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@xxxxxxxxxx>
Thanks,
Paolo
