linux-kernel - Re: [RFT][PATCH v1 3/6] vfio: Pass in starting IOVA to vfio_pin/unpin

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Yqw+goqTJwb0lrxy@infradead.org>
Date:   Fri, 17 Jun 2022 01:42:42 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     Nicolin Chen <nicolinc@...dia.com>
Cc:     kwankhede@...dia.com, corbet@....net, hca@...ux.ibm.com,
        gor@...ux.ibm.com, agordeev@...ux.ibm.com,
        borntraeger@...ux.ibm.com, svens@...ux.ibm.com,
        zhenyuw@...ux.intel.com, zhi.a.wang@...el.com,
        jani.nikula@...ux.intel.com, joonas.lahtinen@...ux.intel.com,
        rodrigo.vivi@...el.com, tvrtko.ursulin@...ux.intel.com,
        airlied@...ux.ie, daniel@...ll.ch, farman@...ux.ibm.com,
        mjrosato@...ux.ibm.com, pasic@...ux.ibm.com, vneethv@...ux.ibm.com,
        oberpar@...ux.ibm.com, freude@...ux.ibm.com,
        akrowiak@...ux.ibm.com, jjherne@...ux.ibm.com,
        alex.williamson@...hat.com, cohuck@...hat.com, jgg@...dia.com,
        kevin.tian@...el.com, jchrist@...ux.ibm.com, kvm@...r.kernel.org,
        linux-doc@...r.kernel.org, linux-kernel@...r.kernel.org,
        linux-s390@...r.kernel.org, intel-gvt-dev@...ts.freedesktop.org,
        intel-gfx@...ts.freedesktop.org, dri-devel@...ts.freedesktop.org
Subject: Re: [RFT][PATCH v1 3/6] vfio: Pass in starting IOVA to
 vfio_pin/unpin_pages API

On Thu, Jun 16, 2022 at 04:52:09PM -0700, Nicolin Chen wrote:
> +	ret = vfio_unpin_pages(&vgpu->vfio_device, gfn << PAGE_SHIFT, npage);
> +	drm_WARN_ON(&i915->drm, ret != npage);

The shifting of gfn seems to happen bother here and in the callers.

Also this is the only caller that does anything withthe vfio_unpin_pages
return value.  Given that you touch the API here we might as well
not return any value, and turn the debug checks that can return errors
into WARN_ON_ONCE calls the vfio/iommu_type1 code.

> +extern int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
>  			  int npage, int prot, unsigned long *phys_pfn);
> -extern int vfio_unpin_pages(struct vfio_device *device, unsigned long *user_pfn,
> +extern int vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova,
>  			    int npage);

This will clash with the extern removal patch that Alex has sent.