x86/xen: Fix secondary processors' FPU initialization

commit fe3e0a13e597c1c8617814bf9b42ab732db5c26e upstream.

Moving the call of fpu__init_cpu() from cpu_init() to start_secondary()
broke Xen PV guests, as those don't call start_secondary() for APs.

Call fpu__init_cpu() in Xen's cpu_bringup(), which is the Xen PV
replacement of start_secondary().

Fixes: b81fac906a8f ("x86/fpu: Move FPU initialization into arch_cpu_finalize_init()")
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20230703130032.22916-1-jgross@suse.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 6175f2c..e97bab7 100644 (file)
--- a/arch/x86/xen/smp_pv.c
+++ b/arch/x86/xen/smp_pv.c
@@ -63,6 +63,7 @@ static void cpu_bringup(void)
 
        cr4_init();
        cpu_init();
 
        cr4_init();
        cpu_init();

+       fpu__init_cpu();

        touch_softlockup_watchdog();
 
        /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */
        touch_softlockup_watchdog();
 
        /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */