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Subject[PATCH 12/13] Unplug emulated disks and nics
Date
From: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

Add a xen_emul_unplug command line option to the kernel to unplug
xen emulated disks and nics.

Set the default value of xen_emul_unplug depending on whether or
not the Xen PV frontends and the Xen platform PCI driver have
been compiled for this kernel (modules or built-in are both OK).

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
Documentation/kernel-parameters.txt | 11 +++
arch/x86/xen/Makefile | 2 +-
arch/x86/xen/enlighten.c | 1 +
arch/x86/xen/platform-pci-unplug.c | 130 +++++++++++++++++++++++++++++++++++
arch/x86/xen/xen-ops.h | 1 +
drivers/xen/platform-pci.c | 4 +
drivers/xen/xenbus/xenbus_probe.c | 4 +
include/xen/platform_pci.h | 49 +++++++++++++
8 files changed, 201 insertions(+), 1 deletions(-)
create mode 100644 arch/x86/xen/platform-pci-unplug.c
create mode 100644 include/xen/platform_pci.h
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 839b21b..716eea8 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -113,6 +113,7 @@ parameter is applicable:
More X86-64 boot options can be found in
Documentation/x86/x86_64/boot-options.txt .
X86 Either 32bit or 64bit x86 (same as X86-32+X86-64)
+ XEN Xen support is enabled

In addition, the following text indicates that the option:

@@ -2834,6 +2835,16 @@ and is between 256 and 4096 characters. It is defined in the file
xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks.
xd_geo= See header of drivers/block/xd.c.

+ xen_emul_unplug= [HW,X86,XEN]
+ Unplug Xen emulated devices
+ Format: [unplug0,][unplug1]
+ ide-disks -- unplug primary master IDE devices
+ aux-ide-disks -- unplug non-primary-master IDE devices
+ nics -- unplug network devices
+ all -- unplug all emulated devices (NICs and IDE disks)
+ ignore -- continue loading the Xen platform PCI driver even
+ if the version check failed
+
xirc2ps_cs= [NET,PCMCIA]
Format:
<irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]]
diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 3bb4fc2..9309546 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -12,7 +12,7 @@ CFLAGS_mmu.o := $(nostackp)

obj-y := enlighten.o setup.o multicalls.o mmu.o irq.o \
time.o xen-asm.o xen-asm_$(BITS).o \
- grant-table.o suspend.o
+ grant-table.o suspend.o platform-pci-unplug.o

obj-$(CONFIG_SMP) += smp.o
obj-$(CONFIG_PARAVIRT_SPINLOCKS)+= spinlock.o
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index bcd98a9..5126b53 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1317,6 +1317,7 @@ void __init xen_hvm_guest_init(void)
if (xen_feature(XENFEAT_hvm_callback_vector))
xen_have_vector_callback = 1;
register_cpu_notifier(&xen_hvm_cpu_notifier);
+ xen_unplug_emulated_devices();
have_vcpu_info_placement = 0;
x86_init.irqs.intr_init = xen_init_IRQ;
xen_hvm_init_time_ops();
diff --git a/arch/x86/xen/platform-pci-unplug.c b/arch/x86/xen/platform-pci-unplug.c
new file mode 100644
index 0000000..d686440
--- /dev/null
+++ b/arch/x86/xen/platform-pci-unplug.c
@@ -0,0 +1,130 @@
+/******************************************************************************
+ * platform-pci-unplug.c
+ *
+ * Xen platform PCI device driver
+ * Copyright (c) 2010, Citrix
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+ * Place - Suite 330, Boston, MA 02111-1307 USA.
+ *
+ */
+
+#include <asm/io.h>
+
+#include <linux/init.h>
+#include <linux/module.h>
+
+#include <xen/platform_pci.h>
+
+/* boolean to signal that the platform pci device can be used */
+bool xen_platform_pci_enabled;
+EXPORT_SYMBOL_GPL(xen_platform_pci_enabled);
+static int xen_emul_unplug;
+
+static int __init check_platform_magic(void)
+{
+ short magic;
+ char protocol;
+
+ magic = inw(XEN_IOPORT_MAGIC);
+ if (magic != XEN_IOPORT_MAGIC_VAL) {
+ printk(KERN_ERR "Xen Platform PCI: unrecognised magic value\n");
+ return -1;
+ }
+
+ protocol = inb(XEN_IOPORT_PROTOVER);
+
+ printk(KERN_DEBUG "Xen Platform PCI: I/O protocol version %d\n",
+ protocol);
+
+ switch (protocol) {
+ case 1:
+ outw(XEN_IOPORT_LINUX_PRODNUM, XEN_IOPORT_PRODNUM);
+ outl(XEN_IOPORT_LINUX_DRVVER, XEN_IOPORT_DRVVER);
+ if (inw(XEN_IOPORT_MAGIC) != XEN_IOPORT_MAGIC_VAL) {
+ printk(KERN_ERR "Xen Platform: blacklisted by host\n");
+ return -3;
+ }
+ break;
+ default:
+ printk(KERN_WARNING "Xen Platform PCI: unknown I/O protocol version");
+ return -2;
+ }
+
+ return 0;
+}
+
+void __init xen_unplug_emulated_devices(void)
+{
+ int r;
+
+ /* check the version of the xen platform PCI device */
+ r = check_platform_magic();
+ /* If the version matches enable the Xen platform PCI driver.
+ * Also enable the Xen platform PCI driver if the version is really old
+ * and the user told us to ignore it. */
+ if (!r || (r == -1 && (xen_emul_unplug & XEN_UNPLUG_IGNORE)))
+ xen_platform_pci_enabled = 1;
+ /* Set the default value of xen_emul_unplug depending on whether or
+ * not the Xen PV frontends and the Xen platform PCI driver have
+ * been compiled for this kernel (modules or built-in are both OK). */
+ if (xen_platform_pci_enabled && !xen_emul_unplug) {
+ if (xen_must_unplug_nics()) {
+ printk(KERN_INFO "Netfront and the Xen platform PCI driver have "
+ "been compiled for this kernel: unplug emulated NICs.\n");
+ xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
+ }
+ if (xen_must_unplug_disks()) {
+ printk(KERN_INFO "Blkfront and the Xen platform PCI driver have "
+ "been compiled for this kernel: unplug emulated disks.\n"
+ "You might have to change the root device\n"
+ "from /dev/hd[a-d] to /dev/xvd[a-d]\n"
+ "in your root= kernel command line option\n");
+ xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
+ }
+ }
+ /* Now unplug the emulated devices */
+ if (xen_platform_pci_enabled && !(xen_emul_unplug & XEN_UNPLUG_IGNORE))
+ outw(xen_emul_unplug, XEN_IOPORT_UNPLUG);
+}
+
+static int __init parse_xen_emul_unplug(char *arg)
+{
+ char *p, *q;
+ int l;
+
+ for (p = arg; p; p = q) {
+ q = strchr(p, ',');
+ if (q) {
+ l = q - p;
+ q++;
+ } else {
+ l = strlen(p);
+ }
+ if (!strncmp(p, "all", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL;
+ else if (!strncmp(p, "ide-disks", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL_IDE_DISKS;
+ else if (!strncmp(p, "aux-ide-disks", l))
+ xen_emul_unplug |= XEN_UNPLUG_AUX_IDE_DISKS;
+ else if (!strncmp(p, "nics", l))
+ xen_emul_unplug |= XEN_UNPLUG_ALL_NICS;
+ else if (!strncmp(p, "ignore", l))
+ xen_emul_unplug |= XEN_UNPLUG_IGNORE;
+ else
+ printk(KERN_WARNING "unrecognised option '%s' "
+ "in module parameter 'dev_unplug'\n", p);
+ }
+ return 0;
+}
+early_param("xen_emul_unplug", parse_xen_emul_unplug);
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 089d189..ed77694 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -40,6 +40,7 @@ void xen_vcpu_restore(void);

void xen_callback_vector(void);
void xen_hvm_init_shared_info(void);
+void __init xen_unplug_emulated_devices(void);

void __init xen_build_dynamic_phys_to_machine(void);

diff --git a/drivers/xen/platform-pci.c b/drivers/xen/platform-pci.c
index 10b92ec..35f162d 100644
--- a/drivers/xen/platform-pci.c
+++ b/drivers/xen/platform-pci.c
@@ -27,6 +27,7 @@
#include <linux/module.h>
#include <linux/pci.h>

+#include <xen/platform_pci.h>
#include <xen/grant_table.h>
#include <xen/xenbus.h>
#include <xen/events.h>
@@ -195,6 +196,9 @@ static int __init platform_pci_module_init(void)
{
int rc;

+ if (!xen_platform_pci_enabled)
+ return -ENODEV;
+
rc = pci_register_driver(&platform_driver);
if (rc) {
printk(KERN_INFO DRV_NAME
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c
index 3d941ec..243279a 100644
--- a/drivers/xen/xenbus/xenbus_probe.c
+++ b/drivers/xen/xenbus/xenbus_probe.c
@@ -56,6 +56,7 @@
#include <xen/events.h>
#include <xen/page.h>

+#include <xen/platform_pci.h>
#include <xen/hvm.h>

#include "xenbus_comms.h"
@@ -977,6 +978,9 @@ static void wait_for_devices(struct xenbus_driver *xendrv)
#ifndef MODULE
static int __init boot_wait_for_devices(void)
{
+ if (xen_hvm_domain() && !xen_platform_pci_enabled)
+ return -ENODEV;
+
ready_to_wait_for_devices = 1;
wait_for_devices(NULL);
return 0;
diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
new file mode 100644
index 0000000..afa8855
--- /dev/null
+++ b/include/xen/platform_pci.h
@@ -0,0 +1,49 @@
+#ifndef _XEN_PLATFORM_PCI_H
+#define _XEN_PLATFORM_PCI_H
+
+#define XEN_IOPORT_MAGIC_VAL 0x49d2
+#define XEN_IOPORT_LINUX_PRODNUM 0x0003
+#define XEN_IOPORT_LINUX_DRVVER 0x0001
+
+#define XEN_IOPORT_BASE 0x10
+
+#define XEN_IOPORT_PLATFLAGS (XEN_IOPORT_BASE + 0) /* 1 byte access (R/W) */
+#define XEN_IOPORT_MAGIC (XEN_IOPORT_BASE + 0) /* 2 byte access (R) */
+#define XEN_IOPORT_UNPLUG (XEN_IOPORT_BASE + 0) /* 2 byte access (W) */
+#define XEN_IOPORT_DRVVER (XEN_IOPORT_BASE + 0) /* 4 byte access (W) */
+
+#define XEN_IOPORT_SYSLOG (XEN_IOPORT_BASE + 2) /* 1 byte access (W) */
+#define XEN_IOPORT_PROTOVER (XEN_IOPORT_BASE + 2) /* 1 byte access (R) */
+#define XEN_IOPORT_PRODNUM (XEN_IOPORT_BASE + 2) /* 2 byte access (W) */
+
+#define XEN_UNPLUG_ALL_IDE_DISKS 1
+#define XEN_UNPLUG_ALL_NICS 2
+#define XEN_UNPLUG_AUX_IDE_DISKS 4
+#define XEN_UNPLUG_ALL 7
+#define XEN_UNPLUG_IGNORE 8
+
+static inline int xen_must_unplug_nics(void) {
+#if (defined(CONFIG_XEN_NETDEV_FRONTEND) || \
+ defined(CONFIG_XEN_NETDEV_FRONTEND_MODULE)) && \
+ (defined(CONFIG_XEN_PLATFORM_PCI) || \
+ defined(CONFIG_XEN_PLATFORM_PCI_MODULE))
+ return 1;
+#else
+ return 0;
+#endif
+}
+
+static inline int xen_must_unplug_disks(void) {
+#if (defined(CONFIG_XEN_BLKDEV_FRONTEND) || \
+ defined(CONFIG_XEN_BLKDEV_FRONTEND_MODULE)) && \
+ (defined(CONFIG_XEN_PLATFORM_PCI) || \
+ defined(CONFIG_XEN_PLATFORM_PCI_MODULE))
+ return 1;
+#else
+ return 0;
+#endif
+}
+
+extern bool xen_platform_pci_enabled;
+
+#endif /* _XEN_PLATFORM_PCI_H */
--
1.7.0.4


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