github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-07 22:14:04 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph
Linux kernel source tree
1,140,115 Commits 1 Branch 933 Tags 20 GiB
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%
891a644b0c
Go to file
Sean Christopherson 891a644b0c KVM: nVMX: Properly expose ENABLE_USR_WAIT_PAUSE control to L1 
commit 31de69f4ee upstream.

Set ENABLE_USR_WAIT_PAUSE in KVM's supported VMX MSR configuration if the
feature is supported in hardware and enabled in KVM's base, non-nested
configuration, i.e. expose ENABLE_USR_WAIT_PAUSE to L1 if it's supported.
This fixes a bug where saving/restoring, i.e. migrating, a vCPU will fail
if WAITPKG (the associated CPUID feature) is enabled for the vCPU, and
obviously allows L1 to enable the feature for L2.

KVM already effectively exposes ENABLE_USR_WAIT_PAUSE to L1 by stuffing
the allowed-1 control ina vCPU's virtual MSR_IA32_VMX_PROCBASED_CTLS2 when
updating secondary controls in response to KVM_SET_CPUID(2), but (a) that
depends on flawed code (KVM shouldn't touch VMX MSRs in response to CPUID
updates) and (b) runs afoul of vmx_restore_control_msr()'s restriction
that the guest value must be a strict subset of the supported host value.

Although no past commit explicitly enabled nested support for WAITPKG,
doing so is safe and functionally correct from an architectural
perspective as no additional KVM support is needed to virtualize TPAUSE,
UMONITOR, and UMWAIT for L2 relative to L1, and KVM already forwards
VM-Exits to L1 as necessary (commit bf653b78f9, "KVM: vmx: Introduce
handle_unexpected_vmexit and handle WAITPKG vmexit").

Note, KVM always keeps the hosts MSR_IA32_UMWAIT_CONTROL resident in
hardware, i.e. always runs both L1 and L2 with the host's power management
settings for TPAUSE and UMWAIT.  See commit bf09fb6cba ("KVM: VMX: Stop
context switching MSR_IA32_UMWAIT_CONTROL") for more details.

Fixes: e69e72faa3 ("KVM: x86: Add support for user wait instructions")
Cc: stable@vger.kernel.org
Reported-by: Aaron Lewis <aaronlewis@google.com>
Reported-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Message-Id: <20221213062306.667649-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-07 11:11:47 +01:00
arch KVM: nVMX: Properly expose ENABLE_USR_WAIT_PAUSE control to L1 2023-01-07 11:11:47 +01:00
block block: Do not reread partition table on exclusively open device 2023-01-04 11:29:01 +01:00
certs certs: make system keyring depend on built-in x509 parser 2022-09-24 04:31:18 +09:00
crypto crypto: tcrypt - Fix multibuffer skcipher speed test mem leak 2022-12-31 13:32:34 +01:00
Documentation kprobes: kretprobe events missing on 2-core KVM guest 2023-01-04 11:28:58 +01:00
drivers of/kexec: Fix reading 32-bit "linux,initrd-{start,end}" values 2023-01-07 11:11:46 +01:00
fs fs: dlm: retry accept() until -EAGAIN or error returns 2023-01-07 11:11:44 +01:00
include mptcp: remove MPTCP 'ifdef' in TCP SYN cookies 2023-01-07 11:11:44 +01:00
init init/Kconfig: fix CC_HAS_ASM_GOTO_TIED_OUTPUT test with dash 2022-11-22 22:42:38 +09:00
io_uring io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups 2023-01-04 11:28:48 +01:00
ipc ipc: fix memory leak in init_mqueue_fs() 2022-12-31 13:32:01 +01:00
kernel perf/core: Call LSM hook after copying perf_event_attr 2023-01-07 11:11:46 +01:00
lib maple_tree: fix mas_spanning_rebalance() on insufficient data 2022-12-31 13:33:11 +01:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm mm, compaction: fix fast_isolate_around() to stay within boundaries 2023-01-04 11:29:01 +01:00
net mptcp: use proper req destructor for IPv6 2023-01-07 11:11:44 +01:00
rust Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
samples samples: vfio-mdev: Fix missing pci_disable_device() in mdpy_fb_probe() 2022-12-31 13:32:42 +01:00
scripts - Handle different output of readelf on different distros running 2022-11-27 12:08:17 -08:00
security ima: Fix hash dependency to correct algorithm 2023-01-07 11:11:46 +01:00
sound ALSA: usb-audio: Add new quirk FIXED_RATE for JBL Quantum810 Wireless 2023-01-07 11:11:43 +01:00
tools selftests: Use optional USERCFLAGS and USERLDFLAGS 2023-01-07 11:11:39 +01:00
usr usr/gen_init_cpio.c: remove unnecessary -1 values from int file 2022-10-03 14:21:44 -07:00
virt Merge branch 'kvm-dwmw2-fixes' into HEAD 2022-11-23 18:59:45 -05:00
.clang-format inet: ping: use hlist_nulls rcu iterator during lookup 2022-12-01 12:42:46 +01:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore Kbuild: add Rust support 2022-09-28 09:02:20 +02:00
.mailmap 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Remove Michal Marek from Kbuild maintainers 2022-11-16 14:53:00 +09:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS 9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address 2022-12-10 17:10:52 -08:00
Makefile Linux 6.1.3 2023-01-04 11:29:02 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.