linux-stable/Documentation
Paolo Bonzini dd6e631220 KVM: x86: add system attribute to retrieve full set of supported xsave states
Because KVM_GET_SUPPORTED_CPUID is meant to be passed (by simple-minded
VMMs) to KVM_SET_CPUID2, it cannot include any dynamic xsave states that
have not been enabled.  Probing those, for example so that they can be
passed to ARCH_REQ_XCOMP_GUEST_PERM, requires a new ioctl or arch_prctl.
The latter is in fact worse, even though that is what the rest of the
API uses, because it would require supported_xcr0 to be moved from the
KVM module to the kernel just for this use.  In addition, the value
would be nonsensical (or an error would have to be returned) until
the KVM module is loaded in.

Therefore, to limit the growth of system ioctls, add a /dev/kvm
variant of KVM_{GET,HAS}_DEVICE_ATTR, and implement it in x86
with just one group (0) and attribute (KVM_X86_XCOMP_GUEST_SUPP).

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2022-01-28 07:33:32 -05:00
..
ABI
accounting
admin-guide Merge branch 'kvm-pi-raw-spinlock' into HEAD 2022-01-19 12:14:02 -05:00
arm
arm64
block
bpf
cdrom
core-api
cpu-freq
crypto
dev-tools
devicetree dt-bindings: spi: cadence-quadspi: document "intel,socfpga-qspi" 2021-12-27 04:20:05 -06:00
doc-guide
driver-api
fault-injection
fb
features
filesystems
firmware-guide
firmware_class
fpga
gpu
hid
hwmon
i2c Docs: Fixes link to I2C specification 2021-12-31 14:39:28 +01:00
ia64
ide
iio
infiniband
input
isdn
kbuild
kernel-hacking
leds
litmus-tests
livepatch
locking
m68k
maintainer
mhi
mips
misc-devices
netlabel
networking Documentation: fix outdated interpretation of ip_no_pmtu_disc 2021-12-30 13:28:04 +00:00
nios2
nvdimm
openrisc
parisc
PCI
pcmcia
power
powerpc
process
RCU
riscv
s390
scheduler
scsi
security
sh
sound
sparc
sphinx
sphinx-static
spi
staging
target
timers
trace
translations
usb
userspace-api
virt KVM: x86: add system attribute to retrieve full set of supported xsave states 2022-01-28 07:33:32 -05:00
vm
w1
watchdog
x86
xtensa
.gitignore
arch.rst
asm-annotations.rst
atomic_bitops.txt
atomic_t.txt
Changes
CodingStyle
conf.py
COPYING-logo
docutils.conf
dontdiff
index.rst
Kconfig
logo.gif
Makefile
memory-barriers.txt
SubmittingPatches
watch_queue.rst