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27 March 2024, 02:37:15 UTC
Revision dd6e631220181162478984d2d46dd979e04d8e75 authored by Paolo Bonzini on 26 January 2022, 12:49:45 UTC, committed by Paolo Bonzini on 28 January 2022, 12:33:32 UTC 
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>
1 parent 56f289a
History
Tip revision: dd6e631220181162478984d2d46dd979e04d8e75 authored by Paolo Bonzini on 26 January 2022, 12:49:45 UTC
KVM: x86: add system attribute to retrieve full set of supported xsave states
Tip revision: dd6e631
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arch
block
certs
crypto
drivers
fs
include
init
ipc
kernel
lib
mm
net
samples
scripts
security
sound
tools
usr
virt
.clang-format -rw-r--r-- 16.6 KB
.cocciconfig -rw-r--r-- 59 bytes
.get_maintainer.ignore -rw-r--r-- 71 bytes
.gitattributes -rw-r--r-- 62 bytes
.gitignore -rw-r--r-- 1.9 KB
.mailmap -rw-r--r-- 20.6 KB
COPYING -rw-r--r-- 496 bytes
CREDITS -rw-r--r-- 98.6 KB
Kbuild -rw-r--r-- 1.3 KB
Kconfig -rw-r--r-- 555 bytes
MAINTAINERS -rw-r--r-- 616.5 KB
Makefile -rw-r--r-- 64.0 KB
README -rw-r--r-- 727 bytes

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