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From:   "Michael Kelley (LINUX)" <mikelley@microsoft.com>
To:     Wei Liu <wei.liu@kernel.org>,
        Jinank Jain <jinankjain@linux.microsoft.com>,
        "g@liuwe-devbox-debian-v2" <g@liuwe-devbox-debian-v2>
CC:     Jinank Jain <jinankjain@microsoft.com>,
        KY Srinivasan <kys@microsoft.com>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Dexuan Cui <decui@microsoft.com>,
        "lpieralisi@kernel.org" <lpieralisi@kernel.org>,
        "kw@linux.com" <kw@linux.com>, "robh@kernel.org" <robh@kernel.org>,
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        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "nunodasneves@linux.microsoft.com" <nunodasneves@linux.microsoft.com>
Subject: RE: [PATCH] PCI: hv: Use nested hypercall for retargeting interrupts
Thread-Topic: [PATCH] PCI: hv: Use nested hypercall for retargeting interrupts
Thread-Index: AQHZZum56E4siTE08ESEN+SkV6gZ4K8ofwKAgAAbefA=
Date:   Thu, 13 Apr 2023 03:05:09 +0000
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From: Wei Liu <wei.liu@kernel.org> Sent: Wednesday, April 12, 2023 6:23 PM
>=20
> 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>
>=20
> Applied to hyperv-next. Thanks.

I'd like to hold off on taking this change.  Nuno and I are discussing
how best to handle nested hypercalls.  In addition to the proposed
nested changes,  we have hypercall changes coming as part of the
TDX and fully enlightened SNP patch sets.  If possible, I'd like to
avoid adding logic at the hv_do_hypercall() call sites.  It's not clear
whether avoiding such logic will really be feasible, but I'd like to
think about it for a bit before reaching that conclusion.

Michael