linux-stable/Documentation
Oliver Upton 828ca89628 KVM: x86: Expose TSC offset controls to userspace
To date, VMM-directed TSC synchronization and migration has been a bit
messy. KVM has some baked-in heuristics around TSC writes to infer if
the VMM is attempting to synchronize. This is problematic, as it depends
on host userspace writing to the guest's TSC within 1 second of the last
write.

A much cleaner approach to configuring the guest's views of the TSC is to
simply migrate the TSC offset for every vCPU. Offsets are idempotent,
and thus not subject to change depending on when the VMM actually
reads/writes values from/to KVM. The VMM can then read the TSC once with
KVM_GET_CLOCK to capture a (realtime, host_tsc) pair at the instant when
the guest is paused.

Cc: David Matlack <dmatlack@google.com>
Cc: Sean Christopherson <seanjc@google.com>
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210916181538.968978-8-oupton@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-10-18 14:43:45 -04:00
..
ABI Misc driver patches for 5.15-rc1, second round 2021-09-10 11:31:47 -07:00
accounting
admin-guide Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version) 2021-09-13 10:43:04 -07:00
arm Documentation: arm: marvell: Add 88F6825 model into list 2021-08-24 13:26:32 -06:00
arm64 Merge remote-tracking branch 'tip/sched/arm64' into for-next/core 2021-08-31 09:10:00 +01:00
block Documentation: block: blk-mq: Fix small typo in multi-queue docs 2021-08-24 13:30:00 -06:00
bpf libbpf: Rename libbpf documentation index file 2021-08-18 08:45:25 -07:00
cdrom
core-api Updates for the SMP and CPU hotplug: 2021-09-12 12:42:51 -07:00
cpu-freq cpufreq: Remove ready() callback 2021-09-02 18:04:17 +02:00
crypto
dev-tools Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
devicetree Devicetree fixes for v5.15, take 2: 2021-09-18 12:40:55 -07:00
doc-guide
driver-api cxl for v5.15 2021-09-09 11:48:27 -07:00
fault-injection Char / Misc driver changes for 5.15-rc1 2021-09-01 08:35:06 -07:00
fb
features RISC-V Patches for the 5.15 Merge Window, Part 2 2021-09-11 14:29:42 -07:00
filesystems block-5.15-2021-09-11 2021-09-11 10:19:51 -07:00
firmware-guide docs: firmware-guide: acpi: dsd: graph.rst: replace some characters 2021-07-25 14:35:46 -06:00
firmware_class
fpga fpga: fix spelling mistakes 2021-07-21 19:54:21 -07:00
gpu drm fixes for 5.15-rc1 2021-09-10 11:22:23 -07:00
hid
hwmon hwmon: add driver for Aquacomputer D5 Next 2021-08-28 08:53:30 -07:00
i2c Documentation: i2c: add i2c-sysfs into index 2021-08-10 22:58:32 +02:00
ia64
ide
iio
infiniband
input
isdn
kbuild Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
kernel-hacking docs: kernel-hacking: Remove inappropriate text 2021-09-03 15:56:45 -06:00
leds Documentation: leds: standartizing LED names 2021-08-20 10:26:24 +02:00
litmus-tests
livepatch
locking Documentation: locking: fix references 2021-08-24 13:20:39 -06:00
m68k
maintainer
mhi
mips
misc-devices
netlabel
networking dt-bindings: net: dsa: sja1105: update nxp,sja1105.yaml reference 2021-09-16 21:01:42 -05:00
nios2
nvdimm
openrisc
parisc
PCI pci-v5.15-changes 2021-09-07 19:13:42 -07:00
pcmcia
power Documentation: power: include kernel-doc in Energy Model doc 2021-09-07 21:17:28 +02:00
powerpc powerpc/doc: Fix htmldocs errors 2021-08-27 00:56:34 +10:00
process Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version) 2021-09-13 10:43:04 -07:00
RCU doc: Update stallwarn.rst with recent changes 2021-07-20 13:36:33 -07:00
riscv
s390
scheduler
scsi
security
sh
sound Yet another set of documentation changes: 2021-09-01 18:49:47 -07:00
sparc
sphinx docs: sphinx-requirements: Move sphinx_rtd_theme to top 2021-08-12 09:15:38 -06:00
sphinx-static
spi
staging
target
timers
trace Tracing updates for 5.15: 2021-09-05 11:50:41 -07:00
translations Merge branch 'gcc-min-version-5.1' (make gcc-5.1 the minimum version) 2021-09-13 10:43:04 -07:00
usb docs: usb: fix malformed table 2021-08-05 12:31:51 +02:00
userspace-api virtio,vdpa,vhost: features, fixes 2021-09-11 14:48:42 -07:00
virt KVM: x86: Expose TSC offset controls to userspace 2021-10-18 14:43:45 -04:00
vm Merge branch 'akpm' (patches from Andrew) 2021-09-08 12:55:35 -07:00
w1
watchdog
x86 Another collection of documentation patches, mostly fixes but also includes 2021-09-08 16:28:14 -07:00
xtensa
.gitignore
arch.rst
asm-annotations.rst
atomic_bitops.txt
atomic_t.txt Documentation/atomic_t: Document forward progress expectations 2021-08-04 15:16:47 +02:00
Changes
CodingStyle
conf.py docs: pdfdocs: Fix typo in CJK-language specific font settings 2021-09-06 16:53:39 -06:00
COPYING-logo
docutils.conf
dontdiff
index.rst
Kconfig
logo.gif
Makefile
memory-barriers.txt
SubmittingPatches
watch_queue.rst