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Message-ID: <354a1247-056c-076f-850c-cda78f00c628@gmail.com>
Date:   Fri, 18 Nov 2022 11:01:53 +0800
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Subject: Re: [PATCH v2] iommu/hyper-v: Allow hyperv irq remapping without
 x2apic
To:     Nuno Das Neves <nunodasneves@linux.microsoft.com>,
        linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
        iommu@lists.linux.dev
Cc:     mikelley@microsoft.com, sunilmut@microsoft.com, wei.liu@kernel.org,
        kys@microsoft.com, Tianyu.Lan@microsoft.com,
        haiyangz@microsoft.com, decui@microsoft.com, dwmw2@infradead.org,
        joro@8bytes.org, will@kernel.org
References: <1668715899-8971-1-git-send-email-nunodasneves@linux.microsoft.com>
Content-Language: en-US
From:   Tianyu Lan <ltykernel@gmail.com>
In-Reply-To: <1668715899-8971-1-git-send-email-nunodasneves@linux.microsoft.com>
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On 11/18/2022 4:11 AM, Nuno Das Neves wrote:
> If x2apic is not available, hyperv-iommu skips remapping
> irqs. This breaks root partition which always needs irqs
> remapped.
> 
> Fix this by allowing irq remapping regardless of x2apic,
> and change hyperv_enable_irq_remapping() to return
> IRQ_REMAP_XAPIC_MODE in case x2apic is missing.
> 
> Tested with root and non-root hyperv partitions.
> 
> Signed-off-by: Nuno Das Neves<nunodasneves@linux.microsoft.com>
> ---
>   arch/x86/kernel/cpu/mshyperv.c |  6 ++++++
>   drivers/iommu/Kconfig          |  6 +++---
>   drivers/iommu/hyperv-iommu.c   | 11 ++++++++---
>   3 files changed, 17 insertions(+), 6 deletions(-)


Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>