Commit 64f14225 authored Jul 03, 2023 by Juergen Gross Committed by Greg Kroah-Hartman Aug 08, 2023

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>

parent 1af834f2

arch/x86/xen/smp_pv.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -27,6 +27,7 @@
		#include <asm/desc.h>
		#include <asm/pgtable.h>
		#include <asm/cpu.h>
		#include <asm/fpu/internal.h>

		#include <xen/interface/xen.h>
		#include <xen/interface/vcpu.h>
		@@ -58,6 +59,7 @@ static void cpu_bringup(void)
		int cpu;

		cpu_init();
		fpu__init_cpu();
		touch_softlockup_watchdog();
		preempt_disable();