remapping.h>
> #include <asm/hypervisor.h>
> +#include <asm/mshyperv.h>
>
> #include "irq_remapping.h"
>
> @@ -143,7 +144,7 @@ static int __init hyperv_prepare_irq_remapping(void)
> int i;
>
> if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) ||
> - !x2apic_supported())
> + !x2apic_supported() || hv_root_partition)
> return -ENODEV;
>
> fn = irq_domain_alloc_named_id_fwnode("HYPERV-IR", 0);

Reviewed-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

--
Vitaly