RE: [PATCH v3 4/5] intel_iommu: Fix address space unmap

[Duan, Zhenzhong]

>-----Original Message-----
>From: Peter Xu <peterx@redhat.com>
>Sent: Thursday, June 8, 2023 9:48 PM
>To: Duan, Zhenzhong <zhenzhong.duan@intel.com>
>Cc: qemu-devel@nongnu.org; mst@redhat.com; jasowang@redhat.com;
>pbonzini@redhat.com; richard.henderson@linaro.org; eduardo@habkost.net;
>marcel.apfelbaum@gmail.com; alex.williamson@redhat.com;
>clg@redhat.com; david@redhat.com; philmd@linaro.org;
>kwankhede@nvidia.com; cjia@nvidia.com; Liu, Yi L <yi.l.liu@intel.com>; Peng,
>Chao P <chao.p.peng@intel.com>
>Subject: Re: [PATCH v3 4/5] intel_iommu: Fix address space unmap
>
>On Thu, Jun 08, 2023 at 05:52:30PM +0800, Zhenzhong Duan wrote:
>> During address space unmap, corresponding IOVA tree entries are also
>> removed. But DMAMap is set beyond notifier's scope by 1, so in theory
>> there is possibility to remove a continuous entry above the notifier's
>> scope but falling in adjacent notifier's scope.
>
>This function is only called in "loop over all notifiers" case (or replay() 
>that just
>got removed, but even so there'll be only 1 notifier normally iiuc at least for
>vt-d), hopefully it means no bug exist (no Fixes needed, no backport needed
>either), but still worth fixing it up.

Not two notifiers as vtd-ir splits for vt-d?

Thanks
Zhenzhong
>
>>
>> There is no issue currently as no use cases allocate notifiers
>> continuously, but let's be robust.
>>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>
>Reviewed-by: Peter Xu <peterx@redhat.com>
>
>--
>Peter Xu