patches/kernel/0030-x86-xen-Fix-secondary-processors-FPU-initialization.patch

   1 From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
   2 From: Juergen Gross <jgross@suse.com>
   3 Date: Mon, 3 Jul 2023 15:00:32 +0200
   4 Subject: [PATCH] x86/xen: Fix secondary processors' FPU initialization
   5
   6 Moving the call of fpu__init_cpu() from cpu_init() to start_secondary()
   7 broke Xen PV guests, as those don't call start_secondary() for APs.
   8
   9 Call fpu__init_cpu() in Xen's cpu_bringup(), which is the Xen PV
  10 replacement of start_secondary().
  11
  12 Fixes: b81fac906a8f ("x86/fpu: Move FPU initialization into arch_cpu_finalize_init()")
  13 Signed-off-by: Juergen Gross <jgross@suse.com>
  14 Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
  15 Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
  16 Acked-by: Thomas Gleixner <tglx@linutronix.de>
  17 Link: https://lore.kernel.org/r/20230703130032.22916-1-jgross@suse.com
  18
  19 (cherry picked from commit fe3e0a13e597c1c8617814bf9b42ab732db5c26e)
  20 CVE-2022-40982
  21 Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
  22 Acked-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
  23 Acked-by: Stefan Bader <stefan.bader@canonical.com>
  24 Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
  25 (cherry picked from commit 96617ee9a5943f6c58fa503257e18b191e84d117)
  26 Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
  27 ---
  28  arch/x86/xen/smp_pv.c | 1 +
  29  1 file changed, 1 insertion(+)
  30
  31 diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
  32 index 6175f2c5c822..e97bab7b0010 100644
  33 --- a/arch/x86/xen/smp_pv.c
  34 +++ b/arch/x86/xen/smp_pv.c
  35 @@ -63,6 +63,7 @@ static void cpu_bringup(void)
  36
  37         cr4_init();
  38         cpu_init();
  39 +       fpu__init_cpu();
  40         touch_softlockup_watchdog();
  41
  42         /* PVH runs in ring 0 and allows us to do native syscalls. Yay! */