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1e557c1cd0
Currently intel_gvt_is_valid_gfn() is called in two places: (1) shadowing guest GGTT entry (2) shadowing guest PPGTT leaf entry, which was introduced in commitcc753fbe1a("drm/i915/gvt: validate gfn before set shadow page entry"). However, now it's not necessary to call this interface any more, because a. GGTT partial write issue has been fixed by commitbc0686ff5f("drm/i915/gvt: support inconsecutive partial gtt entry write") commit510fe10b61("drm/i915/gvt: fix a bug of partially write ggtt enties") b. PPGTT resides in normal guest RAM and we only treat 8-byte writes as valid page table writes. Any invalid GPA found is regarded as an error, either due to guest misbehavior/attack or bug in host shadow code. So,rather than do GFN pre-checking and replace invalid GFNs with scratch GFN and continue silently, just remove the pre-checking and abort PPGTT shadowing on error detected. c. GFN validity check is still performed in intel_gvt_dma_map_guest_page() --> gvt_pin_guest_page(). It's more desirable to call VFIO interface to do both validity check and mapping. Calling intel_gvt_is_valid_gfn() to do GFN validity check from KVM side while later mapping the GFN through VFIO interface is unnecessarily fragile and confusing for unaware readers. Signed-off-by: Yan Zhao <yan.y.zhao@intel.com> [sean: remove now-unused local variables] Acked-by: Zhi Wang <zhi.a.wang@intel.com> Tested-by: Yongwei Ma <yongwei.ma@intel.com> Link: https://lore.kernel.org/r/20230729013535.1070024-3-seanjc@google.com Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.