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Subject: Re: [PATCH v8 4/4] vfio: convey kvm that the vfio-pci device is wc
 safe
Thread-Topic: [PATCH v8 4/4] vfio: convey kvm that the vfio-pci device is wc
 safe
Thread-Index: AQHaY87ElOqCfNqv40aGQwk3/xRuTbES/mYAgAAlXLw=
Date: Tue, 20 Feb 2024 12:11:19 +0000
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References: <20240220072926.6466-1-ankita@nvidia.com>
 <20240220072926.6466-5-ankita@nvidia.com> <ZdR3MI_4pqV0EZcR@arm.com>
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>> diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pc=
i_core.c=0A=
>> index 1cbc990d42e0..c93bea18fc4b 100644=0A=
>> --- a/drivers/vfio/pci/vfio_pci_core.c=0A=
>> +++ b/drivers/vfio/pci/vfio_pci_core.c=0A=
>> @@ -1862,8 +1862,24 @@ int vfio_pci_core_mmap(struct vfio_device *core_v=
dev, struct vm_area_struct *vma=0A=
>>=A0=A0=A0=A0=A0=A0 /*=0A=
>>=A0=A0=A0=A0=A0=A0=A0 * See remap_pfn_range(), called from vfio_pci_fault=
() but we can't=0A=
>>=A0=A0=A0=A0=A0=A0=A0 * change vm_flags within the fault handler.=A0 Set =
them now.=0A=
>> +=A0=A0=A0=A0=A0 *=0A=
>> +=A0=A0=A0=A0=A0 * VM_ALLOW_ANY_UNCACHED: The VMA flag is implemented fo=
r ARM64,=0A=
>> +=A0=A0=A0=A0=A0 * allowing KVM stage 2 device mapping attributes to use=
 Normal-NC=0A=
>> +=A0=A0=A0=A0=A0 * rather than DEVICE_nGnRE, which allows guest mappings=
=0A=
>> +=A0=A0=A0=A0=A0 * supporting combining attributes (WC). ARM does not=0A=
>=0A=
> Nitpick: "supporting write-combining" (if you plan to respin).=0A=
=0A=
Ack.=