Merge branch 'for-queue' of https://github.com/agraf/linux-2.6 into queue

* 'for-queue' of https://github.com/agraf/linux-2.6:
  PPC: ePAPR: Convert hcall header to uapi (round 2)
  KVM: PPC: Book3S HV: Fix thinko in try_lock_hpte()
  KVM: PPC: Book3S HV: Allow DTL to be set to address 0, length 0
  KVM: PPC: Book3S HV: Fix accounting of stolen time
  KVM: PPC: Book3S HV: Run virtual core whenever any vcpus in it can run
  KVM: PPC: Book3S HV: Fixes for late-joining threads
  KVM: PPC: Book3s HV: Don't access runnable threads list without vcore lock
  KVM: PPC: Book3S HV: Fix some races in starting secondary threads
  KVM: PPC: Book3S HV: Allow KVM guests to stop secondary threads coming online
  PPC: ePAPR: Convert header to uapi
  KVM: PPC: Move mtspr/mfspr emulation into own functions
  KVM: Documentation: Fix reentry-to-be-consistent paragraph
  KVM: PPC: 44x: fix DCR read/write

Documentation/virtual/kvm/api.txt

@@ -2183,7 +2183,8 @@ executed a memory-mapped I/O instruction which could not be satisfied
 by kvm.  The 'data' member contains the written data if 'is_write' is
 true, and should be filled by application code otherwise.
 
-NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO and KVM_EXIT_OSI, the corresponding
+NOTE: For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_DCR
+      and KVM_EXIT_PAPR the corresponding
 operations are complete (and guest state is consistent) only after userspace
 has re-entered the kernel with KVM_RUN.  The kernel side will first finish
 incomplete operations and then check for pending signals.  Userspace

arch/powerpc/include/asm/epapr_hcalls.h

+/*
+ * ePAPR hcall interface
+ *
+ * Copyright 2008-2011 Freescale Semiconductor, Inc.
+ *
+ * Author: Timur Tabi <timur@freescale.com>
+ *
+ * This file is provided under a dual BSD/GPL license.  When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Freescale Semiconductor nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* A "hypercall" is an "sc 1" instruction.  This header file file provides C
+ * wrapper functions for the ePAPR hypervisor interface.  It is inteded
+ * for use by Linux device drivers and other operating systems.
+ *
+ * The hypercalls are implemented as inline assembly, rather than assembly
+ * language functions in a .S file, for optimization.  It allows
+ * the caller to issue the hypercall instruction directly, improving both
+ * performance and memory footprint.
+ */
+
+#ifndef _EPAPR_HCALLS_H
+#define _EPAPR_HCALLS_H
+
+#include <uapi/asm/epapr_hcalls.h>
+
+#ifndef __ASSEMBLY__
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <asm/byteorder.h>
+
+/*
+ * Hypercall register clobber list
+ *
+ * These macros are used to define the list of clobbered registers during a
+ * hypercall.  Technically, registers r0 and r3-r12 are always clobbered,
+ * but the gcc inline assembly syntax does not allow us to specify registers
+ * on the clobber list that are also on the input/output list.  Therefore,
+ * the lists of clobbered registers depends on the number of register
+ * parmeters ("+r" and "=r") passed to the hypercall.
+ *
+ * Each assembly block should use one of the HCALL_CLOBBERSx macros.  As a
+ * general rule, 'x' is the number of parameters passed to the assembly
+ * block *except* for r11.
+ *
+ * If you're not sure, just use the smallest value of 'x' that does not
+ * generate a compilation error.  Because these are static inline functions,
+ * the compiler will only check the clobber list for a function if you
+ * compile code that calls that function.
+ *
+ * r3 and r11 are not included in any clobbers list because they are always
+ * listed as output registers.
+ *
+ * XER, CTR, and LR are currently listed as clobbers because it's uncertain
+ * whether they will be clobbered.
+ *
+ * Note that r11 can be used as an output parameter.
+ *
+ * The "memory" clobber is only necessary for hcalls where the Hypervisor
+ * will read or write guest memory. However, we add it to all hcalls because
+ * the impact is minimal, and we want to ensure that it's present for the
+ * hcalls that need it.
+*/
+
+/* List of common clobbered registers.  Do not use this macro. */
+#define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory"
+
+#define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
+#define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"
+#define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9"
+#define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8"
+#define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7"
+#define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6"
+#define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
+#define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
+
+extern bool epapr_paravirt_enabled;
+extern u32 epapr_hypercall_start[];
+
+/*
+ * We use "uintptr_t" to define a register because it's guaranteed to be a
+ * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
+ * platform.
+ *
+ * All registers are either input/output or output only.  Registers that are
+ * initialized before making the hypercall are input/output.  All
+ * input/output registers are represented with "+r".  Output-only registers
+ * are represented with "=r".  Do not specify any unused registers.  The
+ * clobber list will tell the compiler that the hypercall modifies those
+ * registers, which is good enough.
+ */
+
+/**
+ * ev_int_set_config - configure the specified interrupt
+ * @interrupt: the interrupt number
+ * @config: configuration for this interrupt
+ * @priority: interrupt priority
+ * @destination: destination CPU number
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_set_config(unsigned int interrupt,
+	uint32_t config, unsigned int priority, uint32_t destination)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+	register uintptr_t r5 __asm__("r5");
+	register uintptr_t r6 __asm__("r6");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG);
+	r3  = interrupt;
+	r4  = config;
+	r5  = priority;
+	r6  = destination;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6)
+		: : EV_HCALL_CLOBBERS4
+	);
+
+	return r3;
+}
+
+/**
+ * ev_int_get_config - return the config of the specified interrupt
+ * @interrupt: the interrupt number
+ * @config: returned configuration for this interrupt
+ * @priority: returned interrupt priority
+ * @destination: returned destination CPU number
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_get_config(unsigned int interrupt,
+	uint32_t *config, unsigned int *priority, uint32_t *destination)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+	register uintptr_t r5 __asm__("r5");
+	register uintptr_t r6 __asm__("r6");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG);
+	r3 = interrupt;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6)
+		: : EV_HCALL_CLOBBERS4
+	);
+
+	*config = r4;
+	*priority = r5;
+	*destination = r6;
+
+	return r3;
+}
+
+/**
+ * ev_int_set_mask - sets the mask for the specified interrupt source
+ * @interrupt: the interrupt number
+ * @mask: 0=enable interrupts, 1=disable interrupts
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_set_mask(unsigned int interrupt,
+	unsigned int mask)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK);
+	r3 = interrupt;
+	r4 = mask;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "+r" (r4)
+		: : EV_HCALL_CLOBBERS2
+	);
+
+	return r3;
+}
+
+/**
+ * ev_int_get_mask - returns the mask for the specified interrupt source
+ * @interrupt: the interrupt number
+ * @mask: returned mask for this interrupt (0=enabled, 1=disabled)
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_get_mask(unsigned int interrupt,
+	unsigned int *mask)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK);
+	r3 = interrupt;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "=r" (r4)
+		: : EV_HCALL_CLOBBERS2
+	);
+
+	*mask = r4;
+
+	return r3;
+}
+
+/**
+ * ev_int_eoi - signal the end of interrupt processing
+ * @interrupt: the interrupt number
+ *
+ * This function signals the end of processing for the the specified
+ * interrupt, which must be the interrupt currently in service. By
+ * definition, this is also the highest-priority interrupt.
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_eoi(unsigned int interrupt)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_EOI);
+	r3 = interrupt;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3)
+		: : EV_HCALL_CLOBBERS1
+	);
+
+	return r3;
+}
+
+/**
+ * ev_byte_channel_send - send characters to a byte stream
+ * @handle: byte stream handle
+ * @count: (input) num of chars to send, (output) num chars sent
+ * @buffer: pointer to a 16-byte buffer
+ *
+ * @buffer must be at least 16 bytes long, because all 16 bytes will be
+ * read from memory into registers, even if count < 16.
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_byte_channel_send(unsigned int handle,
+	unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+	register uintptr_t r5 __asm__("r5");
+	register uintptr_t r6 __asm__("r6");
+	register uintptr_t r7 __asm__("r7");
+	register uintptr_t r8 __asm__("r8");
+	const uint32_t *p = (const uint32_t *) buffer;
+
+	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND);
+	r3 = handle;
+	r4 = *count;
+	r5 = be32_to_cpu(p[0]);
+	r6 = be32_to_cpu(p[1]);
+	r7 = be32_to_cpu(p[2]);
+	r8 = be32_to_cpu(p[3]);
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3),
+		  "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8)
+		: : EV_HCALL_CLOBBERS6
+	);
+
+	*count = r4;
+
+	return r3;
+}
+
+/**
+ * ev_byte_channel_receive - fetch characters from a byte channel
+ * @handle: byte channel handle
+ * @count: (input) max num of chars to receive, (output) num chars received
+ * @buffer: pointer to a 16-byte buffer
+ *
+ * The size of @buffer must be at least 16 bytes, even if you request fewer
+ * than 16 characters, because we always write 16 bytes to @buffer.  This is
+ * for performance reasons.
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_byte_channel_receive(unsigned int handle,
+	unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+	register uintptr_t r5 __asm__("r5");
+	register uintptr_t r6 __asm__("r6");
+	register uintptr_t r7 __asm__("r7");
+	register uintptr_t r8 __asm__("r8");
+	uint32_t *p = (uint32_t *) buffer;
+
+	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE);
+	r3 = handle;
+	r4 = *count;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "+r" (r4),
+		  "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8)
+		: : EV_HCALL_CLOBBERS6
+	);
+
+	*count = r4;
+	p[0] = cpu_to_be32(r5);
+	p[1] = cpu_to_be32(r6);
+	p[2] = cpu_to_be32(r7);
+	p[3] = cpu_to_be32(r8);
+
+	return r3;
+}
+
+/**
+ * ev_byte_channel_poll - returns the status of the byte channel buffers
+ * @handle: byte channel handle
+ * @rx_count: returned count of bytes in receive queue
+ * @tx_count: returned count of free space in transmit queue
+ *
+ * This function reports the amount of data in the receive queue (i.e. the
+ * number of bytes you can read), and the amount of free space in the transmit
+ * queue (i.e. the number of bytes you can write).
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_byte_channel_poll(unsigned int handle,
+	unsigned int *rx_count,	unsigned int *tx_count)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+	register uintptr_t r5 __asm__("r5");
+
+	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL);
+	r3 = handle;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5)
+		: : EV_HCALL_CLOBBERS3
+	);
+
+	*rx_count = r4;
+	*tx_count = r5;
+
+	return r3;
+}
+
+/**
+ * ev_int_iack - acknowledge an interrupt
+ * @handle: handle to the target interrupt controller
+ * @vector: returned interrupt vector
+ *
+ * If handle is zero, the function returns the next interrupt source
+ * number to be handled irrespective of the hierarchy or cascading
+ * of interrupt controllers. If non-zero, specifies a handle to the
+ * interrupt controller that is the target of the acknowledge.
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_int_iack(unsigned int handle,
+	unsigned int *vector)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+	register uintptr_t r4 __asm__("r4");
+
+	r11 = EV_HCALL_TOKEN(EV_INT_IACK);
+	r3 = handle;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3), "=r" (r4)
+		: : EV_HCALL_CLOBBERS2
+	);
+
+	*vector = r4;
+
+	return r3;
+}
+
+/**
+ * ev_doorbell_send - send a doorbell to another partition
+ * @handle: doorbell send handle
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_doorbell_send(unsigned int handle)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+
+	r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND);
+	r3 = handle;
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "+r" (r3)
+		: : EV_HCALL_CLOBBERS1
+	);
+
+	return r3;
+}
+
+/**
+ * ev_idle -- wait for next interrupt on this core
+ *
+ * Returns 0 for success, or an error code.
+ */
+static inline unsigned int ev_idle(void)
+{
+	register uintptr_t r11 __asm__("r11");
+	register uintptr_t r3 __asm__("r3");
+
+	r11 = EV_HCALL_TOKEN(EV_IDLE);
+
+	asm volatile("bl	epapr_hypercall_start"
+		: "+r" (r11), "=r" (r3)
+		: : EV_HCALL_CLOBBERS1
+	);
+
+	return r3;
+}
+#endif /* !__ASSEMBLY__ */
+#endif /* _EPAPR_HCALLS_H */

arch/powerpc/include/asm/kvm_asm.h

@@ -118,6 +118,7 @@
 
 #define RESUME_FLAG_NV          (1<<0)  /* Reload guest nonvolatile state? */
 #define RESUME_FLAG_HOST        (1<<1)  /* Resume host? */
+#define RESUME_FLAG_ARCH1	(1<<2)
 
 #define RESUME_GUEST            0
 #define RESUME_GUEST_NV         RESUME_FLAG_NV

arch/powerpc/include/asm/kvm_book3s_64.h

@@ -60,7 +60,7 @@ static inline long try_lock_hpte(unsigned long *hpte, unsigned long bits)
 		     "	ori	%0,%0,%4\n"
 		     "  stdcx.	%0,0,%2\n"
 		     "	beq+	2f\n"
-		     "	li	%1,%3\n"
+		     "	mr	%1,%3\n"
 		     "2:	isync"
 		     : "=&r" (tmp), "=&r" (old)
 		     : "r" (hpte), "r" (bits), "i" (HPTE_V_HVLOCK)

arch/powerpc/include/asm/kvm_host.h

@@ -289,9 +289,10 @@ struct kvmppc_vcore {
 
 /* Values for vcore_state */
 #define VCORE_INACTIVE	0
-#define VCORE_RUNNING	1
-#define VCORE_EXITING	2
-#define VCORE_SLEEPING	3
+#define VCORE_SLEEPING	1
+#define VCORE_STARTING	2
+#define VCORE_RUNNING	3
+#define VCORE_EXITING	4
 
 /*
  * Struct used to manage memory for a virtual processor area
@@ -558,13 +559,17 @@ struct kvm_vcpu_arch {
 	unsigned long dtl_index;
 	u64 stolen_logged;
 	struct kvmppc_vpa slb_shadow;
+
+	spinlock_t tbacct_lock;
+	u64 busy_stolen;
+	u64 busy_preempt;
 #endif
 };
 
 /* Values for vcpu->arch.state */
-#define KVMPPC_VCPU_STOPPED		0
-#define KVMPPC_VCPU_BUSY_IN_HOST	1
-#define KVMPPC_VCPU_RUNNABLE		2
+#define KVMPPC_VCPU_NOTREADY		0
+#define KVMPPC_VCPU_RUNNABLE		1
+#define KVMPPC_VCPU_BUSY_IN_HOST	2
 
 /* Values for vcpu->arch.io_gpr */
 #define KVM_MMIO_REG_MASK	0x001f

arch/powerpc/include/asm/smp.h

@@ -67,6 +67,14 @@ void generic_mach_cpu_die(void);
 void generic_set_cpu_dead(unsigned int cpu);
 void generic_set_cpu_up(unsigned int cpu);
 int generic_check_cpu_restart(unsigned int cpu);
+
+extern void inhibit_secondary_onlining(void);
+extern void uninhibit_secondary_onlining(void);
+
+#else /* HOTPLUG_CPU */
+static inline void inhibit_secondary_onlining(void) {}
+static inline void uninhibit_secondary_onlining(void) {}
+
 #endif
 
 #ifdef CONFIG_PPC64

arch/powerpc/include/uapi/asm/Kbuild

@@ -7,6 +7,7 @@ header-y += bootx.h
 header-y += byteorder.h
 header-y += cputable.h
 header-y += elf.h
+header-y += epapr_hcalls.h
 header-y += errno.h
 header-y += fcntl.h
 header-y += ioctl.h
@@ -42,4 +43,3 @@ header-y += termios.h
 header-y += types.h
 header-y += ucontext.h
 header-y += unistd.h
-header-y += epapr_hcalls.h

arch/powerpc/include/uapi/asm/epapr_hcalls.h

@@ -37,18 +37,8 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/* A "hypercall" is an "sc 1" instruction.  This header file file provides C
- * wrapper functions for the ePAPR hypervisor interface.  It is inteded
- * for use by Linux device drivers and other operating systems.
- *
- * The hypercalls are implemented as inline assembly, rather than assembly
- * language functions in a .S file, for optimization.  It allows
- * the caller to issue the hypercall instruction directly, improving both
- * performance and memory footprint.
- */
-
-#ifndef _EPAPR_HCALLS_H
-#define _EPAPR_HCALLS_H
+#ifndef _UAPI_ASM_POWERPC_EPAPR_HCALLS_H
+#define _UAPI_ASM_POWERPC_EPAPR_HCALLS_H
 
 #define EV_BYTE_CHANNEL_SEND		1
 #define EV_BYTE_CHANNEL_RECEIVE		2
@@ -105,407 +95,4 @@
 #define EV_UNIMPLEMENTED	12	/* Unimplemented hypercall */
 #define EV_BUFFER_OVERFLOW	13	/* Caller-supplied buffer too small */
 
-#ifndef __ASSEMBLY__
-#include <linux/types.h>
-#include <linux/errno.h>
-#include <asm/byteorder.h>
-
-/*
- * Hypercall register clobber list
- *
- * These macros are used to define the list of clobbered registers during a
- * hypercall.  Technically, registers r0 and r3-r12 are always clobbered,
- * but the gcc inline assembly syntax does not allow us to specify registers
- * on the clobber list that are also on the input/output list.  Therefore,
- * the lists of clobbered registers depends on the number of register
- * parmeters ("+r" and "=r") passed to the hypercall.
- *
- * Each assembly block should use one of the HCALL_CLOBBERSx macros.  As a
- * general rule, 'x' is the number of parameters passed to the assembly
- * block *except* for r11.
- *
- * If you're not sure, just use the smallest value of 'x' that does not
- * generate a compilation error.  Because these are static inline functions,
- * the compiler will only check the clobber list for a function if you
- * compile code that calls that function.
- *
- * r3 and r11 are not included in any clobbers list because they are always
- * listed as output registers.
- *
- * XER, CTR, and LR are currently listed as clobbers because it's uncertain
- * whether they will be clobbered.
- *
- * Note that r11 can be used as an output parameter.
- *
- * The "memory" clobber is only necessary for hcalls where the Hypervisor
- * will read or write guest memory. However, we add it to all hcalls because
- * the impact is minimal, and we want to ensure that it's present for the
- * hcalls that need it.
-*/
-
-/* List of common clobbered registers.  Do not use this macro. */
-#define EV_HCALL_CLOBBERS "r0", "r12", "xer", "ctr", "lr", "cc", "memory"
-
-#define EV_HCALL_CLOBBERS8 EV_HCALL_CLOBBERS
-#define EV_HCALL_CLOBBERS7 EV_HCALL_CLOBBERS8, "r10"
-#define EV_HCALL_CLOBBERS6 EV_HCALL_CLOBBERS7, "r9"
-#define EV_HCALL_CLOBBERS5 EV_HCALL_CLOBBERS6, "r8"
-#define EV_HCALL_CLOBBERS4 EV_HCALL_CLOBBERS5, "r7"
-#define EV_HCALL_CLOBBERS3 EV_HCALL_CLOBBERS4, "r6"
-#define EV_HCALL_CLOBBERS2 EV_HCALL_CLOBBERS3, "r5"
-#define EV_HCALL_CLOBBERS1 EV_HCALL_CLOBBERS2, "r4"
-
-extern bool epapr_paravirt_enabled;
-extern u32 epapr_hypercall_start[];
-
-/*
- * We use "uintptr_t" to define a register because it's guaranteed to be a
- * 32-bit integer on a 32-bit platform, and a 64-bit integer on a 64-bit
- * platform.
- *
- * All registers are either input/output or output only.  Registers that are
- * initialized before making the hypercall are input/output.  All
- * input/output registers are represented with "+r".  Output-only registers
- * are represented with "=r".  Do not specify any unused registers.  The
- * clobber list will tell the compiler that the hypercall modifies those
- * registers, which is good enough.
- */
-
-/**
- * ev_int_set_config - configure the specified interrupt
- * @interrupt: the interrupt number
- * @config: configuration for this interrupt
- * @priority: interrupt priority
- * @destination: destination CPU number
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_set_config(unsigned int interrupt,
-	uint32_t config, unsigned int priority, uint32_t destination)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-	register uintptr_t r5 __asm__("r5");
-	register uintptr_t r6 __asm__("r6");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_SET_CONFIG);
-	r3  = interrupt;
-	r4  = config;
-	r5  = priority;
-	r6  = destination;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "+r" (r4), "+r" (r5), "+r" (r6)
-		: : EV_HCALL_CLOBBERS4
-	);
-
-	return r3;
-}
-
-/**
- * ev_int_get_config - return the config of the specified interrupt
- * @interrupt: the interrupt number
- * @config: returned configuration for this interrupt
- * @priority: returned interrupt priority
- * @destination: returned destination CPU number
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_get_config(unsigned int interrupt,
-	uint32_t *config, unsigned int *priority, uint32_t *destination)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-	register uintptr_t r5 __asm__("r5");
-	register uintptr_t r6 __asm__("r6");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_GET_CONFIG);
-	r3 = interrupt;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5), "=r" (r6)
-		: : EV_HCALL_CLOBBERS4
-	);
-
-	*config = r4;
-	*priority = r5;
-	*destination = r6;
-
-	return r3;
-}
-
-/**
- * ev_int_set_mask - sets the mask for the specified interrupt source
- * @interrupt: the interrupt number
- * @mask: 0=enable interrupts, 1=disable interrupts
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_set_mask(unsigned int interrupt,
-	unsigned int mask)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_SET_MASK);
-	r3 = interrupt;
-	r4 = mask;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "+r" (r4)
-		: : EV_HCALL_CLOBBERS2
-	);
-
-	return r3;
-}
-
-/**
- * ev_int_get_mask - returns the mask for the specified interrupt source
- * @interrupt: the interrupt number
- * @mask: returned mask for this interrupt (0=enabled, 1=disabled)
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_get_mask(unsigned int interrupt,
-	unsigned int *mask)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_GET_MASK);
-	r3 = interrupt;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "=r" (r4)
-		: : EV_HCALL_CLOBBERS2
-	);
-
-	*mask = r4;
-
-	return r3;
-}
-
-/**
- * ev_int_eoi - signal the end of interrupt processing
- * @interrupt: the interrupt number
- *
- * This function signals the end of processing for the the specified
- * interrupt, which must be the interrupt currently in service. By
- * definition, this is also the highest-priority interrupt.
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_eoi(unsigned int interrupt)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_EOI);
-	r3 = interrupt;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3)
-		: : EV_HCALL_CLOBBERS1
-	);
-
-	return r3;
-}
-
-/**
- * ev_byte_channel_send - send characters to a byte stream
- * @handle: byte stream handle
- * @count: (input) num of chars to send, (output) num chars sent
- * @buffer: pointer to a 16-byte buffer
- *
- * @buffer must be at least 16 bytes long, because all 16 bytes will be
- * read from memory into registers, even if count < 16.
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_byte_channel_send(unsigned int handle,
-	unsigned int *count, const char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-	register uintptr_t r5 __asm__("r5");
-	register uintptr_t r6 __asm__("r6");
-	register uintptr_t r7 __asm__("r7");
-	register uintptr_t r8 __asm__("r8");
-	const uint32_t *p = (const uint32_t *) buffer;
-
-	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_SEND);
-	r3 = handle;
-	r4 = *count;
-	r5 = be32_to_cpu(p[0]);
-	r6 = be32_to_cpu(p[1]);
-	r7 = be32_to_cpu(p[2]);
-	r8 = be32_to_cpu(p[3]);
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3),
-		  "+r" (r4), "+r" (r5), "+r" (r6), "+r" (r7), "+r" (r8)
-		: : EV_HCALL_CLOBBERS6
-	);
-
-	*count = r4;
-
-	return r3;
-}
-
-/**
- * ev_byte_channel_receive - fetch characters from a byte channel
- * @handle: byte channel handle
- * @count: (input) max num of chars to receive, (output) num chars received
- * @buffer: pointer to a 16-byte buffer
- *
- * The size of @buffer must be at least 16 bytes, even if you request fewer
- * than 16 characters, because we always write 16 bytes to @buffer.  This is
- * for performance reasons.
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_byte_channel_receive(unsigned int handle,
-	unsigned int *count, char buffer[EV_BYTE_CHANNEL_MAX_BYTES])
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-	register uintptr_t r5 __asm__("r5");
-	register uintptr_t r6 __asm__("r6");
-	register uintptr_t r7 __asm__("r7");
-	register uintptr_t r8 __asm__("r8");
-	uint32_t *p = (uint32_t *) buffer;
-
-	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_RECEIVE);
-	r3 = handle;
-	r4 = *count;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "+r" (r4),
-		  "=r" (r5), "=r" (r6), "=r" (r7), "=r" (r8)
-		: : EV_HCALL_CLOBBERS6
-	);
-
-	*count = r4;
-	p[0] = cpu_to_be32(r5);
-	p[1] = cpu_to_be32(r6);
-	p[2] = cpu_to_be32(r7);
-	p[3] = cpu_to_be32(r8);
-
-	return r3;
-}
-
-/**
- * ev_byte_channel_poll - returns the status of the byte channel buffers
- * @handle: byte channel handle
- * @rx_count: returned count of bytes in receive queue
- * @tx_count: returned count of free space in transmit queue
- *
- * This function reports the amount of data in the receive queue (i.e. the
- * number of bytes you can read), and the amount of free space in the transmit
- * queue (i.e. the number of bytes you can write).
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_byte_channel_poll(unsigned int handle,
-	unsigned int *rx_count,	unsigned int *tx_count)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-	register uintptr_t r5 __asm__("r5");
-
-	r11 = EV_HCALL_TOKEN(EV_BYTE_CHANNEL_POLL);
-	r3 = handle;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "=r" (r4), "=r" (r5)
-		: : EV_HCALL_CLOBBERS3
-	);
-
-	*rx_count = r4;
-	*tx_count = r5;
-
-	return r3;
-}
-
-/**
- * ev_int_iack - acknowledge an interrupt
- * @handle: handle to the target interrupt controller
- * @vector: returned interrupt vector
- *
- * If handle is zero, the function returns the next interrupt source
- * number to be handled irrespective of the hierarchy or cascading
- * of interrupt controllers. If non-zero, specifies a handle to the
- * interrupt controller that is the target of the acknowledge.
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_int_iack(unsigned int handle,
-	unsigned int *vector)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-	register uintptr_t r4 __asm__("r4");
-
-	r11 = EV_HCALL_TOKEN(EV_INT_IACK);
-	r3 = handle;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3), "=r" (r4)
-		: : EV_HCALL_CLOBBERS2
-	);
-
-	*vector = r4;
-
-	return r3;
-}
-
-/**
- * ev_doorbell_send - send a doorbell to another partition
- * @handle: doorbell send handle
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_doorbell_send(unsigned int handle)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-
-	r11 = EV_HCALL_TOKEN(EV_DOORBELL_SEND);
-	r3 = handle;
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "+r" (r3)
-		: : EV_HCALL_CLOBBERS1
-	);
-
-	return r3;
-}
-
-/**
- * ev_idle -- wait for next interrupt on this core
- *
- * Returns 0 for success, or an error code.
- */
-static inline unsigned int ev_idle(void)
-{
-	register uintptr_t r11 __asm__("r11");
-	register uintptr_t r3 __asm__("r3");
-
-	r11 = EV_HCALL_TOKEN(EV_IDLE);
-
-	asm volatile("bl	epapr_hypercall_start"
-		: "+r" (r11), "=r" (r3)
-		: : EV_HCALL_CLOBBERS1
-	);
-
-	return r3;
-}
-#endif /* !__ASSEMBLY__ */
-#endif
+#endif /* _UAPI_ASM_POWERPC_EPAPR_HCALLS_H */

arch/powerpc/kernel/smp.c

@@ -427,6 +427,45 @@ int generic_check_cpu_restart(unsigned int cpu)
 {
 	return per_cpu(cpu_state, cpu) == CPU_UP_PREPARE;
 }
+
+static atomic_t secondary_inhibit_count;
+
+/*
+ * Don't allow secondary CPU threads to come online
+ */
+void inhibit_secondary_onlining(void)
+{
+	/*
+	 * This makes secondary_inhibit_count stable during cpu
+	 * online/offline operations.
+	 */
+	get_online_cpus();
+
+	atomic_inc(&secondary_inhibit_count);
+	put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(inhibit_secondary_onlining);
+
+/*
+ * Allow secondary CPU threads to come online again
+ */
+void uninhibit_secondary_onlining(void)
+{
+	get_online_cpus();
+	atomic_dec(&secondary_inhibit_count);
+	put_online_cpus();
+}
+EXPORT_SYMBOL_GPL(uninhibit_secondary_onlining);
+
+static int secondaries_inhibited(void)
+{
+	return atomic_read(&secondary_inhibit_count);
+}
+
+#else /* HOTPLUG_CPU */
+
+#define secondaries_inhibited()		0
+
 #endif
 
 static void cpu_idle_thread_init(unsigned int cpu, struct task_struct *idle)
@@ -445,6 +484,13 @@ int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)
 {
 	int rc, c;
 
+	/*
+	 * Don't allow secondary threads to come online if inhibited
+	 */
+	if (threads_per_core > 1 && secondaries_inhibited() &&
+	    cpu % threads_per_core != 0)
+		return -EBUSY;
+
 	if (smp_ops == NULL ||
 	    (smp_ops->cpu_bootable && !smp_ops->cpu_bootable(cpu)))
 		return -EINVAL;

arch/powerpc/kvm/44x_emulate.c

@@ -46,6 +46,7 @@ static int emulate_mtdcr(struct kvm_vcpu *vcpu, int rs, int dcrn)
 		vcpu->run->dcr.dcrn = dcrn;
 		vcpu->run->dcr.data = kvmppc_get_gpr(vcpu, rs);
 		vcpu->run->dcr.is_write = 1;
+		vcpu->arch.dcr_is_write = 1;
 		vcpu->arch.dcr_needed = 1;
 		kvmppc_account_exit(vcpu, DCR_EXITS);
 		return EMULATE_DO_DCR;
@@ -80,6 +81,7 @@ static int emulate_mfdcr(struct kvm_vcpu *vcpu, int rt, int dcrn)
 		vcpu->run->dcr.dcrn = dcrn;
 		vcpu->run->dcr.data =  0;
 		vcpu->run->dcr.is_write = 0;
+		vcpu->arch.dcr_is_write = 0;
 		vcpu->arch.io_gpr = rt;
 		vcpu->arch.dcr_needed = 1;
 		kvmppc_account_exit(vcpu, DCR_EXITS);

arch/powerpc/kvm/book3s_hv.c

@@ -47,6 +47,7 @@
 #include <asm/page.h>
 #include <asm/hvcall.h>
 #include <asm/switch_to.h>
+#include <asm/smp.h>
 #include <linux/gfp.h>
 #include <linux/vmalloc.h>
 #include <linux/highmem.h>
@@ -56,25 +57,77 @@
 /* #define EXIT_DEBUG_SIMPLE */
 /* #define EXIT_DEBUG_INT */
 
+/* Used to indicate that a guest page fault needs to be handled */
+#define RESUME_PAGE_FAULT	(RESUME_GUEST | RESUME_FLAG_ARCH1)
+
+/* Used as a "null" value for timebase values */
+#define TB_NIL	(~(u64)0)
+
 static void kvmppc_end_cede(struct kvm_vcpu *vcpu);
 static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu);
 
+/*
+ * We use the vcpu_load/put functions to measure stolen time.
+ * Stolen time is counted as time when either the vcpu is able to
+ * run as part of a virtual core, but the task running the vcore
+ * is preempted or sleeping, or when the vcpu needs something done
+ * in the kernel by the task running the vcpu, but that task is
+ * preempted or sleeping.  Those two things have to be counted
+ * separately, since one of the vcpu tasks will take on the job
+ * of running the core, and the other vcpu tasks in the vcore will
+ * sleep waiting for it to do that, but that sleep shouldn't count
+ * as stolen time.
+ *
+ * Hence we accumulate stolen time when the vcpu can run as part of
+ * a vcore using vc->stolen_tb, and the stolen time when the vcpu
+ * needs its task to do other things in the kernel (for example,
+ * service a page fault) in busy_stolen.  We don't accumulate
+ * stolen time for a vcore when it is inactive, or for a vcpu
+ * when it is in state RUNNING or NOTREADY.  NOTREADY is a bit of
+ * a misnomer; it means that the vcpu task is not executing in
+ * the KVM_VCPU_RUN ioctl, i.e. it is in userspace or elsewhere in
+ * the kernel.  We don't have any way of dividing up that time
+ * between time that the vcpu is genuinely stopped, time that
+ * the task is actively working on behalf of the vcpu, and time
+ * that the task is preempted, so we don't count any of it as
+ * stolen.
+ *
+ * Updates to busy_stolen are protected by arch.tbacct_lock;
+ * updates to vc->stolen_tb are protected by the arch.tbacct_lock
+ * of the vcpu that has taken responsibility for running the vcore
+ * (i.e. vc->runner).  The stolen times are measured in units of
+ * timebase ticks.  (Note that the != TB_NIL checks below are
+ * purely defensive; they should never fail.)
+ */
+
 void kvmppc_core_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 
-	local_paca->kvm_hstate.kvm_vcpu = vcpu;
-	local_paca->kvm_hstate.kvm_vcore = vc;
-	if (vc->runner == vcpu && vc->vcore_state != VCORE_INACTIVE)
+	spin_lock(&vcpu->arch.tbacct_lock);
+	if (vc->runner == vcpu && vc->vcore_state != VCORE_INACTIVE &&
+	    vc->preempt_tb != TB_NIL) {
 		vc->stolen_tb += mftb() - vc->preempt_tb;
+		vc->preempt_tb = TB_NIL;
+	}
+	if (vcpu->arch.state == KVMPPC_VCPU_BUSY_IN_HOST &&
+	    vcpu->arch.busy_preempt != TB_NIL) {
+		vcpu->arch.busy_stolen += mftb() - vcpu->arch.busy_preempt;
+		vcpu->arch.busy_preempt = TB_NIL;
+	}
+	spin_unlock(&vcpu->arch.tbacct_lock);
 }
 
 void kvmppc_core_vcpu_put(struct kvm_vcpu *vcpu)
 {
 	struct kvmppc_vcore *vc = vcpu->arch.vcore;
 
+	spin_lock(&vcpu->arch.tbacct_lock);
 	if (vc->runner == vcpu && vc->vcore_state != VCORE_INACTIVE)
 		vc->preempt_tb = mftb();
+	if (vcpu->arch.state == KVMPPC_VCPU_BUSY_IN_HOST)
+		vcpu->arch.busy_preempt = mftb();
+	spin_unlock(&vcpu->arch.tbacct_lock);
 }
 
 void kvmppc_set_msr(struct kvm_vcpu *vcpu, u64 msr)
@@ -334,6 +387,11 @@ static void kvmppc_update_vpa(struct kvm_vcpu *vcpu, struct kvmppc_vpa *vpap)
 
 static void kvmppc_update_vpas(struct kvm_vcpu *vcpu)
 {
+	if (!(vcpu->arch.vpa.update_pending ||
+	      vcpu->arch.slb_shadow.update_pending ||
+	      vcpu->arch.dtl.update_pending))
+		return;
+
 	spin_lock(&vcpu->arch.vpa_update_lock);
 	if (vcpu->arch.vpa.update_pending) {
 		kvmppc_update_vpa(vcpu, &vcpu->arch.vpa);
@@ -350,24 +408,61 @@ static void kvmppc_update_vpas(struct kvm_vcpu *vcpu)
 	spin_unlock(&vcpu->arch.vpa_update_lock);
 }
 
+/*
+ * Return the accumulated stolen time for the vcore up until `now'.
+ * The caller should hold the vcore lock.
+ */
+static u64 vcore_stolen_time(struct kvmppc_vcore *vc, u64 now)
+{
+	u64 p;
+
+	/*
+	 * If we are the task running the vcore, then since we hold
+	 * the vcore lock, we can't be preempted, so stolen_tb/preempt_tb
+	 * can't be updated, so we don't need the tbacct_lock.
+	 * If the vcore is inactive, it can't become active (since we
+	 * hold the vcore lock), so the vcpu load/put functions won't
+	 * update stolen_tb/preempt_tb, and we don't need tbacct_lock.
+	 */
+	if (vc->vcore_state != VCORE_INACTIVE &&
+	    vc->runner->arch.run_task != current) {
+		spin_lock(&vc->runner->arch.tbacct_lock);
+		p = vc->stolen_tb;
+		if (vc->preempt_tb != TB_NIL)
+			p += now - vc->preempt_tb;
+		spin_unlock(&vc->runner->arch.tbacct_lock);
+	} else {
+		p = vc->stolen_tb;
+	}
+	return p;
+}
+
 static void kvmppc_create_dtl_entry(struct kvm_vcpu *vcpu,
 				    struct kvmppc_vcore *vc)
 {
 	struct dtl_entry *dt;
 	struct lppaca *vpa;
-	unsigned long old_stolen;
+	unsigned long stolen;
+	unsigned long core_stolen;
+	u64 now;
 
 	dt = vcpu->arch.dtl_ptr;
 	vpa = vcpu->arch.vpa.pinned_addr;
-	old_stolen = vcpu->arch.stolen_logged;
-	vcpu->arch.stolen_logged = vc->stolen_tb;
+	now = mftb();
+	core_stolen = vcore_stolen_time(vc, now);
+	stolen = core_stolen - vcpu->arch.stolen_logged;
+	vcpu->arch.stolen_logged = core_stolen;
+	spin_lock(&vcpu->arch.tbacct_lock);
+	stolen += vcpu->arch.busy_stolen;
+	vcpu->arch.busy_stolen = 0;
+	spin_unlock(&vcpu->arch.tbacct_lock);
 	if (!dt || !vpa)
 		return;
 	memset(dt, 0, sizeof(struct dtl_entry));
 	dt->dispatch_reason = 7;
 	dt->processor_id = vc->pcpu + vcpu->arch.ptid;
-	dt->timebase = mftb();
-	dt->enqueue_to_dispatch_time = vc->stolen_tb - old_stolen;
+	dt->timebase = now;
+	dt->enqueue_to_dispatch_time = stolen;
 	dt->srr0 = kvmppc_get_pc(vcpu);
 	dt->srr1 = vcpu->arch.shregs.msr;
 	++dt;
@@ -432,7 +527,6 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			      struct task_struct *tsk)
 {
 	int r = RESUME_HOST;
-	int srcu_idx;
 
 	vcpu->stat.sum_exits++;
 
@@ -492,16 +586,12 @@ static int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	 * have been handled already.
 	 */
 	case BOOK3S_INTERRUPT_H_DATA_STORAGE:
-		srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-		r = kvmppc_book3s_hv_page_fault(run, vcpu,
-				vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
-		srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
+		r = RESUME_PAGE_FAULT;
 		break;
 	case BOOK3S_INTERRUPT_H_INST_STORAGE:
-		srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
-		r = kvmppc_book3s_hv_page_fault(run, vcpu,
-				kvmppc_get_pc(vcpu), 0);
-		srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
+		vcpu->arch.fault_dar = kvmppc_get_pc(vcpu);
+		vcpu->arch.fault_dsisr = 0;
+		r = RESUME_PAGE_FAULT;
 		break;
 	/*
 	 * This occurs if the guest executes an illegal instruction.
@@ -721,9 +811,8 @@ int kvmppc_set_one_reg(struct kvm_vcpu *vcpu, u64 id, union kvmppc_one_reg *val)
 		addr = val->vpaval.addr;
 		len = val->vpaval.length;
 		r = -EINVAL;
-		if (len < sizeof(struct dtl_entry))
-			break;
-		if (addr && !vcpu->arch.vpa.next_gpa)
+		if (addr && (len < sizeof(struct dtl_entry) ||
+			     !vcpu->arch.vpa.next_gpa))
 			break;
 		len -= len % sizeof(struct dtl_entry);
 		r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len);
@@ -771,13 +860,12 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	vcpu->arch.pvr = mfspr(SPRN_PVR);
 	kvmppc_set_pvr(vcpu, vcpu->arch.pvr);
 	spin_lock_init(&vcpu->arch.vpa_update_lock);
+	spin_lock_init(&vcpu->arch.tbacct_lock);
+	vcpu->arch.busy_preempt = TB_NIL;
 
 	kvmppc_mmu_book3s_hv_init(vcpu);
 
-	/*
-	 * We consider the vcpu stopped until we see the first run ioctl for it.
-	 */
-	vcpu->arch.state = KVMPPC_VCPU_STOPPED;
+	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
 
 	init_waitqueue_head(&vcpu->arch.cpu_run);
 
@@ -789,7 +877,7 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 			INIT_LIST_HEAD(&vcore->runnable_threads);
 			spin_lock_init(&vcore->lock);
 			init_waitqueue_head(&vcore->wq);
-			vcore->preempt_tb = mftb();
+			vcore->preempt_tb = TB_NIL;
 		}
 		kvm->arch.vcores[core] = vcore;
 	}
@@ -802,7 +890,6 @@ struct kvm_vcpu *kvmppc_core_vcpu_create(struct kvm *kvm, unsigned int id)
 	++vcore->num_threads;
 	spin_unlock(&vcore->lock);
 	vcpu->arch.vcore = vcore;
-	vcpu->arch.stolen_logged = vcore->stolen_tb;
 
 	vcpu->arch.cpu_type = KVM_CPU_3S_64;
 	kvmppc_sanity_check(vcpu);
@@ -862,11 +949,18 @@ extern void xics_wake_cpu(int cpu);
 static void kvmppc_remove_runnable(struct kvmppc_vcore *vc,
 				   struct kvm_vcpu *vcpu)
 {
+	u64 now;
+
 	if (vcpu->arch.state != KVMPPC_VCPU_RUNNABLE)
 		return;
+	spin_lock(&vcpu->arch.tbacct_lock);
+	now = mftb();
+	vcpu->arch.busy_stolen += vcore_stolen_time(vc, now) -
+		vcpu->arch.stolen_logged;
+	vcpu->arch.busy_preempt = now;
 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
+	spin_unlock(&vcpu->arch.tbacct_lock);
 	--vc->n_runnable;
-	++vc->n_busy;
 	list_del(&vcpu->arch.run_list);
 }
 
@@ -879,6 +973,7 @@ static int kvmppc_grab_hwthread(int cpu)
 
 	/* Ensure the thread won't go into the kernel if it wakes */
 	tpaca->kvm_hstate.hwthread_req = 1;
+	tpaca->kvm_hstate.kvm_vcpu = NULL;
 
 	/*
 	 * If the thread is already executing in the kernel (e.g. handling
@@ -928,7 +1023,6 @@ static void kvmppc_start_thread(struct kvm_vcpu *vcpu)
 	smp_wmb();
 #if defined(CONFIG_PPC_ICP_NATIVE) && defined(CONFIG_SMP)
 	if (vcpu->arch.ptid) {
-		kvmppc_grab_hwthread(cpu);
 		xics_wake_cpu(cpu);
 		++vc->n_woken;
 	}
@@ -954,7 +1048,8 @@ static void kvmppc_wait_for_nap(struct kvmppc_vcore *vc)
 
 /*
  * Check that we are on thread 0 and that any other threads in
- * this core are off-line.
+ * this core are off-line.  Then grab the threads so they can't
+ * enter the kernel.
  */
 static int on_primary_thread(void)
 {
@@ -966,6 +1061,17 @@ static int on_primary_thread(void)
 	while (++thr < threads_per_core)
 		if (cpu_online(cpu + thr))
 			return 0;
+
+	/* Grab all hw threads so they can't go into the kernel */
+	for (thr = 1; thr < threads_per_core; ++thr) {
+		if (kvmppc_grab_hwthread(cpu + thr)) {
+			/* Couldn't grab one; let the others go */
+			do {
+				kvmppc_release_hwthread(cpu + thr);
+			} while (--thr > 0);
+			return 0;
+		}
+	}
 	return 1;
 }
 
@@ -973,22 +1079,24 @@ static int on_primary_thread(void)
  * Run a set of guest threads on a physical core.
  * Called with vc->lock held.
  */
-static int kvmppc_run_core(struct kvmppc_vcore *vc)
+static void kvmppc_run_core(struct kvmppc_vcore *vc)
 {
 	struct kvm_vcpu *vcpu, *vcpu0, *vnext;
 	long ret;
 	u64 now;
 	int ptid, i, need_vpa_update;
 	int srcu_idx;
+	struct kvm_vcpu *vcpus_to_update[threads_per_core];
 
 	/* don't start if any threads have a signal pending */
 	need_vpa_update = 0;
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
 		if (signal_pending(vcpu->arch.run_task))
-			return 0;
-		need_vpa_update |= vcpu->arch.vpa.update_pending |
-			vcpu->arch.slb_shadow.update_pending |
-			vcpu->arch.dtl.update_pending;
+			return;
+		if (vcpu->arch.vpa.update_pending ||
+		    vcpu->arch.slb_shadow.update_pending ||
+		    vcpu->arch.dtl.update_pending)
+			vcpus_to_update[need_vpa_update++] = vcpu;
 	}
 
 	/*
@@ -998,7 +1106,7 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	vc->n_woken = 0;
 	vc->nap_count = 0;
 	vc->entry_exit_count = 0;
-	vc->vcore_state = VCORE_RUNNING;
+	vc->vcore_state = VCORE_STARTING;
 	vc->in_guest = 0;
 	vc->napping_threads = 0;
 
@@ -1008,23 +1116,11 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	 */
 	if (need_vpa_update) {
 		spin_unlock(&vc->lock);
-		list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
-			kvmppc_update_vpas(vcpu);
+		for (i = 0; i < need_vpa_update; ++i)
+			kvmppc_update_vpas(vcpus_to_update[i]);
 		spin_lock(&vc->lock);
 	}
 
-	/*
-	 * Make sure we are running on thread 0, and that
-	 * secondary threads are offline.
-	 * XXX we should also block attempts to bring any
-	 * secondary threads online.
-	 */
-	if (threads_per_core > 1 && !on_primary_thread()) {
-		list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
-			vcpu->arch.ret = -EBUSY;
-		goto out;
-	}
-
 	/*
 	 * Assign physical thread IDs, first to non-ceded vcpus
 	 * and then to ceded ones.
@@ -1039,21 +1135,28 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		}
 	}
 	if (!vcpu0)
-		return 0;		/* nothing to run */
+		goto out;	/* nothing to run; should never happen */
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
 		if (vcpu->arch.ceded)
 			vcpu->arch.ptid = ptid++;
 
-	vc->stolen_tb += mftb() - vc->preempt_tb;
+	/*
+	 * Make sure we are running on thread 0, and that
+	 * secondary threads are offline.
+	 */
+	if (threads_per_core > 1 && !on_primary_thread()) {
+		list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list)
+			vcpu->arch.ret = -EBUSY;
+		goto out;
+	}
+
 	vc->pcpu = smp_processor_id();
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
 		kvmppc_start_thread(vcpu);
 		kvmppc_create_dtl_entry(vcpu, vc);
 	}
-	/* Grab any remaining hw threads so they can't go into the kernel */
-	for (i = ptid; i < threads_per_core; ++i)
-		kvmppc_grab_hwthread(vc->pcpu + i);
 
+	vc->vcore_state = VCORE_RUNNING;
 	preempt_disable();
 	spin_unlock(&vc->lock);
 
@@ -1062,8 +1165,6 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	srcu_idx = srcu_read_lock(&vcpu0->kvm->srcu);
 
 	__kvmppc_vcore_entry(NULL, vcpu0);
-	for (i = 0; i < threads_per_core; ++i)
-		kvmppc_release_hwthread(vc->pcpu + i);
 
 	spin_lock(&vc->lock);
 	/* disable sending of IPIs on virtual external irqs */
@@ -1072,6 +1173,8 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	/* wait for secondary threads to finish writing their state to memory */
 	if (vc->nap_count < vc->n_woken)
 		kvmppc_wait_for_nap(vc);
+	for (i = 0; i < threads_per_core; ++i)
+		kvmppc_release_hwthread(vc->pcpu + i);
 	/* prevent other vcpu threads from doing kvmppc_start_thread() now */
 	vc->vcore_state = VCORE_EXITING;
 	spin_unlock(&vc->lock);
@@ -1085,6 +1188,7 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 	preempt_enable();
 	kvm_resched(vcpu);
 
+	spin_lock(&vc->lock);
 	now = get_tb();
 	list_for_each_entry(vcpu, &vc->runnable_threads, arch.run_list) {
 		/* cancel pending dec exception if dec is positive */
@@ -1108,10 +1212,8 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 		}
 	}
 
-	spin_lock(&vc->lock);
  out:
 	vc->vcore_state = VCORE_INACTIVE;
-	vc->preempt_tb = mftb();
 	list_for_each_entry_safe(vcpu, vnext, &vc->runnable_threads,
 				 arch.run_list) {
 		if (vcpu->arch.ret != RESUME_GUEST) {
@@ -1119,8 +1221,6 @@ static int kvmppc_run_core(struct kvmppc_vcore *vc)
 			wake_up(&vcpu->arch.cpu_run);
 		}
 	}
-
-	return 1;
 }
 
 /*
@@ -1144,20 +1244,11 @@ static void kvmppc_wait_for_exec(struct kvm_vcpu *vcpu, int wait_state)
 static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 {
 	DEFINE_WAIT(wait);
-	struct kvm_vcpu *v;
-	int all_idle = 1;
 
 	prepare_to_wait(&vc->wq, &wait, TASK_INTERRUPTIBLE);
 	vc->vcore_state = VCORE_SLEEPING;
 	spin_unlock(&vc->lock);
-	list_for_each_entry(v, &vc->runnable_threads, arch.run_list) {
-		if (!v->arch.ceded || v->arch.pending_exceptions) {
-			all_idle = 0;
-			break;
-		}
-	}
-	if (all_idle)
-		schedule();
+	schedule();
 	finish_wait(&vc->wq, &wait);
 	spin_lock(&vc->lock);
 	vc->vcore_state = VCORE_INACTIVE;
@@ -1166,13 +1257,13 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 {
 	int n_ceded;
-	int prev_state;
 	struct kvmppc_vcore *vc;
 	struct kvm_vcpu *v, *vn;
 
 	kvm_run->exit_reason = 0;
 	vcpu->arch.ret = RESUME_GUEST;
 	vcpu->arch.trap = 0;
+	kvmppc_update_vpas(vcpu);
 
 	/*
 	 * Synchronize with other threads in this virtual core
@@ -1182,8 +1273,9 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	vcpu->arch.ceded = 0;
 	vcpu->arch.run_task = current;
 	vcpu->arch.kvm_run = kvm_run;
-	prev_state = vcpu->arch.state;
+	vcpu->arch.stolen_logged = vcore_stolen_time(vc, mftb());
 	vcpu->arch.state = KVMPPC_VCPU_RUNNABLE;
+	vcpu->arch.busy_preempt = TB_NIL;
 	list_add_tail(&vcpu->arch.run_list, &vc->runnable_threads);
 	++vc->n_runnable;
 
@@ -1192,33 +1284,26 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 	 * If the vcore is already running, we may be able to start
 	 * this thread straight away and have it join in.
 	 */
-	if (prev_state == KVMPPC_VCPU_STOPPED) {
+	if (!signal_pending(current)) {
 		if (vc->vcore_state == VCORE_RUNNING &&
 		    VCORE_EXIT_COUNT(vc) == 0) {
 			vcpu->arch.ptid = vc->n_runnable - 1;
+			kvmppc_create_dtl_entry(vcpu, vc);
 			kvmppc_start_thread(vcpu);
+		} else if (vc->vcore_state == VCORE_SLEEPING) {
+			wake_up(&vc->wq);
 		}
 
-	} else if (prev_state == KVMPPC_VCPU_BUSY_IN_HOST)
-		--vc->n_busy;
+	}
 
 	while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE &&
 	       !signal_pending(current)) {
-		if (vc->n_busy || vc->vcore_state != VCORE_INACTIVE) {
+		if (vc->vcore_state != VCORE_INACTIVE) {
 			spin_unlock(&vc->lock);
 			kvmppc_wait_for_exec(vcpu, TASK_INTERRUPTIBLE);
 			spin_lock(&vc->lock);
 			continue;
 		}
-		vc->runner = vcpu;
-		n_ceded = 0;
-		list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
-			n_ceded += v->arch.ceded;
-		if (n_ceded == vc->n_runnable)
-			kvmppc_vcore_blocked(vc);
-		else
-			kvmppc_run_core(vc);
-
 		list_for_each_entry_safe(v, vn, &vc->runnable_threads,
 					 arch.run_list) {
 			kvmppc_core_prepare_to_enter(v);
@@ -1230,22 +1315,40 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 				wake_up(&v->arch.cpu_run);
 			}
 		}
+		if (!vc->n_runnable || vcpu->arch.state != KVMPPC_VCPU_RUNNABLE)
+			break;
+		vc->runner = vcpu;
+		n_ceded = 0;
+		list_for_each_entry(v, &vc->runnable_threads, arch.run_list)
+			if (!v->arch.pending_exceptions)
+				n_ceded += v->arch.ceded;
+		if (n_ceded == vc->n_runnable)
+			kvmppc_vcore_blocked(vc);
+		else
+			kvmppc_run_core(vc);
 		vc->runner = NULL;
 	}
 
-	if (signal_pending(current)) {
-		if (vc->vcore_state == VCORE_RUNNING ||
-		    vc->vcore_state == VCORE_EXITING) {
-			spin_unlock(&vc->lock);
-			kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
-			spin_lock(&vc->lock);
-		}
-		if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
-			kvmppc_remove_runnable(vc, vcpu);
-			vcpu->stat.signal_exits++;
-			kvm_run->exit_reason = KVM_EXIT_INTR;
-			vcpu->arch.ret = -EINTR;
-		}
+	while (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE &&
+	       (vc->vcore_state == VCORE_RUNNING ||
+		vc->vcore_state == VCORE_EXITING)) {
+		spin_unlock(&vc->lock);
+		kvmppc_wait_for_exec(vcpu, TASK_UNINTERRUPTIBLE);
+		spin_lock(&vc->lock);
+	}
+
+	if (vcpu->arch.state == KVMPPC_VCPU_RUNNABLE) {
+		kvmppc_remove_runnable(vc, vcpu);
+		vcpu->stat.signal_exits++;
+		kvm_run->exit_reason = KVM_EXIT_INTR;
+		vcpu->arch.ret = -EINTR;
+	}
+
+	if (vc->n_runnable && vc->vcore_state == VCORE_INACTIVE) {
+		/* Wake up some vcpu to run the core */
+		v = list_first_entry(&vc->runnable_threads,
+				     struct kvm_vcpu, arch.run_list);
+		wake_up(&v->arch.cpu_run);
 	}
 
 	spin_unlock(&vc->lock);
@@ -1255,6 +1358,7 @@ static int kvmppc_run_vcpu(struct kvm_run *kvm_run, struct kvm_vcpu *vcpu)
 int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
 	int r;
+	int srcu_idx;
 
 	if (!vcpu->arch.sane) {
 		run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
@@ -1285,6 +1389,7 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	flush_vsx_to_thread(current);
 	vcpu->arch.wqp = &vcpu->arch.vcore->wq;
 	vcpu->arch.pgdir = current->mm->pgd;
+	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
 
 	do {
 		r = kvmppc_run_vcpu(run, vcpu);
@@ -1293,10 +1398,16 @@ int kvmppc_vcpu_run(struct kvm_run *run, struct kvm_vcpu *vcpu)
 		    !(vcpu->arch.shregs.msr & MSR_PR)) {
 			r = kvmppc_pseries_do_hcall(vcpu);
 			kvmppc_core_prepare_to_enter(vcpu);
+		} else if (r == RESUME_PAGE_FAULT) {
+			srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
+			r = kvmppc_book3s_hv_page_fault(run, vcpu,
+				vcpu->arch.fault_dar, vcpu->arch.fault_dsisr);
+			srcu_read_unlock(&vcpu->kvm->srcu, srcu_idx);
 		}
 	} while (r == RESUME_GUEST);
 
  out:
+	vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
 	atomic_dec(&vcpu->kvm->arch.vcpus_running);
 	return r;
 }
@@ -1730,11 +1841,20 @@ int kvmppc_core_init_vm(struct kvm *kvm)
 
 	kvm->arch.using_mmu_notifiers = !!cpu_has_feature(CPU_FTR_ARCH_206);
 	spin_lock_init(&kvm->arch.slot_phys_lock);
+
+	/*
+	 * Don't allow secondary CPU threads to come online
+	 * while any KVM VMs exist.
+	 */
+	inhibit_secondary_onlining();
+
 	return 0;
 }
 
 void kvmppc_core_destroy_vm(struct kvm *kvm)
 {
+	uninhibit_secondary_onlining();
+
 	if (kvm->arch.rma) {
 		kvm_release_rma(kvm->arch.rma);
 		kvm->arch.rma = NULL;

arch/powerpc/kvm/book3s_hv_rmhandlers.S

@@ -134,8 +134,11 @@ kvm_start_guest:
 
 27:	/* XXX should handle hypervisor maintenance interrupts etc. here */
 
+	/* reload vcpu pointer after clearing the IPI */
+	ld	r4,HSTATE_KVM_VCPU(r13)
+	cmpdi	r4,0
 	/* if we have no vcpu to run, go back to sleep */
-	beq	cr1,kvm_no_guest
+	beq	kvm_no_guest
 
 	/* were we napping due to cede? */
 	lbz	r0,HSTATE_NAPPING(r13)
@@ -1587,6 +1590,10 @@ secondary_too_late:
 	.endr
 
 secondary_nap:
+	/* Clear our vcpu pointer so we don't come back in early */
+	li	r0, 0
+	std	r0, HSTATE_KVM_VCPU(r13)
+	lwsync
 	/* Clear any pending IPI - assume we're a secondary thread */
 	ld	r5, HSTATE_XICS_PHYS(r13)
 	li	r7, XICS_XIRR
@@ -1612,8 +1619,6 @@ secondary_nap:
 kvm_no_guest:
 	li	r0, KVM_HWTHREAD_IN_NAP
 	stb	r0, HSTATE_HWTHREAD_STATE(r13)
-	li	r0, 0
-	std	r0, HSTATE_KVM_VCPU(r13)
 
 	li	r3, LPCR_PECE0
 	mfspr	r4, SPRN_LPCR

arch/powerpc/kvm/emulate.c

@@ -131,6 +131,125 @@ u32 kvmppc_get_dec(struct kvm_vcpu *vcpu, u64 tb)
 	return vcpu->arch.dec - jd;
 }
 
+static int kvmppc_emulate_mtspr(struct kvm_vcpu *vcpu, int sprn, int rs)
+{
+	enum emulation_result emulated = EMULATE_DONE;
+	ulong spr_val = kvmppc_get_gpr(vcpu, rs);
+
+	switch (sprn) {
+	case SPRN_SRR0:
+		vcpu->arch.shared->srr0 = spr_val;
+		break;
+	case SPRN_SRR1:
+		vcpu->arch.shared->srr1 = spr_val;
+		break;
+
+	/* XXX We need to context-switch the timebase for
+	 * watchdog and FIT. */
+	case SPRN_TBWL: break;
+	case SPRN_TBWU: break;
+
+	case SPRN_MSSSR0: break;
+
+	case SPRN_DEC:
+		vcpu->arch.dec = spr_val;
+		kvmppc_emulate_dec(vcpu);
+		break;
+
+	case SPRN_SPRG0:
+		vcpu->arch.shared->sprg0 = spr_val;
+		break;
+	case SPRN_SPRG1:
+		vcpu->arch.shared->sprg1 = spr_val;
+		break;
+	case SPRN_SPRG2:
+		vcpu->arch.shared->sprg2 = spr_val;
+		break;
+	case SPRN_SPRG3:
+		vcpu->arch.shared->sprg3 = spr_val;
+		break;
+
+	default:
+		emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
+						     spr_val);
+		if (emulated == EMULATE_FAIL)
+			printk(KERN_INFO "mtspr: unknown spr "
+				"0x%x\n", sprn);
+		break;
+	}
+
+	kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
+
+	return emulated;
+}
+
+static int kvmppc_emulate_mfspr(struct kvm_vcpu *vcpu, int sprn, int rt)
+{
+	enum emulation_result emulated = EMULATE_DONE;
+	ulong spr_val = 0;
+
+	switch (sprn) {
+	case SPRN_SRR0:
+		spr_val = vcpu->arch.shared->srr0;
+		break;
+	case SPRN_SRR1:
+		spr_val = vcpu->arch.shared->srr1;
+		break;
+	case SPRN_PVR:
+		spr_val = vcpu->arch.pvr;
+		break;
+	case SPRN_PIR:
+		spr_val = vcpu->vcpu_id;
+		break;
+	case SPRN_MSSSR0:
+		spr_val = 0;
+		break;
+
+	/* Note: mftb and TBRL/TBWL are user-accessible, so
+	 * the guest can always access the real TB anyways.
+	 * In fact, we probably will never see these traps. */
+	case SPRN_TBWL:
+		spr_val = get_tb() >> 32;
+		break;
+	case SPRN_TBWU:
+		spr_val = get_tb();
+		break;
+
+	case SPRN_SPRG0:
+		spr_val = vcpu->arch.shared->sprg0;
+		break;
+	case SPRN_SPRG1:
+		spr_val = vcpu->arch.shared->sprg1;
+		break;
+	case SPRN_SPRG2:
+		spr_val = vcpu->arch.shared->sprg2;
+		break;
+	case SPRN_SPRG3:
+		spr_val = vcpu->arch.shared->sprg3;
+		break;
+	/* Note: SPRG4-7 are user-readable, so we don't get
+	 * a trap. */
+
+	case SPRN_DEC:
+		spr_val = kvmppc_get_dec(vcpu, get_tb());
+		break;
+	default:
+		emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
+						     &spr_val);
+		if (unlikely(emulated == EMULATE_FAIL)) {
+			printk(KERN_INFO "mfspr: unknown spr "
+				"0x%x\n", sprn);
+		}
+		break;
+	}
+
+	if (emulated == EMULATE_DONE)
+		kvmppc_set_gpr(vcpu, rt, spr_val);
+	kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
+
+	return emulated;
+}
+
 /* XXX to do:
  * lhax
  * lhaux
@@ -156,7 +275,6 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 	int sprn = get_sprn(inst);
 	enum emulation_result emulated = EMULATE_DONE;
 	int advance = 1;
-	ulong spr_val = 0;
 
 	/* this default type might be overwritten by subcategories */
 	kvmppc_set_exit_type(vcpu, EMULATED_INST_EXITS);
@@ -236,62 +354,7 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			break;
 
 		case OP_31_XOP_MFSPR:
-			switch (sprn) {
-			case SPRN_SRR0:
-				spr_val = vcpu->arch.shared->srr0;
-				break;
-			case SPRN_SRR1:
-				spr_val = vcpu->arch.shared->srr1;
-				break;
-			case SPRN_PVR:
-				spr_val = vcpu->arch.pvr;
-				break;
-			case SPRN_PIR:
-				spr_val = vcpu->vcpu_id;
-				break;
-			case SPRN_MSSSR0:
-				spr_val = 0;
-				break;
-
-			/* Note: mftb and TBRL/TBWL are user-accessible, so
-			 * the guest can always access the real TB anyways.
-			 * In fact, we probably will never see these traps. */
-			case SPRN_TBWL:
-				spr_val = get_tb() >> 32;
-				break;
-			case SPRN_TBWU:
-				spr_val = get_tb();
-				break;
-
-			case SPRN_SPRG0:
-				spr_val = vcpu->arch.shared->sprg0;
-				break;
-			case SPRN_SPRG1:
-				spr_val = vcpu->arch.shared->sprg1;
-				break;
-			case SPRN_SPRG2:
-				spr_val = vcpu->arch.shared->sprg2;
-				break;
-			case SPRN_SPRG3:
-				spr_val = vcpu->arch.shared->sprg3;
-				break;
-			/* Note: SPRG4-7 are user-readable, so we don't get
-			 * a trap. */
-
-			case SPRN_DEC:
-				spr_val = kvmppc_get_dec(vcpu, get_tb());
-				break;
-			default:
-				emulated = kvmppc_core_emulate_mfspr(vcpu, sprn,
-								     &spr_val);
-				if (unlikely(emulated == EMULATE_FAIL)) {
-					printk(KERN_INFO "mfspr: unknown spr "
-						"0x%x\n", sprn);
-				}
-				break;
-			}
-			kvmppc_set_gpr(vcpu, rt, spr_val);
-			kvmppc_set_exit_type(vcpu, EMULATED_MFSPR_EXITS);
+			emulated = kvmppc_emulate_mfspr(vcpu, sprn, rt);
 			break;
 
 		case OP_31_XOP_STHX:
@@ -308,49 +371,7 @@ int kvmppc_emulate_instruction(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			break;
 
 		case OP_31_XOP_MTSPR:
-			spr_val = kvmppc_get_gpr(vcpu, rs);
-			switch (sprn) {
-			case SPRN_SRR0:
-				vcpu->arch.shared->srr0 = spr_val;
-				break;
-			case SPRN_SRR1:
-				vcpu->arch.shared->srr1 = spr_val;
-				break;
-
-			/* XXX We need to context-switch the timebase for
-			 * watchdog and FIT. */
-			case SPRN_TBWL: break;
-			case SPRN_TBWU: break;
-
-			case SPRN_MSSSR0: break;
-
-			case SPRN_DEC:
-				vcpu->arch.dec = spr_val;
-				kvmppc_emulate_dec(vcpu);
-				break;
-
-			case SPRN_SPRG0:
-				vcpu->arch.shared->sprg0 = spr_val;
-				break;
-			case SPRN_SPRG1:
-				vcpu->arch.shared->sprg1 = spr_val;
-				break;
-			case SPRN_SPRG2:
-				vcpu->arch.shared->sprg2 = spr_val;
-				break;
-			case SPRN_SPRG3:
-				vcpu->arch.shared->sprg3 = spr_val;
-				break;
-
-			default:
-				emulated = kvmppc_core_emulate_mtspr(vcpu, sprn,
-								     spr_val);
-				if (emulated == EMULATE_FAIL)
-					printk(KERN_INFO "mtspr: unknown spr "
-						"0x%x\n", sprn);
-				break;
-			}
-			kvmppc_set_exit_type(vcpu, EMULATED_MTSPR_EXITS);
+			emulated = kvmppc_emulate_mtspr(vcpu, sprn, rs);
 			break;
 
 		case OP_31_XOP_DCBI: