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Date:   Wed, 5 Apr 2023 23:17:41 +0000
From:   Wei Liu <wei.liu@kernel.org>
To:     Jinank Jain <jinankjain@linux.microsoft.com>
Cc:     jinankjain@microsoft.com, kys@microsoft.com,
        haiyangz@microsoft.com, wei.liu@kernel.org, decui@microsoft.com,
        lpieralisi@kernel.org, kw@linux.com, robh@kernel.org,
        bhelgaas@google.com, linux-hyperv@vger.kernel.org,
        linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
        nunodasneves@linux.microsoft.com
Subject: Re: [PATCH] PCI: hv: Use nested hypercall for retargeting interrupts
Message-ID: <ZC4BlSo0D1uNliFk@liuwe-devbox-debian-v2>
References: <20230404113546.856813-1-jinankjain@linux.microsoft.com>
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On Tue, Apr 04, 2023 at 11:35:46AM +0000, Jinank Jain wrote:
> In case of nested MSHV, retargeting interrupt hypercall should be sent
> to L0 hypervisor instead of L1 hypervisor.
> 
> Signed-off-by: Jinank Jain <jinankjain@linux.microsoft.com>

While I think this is a sensible change -- how did you discover this?
Can you provide a bit more information?

> ---
>  drivers/pci/controller/pci-hyperv.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/pci/controller/pci-hyperv.c b/drivers/pci/controller/pci-hyperv.c
> index f33370b75628..2123f632ecf7 100644
> --- a/drivers/pci/controller/pci-hyperv.c
> +++ b/drivers/pci/controller/pci-hyperv.c
> @@ -704,8 +704,14 @@ static void hv_arch_irq_unmask(struct irq_data *data)
>  		}
>  	}
>  
> -	res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT | (var_size << 17),
> -			      params, NULL);
> +	if (hv_nested)
> +		res = hv_do_nested_hypercall(HVCALL_RETARGET_INTERRUPT |
> +					     (var_size << 17),
> +					     params, NULL);
> +	else
> +		res = hv_do_hypercall(HVCALL_RETARGET_INTERRUPT |
> +				      (var_size << 17),
> +				      params, NULL);
>  
>  exit_unlock:
>  	spin_unlock_irqrestore(&hbus->retarget_msi_interrupt_lock, flags);
> -- 
> 2.34.1
>