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Subject: Re: [PATCH AUTOSEL 5.14 38/99] KVM: PPC: Book3S HV: XICS: Fix mapping
 of passthrough interrupts
To:     Sasha Levin <sashal@kernel.org>
CC:     <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>,
        Michael Ellerman <mpe@ellerman.id.au>,
        <kvm-ppc@vger.kernel.org>, <linuxppc-dev@lists.ozlabs.org>
References: <20210910001558.173296-1-sashal@kernel.org>
 <20210910001558.173296-38-sashal@kernel.org>
 <27739836-bad2-6b3f-7f40-e84663fbbf24@kaod.org> <YTy+xUtEEpln2Sq4@sashalap>
From:   =?UTF-8?Q?C=c3=a9dric_Le_Goater?= <clg@kaod.org>
Message-ID: <90cd638d-62d2-8c98-cce0-4c71feee8671@kaod.org>
Date:   Mon, 13 Sep 2021 18:19:33 +0200
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On 9/11/21 4:35 PM, Sasha Levin wrote:
> On Fri, Sep 10, 2021 at 07:48:18AM +0200, Cédric Le Goater wrote:
>> On 9/10/21 2:14 AM, Sasha Levin wrote:
>>> From: Cédric Le Goater <clg@kaod.org>
>>>
>>> [ Upstream commit 1753081f2d445f9157550692fcc4221cd3ff0958 ]
>>>
>>> PCI MSIs now live in an MSI domain but the underlying calls, which
>>> will EOI the interrupt in real mode, need an HW IRQ number mapped in
>>> the XICS IRQ domain. Grab it there.
>>>
>>> Signed-off-by: Cédric Le Goater <clg@kaod.org>
>>> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
>>> Link: https://lore.kernel.org/r/20210701132750.1475580-31-clg@kaod.org
>>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>>
>>
>> Why are we backporting this patch in stable trees ?
>>
>> It should be fine but to compile, we need a partial backport of commit
>> 51be9e51a800 ("KVM: PPC: Book3S HV: XIVE: Fix mapping of passthrough
>> interrupts") which exports irq_get_default_host().
> 
> Or, I can drop it if it makes no sense?

Yes I would. 

It makes sense only with the full patchset, the one reworking PCI MSI 
support in the PPC pSeries and PowerNV platforms.

Thanks,

C.