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References: <20210120120058.29138-1-wei.liu@kernel.org> <20210120120058.29138-5-wei.liu@kernel.org>
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From:   Pavel Tatashin <pasha.tatashin@soleen.com>
Date:   Wed, 20 Jan 2021 11:08:34 -0500
Message-ID: <CA+CK2bByGvCr_H3_wv_3-vAOONhRenonFNeHff5UdeFLDxSoUw@mail.gmail.com>
Subject: Re: [PATCH v5 04/16] iommu/hyperv: don't setup IRQ remapping when
 running as root
To:     Wei Liu <wei.liu@kernel.org>
Cc:     Linux on Hyper-V List <linux-hyperv@vger.kernel.org>,
        virtualization@lists.linux-foundation.org,
        Linux Kernel List <linux-kernel@vger.kernel.org>,
        Michael Kelley <mikelley@microsoft.com>,
        Vineeth Pillai <viremana@linux.microsoft.com>,
        Sunil Muthuswamy <sunilmut@microsoft.com>,
        Nuno Das Neves <nunodasneves@linux.microsoft.com>,
        Joerg Roedel <jroedel@suse.de>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        "K. Y. Srinivasan" <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        "open list:IOMMU DRIVERS" <iommu@lists.linux-foundation.org>
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On Wed, Jan 20, 2021 at 7:01 AM Wei Liu <wei.liu@kernel.org> wrote:
>
> The IOMMU code needs more work. We're sure for now the IRQ remapping
> hooks are not applicable when Linux is the root partition.
>
> Signed-off-by: Wei Liu <wei.liu@kernel.org>
> Acked-by: Joerg Roedel <jroedel@suse.de>
> Reviewed-by: Vitaly Kuznetsov <vkuznets@redhat.com>
> ---
>  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 1d21a0b5f724..b7db6024e65c 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"
>
> @@ -122,7 +123,7 @@ static int __init hyperv_prepare_irq_remapping(void)
>
>         if (!hypervisor_is_type(X86_HYPER_MS_HYPERV) ||
>             x86_init.hyper.msi_ext_dest_id() ||
> -           !x2apic_supported())
> +           !x2apic_supported() || hv_root_partition)
>                 return -ENODEV;

Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>