Linux mainline fork with MSM8998 patches | https://mainline.space | Currently supported devices:
OnePlus 5/5T, Xiaomi Mi 6, F(x)tec Pro¹ (2019 QX1000 model) & Sony Xperia XZ Premium (UNTESTED!)
2f57b7051f
Persist the max page level calculated via gfn_lpage_is_disallowed() to the max level "returned" by mapping_level() so that its naturally taken into account by the max level check that conditions calling transparent_hugepage_adjust(). Drop the gfn_lpage_is_disallowed() check in thp_adjust() as it's now handled by mapping_level() and its callers. Add a comment to document the behavior of host_mapping_level() and its interaction with max level and transparent huge pages. Note, transferring the gfn_lpage_is_disallowed() from thp_adjust() to mapping_level() superficially affects how changes to a memslot's disallow_lpage count will be handled due to thp_adjust() being run while holding mmu_lock. In the more common case where a different vCPU increments the count via account_shadowed(), gfn_lpage_is_disallowed() is rechecked by set_spte() to ensure a writable large page isn't created. In the less common case where the count is decremented to zero due to all shadow pages in the memslot being zapped, THP behavior now matches hugetlbfs behavior in the sense that a small page will be created when a large page could be used if the count reaches zero in the miniscule window between mapping_level() and acquiring mmu_lock. Lastly, the new THP behavior also follows hugetlbfs behavior in the absurdly unlikely scenario of a memslot being moved such that the memslot's compatibility with respect to large pages changes, but without changing the validity of the gpf->pfn walk. I.e. if a memslot is moved between mapping_level() and snapshotting mmu_seq, it's theoretically possible to consume a stale disallow_lpage count. But, since KVM zaps all shadow pages when moving a memslot and forces all vCPUs to reload a new MMU, the inserted spte will always be thrown away prior to completing the memslot move, i.e. whether or not the spte accurately reflects disallow_lpage is irrelevant. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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.