[PATCH 4.1 59/65] x86/kaiser: Move feature detection up

From: Pavel Tatashin <pasha.tatashin@oracle.com>
To: steven.sistare@oracle.com, daniel.m.jordan@oracle.com,
	linux-kernel@vger.kernel.org, Alexander.Levin@microsoft.com,
	dan.j.williams@intel.com, sathyanarayanan.kuppuswamy@intel.com,
	pankaj.laxminarayan.bharadiya@intel.com, akuster@mvista.com,
	cminyard@mvista.com, pasha.tatashin@oracle.com,
	gregkh@linuxfoundation.org, stable@vger.kernel.org
Subject: [PATCH 4.1 59/65] x86/kaiser: Move feature detection up
Date: Mon,  5 Mar 2018 19:25:32 -0500	[thread overview]
Message-ID: <20180306002538.1761-60-pasha.tatashin@oracle.com> (raw)
In-Reply-To: <20180306002538.1761-1-pasha.tatashin@oracle.com>

From: Borislav Petkov <bp@suse.de>

... before the first use of kaiser_enabled as otherwise funky
things happen:

  about to get started...
  (XEN) d0v0 Unhandled page fault fault/trap [#14, ec=0000]
  (XEN) Pagetable walk from ffff88022a449090:
  (XEN)  L4[0x110] = 0000000229e0e067 0000000000001e0e
  (XEN)  L3[0x008] = 0000000000000000 ffffffffffffffff
  (XEN) domain_crash_sync called from entry.S: fault at ffff82d08033fd08
  entry.o#create_bounce_frame+0x135/0x14d
  (XEN) Domain 0 (vcpu#0) crashed on cpu#0:
  (XEN) ----[ Xen-4.9.1_02-3.21  x86_64  debug=n   Not tainted ]----
  (XEN) CPU:    0
  (XEN) RIP:    e033:[<ffffffff81007460>]
  (XEN) RFLAGS: 0000000000000286   EM: 1   CONTEXT: pv guest (d0v0)

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 7f79599df9c4a36130f7a4f6778b334a97632477)
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>

Conflicts:
	arch/x86/kernel/setup.c
---
 arch/x86/include/asm/kaiser.h | 2 ++
 arch/x86/kernel/setup.c       | 7 +++++++
 arch/x86/mm/kaiser.c          | 2 --
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/kaiser.h b/arch/x86/include/asm/kaiser.h
index 906150d6094e..b5e46aa683f4 100644
--- a/arch/x86/include/asm/kaiser.h
+++ b/arch/x86/include/asm/kaiser.h
@@ -96,8 +96,10 @@ DECLARE_PER_CPU(unsigned long, x86_cr3_pcid_user);
 extern char __per_cpu_user_mapped_start[], __per_cpu_user_mapped_end[];
 
 extern int kaiser_enabled;
+extern void __init kaiser_check_boottime_disable(void);
 #else
 #define kaiser_enabled	0
+static inline void __init kaiser_check_boottime_disable(void) {}
 #endif /* CONFIG_KAISER */
 
 /*
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index 1473a02e6ccb..1adaca0050b0 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -111,6 +111,7 @@
 #include <asm/mce.h>
 #include <asm/alternative.h>
 #include <asm/prom.h>
+#include <asm/kaiser.h>
 
 /*
  * max_low_pfn_mapped: highest direct mapped pfn under 4GB
@@ -1034,6 +1035,12 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	init_hypervisor_platform();
 
+	/*
+	 * This needs to happen right after XENPV is set on xen and
+	 * kaiser_enabled is checked below in cleanup_highmap().
+	 */
+	kaiser_check_boottime_disable();
+
 	x86_init.resources.probe_roms();
 
 	/* after parse_early_param, so could debug it */
diff --git a/arch/x86/mm/kaiser.c b/arch/x86/mm/kaiser.c
index 9d6b7517fca5..50783ad4861d 100644
--- a/arch/x86/mm/kaiser.c
+++ b/arch/x86/mm/kaiser.c
@@ -306,8 +306,6 @@ void __init kaiser_init(void)
 {
 	int cpu;
 
-	kaiser_check_boottime_disable();
-
 	if (!kaiser_enabled)
 		return;
 
-- 
2.16.2
