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Sean Christopherson 16cfacc808 KVM: x86: Manually calculate reserved bits when loading PDPTRS
Manually generate the PDPTR reserved bit mask when explicitly loading
PDPTRs.  The reserved bits that are being tracked by the MMU reflect the
current paging mode, which is unlikely to be PAE paging in the vast
majority of flows that use load_pdptrs(), e.g. CR0 and CR4 emulation,
__set_sregs(), etc...  This can cause KVM to incorrectly signal a bad
PDPTR, or more likely, miss a reserved bit check and subsequently fail
a VM-Enter due to a bad VMCS.GUEST_PDPTR.

Add a one off helper to generate the reserved bits instead of sharing
code across the MMU's calculations and the PDPTR emulation.  The PDPTR
reserved bits are basically set in stone, and pushing a helper into
the MMU's calculation adds unnecessary complexity without improving
readability.

Oppurtunistically fix/update the comment for load_pdptrs().

Note, the buggy commit also introduced a deliberate functional change,
"Also remove bit 5-6 from rsvd_bits_mask per latest SDM.", which was
effectively (and correctly) reverted by commit cd9ae5fe47 ("KVM: x86:
Fix page-tables reserved bits").  A bit of SDM archaeology shows that
the SDM from late 2008 had a bug (likely a copy+paste error) where it
listed bits 6:5 as AVL and A for PDPTEs used for 4k entries but reserved
for 2mb entries.  I.e. the SDM contradicted itself, and bits 6:5 are and
always have been reserved.

Fixes: 20c466b561 ("KVM: Use rsvd_bits_mask in load_pdptrs()")
Cc: stable@vger.kernel.org
Cc: Nadav Amit <nadav.amit@gmail.com>
Reported-by: Doug Reiland <doug.reiland@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-10 16:41:50 +02:00
arch KVM: x86: Manually calculate reserved bits when loading PDPTRS 2019-09-10 16:41:50 +02:00
block docs conversion for v5.3-rc1 2019-07-16 12:21:41 -07:00
certs Revert "Merge tag 'keys-acl-20190703' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs" 2019-07-10 18:43:43 -07:00
crypto USB / PHY patches for 5.3-rc1 2019-07-11 15:40:06 -07:00
Documentation KVM: x86: Rename access permissions cache member in struct kvm_vcpu_arch 2019-08-22 10:09:23 +02:00
drivers iommu/amd: fix a crash in iova_magazine_free_pfns 2019-07-21 09:57:13 -07:00
fs SMB3 fixes: two fixes for stable, one that had dependency on earlier patch in this merge window and can now go in, and a perf improvement in SMB3 open 2019-07-21 10:01:17 -07:00
include KVM/arm fixes for 5.3, take #2 2019-08-09 16:53:50 +02:00
init Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
ipc Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
kernel dma-mapping fixes for 5.3-rc1 2019-07-20 12:09:52 -07:00
lib Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
net Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-07-19 10:06:06 -07:00
scripts Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
security Merge branch 'work.mount0' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2019-07-19 10:42:02 -07:00
sound sound fixes for 5.3-rc1 2019-07-18 09:36:51 -07:00
tools selftests/kvm: make platform_info_test pass on AMD 2019-08-21 19:08:18 +02:00
usr Kbuild updates for v5.3 (2nd) 2019-07-20 09:34:55 -07:00
virt KVM/arm fixes for 5.3, take #2 2019-08-09 16:53:50 +02:00
.clang-format Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2019-04-17 11:26:25 -07:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: create *.mod with full directory path and remove MODVERDIR 2019-07-18 02:19:31 +09:00
.mailmap MAINTAINERS: Update my email address 2019-06-18 14:37:27 +01:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS Remove references to dead website. 2019-07-19 12:22:04 -07:00
Kbuild Kbuild updates for v5.1 2019-03-10 17:48:21 -07:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS MAINTAINERS: add KVM x86 reviewers 2019-08-14 16:28:35 +02:00
Makefile Linus 5.3-rc1 2019-07-21 14:05:38 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.