linux-stable/arch/x86
Thomas Gleixner 7aa5128b5f x86/fpu/xsave: Handle compacted offsets correctly with supervisor states
So far the cached fixed compacted offsets worked, but with (re-)enabling
of ENQCMD this does no longer work with KVM fpstate.

KVM does not have supervisor features enabled for the guest FPU, which
means that KVM has then a different XSAVE area layout than the host FPU
state. This in turn breaks the copy from/to UABI functions when invoked for
a guest state.

Remove the pre-calculated compacted offsets and calculate the offset
of each component at runtime based on the XCOMP_BV field in the XSAVE
header.

The runtime overhead is not interesting because these copy from/to UABI
functions are not used in critical fast paths. KVM uses them to save and
restore FPU state during migration. The host uses them for ptrace and for
the slow path of 32bit signal handling.

Fixes: 7c1ef59145 ("x86/cpufeatures: Re-enable ENQCMD")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220324134623.627636809@linutronix.de
2022-03-30 11:20:36 +02:00
..
boot x86: clean up symbol aliasing 2022-02-22 16:21:34 +00:00
coco x86/coco: Add API to handle encryption mask 2022-02-23 19:14:29 +01:00
configs x86/config: Make the x86 defconfigs a bit more usable 2022-03-27 20:58:35 +02:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2022-03-21 16:02:36 -07:00
entry Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
events Changes for this cycle were: 2022-03-22 13:06:49 -07:00
hyperv hyperv-next for 5.17 2022-01-16 15:53:00 +02:00
ia32 audit/stable-5.16 PR 20211101 2021-11-01 21:17:39 -07:00
include Changes in this cycle were: 2022-03-22 14:39:12 -07:00
kernel x86/fpu/xsave: Handle compacted offsets correctly with supervisor states 2022-03-30 11:20:36 +02:00
kvm Changes in this cycle were: 2022-03-22 14:39:12 -07:00
lib x86/sev: Unroll string mmio with CC_ATTR_GUEST_UNROLL_STRING_IO 2022-03-29 15:59:16 +02:00
math-emu x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
mm Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
net x86/speculation: Rename RETPOLINE_AMD to RETPOLINE_LFENCE 2022-02-21 10:21:28 +01:00
pci PCI/sysfs: Find shadow ROM before static attribute initialization 2022-01-26 10:41:21 -06:00
platform - Get rid of all the .fixup sections because this generates 2022-01-12 16:31:19 -08:00
power x86: Prepare asm files for straight-line-speculation 2021-12-08 12:25:37 +01:00
purgatory x86/purgatory: Remove -nostdlib compiler flag 2021-12-30 14:13:06 +01:00
ras
realmode - Flush *all* mappings from the TLB after switching to the trampoline 2022-01-10 09:51:38 -08:00
tools x86/build: Use the proper name CONFIG_FW_LOADER 2021-12-29 22:20:38 +01:00
um overflow updates for v5.18-rc1 2022-03-21 19:46:41 -07:00
video
xen xen/x2apic: Fix inconsistent indenting 2022-02-10 11:10:20 +01:00
.gitignore
Kbuild x86/cc: Move arch/x86/{kernel/cc_platform.c => coco/core.c} 2022-02-23 18:25:58 +01:00
Kconfig Merge branch 'akpm' (patches from Andrew) 2022-03-22 16:11:53 -07:00
Kconfig.assembler
Kconfig.cpu x86/mmx_32: Remove X86_USE_3DNOW 2021-12-11 09:09:45 +01:00
Kconfig.debug
Makefile x86: Add straight-line-speculation mitigation 2021-12-09 13:32:25 +01:00
Makefile.um
Makefile_32.cpu