pve-kernel-lowlatency-qoup/patches/kernel/0030-x86-xen-Fix-secondary-processors-FPU-initialization.patch
Stoiko Ivanov 9dd7462461 add fixes for downfall
by cherry-picking the relevant commits from launchpad/lunar [0].
(relevant commits are based on k.o/stable commits for this)

minimally tested by booting my (ryzen) machine with this kernel and
skimming through dmesg after boot.

[0] git://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/lunar

Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
2023-08-16 09:56:23 +02:00

43 lines
1.6 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Juergen Gross <jgross@suse.com>
Date: Mon, 3 Jul 2023 15:00:32 +0200
Subject: [PATCH] x86/xen: Fix secondary processors' FPU initialization
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
(cherry picked from commit fe3e0a13e597c1c8617814bf9b42ab732db5c26e)
CVE-2022-40982
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Acked-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
(cherry picked from commit 96617ee9a5943f6c58fa503257e18b191e84d117)
Signed-off-by: Stoiko Ivanov <s.ivanov@proxmox.com>
---
arch/x86/xen/smp_pv.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c
index 6175f2c5c822..e97bab7b0010 100644
--- 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();
+ fpu__init_cpu();
touch_softlockup_watchdog();
/* PVH runs in ring 0 and allows us to do native syscalls. Yay! */