From: Jason Gunthorpe <jgg@nvidia.com>
To: "Liu, Yi L" <yi.l.liu@intel.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>,
"alex.williamson@redhat.com" <alex.williamson@redhat.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"cohuck@redhat.com" <cohuck@redhat.com>,
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"nicolinc@nvidia.com" <nicolinc@nvidia.com>,
"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
"mjrosato@linux.ibm.com" <mjrosato@linux.ibm.com>,
"chao.p.peng@linux.intel.com" <chao.p.peng@linux.intel.com>,
"yi.y.sun@linux.intel.com" <yi.y.sun@linux.intel.com>,
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"shameerali.kolothum.thodi@huawei.com"
<shameerali.kolothum.thodi@huawei.com>,
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"intel-gvt-dev@lists.freedesktop.org"
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"linux-s390@vger.kernel.org" <linux-s390@vger.kernel.org>,
"Hao, Xudong" <xudong.hao@intel.com>,
"Zhao, Yan Y" <yan.y.zhao@intel.com>,
"Xu, Terrence" <terrence.xu@intel.com>,
"Jiang, Yanting" <yanting.jiang@intel.com>,
"Duan, Zhenzhong" <zhenzhong.duan@intel.com>
Subject: Re: [PATCH v4 6/9] iommufd: Reserved -1 in the iommufd xarray
Date: Thu, 27 Apr 2023 08:55:19 -0300 [thread overview]
Message-ID: <ZEpip09rdbm4czt8@nvidia.com> (raw)
In-Reply-To: <DS0PR11MB752976E4A6838A6769EB1120C36A9@DS0PR11MB7529.namprd11.prod.outlook.com>
On Thu, Apr 27, 2023 at 07:09:38AM +0000, Liu, Yi L wrote:
> > > @@ -50,7 +53,7 @@ struct iommufd_object *_iommufd_object_alloc(struct
> > > iommufd_ctx *ictx,
> > > * before calling iommufd_object_finalize().
> > > */
> > > rc = xa_alloc(&ictx->objects, &obj->id, XA_ZERO_ENTRY,
> > > - xa_limit_32b, GFP_KERNEL_ACCOUNT);
> > > + iommufd_xa_limit_32b, GFP_KERNEL_ACCOUNT);
> >
> > Just direct use XA_LIMIT() here.
>
> Ok.
>
> > btw do we need a contract so vfio can learn 0 and -1 are reserved or
> > fine to have a fixed assumption in later patches?
>
> I doubt how to do it. ☹ @Jason? What about your opinion?
It is probably fine to use xa_limit_31b and just say that -ve values
are reserved in a comment near the define for 0
Jason
next prev parent reply other threads:[~2023-04-27 11:55 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-26 14:54 [PATCH v4 0/9] Enhance vfio PCI hot reset for vfio cdev device Yi Liu
2023-04-26 14:54 ` [PATCH v4 1/9] vfio: Determine noiommu in vfio_device registration Yi Liu
2023-04-27 6:36 ` Tian, Kevin
2023-04-27 7:05 ` Liu, Yi L
2023-04-27 18:35 ` Alex Williamson
2023-04-26 14:54 ` [PATCH v4 2/9] vfio-iommufd: Create iommufd_access for noiommu devices Yi Liu
2023-04-27 6:39 ` Tian, Kevin
2023-04-27 6:59 ` Liu, Yi L
2023-04-27 18:32 ` Alex Williamson
2023-04-28 6:21 ` Yi Liu
2023-04-28 7:00 ` Tian, Kevin
2023-04-28 7:04 ` Yi Liu
2023-04-28 12:07 ` Jason Gunthorpe
2023-04-28 16:07 ` Yi Liu
2023-05-02 18:12 ` Jason Gunthorpe
2023-05-03 9:48 ` Liu, Yi L
2023-05-03 19:42 ` Jason Gunthorpe
2023-05-08 15:46 ` Liu, Yi L
2023-04-28 16:13 ` Yi Liu
2023-05-02 18:22 ` Jason Gunthorpe
2023-05-03 9:57 ` Liu, Yi L
2023-05-03 19:41 ` Jason Gunthorpe
2023-05-03 22:49 ` Alex Williamson
2023-04-26 14:54 ` [PATCH v4 3/9] vfio/pci: Update comment around group_fd get in vfio_pci_ioctl_pci_hot_reset() Yi Liu
2023-04-26 14:54 ` [PATCH v4 4/9] vfio/pci: Move the existing hot reset logic to be a helper Yi Liu
2023-04-27 6:39 ` Tian, Kevin
2023-04-26 14:54 ` [PATCH v4 5/9] vfio: Mark cdev usage in vfio_device Yi Liu
2023-04-27 6:40 ` Tian, Kevin
2023-04-27 18:43 ` Alex Williamson
2023-04-28 6:42 ` Yi Liu
2023-04-26 14:54 ` [PATCH v4 6/9] iommufd: Reserved -1 in the iommufd xarray Yi Liu
2023-04-27 6:41 ` Tian, Kevin
2023-04-27 7:09 ` Liu, Yi L
2023-04-27 11:55 ` Jason Gunthorpe [this message]
2023-04-26 14:54 ` [PATCH v4 7/9] vfio-iommufd: Add helper to retrieve iommufd_ctx and devid for vfio_device Yi Liu
2023-04-27 6:45 ` Tian, Kevin
2023-04-27 7:15 ` Liu, Yi L
2023-04-26 14:54 ` [PATCH v4 8/9] vfio/pci: Extend VFIO_DEVICE_GET_PCI_HOT_RESET_INFO for vfio device cdev Yi Liu
2023-04-27 6:51 ` Tian, Kevin
2023-04-27 20:04 ` Alex Williamson
2023-04-27 20:15 ` Alex Williamson
2023-05-08 15:32 ` Liu, Yi L
2023-05-08 20:29 ` Alex Williamson
2023-04-26 14:54 ` [PATCH v4 9/9] vfio/pci: Allow passing zero-length fd array in VFIO_DEVICE_PCI_HOT_RESET Yi Liu
2023-04-27 6:54 ` Tian, Kevin
2023-04-27 7:02 ` Liu, Yi L
2023-04-27 21:55 ` Alex Williamson
2023-05-02 12:55 ` Liu, Yi L
2023-04-26 15:07 ` [PATCH v4 0/9] Enhance vfio PCI hot reset for vfio cdev device Liu, Yi L
2023-04-28 9:28 ` Jiang, Yanting
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