From c93a4dfb31f2c023da3ad1238c352452f2cc0e05 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@citrix.com>
Date: Mon, 23 Aug 2010 11:59:28 +0100
Subject: [PATCH] xen: pvhvm: allow user to request no emulated device unplug
this allows the user to disable pvhvm and revert to emulated devices
in case of a system misconfiguration (e.g. initramfs with only
emulated drivers in it).
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Acked-by: Stefano Stabellini <Stefano.Stabellini@eu.citrix.com>
---
Documentation/kernel-parameters.txt | 1 +
arch/x86/xen/platform-pci-unplug.c | 5 +++++
include/xen/platform_pci.h | 1 +
3 files changed, 7 insertions(+)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 2c85c0692b015..8bbe83b9d0b29 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2631,6 +2631,7 @@ and is between 256 and 4096 characters. It is defined in the file
all -- unplug all emulated devices (NICs and IDE disks)
ignore -- continue loading the Xen platform PCI driver even
if the version check failed
+ never -- do not unplug even if version check succeeds
xirc2ps_cs= [NET,PCMCIA]
Format:
diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
index 554c002a1e1af..070dfa0654bdc 100644
--- a/arch/x86/xen/platform-pci-unplug.c
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -72,6 +72,9 @@ void __init xen_unplug_emulated_devices(void)
{
int r;
+ /* user explicitly requested no unplug */
+ if (xen_emul_unplug & XEN_UNPLUG_NEVER)
+ return;
/* check the version of the xen platform PCI device */
r = check_platform_magic();
/* If the version matches enable the Xen platform PCI driver.
@@ -127,6 +130,8 @@ static int __init parse_xen_emul_unplug(char *arg)
xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
else if (!strncmp(p, "ignore", l))
xen_emul_unplug |= XEN_UNPLUG_IGNORE;
+ else if (!strncmp(p, "never", l))
+ xen_emul_unplug |= XEN_UNPLUG_NEVER;
else
printk(KERN_WARNING "unrecognised option '%s' "
"in parameter 'xen_emul_unplug'\n", p);
diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
index ce9d671c636c8..123b7752fa6a0 100644
--- a/include/xen/platform_pci.h
+++ b/include/xen/platform_pci.h
@@ -21,6 +21,7 @@
#define XEN_UNPLUG_AUX_IDE_DISKS 4
#define XEN_UNPLUG_ALL 7
#define XEN_UNPLUG_IGNORE 8
+#define XEN_UNPLUG_NEVER 16
static inline int xen_must_unplug_nics(void) {
#if (defined(CONFIG_XEN_NETDEV_FRONTEND) || \
--
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