linux-kernel - [PATCH v5 1/3] x86/xen: fix boot loader version reported for pvh guests

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Date:   Wed, 10 Oct 2018 08:14:54 +0200
From:   Juergen Gross <jgross@...e.com>
To:     linux-kernel@...r.kernel.org, xen-devel@...ts.xenproject.org,
        x86@...nel.org, linux-doc@...r.kernel.org
Cc:     tglx@...utronix.de, mingo@...hat.com, bp@...en8.de, hpa@...or.com,
        corbet@....net, boris.ostrovsky@...cle.com,
        Juergen Gross <jgross@...e.com>, stable@...r.kernel.org
Subject: [PATCH v5 1/3] x86/xen: fix boot loader version reported for pvh guests

The boot loader version reported via sysfs is wrong in case of the
kernel being booted via the Xen PVH boot entry. it should be 2.12
(0x020c), but it is reported to be 2.18 (0x0212).

As the current way to set the version is error prone use the more
readable variant (2 << 8) | 12.

Cc: <stable@...r.kernel.org> # 4.12
Signed-off-by: Juergen Gross <jgross@...e.com>
---
 arch/x86/xen/enlighten_pvh.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/xen/enlighten_pvh.c b/arch/x86/xen/enlighten_pvh.c
index c85d1a88f476..f7f77023288a 100644
--- a/arch/x86/xen/enlighten_pvh.c
+++ b/arch/x86/xen/enlighten_pvh.c
@@ -75,7 +75,7 @@ static void __init init_pvh_bootparams(void)
 	 * Version 2.12 supports Xen entry point but we will use default x86/PC
 	 * environment (i.e. hardware_subarch 0).
 	 */
-	pvh_bootparams.hdr.version = 0x212;
+	pvh_bootparams.hdr.version = (2 << 8) | 12;
 	pvh_bootparams.hdr.type_of_loader = (9 << 4) | 0; /* Xen loader */
 
 	x86_init.acpi.get_root_pointer = pvh_get_root_pointer;
-- 
2.16.4