x86/fpu: Replace KVMs home brewed FPU copy from user

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Copying a user space buffer to the memory buffer is already available in
the FPU core. The copy mechanism in KVM lacks sanity checks and needs to
use cpuid() to lookup the offset of each component, while the FPU core has
this information cached.

Make the FPU core variant accessible for KVM and replace the home brewed
mechanism.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: kvm@vger.kernel.org
Link: https://lkml.kernel.org/r/20211015011539.134065207@linutronix.de

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Thomas Gleixner 2021-10-15 03:16:13 +02:00 • committed by Borislav Petkov

parent a0ff0611c2

commit ea4d6938d4

4 changed files with 43 additions and 74 deletions

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2

arch/x86/include/asm/fpu/api.h

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38

arch/x86/kernel/fpu/core.c

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3

arch/x86/kernel/fpu/xstate.c

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74

arch/x86/kvm/x86.c

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