[PATCH 05/12] unplug emulated disks and nics

[Stefano Stabellini <stefano.stabellini@eu.citrix.com>]

add a xen_unplug command line option to the kernel to unplug
xen emulated disks and nics.

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
---
 arch/x86/xen/enlighten.c             |   66 ++++++++++++++++++++++++++++++++++
 include/xen/hvm.h                    |    2 +
 include/xen/interface/platform_pci.h |   46 +++++++++++++++++++++++
 include/xen/platform_pci.h           |   32 ++++++++++++++++
 4 files changed, 146 insertions(+), 0 deletions(-)
 create mode 100644 include/xen/interface/platform_pci.h
 create mode 100644 include/xen/platform_pci.h

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 502c4f8..aac47b0 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -31,6 +31,7 @@
 #include <linux/gfp.h>
 
 #include <xen/xen.h>
+#include <xen/platform_pci.h>
 #include <xen/interface/xen.h>
 #include <xen/interface/version.h>
 #include <xen/interface/physdev.h>
@@ -38,6 +39,7 @@
 #include <xen/interface/memory.h>
 #include <xen/interface/hvm/hvm_op.h>
 #include <xen/interface/hvm/params.h>
+#include <xen/interface/platform_pci.h>
 #include <xen/features.h>
 #include <xen/page.h>
 #include <xen/hvm.h>
@@ -83,6 +85,8 @@ struct shared_info xen_dummy_shared_info;
 void *xen_initial_gdt;
 
 int xen_have_vector_callback;
+int xen_platform_pci;
+static int unplug;
 
 /*
  * Point at some empty memory to start with. We map the real shared_info
@@ -1309,6 +1313,39 @@ static void xen_callback_vector(void)
 	}
 }
 
+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_guest_init(void)
 {
 	int r;
@@ -1325,6 +1362,35 @@ void __init xen_guest_init(void)
 
 	xen_callback_vector();
 
+	r = check_platform_magic();
+	if (!r || (r == -1 && (unplug & UNPLUG_IGNORE)))
+		xen_platform_pci = 1;
+	if (xen_platform_pci && !(unplug & UNPLUG_IGNORE))
+		outw(unplug, XEN_IOPORT_UNPLUG);
 	have_vcpu_info_placement = 0;
 	x86_init.irqs.intr_init = xen_init_IRQ;
 }
+
+static int __init parse_unplug(char *arg)
+{
+	char *p, *q;
+
+	for (p = arg; p; p = q) {
+		q = strchr(arg, ',');
+		if (q)
+			*q++ = '\0';
+		if (!strcmp(p, "all"))
+			unplug |= UNPLUG_ALL;
+		else if (!strcmp(p, "ide-disks"))
+			unplug |= UNPLUG_ALL_IDE_DISKS;
+		else if (!strcmp(p, "aux-ide-disks"))
+			unplug |= UNPLUG_AUX_IDE_DISKS;
+		else if (!strcmp(p, "nics"))
+			unplug |= UNPLUG_ALL_NICS;
+		else
+			printk(KERN_WARNING "unrecognised option '%s' "
+				 "in module parameter 'dev_unplug'\n", p);
+	}
+	return 0;
+}
+early_param("xen_unplug", parse_unplug);
diff --git a/include/xen/hvm.h b/include/xen/hvm.h
index 5940ee5..777d2ce 100644
--- a/include/xen/hvm.h
+++ b/include/xen/hvm.h
@@ -30,4 +30,6 @@ extern int xen_have_vector_callback;
 #define HVM_CALLBACK_VECTOR(x) (((uint64_t)HVM_CALLBACK_VIA_TYPE_VECTOR)<<\
                                HVM_CALLBACK_VIA_TYPE_SHIFT | (x))
 
+extern int xen_platform_pci;
+
 #endif /* XEN_HVM_H__ */
diff --git a/include/xen/interface/platform_pci.h b/include/xen/interface/platform_pci.h
new file mode 100644
index 0000000..720eaf5
--- /dev/null
+++ b/include/xen/interface/platform_pci.h
@@ -0,0 +1,46 @@
+/******************************************************************************
+ * platform_pci.h
+ *
+ * Interface for granting foreign access to page frames, and receiving
+ * page-ownership transfers.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __XEN_PUBLIC_PLATFORM_PCI_H__
+#define __XEN_PUBLIC_PLATFORM_PCI_H__
+
+#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 UNPLUG_ALL_IDE_DISKS 1
+#define UNPLUG_ALL_NICS 2
+#define UNPLUG_AUX_IDE_DISKS 4
+#define UNPLUG_ALL 7
+#define UNPLUG_IGNORE 8
+
+#endif /* __XEN_PUBLIC_PLATFORM_PCI_H__ */
diff --git a/include/xen/platform_pci.h b/include/xen/platform_pci.h
new file mode 100644
index 0000000..f39f4d3
--- /dev/null
+++ b/include/xen/platform_pci.h
@@ -0,0 +1,32 @@
+/******************************************************************************
+ * platform-pci.h
+ *
+ * Xen platform PCI device driver
+ * Copyright (c) 2004, Intel Corporation. <xiaofeng.ling@intel.com>
+ * Copyright (c) 2007, XenSource Inc.
+ * 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.
+ */
+
+#ifndef _XEN_PLATFORM_PCI_H
+#define _XEN_PLATFORM_PCI_H
+
+#include <linux/version.h>
+
+#define XEN_IOPORT_MAGIC_VAL 0x49d2
+#define XEN_IOPORT_LINUX_PRODNUM 0xffff
+#define XEN_IOPORT_LINUX_DRVVER  ((LINUX_VERSION_CODE << 8) + 0x0)
+
+#endif /* _XEN_PLATFORM_PCI_H */
-- 
1.5.4.3