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From:   "Tian, Kevin" <kevin.tian@intel.com>
To:     Jason Gunthorpe <jgg@nvidia.com>,
        "Zhao, Yan Y" <yan.y.zhao@intel.com>
CC:     "iommu@lists.linux.dev" <iommu@lists.linux.dev>,
        "kvm@vger.kernel.org" <kvm@vger.kernel.org>,
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        "dwmw2@infradead.org" <dwmw2@infradead.org>,
        "Liu, Yi L" <yi.l.liu@intel.com>
Subject: RE: [RFC PATCH 00/42] Sharing KVM TDP to IOMMU
Thread-Topic: [RFC PATCH 00/42] Sharing KVM TDP to IOMMU
Thread-Index: AQHaJQO3kBR+d+LKkUe3K6mDC1fRXbCZPU8AgAEAytA=
Date:   Tue, 5 Dec 2023 06:30:31 +0000
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References: <20231202091211.13376-1-yan.y.zhao@intel.com>
 <20231204150800.GD1493156@nvidia.com>
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> From: Jason Gunthorpe <jgg@nvidia.com>
> Sent: Monday, December 4, 2023 11:08 PM
>=20
> On Sat, Dec 02, 2023 at 05:12:11PM +0800, Yan Zhao wrote:
> > - How to map MSI page on arm platform demands discussions.
>=20
> Yes, the recurring problem :(
>=20
> Probably the same approach as nesting would work for a hack - map the
> ITS page into the fixed reserved slot and tell the guest not to touch
> it and to identity map it.
>=20

yes logically it should follow what is planned for nesting.

just that kvm needs to involve more iommu specific knowledge e.g.
iommu_get_msi_cookie() to reserve the slot.