From c93a4dfb31f2c023da3ad1238c352452f2cc0e05 Mon Sep 17 00:00:00 2001 From: Ian Campbell 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 Acked-by: Jeremy Fitzhardinge Acked-by: Stefano Stabellini --- 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 2c85c0692b01..8bbe83b9d0b2 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 554c002a1e1a..070dfa0654bd 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 ce9d671c636c..123b7752fa6a 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) || \