bitkeeper revision 1.1159.170.76 (41d54a7766O7ds3C9PMWbP5vuyK4Tw)

Add microcode driver to Xen.

9 files changed, 682 insertions, 22 deletions

diff --git a/.rootkeys b/.rootkeys
index b607089e0b..89187e42af 100644
--- a/.rootkeys
+++ b/.rootkeys
@@ -146,6 +146,7 @@
 40f58a0d31M2EkuPbG94ns_nOi0PVA linux-2.6.10-xen-sparse/arch/xen/i386/kernel/i386_ksyms.c
 40faa751_zbZlAmLyQgCXdYekVFdWA linux-2.6.10-xen-sparse/arch/xen/i386/kernel/ioport.c
 40f56238ue3YRsK52HG7iccNzP1AwQ linux-2.6.10-xen-sparse/arch/xen/i386/kernel/ldt.c
+41d54a76YMCA67S8J-TBT3J62Wx6yA linux-2.6.10-xen-sparse/arch/xen/i386/kernel/microcode.c
 4107adf1cNtsuOxOB4T6paAoY2R2PA linux-2.6.10-xen-sparse/arch/xen/i386/kernel/pci-dma.c
 40f56238a8iOVDEoostsbun_sy2i4g linux-2.6.10-xen-sparse/arch/xen/i386/kernel/process.c
 40f56238YQIJoYG2ehDGEcdTgLmGbg linux-2.6.10-xen-sparse/arch/xen/i386/kernel/setup.c
@@ -664,6 +665,7 @@
 3ddb79bcKIkRR0kqWaJhe5VUDkMdxg xen/arch/x86/io_apic.c
 3ddb79bdqfIcjkz_h9Hvtp8Tk_19Zw xen/arch/x86/irq.c
 40ec29ffuOa1ZvmJHzFKyZn4k_RcXg xen/arch/x86/memory.c
+41d54a76qfpO0VnbL2tYs0Jgt3W3XA xen/arch/x86/microcode.c
 3ddb79bdS4UeWWXDH-FaBKqcpMFcnw xen/arch/x86/mpparse.c
 41aaf566Z4sTDgJ77eEg0TzzQ1ka6Q xen/arch/x86/mtrr/amd.c
 41aaf566TOpOBXT00wwQGUh20f1rlA xen/arch/x86/mtrr/centaur.c
diff --git a/linux-2.6.10-xen-sparse/arch/xen/configs/xen0_defconfig b/linux-2.6.10-xen-sparse/arch/xen/configs/xen0_defconfig
index 6f7872ea71..78f1b6028d 100644
--- a/linux-2.6.10-xen-sparse/arch/xen/configs/xen0_defconfig
+++ b/linux-2.6.10-xen-sparse/arch/xen/configs/xen0_defconfig
@@ -115,6 +115,7 @@ CONFIG_X86_USE_PPRO_CHECKSUM=y
 # CONFIG_HPET_EMULATE_RTC is not set
 # CONFIG_SMP is not set
 CONFIG_PREEMPT=y
+CONFIG_MICROCODE=y
 CONFIG_X86_CPUID=y
 
 #
diff --git a/linux-2.6.10-xen-sparse/arch/xen/i386/Kconfig b/linux-2.6.10-xen-sparse/arch/xen/i386/Kconfig
index 30609afa66..7a3a73d869 100644
--- a/linux-2.6.10-xen-sparse/arch/xen/i386/Kconfig
+++ b/linux-2.6.10-xen-sparse/arch/xen/i386/Kconfig
@@ -440,22 +440,23 @@ config PREEMPT
 #	   Enabling this feature will cause a message to be printed when the P4
 #	   enters thermal throttling.
 
-#config MICROCODE
-#	 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
-#	 ---help---
-#	   If you say Y here and also to "/dev file system support" in the
-#	   'File systems' section, you will be able to update the microcode on
-#	   Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
-#	   Pentium III, Pentium 4, Xeon etc.  You will obviously need the
-#	   actual microcode binary data itself which is not shipped with the
-#	   Linux kernel.
-#
-#	   For latest news and information on obtaining all the required
-#	   ingredients for this driver, check:
-#	   <http://www.urbanmyth.org/microcode/>.
-#
-#	   To compile this driver as a module, choose M here: the
-#	   module will be called microcode.
+config MICROCODE
+	 tristate "/dev/cpu/microcode - Intel IA32 CPU microcode support"
+	 depends on XEN_PRIVILEGED_GUEST
+	 ---help---
+	   If you say Y here and also to "/dev file system support" in the
+	   'File systems' section, you will be able to update the microcode on
+	   Intel processors in the IA32 family, e.g. Pentium Pro, Pentium II,
+	   Pentium III, Pentium 4, Xeon etc.  You will obviously need the
+	   actual microcode binary data itself which is not shipped with the
+	   Linux kernel.
+
+	   For latest news and information on obtaining all the required
+	   ingredients for this driver, check:
+	   <http://www.urbanmyth.org/microcode/>.
+
+	   To compile this driver as a module, choose M here: the
+	   module will be called microcode.
 
 #config X86_MSR
 #	 tristate "/dev/cpu/*/msr - Model-specific register support"
diff --git a/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/Makefile b/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/Makefile
index 014f324cc1..c304fbb0cd 100644
--- a/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/Makefile
+++ b/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/Makefile
@@ -25,7 +25,7 @@ c-obj-$(CONFIG_ACPI_BOOT)	+= acpi/
 c-obj-$(CONFIG_MCA)		+= mca.o
 c-obj-$(CONFIG_X86_MSR)		+= msr.o
 c-obj-$(CONFIG_X86_CPUID)	+= cpuid.o
-c-obj-$(CONFIG_MICROCODE)	+= microcode.o
+obj-$(CONFIG_MICROCODE)		+= microcode.o
 c-obj-$(CONFIG_APM)		+= apm.o
 c-obj-$(CONFIG_X86_SMP)		+= smp.o smpboot.o
 c-obj-$(CONFIG_X86_TRAMPOLINE)	+= trampoline.o
diff --git a/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/microcode.c b/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/microcode.c
new file mode 100644
index 0000000000..fa738d152d
--- /dev/null
+++ b/linux-2.6.10-xen-sparse/arch/xen/i386/kernel/microcode.c
@@ -0,0 +1,163 @@
+/*
+ *	Intel CPU Microcode Update Driver for Linux
+ *
+ *	Copyright (C) 2000-2004 Tigran Aivazian
+ *
+ *	This driver allows to upgrade microcode on Intel processors
+ *	belonging to IA-32 family - PentiumPro, Pentium II, 
+ *	Pentium III, Xeon, Pentium 4, etc.
+ *
+ *	Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual, 
+ *	Order Number 245472 or free download from:
+ *		
+ *	http://developer.intel.com/design/pentium4/manuals/245472.htm
+ *
+ *	For more information, go to http://www.urbanmyth.org/microcode
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ */
+
+//#define DEBUG /* pr_debug */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/miscdevice.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/syscalls.h>
+
+#include <asm/msr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+
+MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
+MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
+MODULE_LICENSE("GPL");
+
+#define MICROCODE_VERSION 	"1.14-xen"
+
+#define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */
+#define MC_HEADER_SIZE		(sizeof (microcode_header_t))  	  /* 48 bytes */
+#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
+
+/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
+static DECLARE_MUTEX(microcode_sem);
+
+static void __user *user_buffer;	/* user area microcode data buffer */
+static unsigned int user_buffer_size;	/* it's size */
+				
+static int microcode_open (struct inode *unused1, struct file *unused2)
+{
+	return capable(CAP_SYS_RAWIO) ? 0 : -EPERM;
+}
+
+
+static int do_microcode_update (void)
+{
+	int err;
+	dom0_op_t op;
+
+	err = sys_mlock((unsigned long)user_buffer, user_buffer_size);
+	if (err != 0)
+		return err;
+
+	op.cmd = DOM0_MICROCODE;
+	op.u.microcode.data = user_buffer;
+	op.u.microcode.length = user_buffer_size;
+	err = HYPERVISOR_dom0_op(&op);
+
+	(void)sys_munlock((unsigned long)user_buffer, user_buffer_size);
+
+	return err;
+}
+
+static ssize_t microcode_write (struct file *file, const char __user *buf, size_t len, loff_t *ppos)
+{
+	ssize_t ret;
+
+	if (len < DEFAULT_UCODE_TOTALSIZE) {
+		printk(KERN_ERR "microcode: not enough data\n"); 
+		return -EINVAL;
+	}
+
+	if ((len >> PAGE_SHIFT) > num_physpages) {
+		printk(KERN_ERR "microcode: too much data (max %ld pages)\n", num_physpages);
+		return -EINVAL;
+	}
+
+	down(&microcode_sem);
+
+	user_buffer = (void __user *) buf;
+	user_buffer_size = (int) len;
+
+	ret = do_microcode_update();
+	if (!ret)
+		ret = (ssize_t)len;
+
+	up(&microcode_sem);
+
+	return ret;
+}
+
+static int microcode_ioctl (struct inode *inode, struct file *file, 
+		unsigned int cmd, unsigned long arg)
+{
+	switch (cmd) {
+		/* 
+		 *  XXX: will be removed after microcode_ctl 
+		 *  is updated to ignore failure of this ioctl()
+		 */
+		case MICROCODE_IOCFREE:
+			return 0;
+		default:
+			return -EINVAL;
+	}
+	return -EINVAL;
+}
+
+static struct file_operations microcode_fops = {
+	.owner		= THIS_MODULE,
+	.write		= microcode_write,
+	.ioctl		= microcode_ioctl,
+	.open		= microcode_open,
+};
+
+static struct miscdevice microcode_dev = {
+	.minor		= MICROCODE_MINOR,
+	.name		= "microcode",
+	.devfs_name	= "cpu/microcode",
+	.fops		= &microcode_fops,
+};
+
+static int __init microcode_init (void)
+{
+	int error;
+
+	error = misc_register(&microcode_dev);
+	if (error) {
+		printk(KERN_ERR
+			"microcode: can't misc_register on minor=%d\n",
+			MICROCODE_MINOR);
+		return error;
+	}
+
+	printk(KERN_INFO 
+		"IA-32 Microcode Update Driver: v" MICROCODE_VERSION " <tigran@veritas.com>\n");
+	return 0;
+}
+
+static void __exit microcode_exit (void)
+{
+	misc_deregister(&microcode_dev);
+	printk(KERN_INFO "IA-32 Microcode Update Driver v" MICROCODE_VERSION " unregistered\n");
+}
+
+module_init(microcode_init)
+module_exit(microcode_exit)
+MODULE_ALIAS_MISCDEV(MICROCODE_MINOR);
diff --git a/xen/arch/x86/dom0_ops.c b/xen/arch/x86/dom0_ops.c
index b632e539c7..86479f1d17 100644
--- a/xen/arch/x86/dom0_ops.c
+++ b/xen/arch/x86/dom0_ops.c
@@ -130,6 +130,13 @@ long arch_do_dom0_op(dom0_op_t *op, dom0_op_t *u_dom0_op)
     }
     break;
 
+    case DOM0_MICROCODE:
+    {
+        extern int microcode_update(void *buf, unsigned long len);
+        ret = microcode_update(op->u.microcode.data, op->u.microcode.length);
+    }
+    break;
+
     default:
         ret = -ENOSYS;
 
diff --git a/xen/arch/x86/microcode.c b/xen/arch/x86/microcode.c
new file mode 100644
index 0000000000..2b5a18da50
--- /dev/null
+++ b/xen/arch/x86/microcode.c
@@ -0,0 +1,456 @@
+/*
+ *	Intel CPU Microcode Update Driver for Linux
+ *
+ *	Copyright (C) 2000-2004 Tigran Aivazian
+ *
+ *	This driver allows to upgrade microcode on Intel processors
+ *	belonging to IA-32 family - PentiumPro, Pentium II, 
+ *	Pentium III, Xeon, Pentium 4, etc.
+ *
+ *	Reference: Section 8.10 of Volume III, Intel Pentium 4 Manual, 
+ *	Order Number 245472 or free download from:
+ *		
+ *	http://developer.intel.com/design/pentium4/manuals/245472.htm
+ *
+ *	For more information, go to http://www.urbanmyth.org/microcode
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	1.0	16 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Initial release.
+ *	1.01	18 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Added read() support + cleanups.
+ *	1.02	21 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Added 'device trimming' support. open(O_WRONLY) zeroes
+ *		and frees the saved copy of applied microcode.
+ *	1.03	29 Feb 2000, Tigran Aivazian <tigran@sco.com>
+ *		Made to use devfs (/dev/cpu/microcode) + cleanups.
+ *	1.04	06 Jun 2000, Simon Trimmer <simon@veritas.com>
+ *		Added misc device support (now uses both devfs and misc).
+ *		Added MICROCODE_IOCFREE ioctl to clear memory.
+ *	1.05	09 Jun 2000, Simon Trimmer <simon@veritas.com>
+ *		Messages for error cases (non Intel & no suitable microcode).
+ *	1.06	03 Aug 2000, Tigran Aivazian <tigran@veritas.com>
+ *		Removed ->release(). Removed exclusive open and status bitmap.
+ *		Added microcode_rwsem to serialize read()/write()/ioctl().
+ *		Removed global kernel lock usage.
+ *	1.07	07 Sep 2000, Tigran Aivazian <tigran@veritas.com>
+ *		Write 0 to 0x8B msr and then cpuid before reading revision,
+ *		so that it works even if there were no update done by the
+ *		BIOS. Otherwise, reading from 0x8B gives junk (which happened
+ *		to be 0 on my machine which is why it worked even when I
+ *		disabled update by the BIOS)
+ *		Thanks to Eric W. Biederman <ebiederman@lnxi.com> for the fix.
+ *	1.08	11 Dec 2000, Richard Schaal <richard.schaal@intel.com> and
+ *			     Tigran Aivazian <tigran@veritas.com>
+ *		Intel Pentium 4 processor support and bugfixes.
+ *	1.09	30 Oct 2001, Tigran Aivazian <tigran@veritas.com>
+ *		Bugfix for HT (Hyper-Threading) enabled processors
+ *		whereby processor resources are shared by all logical processors
+ *		in a single CPU package.
+ *	1.10	28 Feb 2002 Asit K Mallick <asit.k.mallick@intel.com> and
+ *		Tigran Aivazian <tigran@veritas.com>,
+ *		Serialize updates as required on HT processors due to speculative
+ *		nature of implementation.
+ *	1.11	22 Mar 2002 Tigran Aivazian <tigran@veritas.com>
+ *		Fix the panic when writing zero-length microcode chunk.
+ *	1.12	29 Sep 2003 Nitin Kamble <nitin.a.kamble@intel.com>, 
+ *		Jun Nakajima <jun.nakajima@intel.com>
+ *		Support for the microcode updates in the new format.
+ *	1.13	10 Oct 2003 Tigran Aivazian <tigran@veritas.com>
+ *		Removed ->read() method and obsoleted MICROCODE_IOCFREE ioctl
+ *		because we no longer hold a copy of applied microcode 
+ *		in kernel memory.
+ *	1.14	25 Jun 2004 Tigran Aivazian <tigran@veritas.com>
+ *		Fix sigmatch() macro to handle old CPUs with pf == 0.
+ *		Thanks to Stuart Swales for pointing out this bug.
+ */
+
+#include <xen/config.h>
+#include <xen/kernel.h>
+#include <xen/init.h>
+#include <xen/sched.h>
+#include <xen/slab.h>
+#include <xen/spinlock.h>
+
+#include <asm/msr.h>
+#include <asm/uaccess.h>
+#include <asm/processor.h>
+
+#define pr_debug(x...) ((void)0)
+#define DECLARE_MUTEX(_m) spinlock_t _m = SPIN_LOCK_UNLOCKED
+#define down(_m) spin_lock(_m)
+#define up(_m) spin_unlock(_m)
+#define vmalloc(_s) xmalloc(_s)
+#define vfree(_p) xfree(_p)
+#define num_online_cpus() smp_num_cpus
+static inline int on_each_cpu(
+    void (*func) (void *info), void *info, int retry, int wait)
+{
+    int ret = smp_call_function(func, info, retry, wait);
+    func(info);
+    return ret;
+}
+
+#if 0
+MODULE_DESCRIPTION("Intel CPU (IA-32) Microcode Update Driver");
+MODULE_AUTHOR("Tigran Aivazian <tigran@veritas.com>");
+MODULE_LICENSE("GPL");
+#endif
+
+#define MICROCODE_VERSION 	"1.14"
+
+#define DEFAULT_UCODE_DATASIZE 	(2000) 	  /* 2000 bytes */
+#define MC_HEADER_SIZE		(sizeof (microcode_header_t))  	  /* 48 bytes */
+#define DEFAULT_UCODE_TOTALSIZE (DEFAULT_UCODE_DATASIZE + MC_HEADER_SIZE) /* 2048 bytes */
+#define EXT_HEADER_SIZE		(sizeof (struct extended_sigtable)) /* 20 bytes */
+#define EXT_SIGNATURE_SIZE	(sizeof (struct extended_signature)) /* 12 bytes */
+#define DWSIZE			(sizeof (u32))
+#define get_totalsize(mc) \
+	(((microcode_t *)mc)->hdr.totalsize ? \
+	 ((microcode_t *)mc)->hdr.totalsize : DEFAULT_UCODE_TOTALSIZE)
+#define get_datasize(mc) \
+	(((microcode_t *)mc)->hdr.datasize ? \
+	 ((microcode_t *)mc)->hdr.datasize : DEFAULT_UCODE_DATASIZE)
+
+#define sigmatch(s1, s2, p1, p2) \
+	(((s1) == (s2)) && (((p1) & (p2)) || (((p1) == 0) && ((p2) == 0))))
+
+#define exttable_size(et) ((et)->count * EXT_SIGNATURE_SIZE + EXT_HEADER_SIZE)
+
+/* serialize access to the physical write to MSR 0x79 */
+static spinlock_t microcode_update_lock = SPIN_LOCK_UNLOCKED;
+
+/* no concurrent ->write()s are allowed on /dev/cpu/microcode */
+static DECLARE_MUTEX(microcode_sem);
+
+static void __user *user_buffer;	/* user area microcode data buffer */
+static unsigned int user_buffer_size;	/* it's size */
+
+typedef enum mc_error_code {
+	MC_SUCCESS 	= 0,
+	MC_NOTFOUND 	= 1,
+	MC_MARKED 	= 2,
+	MC_ALLOCATED 	= 3,
+} mc_error_code_t;
+
+static struct ucode_cpu_info {
+	unsigned int sig;
+	unsigned int pf;
+	unsigned int rev;
+	unsigned int cksum;
+	mc_error_code_t err;
+	microcode_t *mc;
+} ucode_cpu_info[NR_CPUS];
+				
+static void collect_cpu_info (void *unused)
+{
+	int cpu_num = smp_processor_id();
+	struct cpuinfo_x86 *c = cpu_data + cpu_num;
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+	unsigned int val[2];
+
+	uci->sig = uci->pf = uci->rev = uci->cksum = 0;
+	uci->err = MC_NOTFOUND; 
+	uci->mc = NULL;
+
+	if (c->x86_vendor != X86_VENDOR_INTEL || c->x86 < 6 ||
+	    	cpu_has(c, X86_FEATURE_IA64)) {
+		printk(KERN_ERR "microcode: CPU%d not a capable Intel processor\n", cpu_num);
+		return;
+	} else {
+		uci->sig = cpuid_eax(0x00000001);
+
+		if ((c->x86_model >= 5) || (c->x86 > 6)) {
+			/* get processor flags from MSR 0x17 */
+			rdmsr(MSR_IA32_PLATFORM_ID, val[0], val[1]);
+			uci->pf = 1 << ((val[1] >> 18) & 7);
+		}
+	}
+
+	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+	/* get the current revision from MSR 0x8B */
+	rdmsr(MSR_IA32_UCODE_REV, val[0], uci->rev);
+	pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
+			uci->sig, uci->pf, uci->rev);
+}
+
+static inline void mark_microcode_update (int cpu_num, microcode_header_t *mc_header, int sig, int pf, int cksum)
+{
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+
+	pr_debug("Microcode Found.\n");
+	pr_debug("   Header Revision 0x%x\n", mc_header->hdrver);
+	pr_debug("   Loader Revision 0x%x\n", mc_header->ldrver);
+	pr_debug("   Revision 0x%x \n", mc_header->rev);
+	pr_debug("   Date %x/%x/%x\n",
+		((mc_header->date >> 24 ) & 0xff),
+		((mc_header->date >> 16 ) & 0xff),
+		(mc_header->date & 0xFFFF));
+	pr_debug("   Signature 0x%x\n", sig);
+	pr_debug("   Type 0x%x Family 0x%x Model 0x%x Stepping 0x%x\n",
+		((sig >> 12) & 0x3),
+		((sig >> 8) & 0xf),
+		((sig >> 4) & 0xf),
+		((sig & 0xf)));
+	pr_debug("   Processor Flags 0x%x\n", pf);
+	pr_debug("   Checksum 0x%x\n", cksum);
+
+	if (mc_header->rev < uci->rev) {
+		printk(KERN_ERR "microcode: CPU%d not 'upgrading' to earlier revision"
+		       " 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
+		goto out;
+	} else if (mc_header->rev == uci->rev) {
+		/* notify the caller of success on this cpu */
+		uci->err = MC_SUCCESS;
+		printk(KERN_ERR "microcode: CPU%d already at revision"
+			" 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
+		goto out;
+	}
+
+	pr_debug("microcode: CPU%d found a matching microcode update with "
+		" revision 0x%x (current=0x%x)\n", cpu_num, mc_header->rev, uci->rev);
+	uci->cksum = cksum;
+	uci->pf = pf; /* keep the original mc pf for cksum calculation */
+	uci->err = MC_MARKED; /* found the match */
+out:
+	return;
+}
+
+static int find_matching_ucodes (void) 
+{
+	int cursor = 0;
+	int error = 0;
+
+	while (cursor + MC_HEADER_SIZE < user_buffer_size) {
+		microcode_header_t mc_header;
+		void *newmc = NULL;
+		int i, sum, cpu_num, allocated_flag, total_size, data_size, ext_table_size;
+
+		if (copy_from_user(&mc_header, user_buffer + cursor, MC_HEADER_SIZE)) {
+			printk(KERN_ERR "microcode: error! Can not read user data\n");
+			error = -EFAULT;
+			goto out;
+		}
+
+		total_size = get_totalsize(&mc_header);
+		if ((cursor + total_size > user_buffer_size) || (total_size < DEFAULT_UCODE_TOTALSIZE)) {
+			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
+			error = -EINVAL;
+			goto out;
+		}
+
+		data_size = get_datasize(&mc_header);
+		if ((data_size + MC_HEADER_SIZE > total_size) || (data_size < DEFAULT_UCODE_DATASIZE)) {
+			printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
+			error = -EINVAL;
+			goto out;
+		}
+
+		if (mc_header.ldrver != 1 || mc_header.hdrver != 1) {
+			printk(KERN_ERR "microcode: error! Unknown microcode update format\n");
+			error = -EINVAL;
+			goto out;
+		}
+		
+		for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
+			struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+			if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
+				continue;
+
+			if (sigmatch(mc_header.sig, uci->sig, mc_header.pf, uci->pf))
+				mark_microcode_update(cpu_num, &mc_header, mc_header.sig, mc_header.pf, mc_header.cksum);
+		}
+
+		ext_table_size = total_size - (MC_HEADER_SIZE + data_size);
+		if (ext_table_size) {
+			struct extended_sigtable ext_header;
+			struct extended_signature ext_sig;
+			int ext_sigcount;
+
+			if ((ext_table_size < EXT_HEADER_SIZE) 
+					|| ((ext_table_size - EXT_HEADER_SIZE) % EXT_SIGNATURE_SIZE)) {
+				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
+				error = -EINVAL;
+				goto out;
+			}
+			if (copy_from_user(&ext_header, user_buffer + cursor 
+					+ MC_HEADER_SIZE + data_size, EXT_HEADER_SIZE)) {
+				printk(KERN_ERR "microcode: error! Can not read user data\n");
+				error = -EFAULT;
+				goto out;
+			}
+			if (ext_table_size != exttable_size(&ext_header)) {
+				printk(KERN_ERR "microcode: error! Bad data in microcode data file\n");
+				error = -EFAULT;
+				goto out;
+			}
+
+			ext_sigcount = ext_header.count;
+			
+			for (i = 0; i < ext_sigcount; i++) {
+				if (copy_from_user(&ext_sig, user_buffer + cursor + MC_HEADER_SIZE + data_size + EXT_HEADER_SIZE 
+						+ EXT_SIGNATURE_SIZE * i, EXT_SIGNATURE_SIZE)) {
+					printk(KERN_ERR "microcode: error! Can not read user data\n");
+					error = -EFAULT;
+					goto out;
+				}
+				for (cpu_num = 0; cpu_num < num_online_cpus(); cpu_num++) {
+					struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+					if (uci->err != MC_NOTFOUND) /* already found a match or not an online cpu*/
+						continue;
+					if (sigmatch(ext_sig.sig, uci->sig, ext_sig.pf, uci->pf)) {
+						mark_microcode_update(cpu_num, &mc_header, ext_sig.sig, ext_sig.pf, ext_sig.cksum);
+					}
+				}
+			}
+		}
+		/* now check if any cpu has matched */
+		for (cpu_num = 0, allocated_flag = 0, sum = 0; cpu_num < num_online_cpus(); cpu_num++) {
+			if (ucode_cpu_info[cpu_num].err == MC_MARKED) { 
+				struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+				if (!allocated_flag) {
+					allocated_flag = 1;
+					newmc = vmalloc(total_size);
+					if (!newmc) {
+						printk(KERN_ERR "microcode: error! Can not allocate memory\n");
+						error = -ENOMEM;
+						goto out;
+					}
+					if (copy_from_user(newmc + MC_HEADER_SIZE, 
+								user_buffer + cursor + MC_HEADER_SIZE, 
+								total_size - MC_HEADER_SIZE)) {
+						printk(KERN_ERR "microcode: error! Can not read user data\n");
+						vfree(newmc);
+						error = -EFAULT;
+						goto out;
+					}
+					memcpy(newmc, &mc_header, MC_HEADER_SIZE);
+					/* check extended table checksum */
+					if (ext_table_size) {
+						int ext_table_sum = 0;
+						int * ext_tablep = (((void *) newmc) + MC_HEADER_SIZE + data_size);
+						i = ext_table_size / DWSIZE;
+						while (i--) ext_table_sum += ext_tablep[i];
+						if (ext_table_sum) {
+							printk(KERN_WARNING "microcode: aborting, bad extended signature table checksum\n");
+							vfree(newmc);
+							error = -EINVAL;
+							goto out;
+						}
+					}
+
+					/* calculate the checksum */
+					i = (MC_HEADER_SIZE + data_size) / DWSIZE;
+					while (i--) sum += ((int *)newmc)[i];
+					sum -= (mc_header.sig + mc_header.pf + mc_header.cksum);
+				}
+				ucode_cpu_info[cpu_num].mc = newmc;
+				ucode_cpu_info[cpu_num].err = MC_ALLOCATED; /* mc updated */
+				if (sum + uci->sig + uci->pf + uci->cksum != 0) {
+					printk(KERN_ERR "microcode: CPU%d aborting, bad checksum\n", cpu_num);
+					error = -EINVAL;
+					goto out;
+				}
+			}
+		}
+		cursor += total_size; /* goto the next update patch */
+	} /* end of while */
+out:
+	return error;
+}
+
+static void do_update_one (void * unused)
+{
+	unsigned long flags;
+	unsigned int val[2];
+	int cpu_num = smp_processor_id();
+	struct ucode_cpu_info *uci = ucode_cpu_info + cpu_num;
+
+	if (uci->mc == NULL) {
+		printk(KERN_INFO "microcode: No suitable data for CPU%d\n", cpu_num);
+		return;
+	}
+
+	/* serialize access to the physical write to MSR 0x79 */
+	spin_lock_irqsave(&microcode_update_lock, flags);          
+
+	/* write microcode via MSR 0x79 */
+	wrmsr(MSR_IA32_UCODE_WRITE,
+		(unsigned long) uci->mc->bits, 
+		(unsigned long) uci->mc->bits >> 16 >> 16);
+	wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+
+	__asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+	/* get the current revision from MSR 0x8B */
+	rdmsr(MSR_IA32_UCODE_REV, val[0], val[1]);
+
+	/* notify the caller of success on this cpu */
+	uci->err = MC_SUCCESS;
+	spin_unlock_irqrestore(&microcode_update_lock, flags);
+	printk(KERN_INFO "microcode: CPU%d updated from revision "
+	       "0x%x to 0x%x, date = %08x \n", 
+	       cpu_num, uci->rev, val[1], uci->mc->hdr.date);
+	return;
+}
+
+static int do_microcode_update (void)
+{
+	int i, error;
+
+	if (on_each_cpu(collect_cpu_info, NULL, 1, 1) != 0) {
+		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
+		error = -EIO;
+		goto out;
+	}
+
+	if ((error = find_matching_ucodes())) {
+		printk(KERN_ERR "microcode: Error in the microcode data\n");
+		goto out_free;
+	}
+
+	if (on_each_cpu(do_update_one, NULL, 1, 1) != 0) {
+		printk(KERN_ERR "microcode: Error! Could not run on all processors\n");
+		error = -EIO;
+	}
+
+out_free:
+	for (i = 0; i < num_online_cpus(); i++) {
+		if (ucode_cpu_info[i].mc) {
+			int j;
+			void *tmp = ucode_cpu_info[i].mc;
+			vfree(tmp);
+			for (j = i; j < num_online_cpus(); j++) {
+				if (ucode_cpu_info[j].mc == tmp)
+					ucode_cpu_info[j].mc = NULL;
+			}
+		}
+	}
+out:
+	return error;
+}
+
+int microcode_update(void *buf, unsigned long len)
+{
+    int ret;
+
+    if (len < DEFAULT_UCODE_TOTALSIZE) {
+        printk(KERN_ERR "microcode: not enough data\n"); 
+        return -EINVAL;
+    }
+
+    down(&microcode_sem);
+    
+    user_buffer = (void __user *) buf;
+    user_buffer_size = (int) len;
+    
+    ret = do_microcode_update();
+    
+    up(&microcode_sem);
+    
+    return ret;
+}
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index ae5b13b7d1..55deb004a9 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -532,7 +532,7 @@ long set_gdt(struct domain *d,
 
 long set_debugreg(struct domain *p, int reg, unsigned long value);
 
-struct microcode {
+struct microcode_header {
     unsigned int hdrver;
     unsigned int rev;
     unsigned int date;
@@ -540,12 +540,32 @@ struct microcode {
     unsigned int cksum;
     unsigned int ldrver;
     unsigned int pf;
-    unsigned int reserved[5];
-    unsigned int bits[500];
+    unsigned int datasize;
+    unsigned int totalsize;
+    unsigned int reserved[3];
+};
+
+struct microcode {
+    struct microcode_header hdr;
+    unsigned int bits[0];
+};
+
+typedef struct microcode microcode_t;
+typedef struct microcode_header microcode_header_t;
+
+/* microcode format is extended from prescott processors */
+struct extended_signature {
+    unsigned int sig;
+    unsigned int pf;
+    unsigned int cksum;
 };
 
-/* '6' because it used to be for P6 only (but now covers Pentium 4 as well) */
-#define MICROCODE_IOCFREE	_IO('6',0)
+struct extended_sigtable {
+    unsigned int count;
+    unsigned int cksum;
+    unsigned int reserved[3];
+    struct extended_signature sigs[0];
+};
 
 /* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
 static inline void rep_nop(void)
diff --git a/xen/include/public/dom0_ops.h b/xen/include/public/dom0_ops.h
index 9673c88678..eb4766192d 100644
--- a/xen/include/public/dom0_ops.h
+++ b/xen/include/public/dom0_ops.h
@@ -405,6 +405,15 @@ typedef struct {
     MEMORY_PADDING;
 } PACKED dom0_perfccontrol_t; /* 16 bytes */
 
+#define DOM0_MICROCODE           35
+typedef struct {
+    /* IN variables. */
+    void   *data;                     /* 0: Pointer to microcode data */
+    MEMORY_PADDING;
+    u32     length;                   /* 8: Length of microcode data. */
+    u32     _pad0;
+} PACKED dom0_microcode_t; /* 16 bytes */
+
 typedef struct {
     u32 cmd;                          /* 0 */
     u32 interface_version;            /* 4 */ /* DOM0_INTERFACE_VERSION */
@@ -439,6 +448,7 @@ typedef struct {
         dom0_del_memtype_t       del_memtype;
         dom0_read_memtype_t      read_memtype;
         dom0_perfccontrol_t      perfccontrol;
+        dom0_microcode_t         microcode;
     } PACKED u;
 } PACKED dom0_op_t; /* 80 bytes */