Merge branch 'xen-upstream' of ssh://master.kernel.org/pub/scm/linux/kernel/git/jeremy/xen

* 'xen-upstream' of ssh://master.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (44 commits)
  xen: disable all non-virtual drivers
  xen: use iret directly when possible
  xen: suppress abs symbol warnings for unused reloc pointers
  xen: Attempt to patch inline versions of common operations
  xen: Place vcpu_info structure into per-cpu memory
  xen: handle external requests for shutdown, reboot and sysrq
  xen: machine operations
  xen: add virtual network device driver
  xen: add virtual block device driver.
  xen: add the Xenbus sysfs and virtual device hotplug driver
  xen: Add grant table support
  xen: use the hvc console infrastructure for Xen console
  xen: hack to prevent bad segment register reload
  xen: lazy-mmu operations
  xen: Add support for preemption
  xen: SMP guest support
  xen: Implement sched_clock
  xen: Account for stolen time
  xen: ignore RW mapping of RO pages in pagetable_init
  xen: Complete pagetable pinning
  ...

116 files changed, 15031 insertions, 210 deletions

diff --git a/arch/i386/Kconfig b/arch/i386/Kconfig
index c7c9c2a15fa..7a11b905ef4 100644
--- a/arch/i386/Kconfig
+++ b/arch/i386/Kconfig
@@ -222,6 +222,8 @@ config PARAVIRT
 	  However, when run without a hypervisor the kernel is
 	  theoretically slower.  If in doubt, say N.
 
+source "arch/i386/xen/Kconfig"
+
 config VMI
 	bool "VMI Paravirt-ops support"
 	depends on PARAVIRT
diff --git a/arch/i386/Makefile b/arch/i386/Makefile
index 181cc29a7c4..01f0ff0daaf 100644
--- a/arch/i386/Makefile
+++ b/arch/i386/Makefile
@@ -93,6 +93,9 @@ mflags-$(CONFIG_X86_ES7000)	:= -Iinclude/asm-i386/mach-es7000
 mcore-$(CONFIG_X86_ES7000)	:= mach-default
 core-$(CONFIG_X86_ES7000)	:= arch/i386/mach-es7000/
 
+# Xen paravirtualization support
+core-$(CONFIG_XEN)		+= arch/i386/xen/
+
 # default subarch .h files
 mflags-y += -Iinclude/asm-i386/mach-default
 
diff --git a/arch/i386/boot/compressed/relocs.c b/arch/i386/boot/compressed/relocs.c
index ce4fda261aa..b0e21c3cee5 100644
--- a/arch/i386/boot/compressed/relocs.c
+++ b/arch/i386/boot/compressed/relocs.c
@@ -31,6 +31,8 @@ static const char* safe_abs_relocs[] = {
 		"__kernel_rt_sigreturn",
 		"__kernel_sigreturn",
 		"SYSENTER_RETURN",
+		"xen_irq_disable_direct_reloc",
+		"xen_save_fl_direct_reloc",
 };
 
 static int is_safe_abs_reloc(const char* sym_name)
diff --git a/arch/i386/kernel/asm-offsets.c b/arch/i386/kernel/asm-offsets.c
index 27a776c9044..25f7eb51392 100644
--- a/arch/i386/kernel/asm-offsets.c
+++ b/arch/i386/kernel/asm-offsets.c
@@ -17,6 +17,8 @@
 #include <asm/thread_info.h>
 #include <asm/elf.h>
 
+#include <xen/interface/xen.h>
+
 #define DEFINE(sym, val) \
         asm volatile("\n->" #sym " %0 " #val : : "i" (val))
 
@@ -59,6 +61,7 @@ void foo(void)
 	OFFSET(TI_addr_limit, thread_info, addr_limit);
 	OFFSET(TI_restart_block, thread_info, restart_block);
 	OFFSET(TI_sysenter_return, thread_info, sysenter_return);
+	OFFSET(TI_cpu, thread_info, cpu);
 	BLANK();
 
 	OFFSET(GDS_size, Xgt_desc_struct, size);
@@ -115,4 +118,10 @@ void foo(void)
 	OFFSET(PARAVIRT_iret, paravirt_ops, iret);
 	OFFSET(PARAVIRT_read_cr0, paravirt_ops, read_cr0);
 #endif
+
+#ifdef CONFIG_XEN
+	BLANK();
+	OFFSET(XEN_vcpu_info_mask, vcpu_info, evtchn_upcall_mask);
+	OFFSET(XEN_vcpu_info_pending, vcpu_info, evtchn_upcall_pending);
+#endif
 }
diff --git a/arch/i386/kernel/entry.S b/arch/i386/kernel/entry.S
index 3c3c220488c..32980b83493 100644
--- a/arch/i386/kernel/entry.S
+++ b/arch/i386/kernel/entry.S
@@ -1023,6 +1023,91 @@ ENTRY(kernel_thread_helper)
 	CFI_ENDPROC
 ENDPROC(kernel_thread_helper)
 
+#ifdef CONFIG_XEN
+ENTRY(xen_hypervisor_callback)
+	CFI_STARTPROC
+	pushl $0
+	CFI_ADJUST_CFA_OFFSET 4
+	SAVE_ALL
+	TRACE_IRQS_OFF
+
+	/* Check to see if we got the event in the critical
+	   region in xen_iret_direct, after we've reenabled
+	   events and checked for pending events.  This simulates
+	   iret instruction's behaviour where it delivers a
+	   pending interrupt when enabling interrupts. */
+	movl PT_EIP(%esp),%eax
+	cmpl $xen_iret_start_crit,%eax
+	jb   1f
+	cmpl $xen_iret_end_crit,%eax
+	jae  1f
+
+	call xen_iret_crit_fixup
+
+1:	mov %esp, %eax
+	call xen_evtchn_do_upcall
+	jmp  ret_from_intr
+	CFI_ENDPROC
+ENDPROC(xen_hypervisor_callback)
+
+# Hypervisor uses this for application faults while it executes.
+# We get here for two reasons:
+#  1. Fault while reloading DS, ES, FS or GS
+#  2. Fault while executing IRET
+# Category 1 we fix up by reattempting the load, and zeroing the segment
+# register if the load fails.
+# Category 2 we fix up by jumping to do_iret_error. We cannot use the
+# normal Linux return path in this case because if we use the IRET hypercall
+# to pop the stack frame we end up in an infinite loop of failsafe callbacks.
+# We distinguish between categories by maintaining a status value in EAX.
+ENTRY(xen_failsafe_callback)
+	CFI_STARTPROC
+	pushl %eax
+	CFI_ADJUST_CFA_OFFSET 4
+	movl $1,%eax
+1:	mov 4(%esp),%ds
+2:	mov 8(%esp),%es
+3:	mov 12(%esp),%fs
+4:	mov 16(%esp),%gs
+	testl %eax,%eax
+	popl %eax
+	CFI_ADJUST_CFA_OFFSET -4
+	lea 16(%esp),%esp
+	CFI_ADJUST_CFA_OFFSET -16
+	jz 5f
+	addl $16,%esp
+	jmp iret_exc		# EAX != 0 => Category 2 (Bad IRET)
+5:	pushl $0		# EAX == 0 => Category 1 (Bad segment)
+	CFI_ADJUST_CFA_OFFSET 4
+	SAVE_ALL
+	jmp ret_from_exception
+	CFI_ENDPROC
+
+.section .fixup,"ax"
+6:	xorl %eax,%eax
+	movl %eax,4(%esp)
+	jmp 1b
+7:	xorl %eax,%eax
+	movl %eax,8(%esp)
+	jmp 2b
+8:	xorl %eax,%eax
+	movl %eax,12(%esp)
+	jmp 3b
+9:	xorl %eax,%eax
+	movl %eax,16(%esp)
+	jmp 4b
+.previous
+.section __ex_table,"a"
+	.align 4
+	.long 1b,6b
+	.long 2b,7b
+	.long 3b,8b
+	.long 4b,9b
+.previous
+ENDPROC(xen_failsafe_callback)
+
+#endif	/* CONFIG_XEN */
+
 .section .rodata,"a"
 #include "syscall_table.S"
 
diff --git a/arch/i386/kernel/head.S b/arch/i386/kernel/head.S
index 82714668d43..7c52b222207 100644
--- a/arch/i386/kernel/head.S
+++ b/