From: Nicolin Chen <nicolinc@nvidia.com>
To: "Duan, Zhenzhong" <zhenzhong.duan@intel.com>
Cc: "eric.auger@redhat.com" <eric.auger@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"clg@redhat.com" <clg@redhat.com>,
"mst@redhat.com" <mst@redhat.com>,
"jasowang@redhat.com" <jasowang@redhat.com>,
"peterx@redhat.com" <peterx@redhat.com>,
"ddutile@redhat.com" <ddutile@redhat.com>,
"jgg@nvidia.com" <jgg@nvidia.com>,
"skolothumtho@nvidia.com" <skolothumtho@nvidia.com>,
"joao.m.martins@oracle.com" <joao.m.martins@oracle.com>,
"clement.mathieu--drif@eviden.com"
<clement.mathieu--drif@eviden.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
"Liu, Yi L" <yi.l.liu@intel.com>,
"Peng, Chao P" <chao.p.peng@intel.com>
Subject: Re: [PATCH v7 09/23] intel_iommu: Stick to system MR for IOMMUFD backed host device when x-flts=on
Date: Tue, 4 Nov 2025 18:45:47 -0800 [thread overview]
Message-ID: <aQq6W3EHf0rM0x2Z@Asurada-Nvidia> (raw)
In-Reply-To: <IA3PR11MB9136B987085148D724C0144092F8A@IA3PR11MB9136.namprd11.prod.outlook.com>
On Fri, Oct 31, 2025 at 09:52:16AM +0000, Duan, Zhenzhong wrote:
> >> + /*
> >> + * When guest enables scalable mode and sets up first stage page
> >table,
> >> + * we stick to system MR for IOMMUFD backed host device. Then its
> >> + * default hwpt contains GPA->HPA mappings which is used directly if
> >> + * PGTT=PT and used as nesting parent if PGTT=FST. Otherwise fall
> >back
> >> + * to original processing.
> >According to the above comment you have a S1 translation in place but
> >you set use_iommu = false and use system MR?
>
> Yes, we have extended the usages of MRs under IOMMU AS with nesting.
> In nesting mode, system MR on/off isn't aligned with S1 translation anymore.
Does Intel vIOMMU need S1 translation when the working in the HW
accelerated mode? I thought everything is handled by the HW..no?
Nicolin
next prev parent reply other threads:[~2025-11-05 2:47 UTC|newest]
Thread overview: 63+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-24 8:43 [PATCH v7 00/23] intel_iommu: Enable first stage translation for passthrough device Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 01/23] intel_iommu: Rename vtd_ce_get_rid2pasid_entry to vtd_ce_get_pasid_entry Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 02/23] intel_iommu: Delete RPS capability related supporting code Zhenzhong Duan
2025-10-31 7:50 ` Eric Auger
2025-10-31 9:49 ` Duan, Zhenzhong
2025-10-24 8:43 ` [PATCH v7 03/23] intel_iommu: Update terminology to match VTD spec Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 04/23] hw/pci: Export pci_device_get_iommu_bus_devfn() and return bool Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 05/23] hw/pci: Introduce pci_device_get_viommu_flags() Zhenzhong Duan
2025-10-24 17:18 ` Cédric Le Goater
2025-10-28 6:57 ` Duan, Zhenzhong
2025-10-28 15:19 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 06/23] intel_iommu: Implement get_viommu_flags() callback Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 07/23] intel_iommu: Introduce a new structure VTDHostIOMMUDevice Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 08/23] vfio/iommufd: Force creating nesting parent HWPT Zhenzhong Duan
2025-10-24 16:23 ` Cédric Le Goater
2025-10-28 6:00 ` Duan, Zhenzhong
2025-10-24 8:43 ` [PATCH v7 09/23] intel_iommu: Stick to system MR for IOMMUFD backed host device when x-flts=on Zhenzhong Duan
2025-10-31 8:09 ` Eric Auger
2025-10-31 9:52 ` Duan, Zhenzhong
2025-11-05 2:45 ` Nicolin Chen [this message]
2025-10-24 8:43 ` [PATCH v7 10/23] intel_iommu: Check for compatibility with IOMMUFD backed " Zhenzhong Duan
2025-10-24 17:29 ` Cédric Le Goater
2025-10-29 7:37 ` Duan, Zhenzhong
2025-10-24 8:43 ` [PATCH v7 11/23] intel_iommu: Fail passthrough device under PCI bridge if x-flts=on Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 12/23] intel_iommu: Add some macros and inline functions Zhenzhong Duan
2025-10-24 16:39 ` Cédric Le Goater
2025-10-28 6:01 ` Duan, Zhenzhong
2025-11-02 11:15 ` Eric Auger
2025-11-03 3:44 ` Duan, Zhenzhong
2025-11-03 7:23 ` Eric Auger
2025-11-06 4:25 ` Duan, Zhenzhong
2025-10-24 8:43 ` [PATCH v7 13/23] intel_iommu: Bind/unbind guest page table to host Zhenzhong Duan
2025-10-24 17:01 ` Cédric Le Goater
2025-11-03 9:25 ` Eric Auger
2025-10-24 17:33 ` Cédric Le Goater
2025-10-29 9:56 ` Duan, Zhenzhong
2025-11-03 9:37 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 14/23] intel_iommu: Propagate PASID-based iotlb invalidation " Zhenzhong Duan
2025-11-03 10:04 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 15/23] intel_iommu: Replay all pasid bindings when either SRTP or TE bit is changed Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 16/23] intel_iommu: Replay pasid bindings after context cache invalidation Zhenzhong Duan
2025-11-03 10:45 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 17/23] iommufd: Introduce a helper function to extract vendor capabilities Zhenzhong Duan
2025-10-24 16:44 ` Cédric Le Goater
2025-10-28 9:43 ` Duan, Zhenzhong
2025-10-24 17:34 ` Cédric Le Goater
2025-10-28 9:28 ` Duan, Zhenzhong
2025-11-03 12:57 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 18/23] vfio: Add a new element bypass_ro in VFIOContainer Zhenzhong Duan
2025-11-03 13:01 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 19/23] Workaround for ERRATA_772415_SPR17 Zhenzhong Duan
2025-10-24 17:36 ` Cédric Le Goater
2025-10-24 17:38 ` Cédric Le Goater
2025-11-03 13:14 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 20/23] vfio: Bypass readonly region for dirty tracking Zhenzhong Duan
2025-10-24 16:32 ` Cédric Le Goater
2025-10-28 9:47 ` Duan, Zhenzhong
2025-11-03 13:07 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 21/23] intel_iommu: Add migration support with x-flts=on Zhenzhong Duan
2025-11-03 13:16 ` Eric Auger
2025-10-24 8:43 ` [PATCH v7 22/23] intel_iommu: Enable host device when x-flts=on in scalable mode Zhenzhong Duan
2025-10-24 8:43 ` [PATCH v7 23/23] docs/devel: Add IOMMUFD nesting documentation Zhenzhong Duan
2025-11-03 13:23 ` Eric Auger
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