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