From 7bf9a6b46549852a37e6d07e52c601c3c706b562 Mon Sep 17 00:00:00 2001
From: Stefano Stabellini <sstabellini@kernel.org>
Date: Wed, 22 Nov 2023 15:07:41 -0800
Subject: [PATCH] arm/xen: fix xen_vcpu_info allocation alignment
Git-commit: 7bf9a6b46549852a37e6d07e52c601c3c706b562
Patch-mainline: v6.7-rc3
References: git-fixes
xen_vcpu_info is a percpu area than needs to be mapped by Xen.
Currently, it could cross a page boundary resulting in Xen being unable
to map it:
[ 0.567318] kernel BUG at arch/arm64/xen/../../arm/xen/enlighten.c:164!
[ 0.574002] Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
Fix the issue by using __alloc_percpu and requesting alignment for the
memory allocation.
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
Link: https://lore.kernel.org/r/alpine.DEB.2.22.394.2311221501340.2053963@ubuntu-linux-20-04-desktop
Fixes: 24d5373dda7c ("arm/xen: Use alloc_percpu rather than __alloc_percpu")
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
arch/arm/xen/enlighten.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c
index 9afdc4c4a5dc..a395b6c0aae2 100644
--- a/arch/arm/xen/enlighten.c
+++ b/arch/arm/xen/enlighten.c
@@ -484,7 +484,8 @@ static int __init xen_guest_init(void)
* for secondary CPUs as they are brought up.
* For uniformity we use VCPUOP_register_vcpu_info even on cpu0.
*/
- xen_vcpu_info = alloc_percpu(struct vcpu_info);
+ xen_vcpu_info = __alloc_percpu(sizeof(struct vcpu_info),
+ 1 << fls(sizeof(struct vcpu_info) - 1));
if (xen_vcpu_info == NULL)
return -ENOMEM;
--
2.35.3