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Date:   Wed, 2 Mar 2022 09:50:21 +0000
From:   Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To:     Boqun Feng <boqun.feng@gmail.com>
Cc:     Wei Liu <wei.liu@kernel.org>,
        "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
        Sunil Muthuswamy <sunilmut@linux.microsoft.com>,
        KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Stephen Hemminger <sthemmin@microsoft.com>,
        Dexuan Cui <decui@microsoft.com>,
        Rob Herring <robh@kernel.org>,
        Krzysztof =?utf-8?Q?Wilczy=C5=84ski?= <kw@linux.com>,
        Bjorn Helgaas <bhelgaas@google.com>,
        "linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC PATCH v2] PCI: hv: Avoid the retarget interrupt hypercall
 in irq_unmask() on ARM64
Message-ID: <Yh893bdBf7P2z+nY@lpieralisi>
References: <20220217034525.1687678-1-boqun.feng@gmail.com>
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On Wed, Mar 02, 2022 at 11:13:05AM +0800, Boqun Feng wrote:
> On Mon, Feb 21, 2022 at 05:56:00PM +0000, Wei Liu wrote:
> > On Thu, Feb 17, 2022 at 04:31:06PM +0000, Michael Kelley (LINUX) wrote:
> > > From: Boqun Feng <boqun.feng@gmail.com> Sent: Wednesday, February 16, 2022 7:45 PM
> > > > 
> > > > On ARM64 Hyper-V guests, SPIs are used for the interrupts of virtual PCI
> > > > devices, and SPIs can be managed directly via GICD registers. Therefore
> > > > the retarget interrupt hypercall is not needed on ARM64.
> > > > 
> > > > An arch-specific interface hv_arch_irq_unmask() is introduced to handle
> > > > the architecture level differences on this. For x86, the behavior
> > > > remains unchanged, while for ARM64 no hypercall is invoked when
> > > > unmasking an irq for virtual PCI devices.
> > > > 
> > > > Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
> > > > ---
> > > > v1 -> v2:
> > > > 
> > > > *	Introduce arch-specific interface hv_arch_irq_unmask() as
> > > > 	suggested by Bjorn
> > > > 
> > > >  drivers/pci/controller/pci-hyperv.c | 233 +++++++++++++++-------------
> > > >  1 file changed, 122 insertions(+), 111 deletions(-)
> > > 
> > > Reviewed-by: Michael Kelley <mikelley@microsoft.com>
> > 
> > I expect this to go through the PCI tree. Let me know if I should pick
> > this up.
> > 
> 
> I also expect the same.
> 
> Lorenzo, let me know if there is more work needed for this patch.
> Thanks!

It is tagged as an RFC that's why I have not considered it for v5.18,
I will have a look shortly.

Thanks,
Lorenzo