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Tom Lendacky 33af3a7ef9 KVM: SVM: Reduce WBINVD/DF_FLUSH invocations
Performing a WBINVD and DF_FLUSH are expensive operations. Currently, a
WBINVD/DF_FLUSH is performed every time an SEV guest terminates. However,
the WBINVD/DF_FLUSH is only required when an ASID is being re-allocated
to a new SEV guest. Also, a single WBINVD/DF_FLUSH can enable all ASIDs
that have been disassociated from guests through DEACTIVATE.

To reduce the number of WBINVD/DF_FLUSH invocations, introduce a new ASID
bitmap to track ASIDs that need to be reclaimed. When an SEV guest is
terminated, add its ASID to the reclaim bitmap instead of clearing the
bitmap in the existing SEV ASID bitmap. This delays the need to perform a
WBINVD/DF_FLUSH invocation when an SEV guest terminates until all of the
available SEV ASIDs have been used. At that point, the WBINVD/DF_FLUSH
invocation can be performed and all ASIDs in the reclaim bitmap moved to
the available ASIDs bitmap.

The semaphore around DEACTIVATE can be changed to a read semaphore with
the semaphore taken in write mode before performing the WBINVD/DF_FLUSH.

Tested-by: David Rientjes <rientjes@google.com>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-10-22 13:34:09 +02:00
arch KVM: SVM: Reduce WBINVD/DF_FLUSH invocations 2019-10-22 13:34:09 +02:00
block blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
Documentation Pin control fixes for v5.4: 2019-10-22 06:40:07 -04:00
drivers KVM: SVM: Remove unneeded WBINVD and DF_FLUSH when starting SEV guests 2019-10-22 13:34:08 +02:00
fs Merge branch 'akpm' (patches from Andrew) 2019-10-19 06:53:59 -04:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel Kbuild fixes for v5.4 (2nd) 2019-10-20 12:36:57 -04:00
lib copy-struct-from-user-v5.4-rc4 2019-10-18 18:19:04 -04:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
samples samples/bpf: Add a workaround for asm_inline 2019-10-03 17:37:11 +02:00
scripts Kbuild fixes for v5.4 (2nd) 2019-10-20 12:36:57 -04:00
security selinux/stable-5.4 PR 20191007 2019-10-08 10:51:37 -07:00
sound ALSA: hda - Force runtime PM on Nvidia HDMI codecs 2019-10-17 17:45:32 +02:00
tools selftests: kvm: fix sync_regs_test with newer gccs 2019-10-22 13:31:18 +02:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM/arm fixes for 5.4, take #2 2019-10-22 13:31:29 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.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 Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
Makefile Linux 5.4-rc4 2019-10-20 15:56:22 -04:00
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.