Messages in this thread | | | Date | Wed, 5 Jan 2022 14:06:40 +0100 | Subject | Re: [PATCH v5 07/21] x86/fpu: Provide fpu_enable_guest_xfd_features() for KVM | From | Paolo Bonzini <> |
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On 1/5/22 13:35, Yang Zhong wrote: > +int fpu_enable_guest_xfd_features(struct fpu_guest *guest_fpu, u64 xfeatures) > +{ > + lockdep_assert_preemption_enabled(); > +
The old fpu_update_guest_perm_features(guest_fpu) is equivalent to
fpu_enable_guest_xfd_features(guest_fpu, guest_fpu->perm);
Missing doc comment:
/* * fpu_enable_guest_xfd_features - Enable xfeatures according to guest perm * @guest_fpu: Pointer to the guest FPU container * @xfeatures: Features requested by guest CPUID * * Enable all dynamic xfeatures according to guest perm and requested CPUID. * Invoked if the caller wants to conservatively expand fpstate buffer instead * of waiting until XCR0 or XFD MSR is written. * * Return: 0 on success, error code otherwise */
Also, the check for 32-bit is slightly imprecise:
/* Dynamic xfeatures are not supported with 32-bit kernels. */ if (!IS_ENABLED(CONFIG_X86_64)) - return 0; + return -EINVAL;
since we only get here with xfeatures != 0 (if it compiles, just removing the IS_ENABLED check altogether would be even better). With these changes,
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Thanks,
Paolo
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