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.
Sean Christopherson
authored
Now that gvt_pin_guest_page() explicitly verifies the pinned PFN is a transparent hugepage page, don't use KVM's gfn_to_pfn() to pre-check if a 2MiB GTT entry is possible and instead just try to map the GFN with a 2MiB entry. Using KVM to query pfn that is ultimately managed through VFIO is odd, and KVM's gfn_to_pfn() is not intended for non-KVM consumption; it's exported only because of KVM vendor modules (x86 and PPC). Open code the check on 2MiB support instead of keeping is_2MB_gtt_possible() around for a single line of code. Move the call to intel_gvt_dma_map_guest_page() for a 4KiB entry into its case statement, i.e. fork the common path into the 4KiB and 2MiB "direct" shadow paths. Keeping the call in the "common" path is arguably more in the spirit of "one change per patch", but retaining the local "page_size" variable is silly, i.e. the call site will be changed either way, and jumping around the no-longer-common code is more subtle and rather odd, i.e. would just need to be immediately cleaned up. Drop the error message from gvt_pin_guest_page() when KVMGT attempts to shadow a 2MiB guest page that isn't backed by a compatible hugepage in the host. Dropping the pre-check on a THP makes it much more likely that the "error" will be encountered in normal operation. Reviewed-by:Yan Zhao <yan.y.zhao@intel.com> Tested-by: