Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm

* 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (147 commits)
  KVM: kill file->f_count abuse in kvm
  KVM: MMU: kvm_pv_mmu_op should not take mmap_sem
  KVM: SVM: remove selective CR0 comment
  KVM: SVM: remove now obsolete FIXME comment
  KVM: SVM: disable CR8 intercept when tpr is not masking interrupts
  KVM: SVM: sync V_TPR with LAPIC.TPR if CR8 write intercept is disabled
  KVM: export kvm_lapic_set_tpr() to modules
  KVM: SVM: sync TPR value to V_TPR field in the VMCB
  KVM: ppc: PowerPC 440 KVM implementation
  KVM: Add MAINTAINERS entry for PowerPC KVM
  KVM: ppc: Add DCR access information to struct kvm_run
  ppc: Export tlb_44x_hwater for KVM
  KVM: Rename debugfs_dir to kvm_debugfs_dir
  KVM: x86 emulator: fix lea to really get the effective address
  KVM: x86 emulator: fix smsw and lmsw with a memory operand
  KVM: x86 emulator: initialize src.val and dst.val for register operands
  KVM: SVM: force a new asid when initializing the vmcb
  KVM: fix kvm_vcpu_kick vs __vcpu_run race
  KVM: add ioctls to save/store mpstate
  KVM: Rename VCPU_MP_STATE_* to KVM_MP_STATE_*
  ...

27 files changed, 3365 insertions, 548 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 2fadf794483..e5790fe9e33 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -373,6 +373,25 @@ config VMI
 	  at the moment), by linking the kernel to a GPL-ed ROM module
 	  provided by the hypervisor.
 
+config KVM_CLOCK
+	bool "KVM paravirtualized clock"
+	select PARAVIRT
+	depends on !(X86_VISWS || X86_VOYAGER)
+	help
+	  Turning on this option will allow you to run a paravirtualized clock
+	  when running over the KVM hypervisor. Instead of relying on a PIT
+	  (or probably other) emulation by the underlying device model, the host
+	  provides the guest with timing infrastructure such as time of day, and
+	  system time
+
+config KVM_GUEST
+	bool "KVM Guest support"
+	select PARAVIRT
+	depends on !(X86_VISWS || X86_VOYAGER)
+	help
+	 This option enables various optimizations for running under the KVM
+	 hypervisor.
+
 source "arch/x86/lguest/Kconfig"
 
 config PARAVIRT
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 90e092d0af0..fa19c381954 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -80,6 +80,8 @@ obj-$(CONFIG_DEBUG_RODATA_TEST)	+= test_rodata.o
 obj-$(CONFIG_DEBUG_NX_TEST)	+= test_nx.o
 
 obj-$(CONFIG_VMI)		+= vmi_32.o vmiclock_32.o
+obj-$(CONFIG_KVM_GUEST)		+= kvm.o
+obj-$(CONFIG_KVM_CLOCK)		+= kvmclock.o
 obj-$(CONFIG_PARAVIRT)		+= paravirt.o paravirt_patch_$(BITS).o
 
 ifdef CONFIG_INPUT_PCSPKR
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index 2251d0ae957..26855381790 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -25,6 +25,7 @@
 #include <asm/hpet.h>
 #include <linux/kdebug.h>
 #include <asm/smp.h>
+#include <asm/reboot.h>
 
 #include <mach_ipi.h>
 
@@ -117,7 +118,7 @@ static void nmi_shootdown_cpus(void)
 }
 #endif
 
-void machine_crash_shutdown(struct pt_regs *regs)
+void native_machine_crash_shutdown(struct pt_regs *regs)
 {
 	/* This function is only called after the system
 	 * has panicked or is otherwise in a critical state.
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
new file mode 100644
index 00000000000..8b7a3cf37d2
--- /dev/null
+++ b/arch/x86/kernel/kvm.c
@@ -0,0 +1,248 @@
+/*
+ * KVM paravirt_ops implementation
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that 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, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+ *
+ * Copyright (C) 2007, Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright IBM Corporation, 2007
+ *   Authors: Anthony Liguori <aliguori@us.ibm.com>
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/kvm_para.h>
+#include <linux/cpu.h>
+#include <linux/mm.h>
+#include <linux/highmem.h>
+#include <linux/hardirq.h>
+
+#define MMU_QUEUE_SIZE 1024
+
+struct kvm_para_state {
+	u8 mmu_queue[MMU_QUEUE_SIZE];
+	int mmu_queue_len;
+	enum paravirt_lazy_mode mode;
+};
+
+static DEFINE_PER_CPU(struct kvm_para_state, para_state);
+
+static struct kvm_para_state *kvm_para_state(void)
+{
+	return &per_cpu(para_state, raw_smp_processor_id());
+}
+
+/*
+ * No need for any "IO delay" on KVM
+ */
+static void kvm_io_delay(void)
+{
+}
+
+static void kvm_mmu_op(void *buffer, unsigned len)
+{
+	int r;
+	unsigned long a1, a2;
+
+	do {
+		a1 = __pa(buffer);
+		a2 = 0;   /* on i386 __pa() always returns <4G */
+		r = kvm_hypercall3(KVM_HC_MMU_OP, len, a1, a2);
+		buffer += r;
+		len -= r;
+	} while (len);
+}
+
+static void mmu_queue_flush(struct kvm_para_state *state)
+{
+	if (state->mmu_queue_len) {
+		kvm_mmu_op(state->mmu_queue, state->mmu_queue_len);
+		state->mmu_queue_len = 0;
+	}
+}
+
+static void kvm_deferred_mmu_op(void *buffer, int len)
+{
+	struct kvm_para_state *state = kvm_para_state();
+
+	if (state->mode != PARAVIRT_LAZY_MMU) {
+		kvm_mmu_op(buffer, len);
+		return;
+	}
+	if (state->mmu_queue_len + len > sizeof state->mmu_queue)
+		mmu_queue_flush(state);
+	memcpy(state->mmu_queue + state->mmu_queue_len, buffer, len);
+	state->mmu_queue_len += len;
+}
+
+static void kvm_mmu_write(void *dest, u64 val)
+{
+	__u64 pte_phys;
+	struct kvm_mmu_op_write_pte wpte;
+
+#ifdef CONFIG_HIGHPTE
+	struct page *page;
+	unsigned long dst = (unsigned long) dest;
+
+	page = kmap_atomic_to_page(dest);
+	pte_phys = page_to_pfn(page);
+	pte_phys <<= PAGE_SHIFT;
+	pte_phys += (dst & ~(PAGE_MASK));
+#else
+	pte_phys = (unsigned long)__pa(dest);
+#endif
+	wpte.header.op = KVM_MMU_OP_WRITE_PTE;
+	wpte.pte_val = val;
+	wpte.pte_phys = pte_phys;
+
+	kvm_deferred_mmu_op(&wpte, sizeof wpte);
+}
+
+/*
+ * We only need to hook operations that are MMU writes.  We hook these so that
+ * we can use lazy MMU mode to batch these operations.  We could probably
+ * improve the performance of the host code if we used some of the information
+ * here to simplify processing of batched writes.
+ */
+static void kvm_set_pte(pte_t *ptep, pte_t pte)
+{
+	kvm_mmu_write(ptep, pte_val(pte));
+}
+
+static void kvm_set_pte_at(struct mm_struct *mm, unsigned long addr,
+			   pte_t *ptep, pte_t pte)
+{
+	kvm_mmu_write(ptep, pte_val(pte));
+}
+
+static void kvm_set_pmd(pmd_t *pmdp, pmd_t pmd)
+{
+	kvm_mmu_write(pmdp, pmd_val(pmd));
+}
+
+#if PAGETABLE_LEVELS >= 3
+#ifdef CONFIG_X86_PAE
+static void kvm_set_pte_atomic(pte_t *ptep, pte_t pte)
+{
+	kvm_mmu_write(ptep, pte_val(pte));
+}
+
+static void kvm_set_pte_present(struct mm_struct *mm, unsigned long addr,
+				pte_t *ptep, pte_t pte)
+{
+	kvm_mmu_write(ptep, pte_val(pte));
+}
+
+static void kvm_pte_clear(struct mm_struct *mm,
+			  unsigned long addr, pte_t *ptep)
+{
+	kvm_mmu_write(ptep, 0);
+}
+
+static void kvm_pmd_clear(pmd_t *pmdp)
+{
+	kvm_mmu_write(pmdp, 0);
+}
+#endif
+
+static void kvm_set_pud(pud_t *pudp, pud_t pud)
+{
+	kvm_mmu_write(pudp, pud_val(pud));
+}
+
+#if PAGETABLE_LEVELS == 4
+static void kvm_set_pgd(pgd_t *pgdp, pgd_t pgd)
+{
+	kvm_mmu_write(pgdp, pgd_val(pgd));
+}
+#endif
+#endif /* PAGETABLE_LEVELS >= 3 */
+
+static void kvm_flush_tlb(void)
+{
+	struct kvm_mmu_op_flush_tlb ftlb = {
+		.header.op = KVM_MMU_OP_FLUSH_TLB,
+	};
+
+	kvm_deferred_mmu_op(&ftlb, sizeof ftlb);
+}
+
+static void kvm_release_pt(u32 pfn)
+{
+	struct kvm_mmu_op_release_pt rpt = {
+		.header.op = KVM_MMU_OP_RELEASE_PT,
+		.pt_phys = (u64)pfn << PAGE_SHIFT,
+	};
+
+	kvm_mmu_op(&rpt, sizeof rpt);
+}
+
+static void kvm_enter_lazy_mmu(void)
+{
+	struct kvm_para_state *state = kvm_para_state();
+
+	paravirt_enter_lazy_mmu();
+	state->mode = paravirt_get_lazy_mode();
+}
+
+static void kvm_leave_lazy_mmu(void)
+{
+	struct kvm_para_state *state = kvm_para_state();
+
+	mmu_queue_flush(state);
+	paravirt_leave_lazy(paravirt_get_lazy_mode());
+	state->mode = paravirt_get_lazy_mode();
+}
+
+static void paravirt_ops_setup(void)
+{
+	pv_info.name = "KVM";
+	pv_info.paravirt_enabled = 1;
+
+	if (kvm_para_has_feature(KVM_FEATURE_NOP_IO_DELAY))
+		pv_cpu_ops.io_delay = kvm_io_delay;
+
+	if (kvm_para_has_feature(KVM_FEATURE_MMU_OP)) {
+		pv_mmu_ops.set_pte = kvm_set_pte;
+		pv_mmu_ops.set_pte_at = kvm_set_pte_at;
+		pv_mmu_ops.set_pmd = kvm_set_pmd;
+#if PAGETABLE_LEVELS >= 3
+#ifdef CONFIG_X86_PAE
+		pv_mmu_ops.set_pte_atomic = kvm_set_pte_atomic;
+		pv_mmu_ops.set_pte_present = kvm_set_pte_present;
+		pv_mmu_ops.pte_clear = kvm_pte_clear;
+		pv_mmu_ops.pmd_clear = kvm_pmd_clear;
+#endif
+		pv_mmu_ops.set_pud = kvm_set_pud;
+#if PAGETABLE_LEVELS == 4
+		pv_mmu_ops.set_pgd = kvm_set_pgd;
+#endif
+#endif
+		pv_mmu_ops.flush_tlb_user = kvm_flush_tlb;
+		pv_mmu_ops.release_pte = kvm_release_pt;
+		pv_mmu_ops.release_pmd = kvm_release_pt;
+		pv_mmu_ops.release_pud = kvm_release_pt;
+
+		pv_mmu_ops.lazy_mode.enter = kvm_enter_lazy_mmu;
+		pv_mmu_ops.lazy_mode.leave = kvm_leave_lazy_mmu;
+	}
+}
+
+void __init kvm_guest_init(void)
+{
+	if (!kvm_para_available())
+		return;
+
+	paravirt_ops_setup();
+}
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
new file mode 100644
index 00000000000..ddee04043ae
--- /dev/null
+++ b/arch/x86/kernel/kvmclock.c
@@ -0,0 +1,187 @@
+/*  KVM paravirtual clock driver. A clocksource implementation
+    Copyright (C) 2008 Glauber de Oliveira Costa, Red Hat Inc.
+
+    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.
+
+    This program is distributed in the hope that 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include <linux/clocksource.h>
+#include <linux/kvm_para.h>
+#include <asm/arch_hooks.h>
+#include <asm/msr.h>
+#include <asm/apic.h>
+#include <linux/percpu.h>
+#include <asm/reboot.h>
+
+#define KVM_SCALE 22
+
+static int kvmclock = 1;
+
+static int parse_no_kvmclock(char *arg)
+{
+	kvmclock = 0;
+	return 0;
+}
+early_param("no-kvmclock", parse_no_kvmclock);
+
+/* The hypervisor will put information about time periodically here */
+static DEFINE_PER_CPU_SHARED_ALIGNED(struct kvm_vcpu_time_info, hv_clock);
+#define get_clock(cpu, field) per_cpu(hv_clock, cpu).field
+
+static inline u64 kvm_get_delta(u64 last_tsc)
+{
+	int cpu = smp_processor_id();
+	u64 delta = native_read_tsc() - last_tsc;
+	return (delta * get_clock(cpu, tsc_to_system_mul)) >> KVM_SCALE;
+}
+
+static struct kvm_wall_clock wall_clock;
+static cycle_t kvm_clock_read(void);
+/*
+ * The wallclock is the time of day when we booted. Since then, some time may
+ * have elapsed since the hypervisor wrote the data. So we try to account for
+ * that with system time
+ */
+unsigned long kvm_get_wallclock(void)
+{
+	u32 wc_sec, wc_nsec;
+	u64 delta;
+	struct timespec ts;
+	int version, nsec;
+	int low, high;
+
+	low = (int)__pa(&wall_clock);
+	high = ((u64)__pa(&wall_clock) >> 32);
+
+	delta = kvm_clock_read();
+
+	native_write_msr(MSR_KVM_WALL_CLOCK, low, high);
+	do {
+		version = wall_clock.wc_version;
+		rmb();
+		wc_sec = wall_clock.wc_sec;
+		wc_nsec = wall_clock.wc_nsec;
+		rmb();
+	} while ((wall_clock.wc_version != version) || (version & 1));
+
+	delta = kvm_clock_read() - delta;
+	delta += wc_nsec;
+	nsec = do_div(delta, NSEC_PER_SEC);
+	set_normalized_timespec(&ts, wc_sec + delta, nsec);
+	/*
+	 * Of all mechanisms of time adjustment I've tested, this one
+	 * was the champion!
+	 */
+	return ts.tv_sec + 1;
+}
+
+int kvm_set_wallclock(unsigned long now)
+{
+	return 0;
+}
+
+/*
+ * This is our read_clock function. The host puts an tsc timestamp each time
+ * it updates a new time. Without the tsc adjustment, we can have a situation
+ * in which a vcpu starts to run earlier (smaller system_time), but probes
+ * time later (compared to another vcpu), leading to backwards time
+ */
+static cycle_t kvm_clock_read(void)
+{
+	u64 last_tsc, now;
+	int cpu;
+
+	preempt_disable();
+	cpu = smp_processor_id();
+
+	last_tsc = get_clock(cpu, tsc_timestamp);
+	now = get_clock(cpu, system_time);
+
+	now += kvm_get_delta(last_tsc);
+	preempt_enable();
+
+	return now;
+}
+static struct clocksource kvm_clock = {
+	.name = "kvm-clock",
+	.read = kvm_clock_read,
+	.rating = 400,
+	.mask = CLOCKSOURCE_MASK(64),
+	.mult = 1 << KVM_SCALE,
+	.shift = KVM_SCALE,
+	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int kvm_register_clock(void)
+{
+	int cpu = smp_processor_id();
+	int low, high;
+	low = (int)__pa(&per_cpu(hv_clock, cpu)) | 1;
+	high = ((u64)__pa(&per_cpu(hv_clock, cpu)) >> 32);
+
+	return native_write_msr_safe(MSR_KVM_SYSTEM_TIME, low, high);
+}
+
+static void kvm_setup_secondary_clock(void)
+{
+	/*
+	 * Now that the first cpu already had this clocksource initialized,
+	 * we shouldn't fail.
+	 */
+	WARN_ON(kvm_register_clock());
+	/* ok, done with our trickery, call native */
+	setup_secondary_APIC_clock();
+}
+
+/*
+ * After the clock is registered, the host will keep writing to the
+ * registered memory location. If the guest happens to shutdown, this memory
+ * won't be valid. In cases like kexec, in which you install a new kernel, this
+ * means a random memory location will be kept being written. So before any
+ * kind of shutdown from our side, we unregister the clock by writting anything
+ * that does not have the 'enable' bit set in the msr
+ */
+#ifdef CONFIG_KEXEC
+static void kvm_crash_shutdown(struct pt_regs *regs)
+{
+	native_write_msr_safe(MSR_KVM_SYSTEM_TIME, 0, 0);
+	native_machine_crash_shutdown(regs);
+}
+#endif
+
+static void kvm_shutdown(void)
+{
+	native_write_msr_safe(MSR_KVM_SYSTEM_TIME, 0, 0);
+	native_machine_shutdown();
+}
+
+void __init kvmclock_init(void)
+{
+	if (!kvm_para_available())
+		return;
+
+	if (kvmclock && kvm_para_has_feature(KVM_FEATURE_CLOCKSOURCE)) {
+		if (kvm_register_clock())
+			return;
+		pv_time_ops.get_wallclock = kvm_get_wallclock;
+		pv_time_ops.set_wallclock = kvm_set_wallclock;
+		pv_time_ops.sched_clock = kvm_clock_read;
+		pv_apic_ops.setup_secondary_clock = kvm_setup_secondary_clock;
+		machine_ops.shutdown  = kvm_shutdown;
+#ifdef CONFIG_KEXEC
+		machine_ops.crash_shutdown  = kvm_crash_shutdown;
+#endif
+		clocksource_register(&kvm_clock);
+	}
+}
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 1791a751a77..a4a838306b2 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -399,7 +399,7 @@ static void native_machine_emergency_restart(void)
 	}
 }
 
-static void native_machine_shutdown(void)
+void native_machine_shutdown(void)
 {
 	/* Stop the cpus and apics */
 #ifdef CONFIG_SMP
@@ -470,7 +470,10 @@ struct machine_ops machine_ops = {
 	.shutdown = native_machine_shutdown,
 	.emergency_restart = native_machine_emergency_restart,
 	.restart = native_machine_restart,
-	.halt = native_machine_halt
+	.halt = native_machine_halt,
+#ifdef CONFIG_KEXEC
+	.crash_shutdown = native_machine_crash_shutdown,
+#endif
 };
 
 void machine_power_off(void)
@@ -498,3 +501,9 @@ void machine_halt(void)
 	machine_ops.halt();
 }
 
+#ifdef CONFIG_KEXEC
+void machine_crash_shutdown(struct pt_regs *regs)
+{
+	machine_ops.crash_shutdown(regs);
+}
+#endif
diff --git a/arch/x86/kernel/setup_32.c b/arch/x86/kernel/setup_32.c
index 44cc9b93393..2283422af79 100644
--- a/arch/x86/kernel/setup_32.c
+++ b/arch/x86/kernel/setup_32.c
@@ -47,6 +47,7 @@
 #include <linux/pfn.h>
 #include <linux/pci.h>
 #include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
 
 #include <video/edid.h>
 
@@ -820,6 +821,10 @@ void __init setup_arch(char **cmdline_p)
 
 	max_low_pfn = setup_memory();
 
+#ifdef CONFIG_KVM_CLOCK
+	kvmclock_init();
+#endif
+
 #ifdef CONFIG_VMI
 	/*
 	 * Must be after max_low_pfn is determined, and before kernel
@@ -827,6 +832,7 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	vmi_init();
 #endif
+	kvm_guest_init();
 
 	/*
 	 * NOTE: before this point _nobody_ is allowed to allocate
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 60e64c8eee9..a94fb959a87 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -42,6 +42,7 @@
 #include <linux/ctype.h>
 #include <linux/uaccess.h>
 #include <linux/init_ohci1394_dma.h>
+#include <linux/kvm_para.h>
 
 #include <asm/mtrr.h>
 #include <asm/uaccess.h>
@@ -384,6 +385,10 @@ void __init setup_arch(char **cmdline_p)
 
 	io_delay_init();
 
+#ifdef CONFIG_KVM_CLOCK
+	kvmclock_init();
+#endif
+
 #ifdef CONFIG_SMP
 	/* setup to use the early static init tables during kernel startup */
 	x86_cpu_to_apicid_early_ptr = (void *)x86_cpu_to_apicid_init;
@@ -488,6 +493,8 @@ void __init setup_arch(char **cmdline_p)
 	init_apic_mappings();
 	ioapic_init_mappings();
 
+	kvm_guest_init();
+
 	/*
 	 * We trust e820 completely. No explicit ROM probing in memory.
 	 */
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index 41962e793c0..8d45fabc5f3 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -19,7 +19,7 @@ if VIRTUALIZATION
 
 config KVM
 	tristate "Kernel-based Virtual Machine (KVM) support"
-	depends on HAVE_KVM && EXPERIMENTAL
+	depends on HAVE_KVM
 	select PREEMPT_NOTIFIERS
 	select ANON_INODES
 	---help---
@@ -50,6 +50,17 @@ config KVM_AMD
 	  Provides support for KVM on AMD processors equipped with the AMD-V
 	  (SVM) extensions.
 
+config KVM_TRACE
+	bool "KVM trace support"
+	depends on KVM && MARKERS && SYSFS
+	select RELAY
+	select DEBUG_FS
+	default n
+	---help---
+	  This option allows reading a trace of kvm-related events through
+	  relayfs.  Note the ABI is not considered stable and will be
+	  modified in future updates.
+
 # OK, it's a little counter-intuitive to do this, but it puts it neatly under
 # the virtualization menu.
 source drivers/lguest/Kconfig
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index ffdd0b31078..c97d35c218d 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -3,10 +3,14 @@
 #
 
 common-objs = $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o)
+ifeq ($(CONFIG_KVM_TRACE),y)
+common-objs += $(addprefix ../../../virt/kvm/, kvm_trace.o)
+endif
 
 EXTRA_CFLAGS += -Ivirt/kvm -Iarch/x86/kvm
 
-kvm-objs := $(common-objs) x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o
+kvm-objs := $(common-objs) x86.o mmu.o x86_emulate.o i8259.o irq.o lapic.o \
+	i8254.o
 obj-$(CONFIG_KVM) += kvm.o
 kvm-intel-objs = vmx.o
 obj-$(CONFIG_KVM_INTEL) += kvm-intel.o
diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
new file mode 100644
index 00000000000..361e3161127
--- /dev/null
+++ b/arch/x86/kvm/i8254.c
@@ -0,0 +1,611 @@
+/*
+ * 8253/8254 interval timer emulation
+ *
+ * Copyright (c) 2003-2004 Fabrice Bellard
+ * Copyright (c) 2006 Intel Corporation
+ * Copyright (c) 2007 Keir Fraser, XenSource Inc
+ * Copyright (c) 2008 Intel Corporation
+ *
+ * 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.
+ *
+ * Authors:
+ *   Sheng Yang <sheng.yang@intel.com>
+ *   Based on QEMU and Xen.
+ */
+
+#include <linux/kvm_host.h>
+
+#include "irq.h"
+#include "i8254.h"
+
+#ifndef CONFIG_X86_64
+#define mod_64(x, y) ((x) - (y) * div64_64(x, y))
+#else
+#define mod_64(x, y) ((x) % (y))
+#endif
+
+#define RW_STATE_LSB 1
+#define RW_STATE_MSB 2
+#define RW_STATE_WORD0 3
+#define RW_STATE_WORD1 4
+
+/* Compute with 96 bit intermediate result: (a*b)/c */
+static u64 muldiv64(u64 a, u32 b, u32 c)
+{
+	union {
+		u64 ll;
+		struct {
+			u32 low, high;
+		} l;
+	} u, res;
+	u64 rl, rh;
+
+	u.ll = a;
+	rl = (u64)u.l.low * (u64)b;
+	rh = (u64)u.l.high * (u64)b;
+	rh += (rl >> 32);
+	res.l.high = div64_64(rh, c);
+	res.l.low = div64_64(((mod_64(rh, c) << 32) + (rl & 0xffffffff)), c);
+	return res.ll;
+}
+
+static void pit_set_gate(struct kvm *kvm, int channel, u32 val)
+{
+	struct kvm_kpit_channel_state *c =
+		&kvm->arch.vpit->pit_state.channels[channel];
+
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	switch (c->mode) {
+	default:
+	case 0:
+	case 4:
+		/* XXX: just disable/enable counting */
+		break;
+	case 1:
+	case 2:
+	case 3:
+	case 5:
+		/* Restart counting on rising edge. */
+		if (c->gate < val)
+			c->count_load_time = ktime_get();
+		break;
+	}
+
+	c->gate = val;
+}
+
+int pit_get_gate(struct kvm *kvm, int channel)
+{
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	return kvm->arch.vpit->pit_state.channels[channel].gate;
+}
+
+static int pit_get_count(struct kvm *kvm, int channel)
+{
+	struct kvm_kpit_channel_state *c =
+		&kvm->arch.vpit->pit_state.channels[channel];
+	s64 d, t;
+	int counter;
+
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
+	d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
+
+	switch (c->mode) {
+	case 0:
+	case 1:
+	case 4:
+	case 5:
+		counter = (c->count - d) & 0xffff;
+		break;
+	case 3:
+		/* XXX: may be incorrect for odd counts */
+		counter = c->count - (mod_64((2 * d), c->count));
+		break;
+	default:
+		counter = c->count - mod_64(d, c->count);
+		break;
+	}
+	return counter;
+}
+
+static int pit_get_out(struct kvm *kvm, int channel)
+{
+	struct kvm_kpit_channel_state *c =
+		&kvm->arch.vpit->pit_state.channels[channel];
+	s64 d, t;
+	int out;
+
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	t = ktime_to_ns(ktime_sub(ktime_get(), c->count_load_time));
+	d = muldiv64(t, KVM_PIT_FREQ, NSEC_PER_SEC);
+
+	switch (c->mode) {
+	default:
+	case 0:
+		out = (d >= c->count);
+		break;
+	case 1:
+		out = (d < c->count);
+		break;
+	case 2:
+		out = ((mod_64(d, c->count) == 0) && (d != 0));
+		break;
+	case 3:
+		out = (mod_64(d, c->count) < ((c->count + 1) >> 1));
+		break;
+	case 4:
+	case 5:
+		out = (d == c->count);
+		break;
+	}
+
+	return out;
+}
+
+static void pit_latch_count(struct kvm *kvm, int channel)
+{
+	struct kvm_kpit_channel_state *c =
+		&kvm->arch.vpit->pit_state.channels[channel];
+
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	if (!c->count_latched) {
+		c->latched_count = pit_get_count(kvm, channel);
+		c->count_latched = c->rw_mode;
+	}
+}
+
+static void pit_latch_status(struct kvm *kvm, int channel)
+{
+	struct kvm_kpit_channel_state *c =
+		&kvm->arch.vpit->pit_state.channels[channel];
+
+	WARN_ON(!mutex_is_locked(&kvm->arch.vpit->pit_state.lock));
+
+	if (!c->status_latched) {
+		/* TODO: Return NULL COUNT (bit 6). */
+		c->status = ((pit_get_out(kvm, channel) << 7) |
+				(c->rw_mode << 4) |
+				(c->mode << 1) |
+				c->bcd);
+		c->status_latched = 1;
+	}
+}
+
+int __pit_timer_fn(struct kvm_kpit_state *ps)
+{
+	struct kvm_vcpu *vcpu0 = ps->pit->kvm->vcpus[0];
+	struct kvm_kpit_timer *pt = &ps->pit_timer;
+
+	atomic_inc(&pt->pending);
+	smp_mb__after_atomic_inc();
+	/* FIXME: handle case where the guest is in guest mode */
+	if (vcpu0 && waitqueue_active(&vcpu0->wq)) {
+		vcpu0->arch.mp_state = KVM_MP_STATE_RUNNABLE;
+		wake_up_interruptible(&vcpu0->wq);
+	}
+
+	pt->timer.expires = ktime_add_ns(pt->timer.expires, pt->period);
+	pt->scheduled = ktime_to_ns(pt->timer.expires);
+
+	return (pt->period == 0 ? 0 : 1);
+}
+
+int pit_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	struct kvm_pit *pit = vcpu->kvm->arch.vpit;
+
+	if (pit && vcpu->vcpu_id == 0)
+		return atomic_read(&pit->pit_state.pit_timer.pending);
+
+	return 0;
+}
+
+static enum hrtimer_restart pit_timer_fn(struct hrtimer *data)
+{
+	struct kvm_kpit_state *ps;
+	int restart_timer = 0;
+
+	ps = container_of(data, struct kvm_kpit_state, pit_timer.timer);
+
+	restart_timer = __pit_timer_fn(ps);
+
+	if (restart_timer)
+		return HRTIMER_RESTART;
+	else
+		return HRTIMER_NORESTART;
+}
+
+static void destroy_pit_timer(struct kvm_kpit_timer *pt)
+{
+	pr_debug("pit: execute del timer!\n");
+	hrtimer_cancel(&pt->timer);
+}
+
+static void create_pit_timer(struct kvm_kpit_timer *pt, u32 val, int is_period)
+{
+	s64 interval;
+
+	interval = muldiv64(val, NSEC_PER_SEC, KVM_PIT_FREQ);
+
+	pr_debug("pi