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* [PATCH v6 00/12] KVM/ARM Implementation
@ 2012-02-23  7:32 Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 01/12] KVM: Introduce __KVM_HAVE_IRQ_LINE Christoffer Dall
                   ` (11 more replies)
  0 siblings, 12 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

The following series implements KVM support for ARM processors,
specifically on the Cortex A-15 platform.

The patch series applies to commit 24c9a7d43e695f0183ba99638edfcd265bc7a0ca
on Catalin Marinas' linux-arm-arch tree.

The patch series further depends on these two patches:
https://lists.cs.columbia.edu/pipermail/android-virt/2012-February/000603.html
https://lists.cs.columbia.edu/pipermail/android-virt/2012-February/000590.html

This is Version 6 of the patch series, but the first two versions
were reviewed outside of the KVM mailing list. Changes can also be
pulled from:
 git://github.com/virtualopensystems/linux-kvm-arm.git kvm-a15-v6

The implementation is broken up into a logical set of patches, the first
one a preparatory patch and the second one containing a skeleton of files,
makefile changes, the basic user space interface and KVM architecture specific
stubs.  Subsequent patches implement parts of the system as listed:
 1.  Preparatory patch introducing KVM
 2.  Skeleton
 3.  Identity Mapping for Hyp mode
 4.  Hypervisor initialization
 5.  Memory virtualization setup (hyp mode mappings and 2nd stage)
 6.  Inject IRQs and FIQs from userspace
 7.  World-switch implementation and Hyp exception vectors
 8.  Emulation framework and CP15 emulation
 9.  Handle guest user memory aborts
 10. Handle guest MMIO aborts
 11. Support guest wait-for-interrupt instructions.
 12. Handle CP15 CR9 emulation /* hack alert! */

Testing:
Limited testing, but have run GCC inside guest, which compiled a small
hello-world program, which was successfully run. Hardware still
unavailable, so all testing has been done on ARM Fast Models.

For a guide on how to set up a testing environment and try out these
patches, see:
 http://www.virtualopensystems.com/media/pdf/kvm-arm-guide.pdf
 https://wiki.linaro.org/PeterMaydell/KVM/HowTo/ModelSetup

There is an issue list available using the issue tracker on:
https://github.com/virtualopensystems/linux-kvm-arm

Changes since v5:
 - General bugfixes and nit fixes from reviews
 - Implemented re-use of VMIDs
 - Cleaned up the Hyp-mapping code to be readable by non-mm hackers
   (including myself)
 - Integrated preliminary SMP support in base patches
 - Lock-less interrupt injection and WFI support
 - Fixed signal-handling in while in guest (increases overall stability)

Changes since v4:
 - Addressed reviewer comments from v4
    * cleanup debug and trace code
    * remove printks
    * fixup kvm_arch_vcpu_ioctl_run
    * add trace details to mmio emulation
 - Fix from Marc Zyngier: Move kvm_guest_enter/exit into non-preemptible
   section (squashed into world-switch patch)
 - Cleanup create_hyp_mappings/remove_hyp_mappings from Marc Zyngier
   (squashed into hypervisor initialization patch)
 - Removed the remove_hyp_mappings feature. Removing hypervisor mappings
   could potentially unmap other important data shared in the same page.
 - Removed the arm_ prefix from the arch-specific files.
 - Initial SMP host/guest support

Changes since v3:
 - v4 actually works, fully boots a guest
 - Support compiling as a module
 - Use static inlines instead of macros for vcpu_reg and friends
 - Optimize kvm_vcpu_reg function
 - Use Ftrace for trace capabilities
 - Updated documentation and commenting
 - Use KVM_IRQ_LINE instead of KVM_INTERRUPT
 - Emulates load/store instructions not supported through HSR
  syndrome information.
 - Frees 2nd stage translation tables on VM teardown
 - Handles IRQ/FIQ instructions
 - Handles more CP15 accesses
 - Support guest WFI calls
 - Uses debugfs instead of /proc
 - Support compiling in Thumb mode

Changes since v2:
 - Performs world-switch code
 - Maps guest memory using 2nd stage translation
 - Emulates co-processor 15 instructions
 - Forwards I/O faults to QEMU.

---

Christoffer Dall (11):
      KVM: Introduce __KVM_HAVE_IRQ_LINE
      ARM: KVM: Initial skeleton to compile KVM support
      ARM: KVM: Hypervisor identity mapping
      ARM: KVM: Hypervisor inititalization
      ARM: KVM: Memory virtualization setup
      ARM: KVM: Inject IRQs and FIQs from userspace
      ARM: KVM: World-switch implementation
      ARM: KVM: Emulation framework and CP15 emulation
      ARM: KVM: Handle guest faults in KVM
      ARM: KVM: Handle I/O aborts
      ARM: KVM: Guest wait-for-interrupts (WFI) support

Marc Zyngier (1):
      ARM: KVM: Handle CP15 CR9 accesses for L2CTLR emulation


 Documentation/virtual/kvm/api.txt           |   12 
 arch/arm/Kconfig                            |    2 
 arch/arm/Makefile                           |    1 
 arch/arm/include/asm/kvm.h                  |   81 +++
 arch/arm/include/asm/kvm_arm.h              |  130 +++++
 arch/arm/include/asm/kvm_asm.h              |   51 ++
 arch/arm/include/asm/kvm_emulate.h          |  101 ++++
 arch/arm/include/asm/kvm_host.h             |  118 ++++
 arch/arm/include/asm/kvm_mmu.h              |   42 +
 arch/arm/include/asm/kvm_para.h             |    9 
 arch/arm/include/asm/pgtable-3level-hwdef.h |    5 
 arch/arm/include/asm/pgtable-3level.h       |   12 
 arch/arm/include/asm/pgtable.h              |   10 
 arch/arm/include/asm/unified.h              |   12 
 arch/arm/kernel/armksyms.c                  |    7 
 arch/arm/kernel/asm-offsets.c               |   34 +
 arch/arm/kernel/entry-armv.S                |    1 
 arch/arm/kvm/Kconfig                        |   45 ++
 arch/arm/kvm/Makefile                       |   17 +
 arch/arm/kvm/arm.c                          |  777 +++++++++++++++++++++++++++
 arch/arm/kvm/emulate.c                      |  640 ++++++++++++++++++++++
 arch/arm/kvm/exports.c                      |   32 +
 arch/arm/kvm/guest.c                        |  147 +++++
 arch/arm/kvm/init.S                         |  115 ++++
 arch/arm/kvm/interrupts.S                   |  546 +++++++++++++++++++
 arch/arm/kvm/mmu.c                          |  545 +++++++++++++++++++
 arch/arm/kvm/trace.h                        |  117 ++++
 arch/arm/mm/Kconfig                         |    8 
 arch/arm/mm/idmap.c                         |   47 +-
 arch/arm/mm/mmu.c                           |    3 
 arch/ia64/include/asm/kvm.h                 |    1 
 arch/x86/include/asm/kvm.h                  |    1 
 include/linux/kvm.h                         |    1 
 include/trace/events/kvm.h                  |    4 
 mm/memory.c                                 |    2 
 35 files changed, 3667 insertions(+), 9 deletions(-)
 create mode 100644 arch/arm/include/asm/kvm.h
 create mode 100644 arch/arm/include/asm/kvm_arm.h
 create mode 100644 arch/arm/include/asm/kvm_asm.h
 create mode 100644 arch/arm/include/asm/kvm_emulate.h
 create mode 100644 arch/arm/include/asm/kvm_host.h
 create mode 100644 arch/arm/include/asm/kvm_mmu.h
 create mode 100644 arch/arm/include/asm/kvm_para.h
 create mode 100644 arch/arm/kvm/Kconfig
 create mode 100644 arch/arm/kvm/Makefile
 create mode 100644 arch/arm/kvm/arm.c
 create mode 100644 arch/arm/kvm/emulate.c
 create mode 100644 arch/arm/kvm/exports.c
 create mode 100644 arch/arm/kvm/guest.c
 create mode 100644 arch/arm/kvm/init.S
 create mode 100644 arch/arm/kvm/interrupts.S
 create mode 100644 arch/arm/kvm/mmu.c
 create mode 100644 arch/arm/kvm/trace.h

-- 

^ permalink raw reply	[flat|nested] 24+ messages in thread

* [PATCH v6 01/12] KVM: Introduce __KVM_HAVE_IRQ_LINE
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support Christoffer Dall
                   ` (10 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

This is a prepatory patch for the KVM/ARM implementation. KVM/ARM will use
the KVM_IRQ_LINE ioctl, which is currently conditional on
__KVM_HAVE_IOAPIC, but ARM obviously doesn't have any IOAPIC support and we
need a separate define.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/ia64/include/asm/kvm.h |    1 +
 arch/x86/include/asm/kvm.h  |    1 +
 include/trace/events/kvm.h  |    4 +++-
 3 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/include/asm/kvm.h b/arch/ia64/include/asm/kvm.h
index bc90c75..f3999aa 100644
--- a/arch/ia64/include/asm/kvm.h
+++ b/arch/ia64/include/asm/kvm.h
@@ -26,6 +26,7 @@
 
 /* Select x86 specific features in <linux/kvm.h> */
 #define __KVM_HAVE_IOAPIC
+#define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_DEVICE_ASSIGNMENT
 
 /* Architectural interrupt line count. */
diff --git a/arch/x86/include/asm/kvm.h b/arch/x86/include/asm/kvm.h
index 4d8dcbd..05e3466 100644
--- a/arch/x86/include/asm/kvm.h
+++ b/arch/x86/include/asm/kvm.h
@@ -12,6 +12,7 @@
 /* Select x86 specific features in <linux/kvm.h> */
 #define __KVM_HAVE_PIT
 #define __KVM_HAVE_IOAPIC
+#define __KVM_HAVE_IRQ_LINE
 #define __KVM_HAVE_DEVICE_ASSIGNMENT
 #define __KVM_HAVE_MSI
 #define __KVM_HAVE_USER_NMI
diff --git a/include/trace/events/kvm.h b/include/trace/events/kvm.h
index 46e3cd8..ae9779d 100644
--- a/include/trace/events/kvm.h
+++ b/include/trace/events/kvm.h
@@ -36,7 +36,7 @@ TRACE_EVENT(kvm_userspace_exit,
 		  __entry->errno < 0 ? -__entry->errno : __entry->reason)
 );
 
-#if defined(__KVM_HAVE_IOAPIC)
+#if defined(__KVM_HAVE_IRQ_LINE)
 TRACE_EVENT(kvm_set_irq,
 	TP_PROTO(unsigned int gsi, int level, int irq_source_id),
 	TP_ARGS(gsi, level, irq_source_id),
@@ -56,7 +56,9 @@ TRACE_EVENT(kvm_set_irq,
 	TP_printk("gsi %u level %d source %d",
 		  __entry->gsi, __entry->level, __entry->irq_source_id)
 );
+#endif
 
+#if defined(__KVM_HAVE_IOAPIC)
 #define kvm_deliver_mode		\
 	{0x0, "Fixed"},			\
 	{0x1, "LowPrio"},		\


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 01/12] KVM: Introduce __KVM_HAVE_IRQ_LINE Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-24  3:32   ` Rusty Russell
  2012-02-23  7:32 ` [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping Christoffer Dall
                   ` (9 subsequent siblings)
  11 siblings, 1 reply; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

Targets KVM support for Cortex A-15 processors.

Contains no real functionality but all the framework components,
make files, header files and some tracing functionality.

“Nothing to see here. Move along, move along..."

Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/Kconfig                   |    2 
 arch/arm/Makefile                  |    1 
 arch/arm/include/asm/kvm.h         |   72 ++++++++++
 arch/arm/include/asm/kvm_asm.h     |   28 ++++
 arch/arm/include/asm/kvm_emulate.h |   92 +++++++++++++
 arch/arm/include/asm/kvm_host.h    |  116 ++++++++++++++++
 arch/arm/include/asm/kvm_para.h    |    9 +
 arch/arm/include/asm/unified.h     |   12 ++
 arch/arm/kvm/Kconfig               |   45 ++++++
 arch/arm/kvm/Makefile              |   17 ++
 arch/arm/kvm/arm.c                 |  256 ++++++++++++++++++++++++++++++++++++
 arch/arm/kvm/emulate.c             |  121 +++++++++++++++++
 arch/arm/kvm/exports.c             |   16 ++
 arch/arm/kvm/guest.c               |  148 +++++++++++++++++++++
 arch/arm/kvm/init.S                |   17 ++
 arch/arm/kvm/interrupts.S          |   17 ++
 arch/arm/kvm/mmu.c                 |   15 ++
 arch/arm/kvm/trace.h               |   52 +++++++
 arch/arm/mm/Kconfig                |    8 +
 19 files changed, 1044 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/include/asm/kvm.h
 create mode 100644 arch/arm/include/asm/kvm_asm.h
 create mode 100644 arch/arm/include/asm/kvm_emulate.h
 create mode 100644 arch/arm/include/asm/kvm_host.h
 create mode 100644 arch/arm/include/asm/kvm_para.h
 create mode 100644 arch/arm/kvm/Kconfig
 create mode 100644 arch/arm/kvm/Makefile
 create mode 100644 arch/arm/kvm/arm.c
 create mode 100644 arch/arm/kvm/emulate.c
 create mode 100644 arch/arm/kvm/exports.c
 create mode 100644 arch/arm/kvm/guest.c
 create mode 100644 arch/arm/kvm/init.S
 create mode 100644 arch/arm/kvm/interrupts.S
 create mode 100644 arch/arm/kvm/mmu.c
 create mode 100644 arch/arm/kvm/trace.h

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index e12bc34..81aa08f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -2263,3 +2263,5 @@ source "security/Kconfig"
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
+
+source "arch/arm/kvm/Kconfig"
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 40319d9..eca44e0 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -253,6 +253,7 @@ core-$(CONFIG_VFP)		+= arch/arm/vfp/
 
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
+core-y 				+= arch/arm/kvm/
 core-y				+= $(machdirs) $(platdirs)
 
 drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
new file mode 100644
index 0000000..544cb2a
--- /dev/null
+++ b/arch/arm/include/asm/kvm.h
@@ -0,0 +1,72 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_KVM_H__
+#define __ARM_KVM_H__
+
+#include <asm/types.h>
+
+#define __KVM_HAVE_GUEST_DEBUG
+
+/*
+ * Modes used for short-hand mode determinition in the world-switch code and
+ * in emulation code.
+ *
+ * Note: These indices do NOT correspond to the value of the CPSR mode bits!
+ */
+enum vcpu_modes {
+	MODE_FIQ = 0,
+	MODE_IRQ,
+	MODE_SVC,
+	MODE_ABT,
+	MODE_UND,
+	MODE_USR,
+	MODE_SYS
+};
+
+struct kvm_regs {
+	__u32 regs0_7[8];	/* Unbanked regs. (r0 - r7)	   */
+	__u32 fiq_regs8_12[5];	/* Banked fiq regs. (r8 - r12)	   */
+	__u32 usr_regs8_12[5];	/* Banked usr registers (r8 - r12) */
+	__u32 reg13[6];		/* Banked r13, indexed by MODE_	   */
+	__u32 reg14[6];		/* Banked r13, indexed by MODE_	   */
+	__u32 reg15;
+	__u32 cpsr;
+	__u32 spsr[5];		/* Banked SPSR,  indexed by MODE_  */
+	struct {
+		__u32 c0_midr;
+		__u32 c1_sys;
+		__u32 c2_base0;
+		__u32 c2_base1;
+		__u32 c2_control;
+		__u32 c3_dacr;
+	} cp15;
+
+};
+
+struct kvm_sregs {
+};
+
+struct kvm_fpu {
+};
+
+struct kvm_guest_debug_arch {
+};
+
+struct kvm_debug_exit_arch {
+};
+
+#endif /* __ARM_KVM_H__ */
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
new file mode 100644
index 0000000..c3d4458
--- /dev/null
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -0,0 +1,28 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_KVM_ASM_H__
+#define __ARM_KVM_ASM_H__
+
+#define ARM_EXCEPTION_RESET	  0
+#define ARM_EXCEPTION_UNDEFINED   1
+#define ARM_EXCEPTION_SOFTWARE    2
+#define ARM_EXCEPTION_PREF_ABORT  3
+#define ARM_EXCEPTION_DATA_ABORT  4
+#define ARM_EXCEPTION_IRQ	  5
+#define ARM_EXCEPTION_FIQ	  6
+
+#endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
new file mode 100644
index 0000000..4074059
--- /dev/null
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -0,0 +1,92 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_KVM_EMULATE_H__
+#define __ARM_KVM_EMULATE_H__
+
+#include <linux/kvm_host.h>
+#include <asm/kvm_asm.h>
+
+u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
+
+static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)
+{
+	u8 modes_table[16] = {
+		MODE_USR,	/* 0x0 */
+		MODE_FIQ,	/* 0x1 */
+		MODE_IRQ,	/* 0x2 */
+		MODE_SVC,	/* 0x3 */
+		0xf, 0xf, 0xf,
+		MODE_ABT,	/* 0x7 */
+		0xf, 0xf, 0xf,
+		MODE_UND,	/* 0xb */
+		0xf, 0xf, 0xf,
+		MODE_SYS};	/* 0xf */
+
+	BUG_ON(modes_table[vcpu->arch.regs.cpsr & 0xf] == 0xf);
+	return modes_table[vcpu->arch.regs.cpsr & 0xf];
+}
+
+/*
+ * Return the SPSR for the specified mode of the virtual CPU.
+ */
+static inline u32 *kvm_vcpu_spsr(struct kvm_vcpu *vcpu, u32 mode)
+{
+	switch (mode) {
+	case MODE_SVC:
+		return &vcpu->arch.regs.svc_regs[2];
+	case MODE_ABT:
+		return &vcpu->arch.regs.svc_regs[2];
+	case MODE_UND:
+		return &vcpu->arch.regs.svc_regs[2];
+	case MODE_IRQ:
+		return &vcpu->arch.regs.svc_regs[2];
+	case MODE_FIQ:
+		return &vcpu->arch.regs.fiq_regs[7];
+	default:
+		BUG();
+	}
+}
+
+/* Get vcpu register for current mode */
+static inline u32 *vcpu_reg(struct kvm_vcpu *vcpu, unsigned long reg_num)
+{
+	return kvm_vcpu_reg(vcpu, reg_num, vcpu_mode(vcpu));
+}
+
+static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu)
+{
+	return &vcpu->arch.regs.cpsr;
+}
+
+/* Get vcpu SPSR for current mode */
+static inline u32 *vcpu_spsr(struct kvm_vcpu *vcpu)
+{
+	return kvm_vcpu_spsr(vcpu, vcpu_mode(vcpu));
+}
+
+static inline bool mode_has_spsr(struct kvm_vcpu *vcpu)
+{
+	return (vcpu_mode(vcpu) < MODE_USR);
+}
+
+static inline bool vcpu_mode_priv(struct kvm_vcpu *vcpu)
+{
+	BUG_ON(vcpu_mode(vcpu) > MODE_SYS);
+	return vcpu_mode(vcpu) != MODE_USR;
+}
+
+#endif /* __ARM_KVM_EMULATE_H__ */
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
new file mode 100644
index 0000000..2d611df
--- /dev/null
+++ b/arch/arm/include/asm/kvm_host.h
@@ -0,0 +1,116 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_KVM_HOST_H__
+#define __ARM_KVM_HOST_H__
+
+#define KVM_MAX_VCPUS 1
+#define KVM_MEMORY_SLOTS 32
+#define KVM_PRIVATE_MEM_SLOTS 4
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
+/* We don't currently support large pages. */
+#define KVM_HPAGE_GFN_SHIFT(x)	0
+#define KVM_NR_PAGE_SIZES	1
+#define KVM_PAGES_PER_HPAGE(x)	(1UL<<31)
+
+struct kvm_vcpu;
+u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
+
+struct kvm_arch {
+	/* The VMID used for the virt. memory system */
+	u64    vmid;
+
+	/* 1-level 2nd stage table and lock */
+	struct mutex pgd_mutex;
+	pgd_t *pgd;
+
+	/* VTTBR value associated with above pgd and vmid */
+	u64    vttbr;
+};
+
+#define EXCEPTION_NONE      0
+#define EXCEPTION_RESET     0x80
+#define EXCEPTION_UNDEFINED 0x40
+#define EXCEPTION_SOFTWARE  0x20
+#define EXCEPTION_PREFETCH  0x10
+#define EXCEPTION_DATA      0x08
+#define EXCEPTION_IMPRECISE 0x04
+#define EXCEPTION_IRQ       0x02
+#define EXCEPTION_FIQ       0x01
+
+struct kvm_vcpu_regs {
+	u32 usr_regs[15];	/* R0_usr - R14_usr */
+	u32 svc_regs[3];	/* SP_svc, LR_svc, SPSR_svc */
+	u32 abt_regs[3];	/* SP_abt, LR_abt, SPSR_abt */
+	u32 und_regs[3];	/* SP_und, LR_und, SPSR_und */
+	u32 irq_regs[3];	/* SP_irq, LR_irq, SPSR_irq */
+	u32 fiq_regs[8];	/* R8_fiq - R14_fiq, SPSR_fiq */
+	u32 pc;			/* The program counter (r15) */
+	u32 cpsr;		/* The guest CPSR */
+} __packed;
+
+enum cp15_regs {
+	c0_MIDR,		/* Main ID Register */
+	c0_MPIDR,		/* MultiProcessor ID Register */
+	c1_SCTLR,		/* System Control Register */
+	c1_ACTLR,		/* Auxilliary Control Register */
+	c1_CPACR,		/* Coprocessor Access Control */
+	c2_TTBR0,		/* Translation Table Base Register 0 */
+	c2_TTBR0_high,		/* TTBR0 top 32 bits */
+	c2_TTBR1,		/* Translation Table Base Register 1 */
+	c2_TTBR1_high,		/* TTBR1 top 32 bits */
+	c2_TTBCR,		/* Translation Table Base Control R. */
+	c3_DACR,		/* Domain Access Control Register */
+	c10_PRRR,		/* Primary Region Remap Register */
+	c10_NMRR,		/* Normal Memory Remap Register */
+	c13_CID,		/* Context ID Register */
+	c13_TID_URW,		/* Thread ID, User R/W */
+	c13_TID_URO,		/* Thread ID, User R/O */
+	c13_TID_PRIV,		/* Thread ID, Priveleged */
+
+	nr_cp15_regs
+};
+
+struct kvm_vcpu_arch {
+	struct kvm_vcpu_regs regs;
+
+	/* System control coprocessor (cp15) */
+	u32 cp15[nr_cp15_regs];
+
+	/* Exception Information */
+	u32 hsr;		/* Hyp Syndrom Register */
+	u32 hdfar;		/* Hyp Data Fault Address Register */
+	u32 hifar;		/* Hyp Inst. Fault Address Register */
+	u32 hpfar;		/* Hyp IPA Fault Address Register */
+
+	/* IO related fields */
+	u32 mmio_rd;
+
+	/* Interrupt related fields */
+	u32 irq_lines;		/* IRQ and FIQ levels */
+	u32 wait_for_interrupts;
+};
+
+struct kvm_vm_stat {
+	u32 remote_tlb_flush;
+};
+
+struct kvm_vcpu_stat {
+	u32 halt_wakeup;
+};
+
+#endif /* __ARM_KVM_HOST_H__ */
diff --git a/arch/arm/include/asm/kvm_para.h b/arch/arm/include/asm/kvm_para.h
new file mode 100644
index 0000000..ea686f6
--- /dev/null
+++ b/arch/arm/include/asm/kvm_para.h
@@ -0,0 +1,9 @@
+#ifndef _ASM_ARM_KVM_PARA_H
+#define _ASM_ARM_KVM_PARA_H
+
+static inline unsigned int kvm_arch_para_features(void)
+{
+	return 0;
+}
+
+#endif /* _ASM_ARM_KVM_PARA_H */
diff --git a/arch/arm/include/asm/unified.h b/arch/arm/include/asm/unified.h
index f5989f4..e5dc5f6 100644
--- a/arch/arm/include/asm/unified.h
+++ b/arch/arm/include/asm/unified.h
@@ -54,6 +54,18 @@
 
 #endif	/* CONFIG_THUMB2_KERNEL */
 
+#ifdef CONFIG_KVM_ARM_HOST
+#ifdef __ASSEMBLY__
+.arch_extension sec
+.arch_extension virt
+#else
+__asm__(
+"	.arch_extension sec\n"
+"	.arch_extension virt\n"
+);
+#endif
+#endif
+
 #ifndef CONFIG_ARM_ASM_UNIFIED
 
 /*
diff --git a/arch/arm/kvm/Kconfig b/arch/arm/kvm/Kconfig
new file mode 100644
index 0000000..a458a55
--- /dev/null
+++ b/arch/arm/kvm/Kconfig
@@ -0,0 +1,45 @@
+#
+# KVM configuration
+#
+
+source "virt/kvm/Kconfig"
+
+menuconfig VIRTUALIZATION
+	bool "Virtualization"
+	---help---
+	  Say Y here to get to see options for using your Linux host to run
+	  other operating systems inside virtual machines (guests).
+	  This option alone does not add any kernel code.
+
+	  If you say N, all options in this submenu will be skipped and
+	  disabled.
+
+if VIRTUALIZATION
+
+config KVM
+	tristate "Kernel-based Virtual Machine (KVM) support"
+	select PREEMPT_NOTIFIERS
+	select ANON_INODES
+	select KVM_ARM_HOST
+	select KVM_MMIO
+	depends on CPU_V7 && ARM_VIRT_EXT
+	---help---
+	  Support hosting virtualized guest machines. You will also
+	  need to select one or more of the processor modules below.
+
+	  This module provides access to the hardware capabilities through
+	  a character device node named /dev/kvm.
+
+	  If unsure, say N.
+
+config KVM_ARM_HOST
+	bool "KVM host support for ARM cpus."
+	depends on KVM
+	depends on MMU
+	depends on CPU_V7 && ARM_VIRT_EXT
+	---help---
+	  Provides host support for ARM processors.
+
+source drivers/virtio/Kconfig
+
+endif # VIRTUALIZATION
diff --git a/arch/arm/kvm/Makefile b/arch/arm/kvm/Makefile
new file mode 100644
index 0000000..e69a8e1
--- /dev/null
+++ b/arch/arm/kvm/Makefile
@@ -0,0 +1,17 @@
+#
+# Makefile for Kernel-based Virtual Machine module
+#
+
+ccflags-y += -Ivirt/kvm -Iarch/arm/kvm
+CFLAGS_arm.o     := -I.
+CFLAGS_mmu.o := -I.
+
+AFLAGS_interrupts.o := -I$(obj)
+
+obj-$(CONFIG_KVM_ARM_HOST) += init.o interrupts.o exports.o
+
+kvm-arm-y += $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o)
+
+kvm-arm-y += arm.o guest.o mmu.o emulate.o
+
+obj-$(CONFIG_KVM) += kvm-arm.o
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
new file mode 100644
index 0000000..cf11296
--- /dev/null
+++ b/arch/arm/kvm/arm.c
@@ -0,0 +1,256 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/mman.h>
+#include <linux/sched.h>
+#include <trace/events/kvm.h>
+
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+
+#include <asm/unified.h>
+#include <asm/uaccess.h>
+#include <asm/ptrace.h>
+#include <asm/mman.h>
+
+int kvm_arch_hardware_enable(void *garbage)
+{
+	return 0;
+}
+
+void kvm_arch_hardware_disable(void *garbage)
+{
+}
+
+int kvm_arch_hardware_setup(void)
+{
+	return 0;
+}
+
+void kvm_arch_hardware_unsetup(void)
+{
+}
+
+void kvm_arch_check_processor_compat(void *rtn)
+{
+	*(int *)rtn = 0;
+}
+
+void kvm_arch_sync_events(struct kvm *kvm)
+{
+}
+
+int kvm_arch_init_vm(struct kvm *kvm)
+{
+	return 0;
+}
+
+void kvm_arch_destroy_vm(struct kvm *kvm)
+{
+	int i;
+
+	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
+		if (kvm->vcpus[i]) {
+			kvm_arch_vcpu_free(kvm->vcpus[i]);
+			kvm->vcpus[i] = NULL;
+		}
+	}
+}
+
+int kvm_dev_ioctl_check_extension(long ext)
+{
+	int r;
+	switch (ext) {
+	case KVM_CAP_USER_MEMORY:
+	case KVM_CAP_DESTROY_MEMORY_REGION_WORKS:
+		r = 1;
+		break;
+	case KVM_CAP_COALESCED_MMIO:
+		r = KVM_COALESCED_MMIO_PAGE_OFFSET;
+		break;
+	default:
+		r = 0;
+		break;
+	}
+	return r;
+}
+
+long kvm_arch_dev_ioctl(struct file *filp,
+			unsigned int ioctl, unsigned long arg)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_set_memory_region(struct kvm *kvm,
+			       struct kvm_userspace_memory_region *mem,
+			       struct kvm_memory_slot old,
+			       int user_alloc)
+{
+	return 0;
+}
+
+int kvm_arch_prepare_memory_region(struct kvm *kvm,
+				   struct kvm_memory_slot *memslot,
+				   struct kvm_memory_slot old,
+				   struct kvm_userspace_memory_region *mem,
+				   int user_alloc)
+{
+	return 0;
+}
+
+void kvm_arch_commit_memory_region(struct kvm *kvm,
+				   struct kvm_userspace_memory_region *mem,
+				   struct kvm_memory_slot old,
+				   int user_alloc)
+{
+}
+
+void kvm_arch_flush_shadow(struct kvm *kvm)
+{
+}
+
+struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
+{
+	int err;
+	struct kvm_vcpu *vcpu;
+
+	vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL);
+	if (!vcpu) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	err = kvm_vcpu_init(vcpu, kvm, id);
+	if (err)
+		goto free_vcpu;
+
+	return vcpu;
+free_vcpu:
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
+out:
+	return ERR_PTR(err);
+}
+
+void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
+{
+}
+
+void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
+{
+	kvm_arch_vcpu_free(vcpu);
+}
+
+int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
+{
+}
+
+void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
+{
+}
+
+void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
+{
+}
+
+int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
+					struct kvm_guest_debug *dbg)
+{
+	return -EINVAL;
+}
+
+
+int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
+				    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
+				    struct kvm_mp_state *mp_state)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *v)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
+
+long kvm_arch_vcpu_ioctl(struct file *filp,
+			 unsigned int ioctl, unsigned long arg)
+{
+	return -EINVAL;
+}
+
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
+{
+	return -EINVAL;
+}
+
+long kvm_arch_vm_ioctl(struct file *filp,
+		       unsigned int ioctl, unsigned long arg)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_init(void *opaque)
+{
+	return 0;
+}
+
+void kvm_arch_exit(void)
+{
+}
+
+static int arm_init(void)
+{
+	int rc = kvm_init(NULL, sizeof(struct kvm_vcpu), 0, THIS_MODULE);
+	return rc;
+}
+
+static void __exit arm_exit(void)
+{
+	kvm_exit();
+}
+
+module_init(arm_init);
+module_exit(arm_exit)
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
new file mode 100644
index 0000000..cd634a1
--- /dev/null
+++ b/arch/arm/kvm/emulate.c
@@ -0,0 +1,121 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#include <asm/kvm_emulate.h>
+
+#define USR_REG_OFFSET(_reg) \
+	offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
+
+static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
+	/* FIQ Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7),
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r8 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r9 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[2]), /* r10 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[3]), /* r11 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[4]), /* r12 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[5]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[6]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)		  /* r15 */
+	},
+
+	/* IRQ Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.irq_regs[0]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.irq_regs[1]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+	},
+
+	/* SVC Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.svc_regs[0]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.svc_regs[1]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)		  /* r15 */
+	},
+
+	/* ABT Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.abt_regs[0]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.abt_regs[1]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+	},
+
+	/* UND Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.und_regs[0]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.und_regs[1]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+	},
+
+	/* USR Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)	           /* r15 */
+	},
+
+	/* SYS Registers */
+	{
+		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
+		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
+		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
+		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
+		USR_REG_OFFSET(12),
+		offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
+		offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
+		offsetof(struct kvm_vcpu_arch, regs.pc)	           /* r15 */
+	},
+};
+
+/*
+ * Return a pointer to the register number valid in the specified mode of
+ * the virtual CPU.
+ */
+u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
+{
+	BUG_ON(reg_num > 15);
+	BUG_ON(mode > MODE_SYS);
+
+	return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
+}
diff --git a/arch/arm/kvm/exports.c b/arch/arm/kvm/exports.c
new file mode 100644
index 0000000..d8a7fd5
--- /dev/null
+++ b/arch/arm/kvm/exports.c
@@ -0,0 +1,16 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
new file mode 100644
index 0000000..9c75ec4
--- /dev/null
+++ b/arch/arm/kvm/guest.c
@@ -0,0 +1,148 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/kvm_host.h>
+#include <linux/module.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <asm/uaccess.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_emulate.h>
+
+
+struct kvm_stats_debugfs_item debugfs_entries[] = {
+	{ NULL }
+};
+
+int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
+{
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	struct kvm_vcpu_regs *vcpu_regs = &vcpu->arch.regs;
+
+	/*
+	 * GPRs and PSRs
+	 */
+	memcpy(regs->regs0_7, &(vcpu_regs->usr_regs[0]), sizeof(u32) * 8);
+	memcpy(regs->usr_regs8_12, &(vcpu_regs->usr_regs[8]), sizeof(u32) * 5);
+	memcpy(regs->fiq_regs8_12, &(vcpu_regs->fiq_regs[0]), sizeof(u32) * 5);
+	regs->reg13[MODE_FIQ] = vcpu_regs->fiq_regs[5];
+	regs->reg14[MODE_FIQ] = vcpu_regs->fiq_regs[6];
+	regs->reg13[MODE_IRQ] = vcpu_regs->irq_regs[0];
+	regs->reg14[MODE_IRQ] = vcpu_regs->irq_regs[1];
+	regs->reg13[MODE_SVC] = vcpu_regs->svc_regs[0];
+	regs->reg14[MODE_SVC] = vcpu_regs->svc_regs[1];
+	regs->reg13[MODE_ABT] = vcpu_regs->abt_regs[0];
+	regs->reg14[MODE_ABT] = vcpu_regs->abt_regs[1];
+	regs->reg13[MODE_UND] = vcpu_regs->und_regs[0];
+	regs->reg14[MODE_UND] = vcpu_regs->und_regs[1];
+	regs->reg13[MODE_USR] = vcpu_regs->usr_regs[0];
+	regs->reg14[MODE_USR] = vcpu_regs->usr_regs[1];
+
+	regs->spsr[MODE_FIQ]  = vcpu_regs->fiq_regs[7];
+	regs->spsr[MODE_IRQ]  = vcpu_regs->irq_regs[2];
+	regs->spsr[MODE_SVC]  = vcpu_regs->svc_regs[2];
+	regs->spsr[MODE_ABT]  = vcpu_regs->abt_regs[2];
+	regs->spsr[MODE_UND]  = vcpu_regs->und_regs[2];
+
+	regs->reg15 = vcpu_regs->pc;
+	regs->cpsr = vcpu_regs->cpsr;
+
+
+	/*
+	 * Co-processor registers.
+	 */
+	regs->cp15.c0_midr = vcpu->arch.cp15[c0_MIDR];
+	regs->cp15.c1_sys = vcpu->arch.cp15[c1_SCTLR];
+	regs->cp15.c2_base0 = vcpu->arch.cp15[c2_TTBR0];
+	regs->cp15.c2_base1 = vcpu->arch.cp15[c2_TTBR1];
+	regs->cp15.c2_control = vcpu->arch.cp15[c2_TTBCR];
+	regs->cp15.c3_dacr = vcpu->arch.cp15[c3_DACR];
+
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_set_regs(struct kvm_vcpu *vcpu, struct kvm_regs *regs)
+{
+	struct kvm_vcpu_regs *vcpu_regs = &vcpu->arch.regs;
+
+	memcpy(&(vcpu_regs->usr_regs[0]), regs->regs0_7, sizeof(u32) * 8);
+	memcpy(&(vcpu_regs->usr_regs[8]), regs->usr_regs8_12, sizeof(u32) * 5);
+	memcpy(&(vcpu_regs->fiq_regs[0]), regs->fiq_regs8_12, sizeof(u32) * 5);
+
+	vcpu_regs->fiq_regs[5] = regs->reg13[MODE_FIQ];
+	vcpu_regs->fiq_regs[6] = regs->reg14[MODE_FIQ];
+	vcpu_regs->irq_regs[0] = regs->reg13[MODE_IRQ];
+	vcpu_regs->irq_regs[1] = regs->reg14[MODE_IRQ];
+	vcpu_regs->svc_regs[0] = regs->reg13[MODE_SVC];
+	vcpu_regs->svc_regs[1] = regs->reg14[MODE_SVC];
+	vcpu_regs->abt_regs[0] = regs->reg13[MODE_ABT];
+	vcpu_regs->abt_regs[1] = regs->reg14[MODE_ABT];
+	vcpu_regs->und_regs[0] = regs->reg13[MODE_UND];
+	vcpu_regs->und_regs[1] = regs->reg14[MODE_UND];
+	vcpu_regs->usr_regs[0] = regs->reg13[MODE_USR];
+	vcpu_regs->usr_regs[1] = regs->reg14[MODE_USR];
+
+	vcpu_regs->fiq_regs[7] = regs->spsr[MODE_FIQ];
+	vcpu_regs->irq_regs[2] = regs->spsr[MODE_IRQ];
+	vcpu_regs->svc_regs[2] = regs->spsr[MODE_SVC];
+	vcpu_regs->abt_regs[2] = regs->spsr[MODE_ABT];
+	vcpu_regs->und_regs[2] = regs->spsr[MODE_UND];
+
+	/*
+	 * Co-processor registers.
+	 */
+	vcpu->arch.cp15[c0_MIDR] = regs->cp15.c0_midr;
+	vcpu->arch.cp15[c1_SCTLR] = regs->cp15.c1_sys;
+
+	vcpu_regs->pc = regs->reg15;
+	vcpu_regs->cpsr = regs->cpsr;
+
+	return 0;
+}
+
+int kvm_arch_vcpu_ioctl_get_sregs(struct kvm_vcpu *vcpu,
+				  struct kvm_sregs *sregs)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu,
+				  struct kvm_sregs *sregs)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_set_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
+{
+	return -EINVAL;
+}
+
+int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
+				  struct kvm_translation *tr)
+{
+	return -EINVAL;
+}
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
new file mode 100644
index 0000000..073a494
--- /dev/null
+++ b/arch/arm/kvm/init.S
@@ -0,0 +1,17 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+#include <asm/asm-offsets.h>
+#include <asm/kvm_asm.h>
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
new file mode 100644
index 0000000..073a494
--- /dev/null
+++ b/arch/arm/kvm/interrupts.S
@@ -0,0 +1,17 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+#include <asm/asm-offsets.h>
+#include <asm/kvm_asm.h>
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
new file mode 100644
index 0000000..2cccd48
--- /dev/null
+++ b/arch/arm/kvm/mmu.c
@@ -0,0 +1,15 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
new file mode 100644
index 0000000..f8869c1
--- /dev/null
+++ b/arch/arm/kvm/trace.h
@@ -0,0 +1,52 @@
+#if !defined(_TRACE_KVM_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_KVM_H
+
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM kvm
+
+/*
+ * Tracepoints for entry/exit to guest
+ */
+TRACE_EVENT(kvm_entry,
+	TP_PROTO(unsigned long vcpu_pc),
+	TP_ARGS(vcpu_pc),
+
+	TP_STRUCT__entry(
+		__field(	unsigned long,	vcpu_pc		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_pc		= vcpu_pc;
+	),
+
+	TP_printk("PC: 0x%08lx", __entry->vcpu_pc)
+);
+
+TRACE_EVENT(kvm_exit,
+	TP_PROTO(unsigned long vcpu_pc),
+	TP_ARGS(vcpu_pc),
+
+	TP_STRUCT__entry(
+		__field(	unsigned long,	vcpu_pc		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_pc		= vcpu_pc;
+	),
+
+	TP_printk("PC: 0x%08lx", __entry->vcpu_pc)
+);
+
+
+
+#endif /* _TRACE_KVM_H */
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH arch/arm/kvm
+#undef TRACE_INCLUDE_FILE
+#define TRACE_INCLUDE_FILE trace
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 1a3ca24..5467b28 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -640,6 +640,14 @@ config ARM_LPAE
 
 	  If unsure, say N.
 
+config ARM_VIRT_EXT
+	bool "Support for ARM Virtualization Extensions"
+	depends on ARM_LPAE
+	help
+	  Say Y if you have an ARMv7 processor supporting the ARM hardware
+	  Virtualization extensions. KVM depends on this feature and will
+	  not run without it being selected.
+
 config ARCH_PHYS_ADDR_T_64BIT
 	def_bool ARM_LPAE
 


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 01/12] KVM: Introduce __KVM_HAVE_IRQ_LINE Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-24  3:33   ` Rusty Russell
  2012-02-23  7:32 ` [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization Christoffer Dall
                   ` (8 subsequent siblings)
  11 siblings, 1 reply; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

Adds support in the identity mapping feature that allows KVM to setup
identity mapping for the Hyp mode with the AP[1] bit set as required by
the specification and also supports freeing created sub pmd's after
finished use.

These two functions:
 - hyp_idmap_add(pgd, addr, end);
 - hyp_idmap_del(pgd, addr, end);
are essentially calls to the same function as the non-hyp versions but
with a different argument value. KVM calls these functions to setup
and teardown the identity mapping used to initialize the hypervisor.

Note, the hyp-version of the _del function actually frees the pmd's
pointed to by the pgd as opposed to the non-hyp version which just
clears them.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/pgtable-3level-hwdef.h |    1 +
 arch/arm/include/asm/pgtable.h              |    5 +++
 arch/arm/kvm/guest.c                        |    1 -
 arch/arm/mm/idmap.c                         |   47 +++++++++++++++++++++++++--
 4 files changed, 49 insertions(+), 5 deletions(-)

diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index d795282..a2d404e 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -44,6 +44,7 @@
 #define PMD_SECT_XN		(_AT(pmdval_t, 1) << 54)
 #define PMD_SECT_AP_WRITE	(_AT(pmdval_t, 0))
 #define PMD_SECT_AP_READ	(_AT(pmdval_t, 0))
+#define PMD_SECT_AP1		(_AT(pmdval_t, 1) << 6)
 #define PMD_SECT_TEX(x)		(_AT(pmdval_t, 0))
 
 /*
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index f66626d..c7bd809 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -310,6 +310,11 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 
 #define pgtable_cache_init() do { } while (0)
 
+#ifdef CONFIG_KVM_ARM_HOST
+void hyp_idmap_add(pgd_t *, unsigned long, unsigned long);
+void hyp_idmap_del(pgd_t *pgd, unsigned long addr, unsigned long end);
+#endif
+
 #endif /* !__ASSEMBLY__ */
 
 #endif /* CONFIG_MMU */
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 9c75ec4..c0adab0 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -24,7 +24,6 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
 
-
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	{ NULL }
 };
diff --git a/arch/arm/mm/idmap.c b/arch/arm/mm/idmap.c
index feacf4c..35902d7 100644
--- a/arch/arm/mm/idmap.c
+++ b/arch/arm/mm/idmap.c
@@ -1,3 +1,4 @@
+#include <linux/module.h>
 #include <linux/kernel.h>
 
 #include <asm/cputype.h>
@@ -58,11 +59,13 @@ static void idmap_add_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
 	} while (pud++, addr = next, addr != end);
 }
 
-static void identity_mapping_add(pgd_t *pgd, unsigned long addr, unsigned long end)
+static void identity_mapping_add(pgd_t *pgd, unsigned long addr,
+				 unsigned long end, unsigned long prot)
 {
-	unsigned long prot, next;
+	unsigned long next;
+
+	prot |= PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
 
-	prot = PMD_TYPE_SECT | PMD_SECT_AP_WRITE | PMD_SECT_AF;
 	if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
 		prot |= PMD_BIT4;
 
@@ -89,12 +92,48 @@ static int __init init_static_idmap(void)
 
 	pr_info("Setting up static identity map for 0x%llx - 0x%llx\n",
 		(long long)idmap_start, (long long)idmap_end);
-	identity_mapping_add(idmap_pgd, idmap_start, idmap_end);
+	identity_mapping_add(idmap_pgd, idmap_start, idmap_end, 0);
 
 	return 0;
 }
 early_initcall(init_static_idmap);
 
+#ifdef CONFIG_KVM_ARM_HOST
+void hyp_idmap_add(pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+	identity_mapping_add(pgd, addr, end, PMD_SECT_AP1);
+}
+EXPORT_SYMBOL_GPL(hyp_idmap_add);
+
+static void hyp_idmap_del_pmd(pgd_t *pgd, unsigned long addr)
+{
+	pud_t *pud;
+	pmd_t *pmd;
+
+	pud = pud_offset(pgd, addr);
+	pmd = pmd_offset(pud, addr);
+	pmd_free(NULL, pmd);
+	pud_clear(pud);
+}
+
+/*
+ * This version actually frees the underlying pmds for all pgds in range and
+ * clear the pgds themselves afterwards.
+ */
+void hyp_idmap_del(pgd_t *pgd, unsigned long addr, unsigned long end)
+{
+	unsigned long next;
+
+	pgd += pgd_index(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (!pgd_none_or_clear_bad(pgd))
+			hyp_idmap_del_pmd(pgd, addr);
+	} while (pgd++, addr = next, addr < end);
+}
+EXPORT_SYMBOL_GPL(hyp_idmap_del);
+#endif
+
 /*
  * In order to soft-boot, we need to switch to a 1:1 mapping for the
  * cpu_reset functions. This will then ensure that we have predictable


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (2 preceding siblings ...)
  2012-02-23  7:32 ` [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-24  4:00   ` Rusty Russell
  2012-03-05  1:12   ` Rusty Russell
  2012-02-23  7:32 ` [PATCH v6 05/12] ARM: KVM: Memory virtualization setup Christoffer Dall
                   ` (7 subsequent siblings)
  11 siblings, 2 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

Sets up the required registers to run code in HYP-mode from the kernel.

By setting the HVBAR the kernel can execute code in Hyp-mode with
the MMU disabled. The HVBAR initially points to initialization code,
which initializes other Hyp-mode registers and enables the MMU
for Hyp-mode. Afterwards, the HVBAR is changed to point to KVM
Hyp vectors used to catch guest faults and to switch to Hyp mode
to perform a world-switch into a KVM guest.

Also provides memory mapping code to map required code pages and data
structures accessed in Hyp mode at the same virtual address as the
host kernel virtual addresses, but which conforms to the architectural
requirements for translations in Hyp mode. This interface is added in
arch/arm/kvm/arm_mmu.c and is comprised of:
 - create_hyp_mappings(hyp_pgd, start, end);
 - free_hyp_pmds(pgd_hyp);

Note: The initialization mechanism currently relies on an SMC #0 call
to the secure monitor, which was merely a fast way of getting to the
hypervisor. Dave Marting and Rusty Russel have patches out to make the
boot-wrapper and the kernel boot in Hyp-mode and setup a generic way for
hypervisors to get access to Hyp-mode if the boot-loader allows such
access.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_arm.h              |  103 +++++++++++++++
 arch/arm/include/asm/kvm_asm.h              |   23 +++
 arch/arm/include/asm/kvm_mmu.h              |   36 +++++
 arch/arm/include/asm/pgtable-3level-hwdef.h |    4 +
 arch/arm/include/asm/pgtable-3level.h       |    4 +
 arch/arm/include/asm/pgtable.h              |    1 
 arch/arm/kvm/arm.c                          |  182 +++++++++++++++++++++++++++
 arch/arm/kvm/exports.c                      |   16 ++
 arch/arm/kvm/init.S                         |   98 +++++++++++++++
 arch/arm/kvm/interrupts.S                   |   41 ++++++
 arch/arm/kvm/mmu.c                          |  153 +++++++++++++++++++++++
 mm/memory.c                                 |    2 
 12 files changed, 663 insertions(+), 0 deletions(-)
 create mode 100644 arch/arm/include/asm/kvm_arm.h
 create mode 100644 arch/arm/include/asm/kvm_mmu.h

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
new file mode 100644
index 0000000..835abd1
--- /dev/null
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -0,0 +1,103 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __KVM_ARM_H__
+#define __KVM_ARM_H__
+
+#include <asm/types.h>
+
+/* Hyp Configuration Register (HCR) bits */
+#define HCR_TGE		(1 << 27)
+#define HCR_TVM		(1 << 26)
+#define HCR_TTLB	(1 << 25)
+#define HCR_TPU		(1 << 24)
+#define HCR_TPC		(1 << 23)
+#define HCR_TSW		(1 << 22)
+#define HCR_TAC		(1 << 21)
+#define HCR_TIDCP	(1 << 20)
+#define HCR_TSC		(1 << 19)
+#define HCR_TID3	(1 << 18)
+#define HCR_TID2	(1 << 17)
+#define HCR_TID1	(1 << 16)
+#define HCR_TID0	(1 << 15)
+#define HCR_TWE		(1 << 14)
+#define HCR_TWI		(1 << 13)
+#define HCR_DC		(1 << 12)
+#define HCR_BSU		(3 << 10)
+#define HCR_FB		(1 << 9)
+#define HCR_VA		(1 << 8)
+#define HCR_VI		(1 << 7)
+#define HCR_VF		(1 << 6)
+#define HCR_AMO		(1 << 5)
+#define HCR_IMO		(1 << 4)
+#define HCR_FMO		(1 << 3)
+#define HCR_PTW		(1 << 2)
+#define HCR_SWIO	(1 << 1)
+#define HCR_VM		1
+#define HCR_GUEST_MASK (HCR_TSC | HCR_TWE | HCR_TWI | HCR_VM | HCR_AMO | \
+			HCR_AMO | HCR_IMO | HCR_FMO | HCR_SWIO)
+
+/* Hyp System Control Register (HSCTLR) bits */
+#define HSCTLR_TE	(1 << 30)
+#define HSCTLR_EE	(1 << 25)
+#define HSCTLR_FI	(1 << 21)
+#define HSCTLR_WXN	(1 << 19)
+#define HSCTLR_I	(1 << 12)
+#define HSCTLR_C	(1 << 2)
+#define HSCTLR_A	(1 << 1)
+#define HSCTLR_M	1
+#define HSCTLR_MASK	(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I | \
+			 HSCTLR_WXN | HSCTLR_FI | HSCTLR_EE | HSCTLR_TE)
+
+/* TTBCR and HTCR Registers bits */
+#define TTBCR_EAE	(1 << 31)
+#define TTBCR_IMP	(1 << 30)
+#define TTBCR_SH1	(3 << 28)
+#define TTBCR_ORGN1	(3 << 26)
+#define TTBCR_IRGN1	(3 << 24)
+#define TTBCR_EPD1	(1 << 23)
+#define TTBCR_A1	(1 << 22)
+#define TTBCR_T1SZ	(3 << 16)
+#define TTBCR_SH0	(3 << 12)
+#define TTBCR_ORGN0	(3 << 10)
+#define TTBCR_IRGN0	(3 << 8)
+#define TTBCR_EPD0	(1 << 7)
+#define TTBCR_T0SZ	3
+#define HTCR_MASK	(TTBCR_T0SZ | TTBCR_IRGN0 | TTBCR_ORGN0 | TTBCR_SH0)
+
+
+/* Virtualization Translation Control Register (VTCR) bits */
+#define VTCR_SH0	(3 << 12)
+#define VTCR_ORGN0	(3 << 10)
+#define VTCR_IRGN0	(3 << 8)
+#define VTCR_SL0	(3 << 6)
+#define VTCR_S		(1 << 4)
+#define VTCR_T0SZ	3
+#define VTCR_MASK	(VTCR_SH0 | VTCR_ORGN0 | VTCR_IRGN0 | VTCR_SL0 | \
+			 VTCR_S | VTCR_T0SZ | VTCR_MASK)
+#define VTCR_HTCR_SH	(VTCR_SH0 | VTCR_ORGN0 | VTCR_IRGN0)
+#define VTCR_SL_L2	0		/* Starting-level: 2 */
+#define VTCR_SL_L1	(1 << 6)	/* Starting-level: 1 */
+#define VTCR_GUEST_SL	VTCR_SL_L1
+#define VTCR_GUEST_T0SZ	0
+#if VTCR_GUEST_SL == 0
+#define VTTBR_X		(14 - VTCR_GUEST_T0SZ)
+#else
+#define VTTBR_X		(5 - VTCR_GUEST_T0SZ)
+#endif
+
+
+#endif /* __KVM_ARM_H__ */
diff --git a/arch/arm/include/asm/kvm_asm.h b/arch/arm/include/asm/kvm_asm.h
index c3d4458..008702c 100644
--- a/arch/arm/include/asm/kvm_asm.h
+++ b/arch/arm/include/asm/kvm_asm.h
@@ -24,5 +24,28 @@
 #define ARM_EXCEPTION_DATA_ABORT  4
 #define ARM_EXCEPTION_IRQ	  5
 #define ARM_EXCEPTION_FIQ	  6
+#define ARM_EXCEPTION_HVC	  7
+
+/*
+ * SMC Hypervisor API call number
+ */
+#define SMCHYP_HVBAR_W 0xfffffff0
+
+#ifndef __ASSEMBLY__
+struct kvm_vcpu;
+
+extern char __kvm_hyp_init[];
+extern char __kvm_hyp_init_end[];
+
+extern char __kvm_hyp_vector[];
+extern char __kvm_hyp_vector_end[];
+
+extern char __kvm_hyp_code_start[];
+extern char __kvm_hyp_code_end[];
+
+extern void __kvm_flush_vm_context(void);
+
+extern int __kvm_vcpu_run(struct kvm_vcpu *vcpu);
+#endif
 
 #endif /* __ARM_KVM_ASM_H__ */
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
new file mode 100644
index 0000000..db55bb6
--- /dev/null
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -0,0 +1,36 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ */
+
+#ifndef __ARM_KVM_MMU_H__
+#define __ARM_KVM_MMU_H__
+
+/*
+ * The architecture supports 40-bit IPA as input to the 2nd stage translations
+ * and PTRS_PER_PGD2 could therefore be 1024.
+ *
+ * To save a bit of memory and to avoid alignment issues we assume 39-bit IPA
+ * for now, but remember that the level-1 table must be aligned to its size.
+ */
+#define PTRS_PER_PGD2	512
+#define PGD2_ORDER	get_order(PTRS_PER_PGD2 * sizeof(pgd_t))
+
+extern pgd_t *kvm_hyp_pgd;
+extern struct mutex kvm_hyp_pgd_mutex;
+
+int create_hyp_mappings(pgd_t *hyp_pgd, void *from, void *to);
+void free_hyp_pmds(pgd_t *hyp_pgd);
+
+#endif /* __ARM_KVM_MMU_H__ */
diff --git a/arch/arm/include/asm/pgtable-3level-hwdef.h b/arch/arm/include/asm/pgtable-3level-hwdef.h
index a2d404e..18f5cef 100644
--- a/arch/arm/include/asm/pgtable-3level-hwdef.h
+++ b/arch/arm/include/asm/pgtable-3level-hwdef.h
@@ -32,6 +32,9 @@
 #define PMD_TYPE_SECT		(_AT(pmdval_t, 1) << 0)
 #define PMD_BIT4		(_AT(pmdval_t, 0))
 #define PMD_DOMAIN(x)		(_AT(pmdval_t, 0))
+#define PMD_APTABLE_SHIFT	(61)
+#define PMD_APTABLE		(_AT(pgdval_t, 3) << PGD_APTABLE_SHIFT)
+#define PMD_PXNTABLE		(_AT(pgdval_t, 1) << 59)
 
 /*
  *   - section
@@ -41,6 +44,7 @@
 #define PMD_SECT_S		(_AT(pmdval_t, 3) << 8)
 #define PMD_SECT_AF		(_AT(pmdval_t, 1) << 10)
 #define PMD_SECT_nG		(_AT(pmdval_t, 1) << 11)
+#define PMD_SECT_PXN		(_AT(pmdval_t, 1) << 53)
 #define PMD_SECT_XN		(_AT(pmdval_t, 1) << 54)
 #define PMD_SECT_AP_WRITE	(_AT(pmdval_t, 0))
 #define PMD_SECT_AP_READ	(_AT(pmdval_t, 0))
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index 759af70..edc3cb9 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -109,6 +109,10 @@
 #define pud_none(pud)		(!pud_val(pud))
 #define pud_bad(pud)		(!(pud_val(pud) & 2))
 #define pud_present(pud)	(pud_val(pud))
+#define pmd_table(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
+						 PMD_TYPE_TABLE)
+#define pmd_sect(pmd)		((pmd_val(pmd) & PMD_TYPE_MASK) == \
+						 PMD_TYPE_SECT)
 
 #define pud_clear(pudp)			\
 	do {				\
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index c7bd809..4b72287 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -82,6 +82,7 @@ extern pgprot_t		pgprot_kernel;
 #define PAGE_READONLY_EXEC	_MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
 #define PAGE_KERNEL		_MOD_PROT(pgprot_kernel, L_PTE_XN)
 #define PAGE_KERNEL_EXEC	pgprot_kernel
+#define PAGE_HYP		_MOD_PROT(pgprot_kernel, L_PTE_USER)
 
 #define __PAGE_NONE		__pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
 #define __PAGE_SHARED		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index cf11296..310f3bd 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -31,6 +31,12 @@
 #include <asm/uaccess.h>
 #include <asm/ptrace.h>
 #include <asm/mman.h>
+#include <asm/tlbflush.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
+#include <asm/kvm_mmu.h>
+
+static DEFINE_PER_CPU(void *, kvm_arm_hyp_stack_page);
 
 int kvm_arch_hardware_enable(void *garbage)
 {
@@ -232,13 +238,189 @@ long kvm_arch_vm_ioctl(struct file *filp,
 	return -EINVAL;
 }
 
+static void cpu_set_vector(void *vector)
+{
+	unsigned long vector_ptr;
+	unsigned long smc_hyp_nr;
+
+	vector_ptr = (unsigned long)vector;
+	smc_hyp_nr = SMCHYP_HVBAR_W;
+
+	/*
+	 * Set the HVBAR
+	 */
+	asm volatile (
+		"mov	r0, %[vector_ptr]\n\t"
+		"mov	r7, %[smc_hyp_nr]\n\t"
+		"smc	#0\n\t" : :
+		[vector_ptr] "r" (vector_ptr),
+		[smc_hyp_nr] "r" (smc_hyp_nr) :
+		"r0", "r1");
+}
+
+static void cpu_init_hyp_mode(void *vector)
+{
+	unsigned long pgd_ptr;
+	unsigned long hyp_stack_ptr;
+	void *stack_page;
+
+	cpu_set_vector(vector);
+
+	pgd_ptr = virt_to_phys(kvm_hyp_pgd);
+	stack_page = __get_cpu_var(kvm_arm_hyp_stack_page);
+	hyp_stack_ptr = (unsigned long)stack_page + PAGE_SIZE;
+
+	/*
+	 * Call initialization code
+	 */
+	asm volatile (
+		"mov	r0, %[pgd_ptr]\n\t"
+		"mov	r1, %[hyp_stack_ptr]\n\t"
+		"hvc	#0\n\t" : :
+		[pgd_ptr] "r" (pgd_ptr),
+		[hyp_stack_ptr] "r" (hyp_stack_ptr) :
+		"r0", "r1");
+}
+
+/**
+ * Inits Hyp-mode on all online CPUs
+ */
+static int init_hyp_mode(void)
+{
+	phys_addr_t init_phys_addr, init_end_phys_addr;
+	int cpu;
+	int err = 0;
+
+	/*
+	 * Allocate Hyp level-1 page table
+	 */
+	kvm_hyp_pgd = kzalloc(PTRS_PER_PGD * sizeof(pgd_t), GFP_KERNEL);
+	if (!kvm_hyp_pgd)
+		return -ENOMEM;
+
+	/*
+	 * Allocate stack pages for Hypervisor-mode
+	 */
+	for_each_possible_cpu(cpu)
+		per_cpu(kvm_arm_hyp_stack_page, cpu) = NULL;
+	for_each_possible_cpu(cpu) {
+		void *stack_page;
+
+		stack_page = (void *)__get_free_page(GFP_KERNEL);
+		if (!stack_page) {
+			err = -ENOMEM;
+			goto out_free_stack_pages;
+		}
+
+		per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
+	}
+
+	init_phys_addr = virt_to_phys(__kvm_hyp_init);
+	init_end_phys_addr = virt_to_phys(__kvm_hyp_init_end);
+	BUG_ON(init_phys_addr & 0x1f);
+
+	/*
+	 * Create identity mapping for the init code.
+	 */
+	hyp_idmap_add(kvm_hyp_pgd, (unsigned long)init_phys_addr,
+				   (unsigned long)init_end_phys_addr);
+
+	/*
+	 * Execute the init code on each CPU.
+	 *
+	 * Note: The stack is not mapped yet, so don't do anything else than
+	 * initializing the hypervisor mode on each CPU using a local stack
+	 * space for temporary storage.
+	 */
+	for_each_online_cpu(cpu) {
+		smp_call_function_single(cpu, cpu_init_hyp_mode,
+					 (void *)(long)init_phys_addr, 1);
+	}
+
+	/*
+	 * Unmap the identity mapping
+	 */
+	hyp_idmap_del(kvm_hyp_pgd, (unsigned long)init_phys_addr,
+				   (unsigned long)init_end_phys_addr);
+
+	/*
+	 * Map Hyp exception vectors
+	 */
+	err = create_hyp_mappings(kvm_hyp_pgd,
+				  __kvm_hyp_vector, __kvm_hyp_vector_end);
+	if (err) {
+		kvm_err("Cannot map hyp vector\n");
+		goto out_free_mappings;
+	}
+
+	/*
+	 * Map the Hyp-code called directly from the host
+	 */
+	if (__kvm_hyp_code_end - __kvm_hyp_code_start > PAGE_SIZE) {
+		kvm_err("Cannot initialize module, Hyp-code spans two pages\n");
+		return -EFAULT;
+	}
+
+	err = create_hyp_mappings(kvm_hyp_pgd,
+				  __kvm_hyp_code_start, __kvm_hyp_code_end);
+	if (err) {
+		kvm_err("Cannot map world-switch code\n");
+		goto out_free_mappings;
+	}
+
+	/*
+	 * Map the Hyp stack pages
+	 */
+	for_each_possible_cpu(cpu) {
+		char *stack_page = per_cpu(kvm_arm_hyp_stack_page, cpu);
+		err = create_hyp_mappings(kvm_hyp_pgd,
+					  stack_page, stack_page + PAGE_SIZE);
+
+		if (err) {
+			kvm_err("Cannot map hyp stack\n");
+			goto out_free_mappings;
+		}
+	}
+
+	/*
+	 * Set the HVBAR to the virtual kernel address
+	 */
+	for_each_online_cpu(cpu)
+		smp_call_function_single(cpu, cpu_set_vector,
+					 __kvm_hyp_vector, 1);
+
+	return 0;
+out_free_mappings:
+	free_hyp_pmds(kvm_hyp_pgd);
+out_free_stack_pages:
+	for_each_possible_cpu(cpu)
+		free_page((unsigned long)per_cpu(kvm_arm_hyp_stack_page, cpu));
+	kfree(kvm_hyp_pgd);
+	kvm_hyp_pgd = NULL;
+	return err;
+}
+
+/**
+ * Initialize Hyp-mode and memory mappings on all CPUs.
+ */
 int kvm_arch_init(void *opaque)
 {
+	int err;
+
+	err = init_hyp_mode();
+	if (err)
+		goto out_err;
+
 	return 0;
+out_err:
+	return err;
 }
 
 void kvm_arch_exit(void)
 {
+	free_hyp_pmds(kvm_hyp_pgd);
+	kfree(kvm_hyp_pgd);
+	kvm_hyp_pgd = NULL;
 }
 
 static int arm_init(void)
diff --git a/arch/arm/kvm/exports.c b/arch/arm/kvm/exports.c
index d8a7fd5..e3d7c68 100644
--- a/arch/arm/kvm/exports.c
+++ b/arch/arm/kvm/exports.c
@@ -14,3 +14,19 @@
  */
 
 #include <linux/module.h>
+#include <asm/kvm_asm.h>
+
+EXPORT_SYMBOL_GPL(__kvm_hyp_init);
+EXPORT_SYMBOL_GPL(__kvm_hyp_init_end);
+
+EXPORT_SYMBOL_GPL(__kvm_hyp_vector);
+EXPORT_SYMBOL_GPL(__kvm_hyp_vector_end);
+
+EXPORT_SYMBOL_GPL(__kvm_hyp_code_start);
+EXPORT_SYMBOL_GPL(__kvm_hyp_code_end);
+
+EXPORT_SYMBOL_GPL(__kvm_vcpu_run);
+
+EXPORT_SYMBOL_GPL(__kvm_flush_vm_context);
+
+EXPORT_SYMBOL_GPL(smp_send_reschedule);
diff --git a/arch/arm/kvm/init.S b/arch/arm/kvm/init.S
index 073a494..0bcc739 100644
--- a/arch/arm/kvm/init.S
+++ b/arch/arm/kvm/init.S
@@ -13,5 +13,103 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
+
+#include <linux/linkage.h>
+#include <asm/unified.h>
 #include <asm/asm-offsets.h>
 #include <asm/kvm_asm.h>
+#include <asm/kvm_arm.h>
+
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@  Hypervisor initialization
+@    - should be called with:
+@        r0 = Hypervisor pgd pointer
+@        r1 = top of Hyp stack (kernel VA)
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+	.text
+	.arm
+	.align 12
+__kvm_hyp_init:
+	.globl __kvm_hyp_init
+
+	@ Hyp-mode exception vector
+	nop
+	nop
+	nop
+	nop
+	nop
+	b	__do_hyp_init
+	nop
+	nop
+
+__do_hyp_init:
+	@ Set the sp to end of this page and push data for later use
+	mov	sp, pc
+	bic	sp, sp, #0x0ff
+	bic	sp, sp, #0xf00
+	add	sp, sp, #0x1000
+	push	{r0, r1, r2, r12}
+
+	@ Set the HTTBR to point to the hypervisor PGD pointer passed to
+	@ function and set the upper bits equal to the kernel PGD.
+	mrrc	p15, 1, r1, r2, c2
+	mcrr	p15, 4, r0, r2, c2
+
+	@ Set the HTCR and VTCR to the same shareability and cacheability
+	@ settings as the non-secure TTBCR and with T0SZ == 0.
+	mrc	p15, 4, r0, c2, c0, 2	@ HTCR
+	ldr	r12, =HTCR_MASK
+	bic	r0, r0, r12
+	mrc	p15, 0, r1, c2, c0, 2	@ TTBCR
+	and	r1, r1, #(HTCR_MASK & ~TTBCR_T0SZ)
+	orr	r0, r0, r1
+	mcr	p15, 4, r0, c2, c0, 2	@ HTCR
+
+	mrc	p15, 4, r1, c2, c1, 2	@ VTCR
+	bic	r1, r1, #(VTCR_HTCR_SH | VTCR_SL0)
+	bic	r0, r0, #(~VTCR_HTCR_SH)
+	orr	r1, r0, r1
+	orr	r1, r1, #(VTCR_SL_L1 | VTCR_GUEST_T0SZ)
+	mcr	p15, 4, r1, c2, c1, 2	@ VTCR
+
+	@ Use the same memory attributes for hyp. accesses as the kernel
+	@ (copy MAIRx ro HMAIRx).
+	mrc	p15, 0, r0, c10, c2, 0
+	mcr	p15, 4, r0, c10, c2, 0
+	mrc	p15, 0, r0, c10, c2, 1
+	mcr	p15, 4, r0, c10, c2, 1
+
+	@ Set the HSCTLR to:
+	@  - ARM/THUMB exceptions: ARM
+	@  - Endianness: Kernel config
+	@  - Fast Interrupt Features: Kernel config
+	@  - Write permission implies XN: disabled
+	@  - Instruction cache: enabled
+	@  - Data/Unified cache: enabled
+	@  - Memory alignment checks: enabled
+	@  - MMU: enabled (this code must be run from an identity mapping)
+	mrc	p15, 4, r0, c1, c0, 0	@ HSCR
+	ldr	r12, =HSCTLR_MASK
+	bic	r0, r0, r12
+	mrc	p15, 0, r1, c1, c0, 0	@ SCTLR
+	ldr	r12, =(HSCTLR_EE | HSCTLR_FI)
+	and	r1, r1, r12
+	ldr	r12, =(HSCTLR_M | HSCTLR_A | HSCTLR_I)
+	orr	r1, r1, r12
+	orr	r0, r0, r1
+	isb
+	mcr	p15, 4, r0, c1, c0, 0	@ HSCR
+	isb
+
+	@ Set stack pointer and return to the kernel
+	pop	{r0, r1, r2, r12}
+	mov	sp, r1
+	eret
+
+	.ltorg
+
+	.align 12
+
+	__kvm_init_sp:
+	.globl __kvm_hyp_init_end
+__kvm_hyp_init_end:
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index 073a494..50dfc40 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -13,5 +13,46 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
+
+#include <linux/linkage.h>
+#include <asm/unified.h>
+#include <asm/page.h>
 #include <asm/asm-offsets.h>
 #include <asm/kvm_asm.h>
+#include <asm/kvm_arm.h>
+
+	.text
+	.arm
+	.align 12
+
+__kvm_hyp_code_start:
+	.globl __kvm_hyp_code_start
+
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@ Flush TLBs and instruction caches of current CPU for all VMIDs
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+
+ENTRY(__kvm_flush_vm_context)
+	mov	pc, lr
+
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@  Hypervisor world-switch code
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+
+ENTRY(__kvm_vcpu_run)
+THUMB(	orr	lr, lr, #1)
+	mov	pc, lr
+
+__kvm_hyp_code_end:
+	.globl __kvm_hyp_code_end
+
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+@  Hypervisor exception vector and handlers
+@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
+
+	.align 5
+__kvm_hyp_vector:
+	.globl __kvm_hyp_vector
+	nop
+__kvm_hyp_vector_end:
+	.globl __kvm_hyp_vector_end
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 2cccd48..a6dc28f 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -13,3 +13,156 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  *
  */
+
+#include <linux/mman.h>
+#include <linux/kvm_host.h>
+#include <asm/pgalloc.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_mmu.h>
+
+pgd_t *kvm_hyp_pgd;
+DEFINE_MUTEX(kvm_hyp_pgd_mutex);
+
+static void free_ptes(pmd_t *pmd, unsigned long addr)
+{
+	pte_t *pte;
+	unsigned int i;
+
+	for (i = 0; i < PTRS_PER_PMD; i++, addr += PMD_SIZE) {
+		if (!pmd_none(*pmd) && pmd_table(*pmd)) {
+			pte = pte_offset_kernel(pmd, addr);
+			pte_free_kernel(NULL, pte);
+		}
+		pmd++;
+	}
+}
+
+/**
+ * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables
+ * @hypd_pgd:	The Hyp-mode page table pointer
+ *
+ * Assumes this is a page table used strictly in Hyp-mode and therefore contains
+ * only mappings in the kernel memory area, which is above PAGE_OFFSET.
+ */
+void free_hyp_pmds(pgd_t *hyp_pgd)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	unsigned long addr;
+
+	mutex_lock(&kvm_hyp_pgd_mutex);
+	for (addr = PAGE_OFFSET; addr != 0; addr += PGDIR_SIZE) {
+		pgd = hyp_pgd + pgd_index(addr);
+		pud = pud_offset(pgd, addr);
+
+		BUG_ON(pud_bad(*pud));
+
+		if (pud_none(*pud))
+			continue;
+
+		pmd = pmd_offset(pud, addr);
+		free_ptes(pmd, addr);
+		pmd_free(NULL, pmd);
+	}
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+}
+
+static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
+						unsigned long end)
+{
+	pte_t *pte;
+	struct page *page;
+	unsigned long addr;
+
+	for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
+		pte = pte_offset_kernel(pmd, addr);
+		BUG_ON(!virt_addr_valid(addr));
+		page = virt_to_page(addr);
+
+		set_pte_ext(pte, mk_pte(page, PAGE_HYP), 0);
+	}
+}
+
+static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
+					       unsigned long end)
+{
+	pmd_t *pmd;
+	pte_t *pte;
+	unsigned long addr, next;
+
+	for (addr = start; addr < end; addr = next) {
+		pmd = pmd_offset(pud, addr);
+
+		BUG_ON(pmd_sect(*pmd));
+
+		if (pmd_none(*pmd)) {
+			pte = pte_alloc_one_kernel(NULL, addr);
+			if (!pte) {
+				kvm_err("Cannot allocate Hyp pte\n");
+				return -ENOMEM;
+			}
+			pmd_populate_kernel(NULL, pmd, pte);
+		}
+
+		next = pmd_addr_end(addr, end);
+		create_hyp_pte_mappings(pmd, addr, next);
+	}
+
+	return 0;
+}
+
+/**
+ * create_hyp_mappings - map a kernel virtual address range in Hyp mode
+ * @hyp_pgd:	The allocated hypervisor level-1 table
+ * @from:	The virtual kernel start address of the range
+ * @to:		The virtual kernel end address of the range (exclusive)
+ *
+ * The same virtual address as the kernel virtual address is also used in
+ * Hyp-mode mapping to the same underlying physical pages.
+ *
+ * Note: Wrapping around zero in the "to" address is not supported.
+ */
+int create_hyp_mappings(pgd_t *hyp_pgd, void *from, void *to)
+{
+	unsigned long start = (unsigned long)from;
+	unsigned long end = (unsigned long)to;
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	unsigned long addr, next;
+	int err = 0;
+
+	BUG_ON(start > end);
+	if (start < PAGE_OFFSET)
+		return -EINVAL;
+
+	mutex_lock(&kvm_hyp_pgd_mutex);
+	for (addr = start; addr < end; addr = next) {
+		pgd = hyp_pgd + pgd_index(addr);
+		pud = pud_offset(pgd, addr);
+
+		if (pud_none_or_clear_bad(pud)) {
+			pmd = pmd_alloc_one(NULL, addr);
+			if (!pmd) {
+				kvm_err("Cannot allocate Hyp pmd\n");
+				err = -ENOMEM;
+				goto out;
+			}
+			pud_populate(NULL, pud, pmd);
+		}
+
+		next = pgd_addr_end(addr, end);
+		err = create_hyp_pmd_mappings(pud, addr, next);
+		if (err)
+			goto out;
+	}
+out:
+	mutex_unlock(&kvm_hyp_pgd_mutex);
+	return err;
+}
+
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
diff --git a/mm/memory.c b/mm/memory.c
index 5e30583..0733244 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -402,12 +402,14 @@ void pgd_clear_bad(pgd_t *pgd)
 	pgd_ERROR(*pgd);
 	pgd_clear(pgd);
 }
+EXPORT_SYMBOL_GPL(pgd_clear_bad);
 
 void pud_clear_bad(pud_t *pud)
 {
 	pud_ERROR(*pud);
 	pud_clear(pud);
 }
+EXPORT_SYMBOL_GPL(pud_clear_bad);
 
 void pmd_clear_bad(pmd_t *pmd)
 {


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 05/12] ARM: KVM: Memory virtualization setup
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (3 preceding siblings ...)
  2012-02-23  7:32 ` [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 06/12] ARM: KVM: Inject IRQs and FIQs from userspace Christoffer Dall
                   ` (6 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

This commit introduces the framework for guest memory management
through the use of 2nd stage translation. Each VM has a pointer
to a level-1 table (the pgd field in struct kvm_arch) which is
used for the 2nd stage translations. Entries are added when handling
guest faults (later patch) and the table itself can be allocated and
freed through the following functions implemented in
arch/arm/kvm/arm_mmu.c:
 - kvm_alloc_stage2_pgd(struct kvm *kvm);
 - kvm_free_stage2_pgd(struct kvm *kvm);

Further, each entry in TLBs and caches are tagged with a VMID
identifier in addition to ASIDs. The VMIDs are assigned consecutively
to VMs in the order that VMs are executed, and caches and tlbs are
invalidated when the VMID space has been used to allow for more than
255 simultaenously running guests.

The 2nd stage pgd is allocated in kvm_arch_init_vm(). The table is
freed in kvm_arch_destroy_vm(). Both functions are called from the main
KVM code.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_mmu.h |    5 ++
 arch/arm/kvm/arm.c             |   51 +++++++++++++++++++-
 arch/arm/kvm/mmu.c             |  103 ++++++++++++++++++++++++++++++++++++++++
 3 files changed, 158 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index db55bb6..b142043 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -33,4 +33,9 @@ extern struct mutex kvm_hyp_pgd_mutex;
 int create_hyp_mappings(pgd_t *hyp_pgd, void *from, void *to);
 void free_hyp_pmds(pgd_t *hyp_pgd);
 
+int kvm_alloc_stage2_pgd(struct kvm *kvm);
+void kvm_free_stage2_pgd(struct kvm *kvm);
+
+int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
+
 #endif /* __ARM_KVM_MMU_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 310f3bd..30b9fde 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -38,6 +38,13 @@
 
 static DEFINE_PER_CPU(void *, kvm_arm_hyp_stack_page);
 
+/* The VMID used in the VTTBR */
+#define VMID_BITS               8
+#define VMID_MASK               ((1 << VMID_BITS) - 1)
+#define VMID_FIRST_GENERATION	(1 << VMID_BITS)
+static u64 next_vmid;		/* The next available VMID in the sequence */
+DEFINE_SPINLOCK(kvm_vmid_lock);
+
 int kvm_arch_hardware_enable(void *garbage)
 {
 	return 0;
@@ -65,15 +72,43 @@ void kvm_arch_sync_events(struct kvm *kvm)
 {
 }
 
+/**
+ * kvm_arch_init_vm - initializes a VM data structure
+ * @kvm:	pointer to the KVM struct
+ */
 int kvm_arch_init_vm(struct kvm *kvm)
 {
-	return 0;
+	int ret = 0;
+
+	ret = kvm_alloc_stage2_pgd(kvm);
+	if (ret)
+		goto out_fail_alloc;
+	mutex_init(&kvm->arch.pgd_mutex);
+
+	ret = create_hyp_mappings(kvm_hyp_pgd, kvm, kvm + 1);
+	if (ret)
+		goto out_free_stage2_pgd;
+
+	/* Mark the initial VMID invalid */
+	kvm->arch.vmid = 0;
+
+	return ret;
+out_free_stage2_pgd:
+	kvm_free_stage2_pgd(kvm);
+out_fail_alloc:
+	return ret;
 }
 
+/**
+ * kvm_arch_destroy_vm - destroy the VM data structure
+ * @kvm:	pointer to the KVM struct
+ */
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	int i;
 
+	kvm_free_stage2_pgd(kvm);
+
 	for (i = 0; i < KVM_MAX_VCPUS; ++i) {
 		if (kvm->vcpus[i]) {
 			kvm_arch_vcpu_free(kvm->vcpus[i]);
@@ -149,6 +184,10 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id)
 	if (err)
 		goto free_vcpu;
 
+	err = create_hyp_mappings(kvm_hyp_pgd, vcpu, vcpu + 1);
+	if (err)
+		goto free_vcpu;
+
 	return vcpu;
 free_vcpu:
 	kmem_cache_free(kvm_vcpu_cache, vcpu);
@@ -158,6 +197,7 @@ out:
 
 void kvm_arch_vcpu_free(struct kvm_vcpu *vcpu)
 {
+	kmem_cache_free(kvm_vcpu_cache, vcpu);
 }
 
 void kvm_arch_vcpu_destroy(struct kvm_vcpu *vcpu)
@@ -411,6 +451,15 @@ int kvm_arch_init(void *opaque)
 	if (err)
 		goto out_err;
 
+	/*
+	 * The upper 56 bits of VMIDs are used to identify the generation
+	 * counter, so VMIDs initialized to 0, having generation == 0, will
+	 * never be considered valid and therefor a new VMID must always be
+	 * assigned. Whent he VMID generation rolls over, we start from
+	 * VMID_FIRST_GENERATION again.
+	 */
+	next_vmid = VMID_FIRST_GENERATION;
+
 	return 0;
 out_err:
 	return err;
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index a6dc28f..94411a6 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -162,6 +162,109 @@ out:
 	return err;
 }
 
+/**
+ * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
+ * @kvm:	The KVM struct pointer for the VM.
+ *
+ * Allocates the 1st level table only of size defined by PGD2_ORDER (can
+ * support either full 40-bit input addresses or limited to 32-bit input
+ * addresses). Clears the allocated pages.
+ */
+int kvm_alloc_stage2_pgd(struct kvm *kvm)
+{
+	pgd_t *pgd;
+
+	if (kvm->arch.pgd != NULL) {
+		kvm_err("kvm_arch already initialized?\n");
+		return -EINVAL;
+	}
+
+	pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, PGD2_ORDER);
+	if (!pgd)
+		return -ENOMEM;
+
+	memset(pgd, 0, PTRS_PER_PGD2 * sizeof(pgd_t));
+	kvm->arch.pgd = pgd;
+
+	return 0;
+}
+
+static void free_guest_pages(pte_t *pte, unsigned long addr)
+{
+	unsigned int i;
+	struct page *page;
+
+	for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
+		if (!pte_present(*pte))
+			goto next_page;
+		page = pfn_to_page(pte_pfn(*pte));
+		put_page(page);
+next_page:
+		pte++;
+	}
+}
+
+static void free_stage2_ptes(pmd_t *pmd, unsigned long addr)
+{
+	unsigned int i;
+	pte_t *pte;
+	struct page *page;
+
+	for (i = 0; i < PTRS_PER_PMD; i++, addr += PMD_SIZE) {
+		BUG_ON(pmd_sect(*pmd));
+		if (!pmd_none(*pmd) && pmd_table(*pmd)) {
+			pte = pte_offset_kernel(pmd, addr);
+			free_guest_pages(pte, addr);
+			page = virt_to_page((void *)pte);
+			WARN_ON(atomic_read(&page->_count) != 1);
+			pte_free_kernel(NULL, pte);
+		}
+		pmd++;
+	}
+}
+
+/**
+ * kvm_free_stage2_pgd - free all stage-2 tables
+ * @kvm:	The KVM struct pointer for the VM.
+ *
+ * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
+ * underlying level-2 and level-3 tables before freeing the actual level-1 table
+ * and setting the struct pointer to NULL.
+ */
+void kvm_free_stage2_pgd(struct kvm *kvm)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	unsigned long long i, addr;
+
+	if (kvm->arch.pgd == NULL)
+		return;
+
+	/*
+	 * We do this slightly different than other places, since we need more
+	 * than 32 bits and for instance pgd_addr_end converts to unsigned long.
+	 */
+	addr = 0;
+	for (i = 0; i < PTRS_PER_PGD2; i++) {
+		addr = i * (unsigned long long)PGDIR_SIZE;
+		pgd = kvm->arch.pgd + i;
+		pud = pud_offset(pgd, addr);
+
+		if (pud_none(*pud))
+			continue;
+
+		BUG_ON(pud_bad(*pud));
+
+		pmd = pmd_offset(pud, addr);
+		free_stage2_ptes(pmd, addr);
+		pmd_free(NULL, pmd);
+	}
+
+	free_pages((unsigned long)kvm->arch.pgd, PGD2_ORDER);
+	kvm->arch.pgd = NULL;
+}
+
 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	return -EINVAL;


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 06/12] ARM: KVM: Inject IRQs and FIQs from userspace
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (4 preceding siblings ...)
  2012-02-23  7:32 ` [PATCH v6 05/12] ARM: KVM: Memory virtualization setup Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-23  7:32 ` [PATCH v6 07/12] ARM: KVM: World-switch implementation Christoffer Dall
                   ` (5 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

Userspace can inject IRQs and FIQs through the KVM_IRQ_LINE VM ioctl.
This ioctl is used since the sematics are in fact two lines that can be
either raised or lowered on the VCPU - the IRQ and FIQ lines.

KVM needs to know which VCPU it must operate on and whether the FIQ or
IRQ line is raised/lowered. Hence both pieces of information is packed
in the kvm_irq_level->irq field. The irq fild value will be:
  IRQ: vcpu_index << 1
  FIQ: (vcpu_index << 1) | 1

This is documented in Documentation/kvm/api.txt.

The effect of the ioctl is simply to simply raise/lower the
corresponding irq_line field on the VCPU struct, which will cause the
world-switch code to raise/lower virtual interrupts when running the
guest on next switch. The wait_for_interrupt flag is also cleared for
raised IRQs or FIQs causing an idle VCPU to become active again. CPUs
in guest mode are kicked to make sure they refresh their interrupt status.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 Documentation/virtual/kvm/api.txt |   12 +++++--
 arch/arm/include/asm/kvm.h        |    9 +++++
 arch/arm/include/asm/kvm_arm.h    |    1 +
 arch/arm/kvm/arm.c                |   62 ++++++++++++++++++++++++++++++++++++-
 include/linux/kvm.h               |    1 +
 5 files changed, 80 insertions(+), 5 deletions(-)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index e1d94bf..a53da06 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -572,15 +572,19 @@ only go to the IOAPIC.  On ia64, a IOSAPIC is created.
 4.25 KVM_IRQ_LINE
 
 Capability: KVM_CAP_IRQCHIP
-Architectures: x86, ia64
+Architectures: x86, ia64, arm
 Type: vm ioctl
 Parameters: struct kvm_irq_level
 Returns: 0 on success, -1 on error
 
 Sets the level of a GSI input to the interrupt controller model in the kernel.
-Requires that an interrupt controller model has been previously created with
-KVM_CREATE_IRQCHIP.  Note that edge-triggered interrupts require the level
-to be set to 1 and then back to 0.
+On some architectures it is required that an interrupt controller model has
+been previously created with KVM_CREATE_IRQCHIP.  Note that edge-triggered
+interrupts require the level to be set to 1 and then back to 0.
+
+ARM uses two types of interrupt lines per CPU: IRQ and FIQ.  The value of the
+irq field should be (vcpu_index << 1) for IRQs and ((vcpu_index << 1) | 1) for
+FIQs. Level is used to raise/lower the line.
 
 struct kvm_irq_level {
 	union {
diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
index 544cb2a..791ba1d 100644
--- a/arch/arm/include/asm/kvm.h
+++ b/arch/arm/include/asm/kvm.h
@@ -20,6 +20,15 @@
 #include <asm/types.h>
 
 #define __KVM_HAVE_GUEST_DEBUG
+#define __KVM_HAVE_IRQ_LINE
+
+/*
+ * KVM_IRQ_LINE macros to set/read IRQ/FIQ for specific VCPU index.
+ */
+enum KVM_ARM_IRQ_LINE_TYPE {
+	KVM_ARM_IRQ_LINE = 0,
+	KVM_ARM_FIQ_LINE = 1,
+};
 
 /*
  * Modes used for short-hand mode determinition in the world-switch code and
diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index 835abd1..e378a37 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -49,6 +49,7 @@
 #define HCR_VM		1
 #define HCR_GUEST_MASK (HCR_TSC | HCR_TWE | HCR_TWI | HCR_VM | HCR_AMO | \
 			HCR_AMO | HCR_IMO | HCR_FMO | HCR_SWIO)
+#define HCR_VIRT_EXCP_MASK (HCR_VA | HCR_VI | HCR_VF)
 
 /* Hyp System Control Register (HSCTLR) bits */
 #define HSCTLR_TE	(1 << 30)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 30b9fde..16357e8 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -22,6 +22,7 @@
 #include <linux/fs.h>
 #include <linux/mman.h>
 #include <linux/sched.h>
+#include <linux/kvm.h>
 #include <trace/events/kvm.h>
 
 #define CREATE_TRACE_POINTS
@@ -221,6 +222,7 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 
 void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
 {
+	vcpu->cpu = cpu;
 }
 
 void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
@@ -261,6 +263,51 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	return -EINVAL;
 }
 
+static int kvm_arch_vm_ioctl_irq_line(struct kvm *kvm,
+				      struct kvm_irq_level *irq_level)
+{
+	int mask;
+	unsigned int vcpu_idx;
+	struct kvm_vcpu *vcpu;
+	unsigned long old, new, *ptr;
+
+	vcpu_idx = irq_level->irq >> 1;
+	if (vcpu_idx >= KVM_MAX_VCPUS)
+		return -EINVAL;
+
+	vcpu = kvm_get_vcpu(kvm, vcpu_idx);
+	if (!vcpu)
+		return -EINVAL;
+
+	if ((irq_level->irq & 1) == KVM_ARM_IRQ_LINE)
+		mask = HCR_VI;
+	else /* KVM_ARM_FIQ_LINE */
+		mask = HCR_VF;
+
+	trace_kvm_set_irq(irq_level->irq, irq_level->level, 0);
+
+	ptr = (unsigned long *)&vcpu->arch.irq_lines;
+	do {
+		old = ACCESS_ONCE(*ptr);
+		if (irq_level->level)
+			new = old | mask;
+		else
+			new = old & ~mask;
+
+		if (new == old)
+			return 0; /* no change */
+	} while (cmpxchg(ptr, old, new) != old);
+
+	/*
+	 * The vcpu irq_lines field was updated, wake up sleeping VCPUs and
+	 * trigger a world-switch round on the running physical CPU to set the
+	 * virtual IRQ/FIQ fields in the HCR appropriately.
+	 */
+	kvm_vcpu_kick(vcpu);
+
+	return 0;
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {
@@ -275,7 +322,20 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm, struct kvm_dirty_log *log)
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
-	return -EINVAL;
+	struct kvm *kvm = filp->private_data;
+	void __user *argp = (void __user *)arg;
+
+	switch (ioctl) {
+	case KVM_IRQ_LINE: {
+		struct kvm_irq_level irq_event;
+
+		if (copy_from_user(&irq_event, argp, sizeof irq_event))
+			return -EFAULT;
+		return kvm_arch_vm_ioctl_irq_line(kvm, &irq_event);
+	}
+	default:
+		return -EINVAL;
+	}
 }
 
 static void cpu_set_vector(void *vector)
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 68e67e5..bdbc6b8 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -111,6 +111,7 @@ struct kvm_irq_level {
 	 * ACPI gsi notion of irq.
 	 * For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47..
 	 * For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23..
+	 * For ARM: IRQ: irq = (2*vcpu_index). FIQ: irq = (2*vcpu_indx + 1).
 	 */
 	union {
 		__u32 irq;


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 07/12] ARM: KVM: World-switch implementation
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (5 preceding siblings ...)
  2012-02-23  7:32 ` [PATCH v6 06/12] ARM: KVM: Inject IRQs and FIQs from userspace Christoffer Dall
@ 2012-02-23  7:32 ` Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 08/12] ARM: KVM: Emulation framework and CP15 emulation Christoffer Dall
                   ` (4 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:32 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

Provides complete world-switch implementation to switch to other guests
running in non-secure modes. Includes Hyp exception handlers that
capture necessary exception information and stores the information on
the VCPU and KVM structures.

Switching to Hyp mode is done through a simple HVC instructions. The
exception vector code will check that the HVC comes from VMID==0 and if
so will store the necessary state on the Hyp stack, which will look like
this (see hyp_hvc):
  ...
  Hyp_Sp + 4: lr_usr
  Hyp_Sp    : spsr (Host-SVC cpsr)

When returning from Hyp mode to SVC mode, another HVC instruction is
executed from Hyp mode, which is taken in the Hyp_Svc handler. The Hyp
stack pointer should be where it was left from the above initial call,
since the values on the stack will be used to restore state (see
hyp_svc).

Otherwise, the world-switch is pretty straight-forward. All state that
can be modified by the guest is first backed up on the Hyp stack and the
VCPU values is loaded onto the hardware. State, which is not loaded, but
theoretically modifiable by the guest is protected through the
virtualiation features to generate a trap and cause software emulation.
Upon guest returns, all state is restored from hardware onto the VCPU
struct and the original state is restored from the Hyp-stack onto the
hardware.

One controversy may be the back-door call to __irq_svc (the host
kernel's own physical IRQ handler) which is called when a physical IRQ
exception is taken in Hyp mode while running in the guest.

SMP support using the VMPIDR calculated on the basis of the host MPIDR
and overriding the low bits with KVM vcpu_id contributed by Marc Zyngier.

Reuse of VMIDs has been implemented by Antonios Motakis and adapated from
a separate patch into the appropriate patches introducing the
functionality. Note that the VMIDs are stored per VM as required by the ARM
architecture reference manual.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_arm.h  |   26 ++
 arch/arm/include/asm/kvm_host.h |    1 
 arch/arm/kernel/armksyms.c      |    7 +
 arch/arm/kernel/asm-offsets.c   |   34 +++
 arch/arm/kernel/entry-armv.S    |    1 
 arch/arm/kvm/arm.c              |  136 +++++++++++
 arch/arm/kvm/interrupts.S       |  492 +++++++++++++++++++++++++++++++++++++++
 7 files changed, 693 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/kvm_arm.h b/arch/arm/include/asm/kvm_arm.h
index e378a37..1769187 100644
--- a/arch/arm/include/asm/kvm_arm.h
+++ b/arch/arm/include/asm/kvm_arm.h
@@ -100,5 +100,31 @@
 #define VTTBR_X		(5 - VTCR_GUEST_T0SZ)
 #endif
 
+/* Hyp Syndrome Register (HSR) bits */
+#define HSR_EC_SHIFT	(26)
+#define HSR_EC		(0x3fU << HSR_EC_SHIFT)
+#define HSR_IL		(1U << 25)
+#define HSR_ISS		(HSR_IL - 1)
+#define HSR_ISV_SHIFT	(24)
+#define HSR_ISV		(1U << HSR_ISV_SHIFT)
+
+#define HSR_EC_UNKNOWN	(0x00)
+#define HSR_EC_WFI	(0x01)
+#define HSR_EC_CP15_32	(0x03)
+#define HSR_EC_CP15_64	(0x04)
+#define HSR_EC_CP14_MR	(0x05)
+#define HSR_EC_CP14_LS	(0x06)
+#define HSR_EC_CP_0_13	(0x07)
+#define HSR_EC_CP10_ID	(0x08)
+#define HSR_EC_JAZELLE	(0x09)
+#define HSR_EC_BXJ	(0x0A)
+#define HSR_EC_CP14_64	(0x0C)
+#define HSR_EC_SVC_HYP	(0x11)
+#define HSR_EC_HVC	(0x12)
+#define HSR_EC_SMC	(0x13)
+#define HSR_EC_IABT	(0x20)
+#define HSR_EC_IABT_HYP	(0x21)
+#define HSR_EC_DABT	(0x24)
+#define HSR_EC_DABT_HYP	(0x25)
 
 #endif /* __KVM_ARM_H__ */
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 2d611df..72ba708 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -96,6 +96,7 @@ struct kvm_vcpu_arch {
 	u32 hdfar;		/* Hyp Data Fault Address Register */
 	u32 hifar;		/* Hyp Inst. Fault Address Register */
 	u32 hpfar;		/* Hyp IPA Fault Address Register */
+	u64 pc_ipa;		/* IPA for the current PC (VA to PA result) */
 
 	/* IO related fields */
 	u32 mmio_rd;
diff --git a/arch/arm/kernel/armksyms.c b/arch/arm/kernel/armksyms.c
index 5b0bce6..2a14b6e 100644
--- a/arch/arm/kernel/armksyms.c
+++ b/arch/arm/kernel/armksyms.c
@@ -49,6 +49,13 @@ extern void __aeabi_ulcmp(void);
 
 extern void fpundefinstr(void);
 
+#ifdef CONFIG_KVM_ARM_HOST
+/* This is needed for KVM */
+extern void __irq_svc(void);
+
+EXPORT_SYMBOL_GPL(__irq_svc);
+#endif
+
 	/* platform dependent support */
 EXPORT_SYMBOL(__udelay);
 EXPORT_SYMBOL(__const_udelay);
diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c
index 1429d89..c8c1b91 100644
--- a/arch/arm/kernel/asm-offsets.c
+++ b/arch/arm/kernel/asm-offsets.c
@@ -13,6 +13,7 @@
 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/dma-mapping.h>
+#include <linux/kvm_host.h>
 #include <asm/cacheflush.h>
 #include <asm/glue-df.h>
 #include <asm/glue-pf.h>
@@ -144,5 +145,38 @@ int main(void)
   DEFINE(DMA_BIDIRECTIONAL,	DMA_BIDIRECTIONAL);
   DEFINE(DMA_TO_DEVICE,		DMA_TO_DEVICE);
   DEFINE(DMA_FROM_DEVICE,	DMA_FROM_DEVICE);
+#ifdef CONFIG_KVM_ARM_HOST
+  DEFINE(VCPU_KVM,		offsetof(struct kvm_vcpu, kvm));
+  DEFINE(VCPU_MIDR,		offsetof(struct kvm_vcpu, arch.cp15[c0_MIDR]));
+  DEFINE(VCPU_MPIDR,		offsetof(struct kvm_vcpu, arch.cp15[c0_MPIDR]));
+  DEFINE(VCPU_SCTLR,		offsetof(struct kvm_vcpu, arch.cp15[c1_SCTLR]));
+  DEFINE(VCPU_CPACR,		offsetof(struct kvm_vcpu, arch.cp15[c1_CPACR]));
+  DEFINE(VCPU_TTBR0,		offsetof(struct kvm_vcpu, arch.cp15[c2_TTBR0]));
+  DEFINE(VCPU_TTBR1,		offsetof(struct kvm_vcpu, arch.cp15[c2_TTBR1]));
+  DEFINE(VCPU_TTBCR,		offsetof(struct kvm_vcpu, arch.cp15[c2_TTBCR]));
+  DEFINE(VCPU_DACR,		offsetof(struct kvm_vcpu, arch.cp15[c3_DACR]));
+  DEFINE(VCPU_PRRR,		offsetof(struct kvm_vcpu, arch.cp15[c10_PRRR]));
+  DEFINE(VCPU_NMRR,		offsetof(struct kvm_vcpu, arch.cp15[c10_NMRR]));
+  DEFINE(VCPU_CID,		offsetof(struct kvm_vcpu, arch.cp15[c13_CID]));
+  DEFINE(VCPU_TID_URW,		offsetof(struct kvm_vcpu, arch.cp15[c13_TID_URW]));
+  DEFINE(VCPU_TID_URO,		offsetof(struct kvm_vcpu, arch.cp15[c13_TID_URO]));
+  DEFINE(VCPU_TID_PRIV,		offsetof(struct kvm_vcpu, arch.cp15[c13_TID_PRIV]));
+  DEFINE(VCPU_REGS,		offsetof(struct kvm_vcpu, arch.regs));
+  DEFINE(VCPU_USR_REGS,		offsetof(struct kvm_vcpu, arch.regs.usr_regs));
+  DEFINE(VCPU_SVC_REGS,		offsetof(struct kvm_vcpu, arch.regs.svc_regs));
+  DEFINE(VCPU_ABT_REGS,		offsetof(struct kvm_vcpu, arch.regs.abt_regs));
+  DEFINE(VCPU_UND_REGS,		offsetof(struct kvm_vcpu, arch.regs.und_regs));
+  DEFINE(VCPU_IRQ_REGS,		offsetof(struct kvm_vcpu, arch.regs.irq_regs));
+  DEFINE(VCPU_FIQ_REGS,		offsetof(struct kvm_vcpu, arch.regs.fiq_regs));
+  DEFINE(VCPU_PC,		offsetof(struct kvm_vcpu, arch.regs.pc));
+  DEFINE(VCPU_CPSR,		offsetof(struct kvm_vcpu, arch.regs.cpsr));
+  DEFINE(VCPU_IRQ_LINES,	offsetof(struct kvm_vcpu, arch.irq_lines));
+  DEFINE(VCPU_HSR,		offsetof(struct kvm_vcpu, arch.hsr));
+  DEFINE(VCPU_HDFAR,		offsetof(struct kvm_vcpu, arch.hdfar));
+  DEFINE(VCPU_HIFAR,		offsetof(struct kvm_vcpu, arch.hifar));
+  DEFINE(VCPU_HPFAR,		offsetof(struct kvm_vcpu, arch.hpfar));
+  DEFINE(VCPU_PC_IPA,		offsetof(struct kvm_vcpu, arch.pc_ipa));
+  DEFINE(KVM_VTTBR,		offsetof(struct kvm, arch.vttbr));
+#endif
   return 0; 
 }
diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 3a456c6..aaa557b 100644
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -206,6 +206,7 @@ __dabt_svc:
 ENDPROC(__dabt_svc)
 
 	.align	5
+	.globl __irq_svc
 __irq_svc:
 	svc_entry
 	irq_handler
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 16357e8..4b86fef 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -33,6 +33,7 @@
 #include <asm/ptrace.h>
 #include <asm/mman.h>
 #include <asm/tlbflush.h>
+#include <asm/cputype.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
@@ -213,6 +214,24 @@ int kvm_cpu_has_pending_timer(struct kvm_vcpu *vcpu)
 
 int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
 {
+	unsigned long cpsr;
+	unsigned long sctlr;
+
+
+	/* Init execution CPSR */
+	asm volatile ("mrs	%[cpsr], cpsr" :
+			[cpsr] "=r" (cpsr));
+	vcpu->arch.regs.cpsr = SVC_MODE | PSR_I_BIT | PSR_F_BIT | PSR_A_BIT |
+				(cpsr & PSR_E_BIT);
+
+	/* Init SCTLR with MMU disabled */
+	asm volatile ("mrc	p15, 0, %[sctlr], c1, c0, 0" :
+			[sctlr] "=r" (sctlr));
+	vcpu->arch.cp15[c1_SCTLR] = sctlr & ~1U;
+
+	/* Compute guest MPIDR */
+	vcpu->arch.cp15[c0_MPIDR] = (read_cpuid_mpidr() & ~0xff)
+				    | vcpu->vcpu_id;
 	return 0;
 }
 
@@ -255,12 +274,125 @@ int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 
 int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *v)
 {
-	return 0;
+	return v->mode == IN_GUEST_MODE;
 }
 
+static void reset_vm_context(void *info)
+{
+	__kvm_flush_vm_context();
+}
+
+/**
+ * update_vttbr - Update the VTTBR with a valid VMID before the guest runs
+ * @kvm	The guest that we are about to run
+ *
+ * Called from kvm_arch_vcpu_ioctl_run before entering the guest to ensure the
+ * VM has a valid VMID, otherwise assigns a new one and flushes corresponding
+ * caches and TLBs.
+ */
+static void update_vttbr(struct kvm *kvm)
+{
+	phys_addr_t pgd_phys;
+
+	spin_lock(&kvm_vmid_lock);
+
+	/*
+	 *  Check that the VMID is still valid.
+	 *  (The hardware supports only 256 values with the value zero
+	 *   reserved for the host, so we check if an assigned value has rolled
+	 *   over a sequence, which requires us to assign a new value and flush
+	 *   necessary caches and TLBs on all CPUs.)
+	 */
+	if (unlikely((kvm->arch.vmid ^ next_vmid) >> VMID_BITS)) {
+		/* Check for a new VMID generation */
+		if (unlikely((next_vmid & VMID_MASK) == 0)) {
+			/* Check for the (very unlikely) 64-bit wrap around */
+			if (unlikely(next_vmid == 0))
+				next_vmid = VMID_FIRST_GENERATION;
+
+			next_vmid++;
+
+			/* This does nothing on UP */
+			smp_call_function(reset_vm_context, NULL, 1);
+
+			/*
+			 * On SMP we know no other CPUs can use this CPU's or
+			 * each other's VMID since the kvm_vmid_lock blocks
+			 * them from reentry to the guest.
+			 */
+
+			reset_vm_context(NULL);
+		}
+
+		kvm->arch.vmid = next_vmid++;
+
+		/* update vttbr to be used with the new vmid */
+		pgd_phys = virt_to_phys(kvm->arch.pgd);
+		kvm->arch.vttbr = pgd_phys & ((1LLU << 40) - 1)
+				  & ~((2 << VTTBR_X) - 1);
+		kvm->arch.vttbr |= kvm->arch.vmid << 48;
+	}
+
+	spin_unlock(&kvm_vmid_lock);
+}
+
+/**
+ * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
+ * @vcpu:	The VCPU pointer
+ * @run:	The kvm_run structure pointer used for userspace state exchange
+ *
+ * This function is called through the VCPU_RUN ioctl called from user space. It
+ * will execute VM code in a loop until the time slice for the process is used
+ * or some emulation is needed from user space in which case the function will
+ * return with return value 0 and with the kvm_run structure filled in with the
+ * required data for the requested emulation.
+ */
 int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	return -EINVAL;
+	int ret = 0;
+	sigset_t sigsaved;
+
+	if (vcpu->sigset_active)
+		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
+
+	run->exit_reason = KVM_EXIT_UNKNOWN;
+	while (run->exit_reason == KVM_EXIT_UNKNOWN) {
+		/*
+		 * Check conditions before entering the guest
+		 */
+		if (need_resched())
+			kvm_resched(vcpu);
+
+		if (signal_pending(current)) {
+			ret = -EINTR;
+			run->exit_reason = KVM_EXIT_INTR;
+			break;
+		}
+
+		/*
+		 * Enter the guest
+		 */
+		trace_kvm_entry(vcpu->arch.regs.pc);
+
+		update_vttbr(vcpu->kvm);
+
+		local_irq_disable();
+		kvm_guest_enter();
+		vcpu->mode = IN_GUEST_MODE;
+
+		ret = __kvm_vcpu_run(vcpu);
+
+		vcpu->mode = OUTSIDE_GUEST_MODE;
+		kvm_guest_exit();
+		local_irq_enable();
+
+		trace_kvm_exit(vcpu->arch.regs.pc);
+	}
+
+	if (vcpu->sigset_active)
+		sigprocmask(SIG_SETMASK, &sigsaved, NULL);
+
+	return ret;
 }
 
 static int kvm_arch_vm_ioctl_irq_line(struct kvm *kvm,
diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S
index 50dfc40..ee567d1 100644
--- a/arch/arm/kvm/interrupts.S
+++ b/arch/arm/kvm/interrupts.S
@@ -21,6 +21,11 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_arm.h>
 
+#define VCPU_USR_REG(_reg_nr)	(VCPU_USR_REGS + (_reg_nr * 4))
+#define VCPU_USR_SP		(VCPU_USR_REG(13))
+#define VCPU_FIQ_REG(_reg_nr)	(VCPU_FIQ_REGS + (_reg_nr * 4))
+#define VCPU_FIQ_SPSR		(VCPU_FIQ_REG(7))
+
 	.text
 	.arm
 	.align 12
@@ -33,16 +38,340 @@ __kvm_hyp_code_start:
 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 
 ENTRY(__kvm_flush_vm_context)
-	mov	pc, lr
+	hvc	#0			@ switch to hyp-mode
+
+	mov	r0, #0			@ rn parameter for c15 flushes is SBZ
+	mcr     p15, 4, r0, c8, c7, 4   @ Invalidate Non-secure Non-Hyp TLB
+	mcr     p15, 0, r0, c7, c5, 0   @ Invalidate instruction caches
+	dsb
+	isb
+
+	hvc	#0			@ switch back to svc-mode, see hyp_svc
+	bx lr
 
 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 @  Hypervisor world-switch code
 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 
+/* These are simply for the macros to work - value don't have meaning */
+.equ usr, 0
+.equ svc, 1
+.equ abt, 2
+.equ und, 3
+.equ irq, 4
+.equ fiq, 5
+
+.macro store_mode_state base_reg, mode
+	.if \mode == usr
+	mrs	r2, SP_usr
+	mov	r3, lr
+	stmdb	\base_reg!, {r2, r3}
+	.elseif \mode != fiq
+	mrs	r2, SP_\mode
+	mrs	r3, LR_\mode
+	mrs	r4, SPSR_\mode
+	stmdb	\base_reg!, {r2, r3, r4}
+	.else
+	mrs	r2, r8_fiq
+	mrs	r3, r9_fiq
+	mrs	r4, r10_fiq
+	mrs	r5, r11_fiq
+	mrs	r6, r12_fiq
+	mrs	r7, SP_fiq
+	mrs	r8, LR_fiq
+	mrs	r9, SPSR_fiq
+	stmdb	\base_reg!, {r2-r9}
+	.endif
+.endm
+
+.macro load_mode_state base_reg, mode
+	.if \mode == usr
+	ldmia	\base_reg!, {r2, r3}
+	msr	SP_usr, r2
+	mov	lr, r3
+	.elseif \mode != fiq
+	ldmia	\base_reg!, {r2, r3, r4}
+	msr	SP_\mode, r2
+	msr	LR_\mode, r3
+	msr	SPSR_\mode, r4
+	.else
+	ldmia	\base_reg!, {r2-r9}
+	msr	r8_fiq, r2
+	msr	r9_fiq, r3
+	msr	r10_fiq, r4
+	msr	r11_fiq, r5
+	msr	r12_fiq, r6
+	msr	SP_fiq, r7
+	msr	LR_fiq, r8
+	msr	SPSR_fiq, r9
+	.endif
+.endm
+
+/* Reads cp15 registers from hardware and stores them in memory
+ * @vcpu:   If 0, registers are written in-order to the stack,
+ * 	    otherwise to the VCPU struct pointed to by vcpup
+ * @vcpup:  Register pointing to VCPU struct
+ */
+.macro read_cp15_state vcpu=0, vcpup
+	mrc	p15, 0, r2, c1, c0, 0	@ SCTLR
+	mrc	p15, 0, r3, c1, c0, 2	@ CPACR
+	mrc	p15, 0, r4, c2, c0, 2	@ TTBCR
+	mrc	p15, 0, r5, c3, c0, 0	@ DACR
+	mrrc	p15, 0, r6, r7, c2	@ TTBR 0
+	mrrc	p15, 1, r8, r9, c2	@ TTBR 1
+	mrc	p15, 0, r10, c10, c2, 0	@ PRRR
+	mrc	p15, 0, r11, c10, c2, 1	@ NMRR
+
+	.if \vcpu == 0
+	push	{r2-r11}		@ Push CP15 registers
+	.else
+	str	r2, [\vcpup, #VCPU_SCTLR]
+	str	r3, [\vcpup, #VCPU_CPACR]
+	str	r4, [\vcpup, #VCPU_TTBCR]
+	str	r5, [\vcpup, #VCPU_DACR]
+	add	\vcpup, \vcpup, #VCPU_TTBR0
+	strd	r6, r7, [\vcpup]
+	add	\vcpup, \vcpup, #(VCPU_TTBR1 - VCPU_TTBR0)
+	strd	r8, r9, [\vcpup]
+	sub	\vcpup, \vcpup, #(VCPU_TTBR1)
+	str	r10, [\vcpup, #VCPU_PRRR]
+	str	r11, [\vcpup, #VCPU_NMRR]
+	.endif
+
+	mrc	p15, 0, r2, c13, c0, 1	@ CID
+	mrc	p15, 0, r3, c13, c0, 2	@ TID_URW
+	mrc	p15, 0, r4, c13, c0, 3	@ TID_URO
+	mrc	p15, 0, r5, c13, c0, 4	@ TID_PRIV
+	.if \vcpu == 0
+	push	{r2-r5}			@ Push CP15 registers
+	.else
+	str	r2, [\vcpup, #VCPU_CID]
+	str	r3, [\vcpup, #VCPU_TID_URW]
+	str	r4, [\vcpup, #VCPU_TID_URO]
+	str	r5, [\vcpup, #VCPU_TID_PRIV]
+	.endif
+.endm
+
+/* Reads cp15 registers from memory and writes them to hardware
+ * @vcpu:   If 0, registers are read in-order from the stack,
+ * 	    otherwise from the VCPU struct pointed to by vcpup
+ * @vcpup:  Register pointing to VCPU struct
+ */
+.macro write_cp15_state vcpu=0, vcpup
+	.if \vcpu == 0
+	pop	{r2-r5}
+	.else
+	ldr	r2, [\vcpup, #VCPU_CID]
+	ldr	r3, [\vcpup, #VCPU_TID_URW]
+	ldr	r4, [\vcpup, #VCPU_TID_URO]
+	ldr	r5, [\vcpup, #VCPU_TID_PRIV]
+	.endif
+
+	mcr	p15, 0, r2, c13, c0, 1	@ CID
+	mcr	p15, 0, r3, c13, c0, 2	@ TID_URW
+	mcr	p15, 0, r4, c13, c0, 3	@ TID_URO
+	mcr	p15, 0, r5, c13, c0, 4	@ TID_PRIV
+
+	.if \vcpu == 0
+	pop	{r2-r11}
+	.else
+	ldr	r2, [\vcpup, #VCPU_SCTLR]
+	ldr	r3, [\vcpup, #VCPU_CPACR]
+	ldr	r4, [\vcpup, #VCPU_TTBCR]
+	ldr	r5, [\vcpup, #VCPU_DACR]
+	add	\vcpup, \vcpup, #VCPU_TTBR0
+	ldrd	r6, r7, [\vcpup]
+	add	\vcpup, \vcpup, #(VCPU_TTBR1 - VCPU_TTBR0)
+	ldrd	r8, r9, [\vcpup]
+	sub	\vcpup, \vcpup, #(VCPU_TTBR1)
+	ldr	r10, [\vcpup, #VCPU_PRRR]
+	ldr	r11, [\vcpup, #VCPU_NMRR]
+	.endif
+
+	mcr	p15, 0, r2, c1, c0, 0	@ SCTLR
+	mcr	p15, 0, r3, c1, c0, 2	@ CPACR
+	mcr	p15, 0, r4, c2, c0, 2	@ TTBCR
+	mcr	p15, 0, r5, c3, c0, 0	@ DACR
+	mcrr	p15, 0, r6, r7, c2	@ TTBR 0
+	mcrr	p15, 1, r8, r9, c2	@ TTBR 1
+	mcr	p15, 0, r10, c10, c2, 0	@ PRRR
+	mcr	p15, 0, r11, c10, c2, 1	@ NMRR
+.endm
+
+/* Configures the HSTR (Hyp System Trap Register) on entry/return
+ * (hardware reset value is 0) */
+.macro set_hstr entry
+	mrc	p15, 4, r2, c1, c1, 3
+	ldr	r3, =0x9e00
+	.if \entry == 1
+	orr	r2, r2, r3		@ Trap CR{9,10,11,12,15}
+	.else
+	bic	r2, r2, r3		@ Don't trap any CRx accesses
+	.endif
+	mcr	p15, 4, r2, c1, c1, 3
+.endm
+
+/* Enable/Disable: stage-2 trans., trap interrupts, trap wfi/wfe, trap smc */
+.macro configure_hyp_role entry, vcpu_ptr
+	mrc	p15, 4, r2, c1, c1, 0	@ HCR
+	bic	r2, r2, #HCR_VIRT_EXCP_MASK
+	ldr	r3, =HCR_GUEST_MASK
+	.if \entry == 1
+	orr	r2, r2, r3
+	ldr	r3, [\vcpu_ptr, #VCPU_IRQ_LINES]
+	orr	r2, r2, r3
+	.else
+	bic	r2, r2, r3
+	.endif
+	mcr	p15, 4, r2, c1, c1, 0
+.endm
+
+@ Arguments:
+@  r0: pointer to vcpu struct
 ENTRY(__kvm_vcpu_run)
+	hvc	#0			@ switch to hyp-mode
+
+	@ Now we're in Hyp-mode and lr_usr, spsr_hyp are on the stack
+	mrs	r2, sp_usr
+	push	{r2}			@ Push r13_usr
+	push	{r4-r12}		@ Push r4-r12
+
+	store_mode_state sp, svc
+	store_mode_state sp, abt
+	store_mode_state sp, und
+	store_mode_state sp, irq
+	store_mode_state sp, fiq
+
+	@ Store hardware CP15 state and load guest state
+	read_cp15_state
+	write_cp15_state 1, r0
+
+	push	{r0}			@ Push the VCPU pointer
+
+	@ Set up guest memory translation
+	ldr	r1, [r0, #VCPU_KVM]	@ r1 points to kvm struct
+	ldrd	r2, r3, [r1, #KVM_VTTBR]
+	mcrr	p15, 6, r2, r3, c2	@ Write VTTBR
+
+	@ Configure Hyp-role
+	configure_hyp_role 1, r0
+
+	@ Trap coprocessor CRx for all x except 2 and 14
+	set_hstr 1
+
+	@ Write standard A-9 CPU id in MIDR
+	ldr	r1, [r0, #VCPU_MIDR]
+	mcr	p15, 4, r1, c0, c0, 0
+
+	@ Write guest view of MPIDR into VMPIDR
+	ldr	r1, [r0, #VCPU_MPIDR]
+	mcr	p15, 4, r1, c0, c0, 5
+
+	@ Load guest registers
+	add	r0, r0, #(VCPU_USR_SP)
+	load_mode_state r0, usr
+	load_mode_state r0, svc
+	load_mode_state r0, abt
+	load_mode_state r0, und
+	load_mode_state r0, irq
+	load_mode_state r0, fiq
+
+	@ Load return state (r0 now points to vcpu->arch.regs.pc)
+	ldmia	r0, {r2, r3}
+	msr	ELR_hyp, r2
+	msr	spsr, r3
+
+	@ Load remaining registers and do the switch
+	sub	r0, r0, #(VCPU_PC - VCPU_USR_REGS)
+	ldmia	r0, {r0-r12}
+	eret
+
+__kvm_vcpu_return:
+	@ Store return state
+	mrs	r2, ELR_hyp
+	mrs	r3, spsr
+	str	r2, [r1, #VCPU_PC]
+	str	r3, [r1, #VCPU_CPSR]
+
+	@ Store guest registers
+	add	r1, r1, #(VCPU_FIQ_SPSR + 4)
+	store_mode_state r1, fiq
+	store_mode_state r1, irq
+	store_mode_state r1, und
+	store_mode_state r1, abt
+	store_mode_state r1, svc
+	store_mode_state r1, usr
+	sub	r1, r1, #(VCPU_USR_REG(13))
+
+	@ Don't trap coprocessor accesses for host kernel
+	set_hstr 0
+
+	@ Reset Hyp-role
+	configure_hyp_role 0, r1
+
+	@ Let guest read hardware MIDR
+	mrc	p15, 0, r2, c0, c0, 0
+	mcr	p15, 4, r2, c0, c0, 0
+
+	@ Back to hardware MPIDR
+	mrc	p15, 0, r2, c0, c0, 5
+	mcr	p15, 4, r2, c0, c0, 5
+
+	@ Set VMID == 0
+	mov	r2, #0
+	mov	r3, #0
+	mcrr	p15, 6, r2, r3, c2	@ Write VTTBR
+
+	@ Store guest CP15 state and restore host state
+	read_cp15_state 1, r1
+	write_cp15_state
+
+	load_mode_state sp, fiq
+	load_mode_state sp, irq
+	load_mode_state sp, und
+	load_mode_state sp, abt
+	load_mode_state sp, svc
+
+	pop	{r4-r12}		@ Pop r4-r12
+	pop	{r2}			@ Pop r13_usr
+	msr	sp_usr, r2
+
+	hvc	#0			@ switch back to svc-mode, see hyp_svc
+
+	cmp	r0, #ARM_EXCEPTION_IRQ
+	bne	return_to_ioctl
+
+	/*
+	 * It's time to launch the kernel IRQ handler for IRQ exceptions. This
+	 * requires some manipulation though.
+	 *
+	 *  - The easiest entry point to the host handler is __irq_svc.
+	 *  - The __irq_svc expects to be called from SVC mode, which has been
+	 *    switched to from vector_stub code in entry-armv.S. The __irq_svc
+	 *    calls svc_entry which uses values stored in memory and pointed to
+	 *    by r0 to return from handler. We allocate this memory on the
+	 *    stack, which will contain these values:
+	 *      0x8:   cpsr
+	 *      0x4:   return_address
+	 *      0x0:   r0
+	 */
+	adr	r1, irq_kernel_resume	@ Where to resume
+	mrs	r2, cpsr		@ CPSR when we return
+	push	{r0 - r2}
+	mov	r0, sp
+	b	__irq_svc
+
+irq_kernel_resume:
+	pop	{r0}
+	add	sp, sp, #8
+
+return_to_ioctl:
 THUMB(	orr	lr, lr, #1)
 	mov	pc, lr
 
+	.ltorg
+
+
 __kvm_hyp_code_end:
 	.globl __kvm_hyp_code_end
 
@@ -50,9 +379,168 @@ __kvm_hyp_code_end:
 @  Hypervisor exception vector and handlers
 @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
 
+/*
+ * The KVM/ARM Hypervisor ABI is defined as follows:
+ *
+ * Entry to Hyp mode from the host kernel will happen _only_ when an HVC
+ * instruction is issued since all traps are disabled when running the host
+ * kernel as per the Hyp-mode initialization at boot time.
+ *
+ * HVC instructions cause a trap to the vector page + offset 0x18 (see hyp_hvc
+ * below) when the HVC instruction is called from SVC mode (i.e. a guest or the
+ * host kernel) and they cause a trap to the vector page + offset 0xc when HVC
+ * instructions are called from within Hyp-mode.
+ *
+ * Hyp-ABI: Switching from host kernel to Hyp-mode:
+ *    Switching to Hyp mode is done through a simple HVC instructions. The
+ *    exception vector code will check that the HVC comes from VMID==0 and if
+ *    so will store the necessary state on the Hyp stack, which will look like
+ *    this (see the hyp_hvc handler):
+ *      ...
+ *      Hyp_Sp + 4: lr_usr
+ *      Hyp_Sp    : spsr (Host-SVC cpsr)
+ *
+ * Hyp-ABI: Switching from Hyp-mode to host kernel SVC mode:
+ *    When returning from Hyp mode to SVC mode, another HVC instruction is
+ *    executed from Hyp mode, which is taken in the hyp_svc handler. The Hyp
+ *    stack pointer should be where it was left from the above initial call,
+ *    since the values on the stack will be used to restore state.
+ *
+ *
+ * Note that the above is used to execute code in Hyp-mode from a host-kernel
+ * point of view, and is a different concept from performing a world-switch and
+ * executing guest code SVC mode (with a VMID != 0).
+ */
+	.text
+	.arm
+
 	.align 5
 __kvm_hyp_vector:
 	.globl __kvm_hyp_vector
-	nop
+
+	@ Hyp-mode exception vector
+	b	hyp_reset
+	b	hyp_undef
+	b	hyp_svc
+	b	hyp_pabt
+	b	hyp_dabt
+	b	hyp_hvc
+	b	hyp_irq
+	b	hyp_fiq
+
+	.align
+hyp_reset:
+	sub	pc, pc, #8
+
+	.align
+hyp_undef:
+	sub	pc, pc, #8
+
+	.align
+hyp_svc:
+	@ Can only get here if HVC or SVC is called from Hyp, mode which means
+	@ we want to change mode back to SVC mode.
+	@ NB: Stack pointer should be where hyp_hvc handler left it!
+	ldr	lr, [sp, #4]
+	msr	spsr, lr
+	ldr	lr, [sp]
+	add	sp, sp, #8
+	eret
+
+	.align
+hyp_pabt:
+	sub	pc, pc, #8
+
+	.align
+hyp_dabt:
+	sub	pc, pc, #8
+
+	.align
+hyp_hvc:
+	@ Getting here is either becuase of a trap from a guest or from calling
+	@ HVC from the host kernel, which means "switch to Hyp mode".
+	push	{r0, r1, r2}
+
+	@ Check syndrome register
+	mrc	p15, 4, r0, c5, c2, 0	@ HSR
+	lsr	r1, r0, #HSR_EC_SHIFT
+	cmp	r1, #HSR_EC_HVC
+	bne	guest_trap		@ Not HVC instr.
+
+	@ Let's check if the HVC came from VMID 0 and allow simple
+	@ switch to Hyp mode
+	mrrc    p15, 6, r1, r2, c2
+	lsr     r2, r2, #16
+	and     r2, r2, #0xff
+	cmp     r2, #0
+	bne	guest_trap		@ Guest called HVC
+
+	pop	{r0, r1, r2}
+
+	@ Store lr_usr,spsr (svc cpsr) on stack
+	sub	sp, sp, #8
+	str	lr, [sp]
+	mrs	lr, spsr
+	str	lr, [sp, #4]
+
+	@ Return to caller in Hyp mode
+	mrs	lr, ELR_hyp
+	mov	pc, lr
+
+guest_trap:
+	ldr	r1, [sp, #12]		@ Load VCPU pointer
+	str	r0, [r1, #VCPU_HSR]
+	add	r1, r1, #VCPU_USR_REG(3)
+	stmia	r1, {r3-r12}
+	sub	r1, r1, #(VCPU_USR_REG(3) - VCPU_USR_REG(0))
+	pop	{r3, r4, r5}
+	add	sp, sp, #4		@ We loaded the VCPU pointer above
+	stmia	r1, {r3, r4, r5}
+	sub	r1, r1, #VCPU_USR_REG(0)
+
+	@ Check if we need the fault information
+	lsr	r2, r0, #HSR_EC_SHIFT
+	cmp	r2, #HSR_EC_IABT
+	beq	2f
+	cmpne	r2, #HSR_EC_DABT
+	bne	1f
+
+	@ For non-valid data aborts, get the offending instr. PA
+	lsr	r2, r0, #HSR_ISV_SHIFT
+	ands	r2, r2, #1
+	bne	2f
+	mrs	r3, ELR_hyp
+	mcr	p15, 0, r3, c7, c8, 0	@ VA to PA, V2PCWPR
+	mrrc	p15, 0, r4, r5, c7	@ PAR
+	add	r6, r1, #VCPU_PC_IPA
+	strd	r4, r5, [r6]
+
+2:	mrc	p15, 4, r2, c6, c0, 0	@ HDFAR
+	mrc	p15, 4, r3, c6, c0, 2	@ HIFAR
+	mrc	p15, 4, r4, c6, c0, 4	@ HPFAR
+	add	r5, r1, #VCPU_HDFAR
+	stmia	r5, {r2, r3, r4}
+
+1:	mov	r0, #ARM_EXCEPTION_HVC
+	b	__kvm_vcpu_return
+
+	.align
+hyp_irq:
+	push	{r0}
+	ldr	r0, [sp, #4]		@ Load VCPU pointer
+	add	r0, r0, #(VCPU_USR_REG(1))
+	stmia	r0, {r1-r12}
+	pop	{r0, r1}		@ r1 == vcpu pointer
+	str	r0, [r1, #VCPU_USR_REG(0)]
+
+	mov	r0, #ARM_EXCEPTION_IRQ
+	b	__kvm_vcpu_return
+
+	.align
+hyp_fiq:
+	sub	pc, pc, #8
+
+	.ltorg
+
 __kvm_hyp_vector_end:
 	.globl __kvm_hyp_vector_end


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 08/12] ARM: KVM: Emulation framework and CP15 emulation
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (6 preceding siblings ...)
  2012-02-23  7:32 ` [PATCH v6 07/12] ARM: KVM: World-switch implementation Christoffer Dall
@ 2012-02-23  7:33 ` Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 09/12] ARM: KVM: Handle guest faults in KVM Christoffer Dall
                   ` (3 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:33 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

Adds a new important function in the main KVM/ARM code called
handle_exit() which is called from kvm_arch_vcpu_ioctl_run() on returns
from guest execution. This function examines the Hyp-Syndrome-Register
(HSR), which contains information telling KVM what caused the exit from
the guest.

Some of the reasons for an exit are CP15 accesses, which are
not allowed from the guest and this commit handles these exits by
emulating the intended operation in software and skip the guest
instruction.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_emulate.h |    7 +
 arch/arm/kvm/arm.c                 |   79 ++++++++++++++
 arch/arm/kvm/emulate.c             |  198 ++++++++++++++++++++++++++++++++++++
 arch/arm/kvm/trace.h               |   28 +++++
 4 files changed, 312 insertions(+), 0 deletions(-)

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 4074059..80fe35f 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -40,6 +40,13 @@ static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)
 	return modes_table[vcpu->arch.regs.cpsr & 0xf];
 }
 
+int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_handle_cp_0_13_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_handle_cp15_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run);
+
 /*
  * Return the SPSR for the specified mode of the virtual CPU.
  */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 4b86fef..1566e9d 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -37,6 +37,7 @@
 #include <asm/kvm_arm.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmu.h>
+#include <asm/kvm_emulate.h>
 
 static DEFINE_PER_CPU(void *, kvm_arm_hyp_stack_page);
 
@@ -336,6 +337,78 @@ static void update_vttbr(struct kvm *kvm)
 	spin_unlock(&kvm_vmid_lock);
 }
 
+static int handle_svc_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	/* SVC called from Hyp mode should never get here */
+	kvm_debug("SVC called from Hyp mode shouldn't go here\n");
+	BUG();
+	return -EINVAL; /* Squash warning */
+}
+
+static int handle_hvc(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	/*
+	 * Guest called HVC instruction:
+	 * So far we are not doing anything here, but in the longer run we are
+	 * probably going to have some hypercall interface entry point
+	 * starting from here.
+	 */
+	kvm_debug("hvc: %x (at %08x)", vcpu->arch.hsr & ((1 << 16) - 1),
+				     vcpu->arch.regs.pc);
+	kvm_debug("         HSR: %8x", vcpu->arch.hsr);
+	return 0;
+}
+
+static int handle_dabt_hyp(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	/* The hypervisor should never cause aborts */
+	kvm_debug("The hypervisor itself shouldn't cause aborts\n");
+	BUG();
+	return -EINVAL; /* Squash warning */
+}
+
+static int (*arm_exit_handlers[])(struct kvm_vcpu *vcpu, struct kvm_run *r) = {
+	[HSR_EC_WFI]		= kvm_handle_wfi,
+	[HSR_EC_CP15_32]	= kvm_handle_cp15_access,
+	[HSR_EC_CP15_64]	= kvm_handle_cp15_access,
+	[HSR_EC_CP14_MR]	= kvm_handle_cp14_access,
+	[HSR_EC_CP14_LS]	= kvm_handle_cp14_load_store,
+	[HSR_EC_CP14_64]	= kvm_handle_cp14_access,
+	[HSR_EC_CP_0_13]	= kvm_handle_cp_0_13_access,
+	[HSR_EC_CP10_ID]	= kvm_handle_cp10_id,
+	[HSR_EC_SVC_HYP]	= handle_svc_hyp,
+	[HSR_EC_HVC]		= handle_hvc,
+	[HSR_EC_IABT]		= kvm_handle_guest_abort,
+	[HSR_EC_DABT]		= kvm_handle_guest_abort,
+	[HSR_EC_DABT_HYP]	= handle_dabt_hyp,
+};
+
+static inline int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
+			      int exception_index)
+{
+	unsigned long hsr_ec;
+
+	if (exception_index == ARM_EXCEPTION_IRQ)
+		return 0;
+
+	if (exception_index != ARM_EXCEPTION_HVC) {
+		kvm_pr_unimpl("Unsupported exception type: %d",
+			      exception_index);
+		return -EINVAL;
+	}
+
+	hsr_ec = (vcpu->arch.hsr & HSR_EC) >> HSR_EC_SHIFT;
+
+	if (hsr_ec >= ARRAY_SIZE(arm_exit_handlers)
+	    || !arm_exit_handlers[hsr_ec]) {
+		kvm_err("Unkown exception class: %08lx, hsr: %08x\n", hsr_ec,
+			(unsigned int)vcpu->arch.hsr);
+		BUG();
+	}
+
+	return arm_exit_handlers[hsr_ec](vcpu, run);
+}
+
 /**
  * kvm_arch_vcpu_ioctl_run - the main VCPU run function to execute guest code
  * @vcpu:	The VCPU pointer
@@ -387,6 +460,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		local_irq_enable();
 
 		trace_kvm_exit(vcpu->arch.regs.pc);
+
+		ret = handle_exit(vcpu, run, ret);
+		if (ret) {
+			kvm_err("Error in handle_exit\n");
+			break;
+		}
 	}
 
 	if (vcpu->sigset_active)
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index cd634a1..ea6fa7e 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -14,7 +14,13 @@
  *
  */
 
+#include <linux/mm.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_host.h>
 #include <asm/kvm_emulate.h>
+#include <trace/events/kvm.h>
+
+#include "trace.h"
 
 #define USR_REG_OFFSET(_reg) \
 	offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
@@ -119,3 +125,195 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
 
 	return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
 }
+
+/******************************************************************************
+ * Co-processor emulation
+ */
+
+struct coproc_params {
+	unsigned long CRm;
+	unsigned long CRn;
+	unsigned long Op1;
+	unsigned long Op2;
+	unsigned long Rt1;
+	unsigned long Rt2;
+	bool is_64bit;
+	bool is_write;
+};
+
+static void cp15_op(struct kvm_vcpu *vcpu, struct coproc_params *p,
+			   enum cp15_regs cp15_reg)
+{
+	if (p->is_write)
+		vcpu->arch.cp15[cp15_reg] = *vcpu_reg(vcpu, p->Rt1);
+	else
+		*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[cp15_reg];
+}
+
+static void print_cp_instr(struct coproc_params *p)
+{
+	if (p->is_64bit) {
+		kvm_debug("%s\tp15, %lu, r%lu, r%lu, c%lu",
+			  (p->is_write) ? "mcrr" : "mrrc",
+			  p->Op1, p->Rt1, p->Rt2, p->CRm);
+	} else {
+		kvm_debug("%s\tp15, %lu, r%lu, c%lu, c%lu, %lu",
+			  (p->is_write) ? "mcr" : "mrc",
+			  p->Op1, p->Rt1, p->CRn, p->CRm, p->Op2);
+	}
+}
+
+int kvm_handle_cp10_id(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
+
+int kvm_handle_cp_0_13_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
+
+int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
+
+int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return -EINVAL;
+}
+
+/**
+ * emulate_cp15_c10_access -- emulates cp15 accesses for CRn == 10
+ * @vcpu: The VCPU pointer
+ * @p:    The coprocessor parameters struct pointer holding trap inst. details
+ *
+ * This function may not need to exist - if we can ignore guest attempts to
+ * tamper with TLB lockdowns then it should be enough to store/restore the
+ * host/guest PRRR and NMRR memory remap registers and allow guest direct access
+ * to these registers.
+ */
+static int emulate_cp15_c10_access(struct kvm_vcpu *vcpu,
+				   struct coproc_params *p)
+{
+	BUG_ON(p->CRn != 10);
+	BUG_ON(p->is_64bit);
+
+	if ((p->CRm == 0 || p->CRm == 1 || p->CRm == 4 || p->CRm == 8) &&
+	    (p->Op2 <= 7)) {
+		/* TLB Lockdown operations - ignored */
+		return 0;
+	}
+
+	/*
+	 * The role of these registers depends on whether LPAE is defined or
+	 * not, but there shouldn't be any breakage in any case - we may
+	 * simply not respect the nomenclature here.
+	 */
+
+	if (p->CRm == 2 && p->Op1 == 0 && p->Op2 == 0) {
+		cp15_op(vcpu, p, c10_PRRR);
+		return 0;
+	}
+
+	if (p->CRm == 2 && p->Op1 == 0 && p->Op2 == 1) {
+		cp15_op(vcpu, p, c10_NMRR);
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+/**
+ * emulate_cp15_c15_access -- emulates cp15 accesses for CRn == 15
+ * @vcpu: The VCPU pointer
+ * @p:    The coprocessor parameters struct pointer holding trap inst. details
+ *
+ * The CP15 c15 register is architecturally implementation defined, but some
+ * guest kernels attempt to read/write a diagnostics register here. We always
+ * return 0 and ignore writes and hope for the best.
+ *
+ * This may need to be refined.
+ */
+static int emulate_cp15_c15_access(struct kvm_vcpu *vcpu,
+				   struct coproc_params *p)
+{
+	trace_kvm_emulate_cp15_imp(p->Op1, p->Rt1, p->CRn, p->CRm,
+				   p->Op2, p->is_write);
+
+	if (!p->is_write)
+		*vcpu_reg(vcpu, p->Rt1) = 0;
+
+	return 0;
+}
+
+/**
+ * kvm_handle_cp15_access -- handles a trap on a guest CP15 access
+ * @vcpu: The VCPU pointer
+ * @run:  The kvm_run struct
+ *
+ * Investigates the CRn/CRm and wether this was mcr/mrc or mcrr/mrrc and either
+ * simply errors out if the operation was not supported (should maybe raise
+ * undefined to guest instead?) and otherwise emulated access.
+ */
+int kvm_handle_cp15_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	unsigned long hsr_ec, instr_len;
+	struct coproc_params params;
+	int ret = 0;
+
+	hsr_ec = vcpu->arch.hsr >> HSR_EC_SHIFT;
+	params.CRm = (vcpu->arch.hsr >> 1) & 0xf;
+	params.Rt1 = (vcpu->arch.hsr >> 5) & 0xf;
+	BUG_ON(params.Rt1 >= 15);
+	params.is_write = ((vcpu->arch.hsr & 1) == 0);
+	params.is_64bit = (hsr_ec == HSR_EC_CP15_64);
+
+	if (params.is_64bit) {
+		/* mrrc, mccr operation */
+		params.Op1 = (vcpu->arch.hsr >> 16) & 0xf;
+		params.Op2 = 0;
+		params.Rt2 = (vcpu->arch.hsr >> 10) & 0xf;
+		BUG_ON(params.Rt2 >= 15);
+		params.CRn = 0;
+	} else {
+		params.CRn = (vcpu->arch.hsr >> 10) & 0xf;
+		params.Op1 = (vcpu->arch.hsr >> 14) & 0x7;
+		params.Op2 = (vcpu->arch.hsr >> 17) & 0x7;
+		params.Rt2 = 0;
+	}
+
+	/* So far no mrrc/mcrr accesses are emulated */
+	if (params.is_64bit)
+		goto unsupp_err_out;
+
+	switch (params.CRn) {
+	case 10:
+		ret = emulate_cp15_c10_access(vcpu, &params);
+		break;
+	case 15:
+		ret = emulate_cp15_c15_access(vcpu, &params);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	if (ret)
+		goto unsupp_err_out;
+
+	/* Skip instruction, since it was emulated */
+	instr_len = ((vcpu->arch.hsr >> 25) & 1) ? 4 : 2;
+	*vcpu_reg(vcpu, 15) += instr_len;
+
+	return ret;
+unsupp_err_out:
+	kvm_err("Unsupported guest CP15 access at: %08x\n", vcpu->arch.regs.pc);
+	print_cp_instr(&params);
+	return -EINVAL;
+}
+
+int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	return 0;
+}
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index f8869c1..e474a0a 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -39,7 +39,35 @@ TRACE_EVENT(kvm_exit,
 	TP_printk("PC: 0x%08lx", __entry->vcpu_pc)
 );
 
+/* Architecturally implementation defined CP15 register access */
+TRACE_EVENT(kvm_emulate_cp15_imp,
+	TP_PROTO(unsigned long Op1, unsigned long Rt1, unsigned long CRn,
+		 unsigned long CRm, unsigned long Op2, bool is_write),
+	TP_ARGS(Op1, Rt1, CRn, CRm, Op2, is_write),
 
+	TP_STRUCT__entry(
+		__field(	unsigned int,	Op1		)
+		__field(	unsigned int,	Rt1		)
+		__field(	unsigned int,	CRn		)
+		__field(	unsigned int,	CRm		)
+		__field(	unsigned int,	Op2		)
+		__field(	bool,		is_write	)
+	),
+
+	TP_fast_assign(
+		__entry->is_write		= is_write;
+		__entry->Op1			= Op1;
+		__entry->Rt1			= Rt1;
+		__entry->CRn			= CRn;
+		__entry->CRm			= CRm;
+		__entry->Op2			= Op2;
+	),
+
+	TP_printk("Implementation defined CP15: %s\tp15, %u, r%u, c%u, c%u, %u",
+			(__entry->is_write) ? "mcr" : "mrc",
+			__entry->Op1, __entry->Rt1, __entry->CRn,
+			__entry->CRm, __entry->Op2)
+);
 
 #endif /* _TRACE_KVM_H */
 


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 09/12] ARM: KVM: Handle guest faults in KVM
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (7 preceding siblings ...)
  2012-02-23  7:33 ` [PATCH v6 08/12] ARM: KVM: Emulation framework and CP15 emulation Christoffer Dall
@ 2012-02-23  7:33 ` Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 10/12] ARM: KVM: Handle I/O aborts Christoffer Dall
                   ` (2 subsequent siblings)
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:33 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

Handles the guest faults in KVM by mapping in corresponding user pages
in the 2nd stage page tables.

Introduces new ARM-specific kernel memory types, PAGE_KVM_GUEST and
pgprot_guest variables used to map 2nd stage memory for KVM guests.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/pgtable-3level.h |    8 ++
 arch/arm/include/asm/pgtable.h        |    4 +
 arch/arm/kvm/mmu.c                    |  127 +++++++++++++++++++++++++++++++++
 arch/arm/mm/mmu.c                     |    3 +
 4 files changed, 141 insertions(+), 1 deletions(-)

diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h
index edc3cb9..6dc5331 100644
--- a/arch/arm/include/asm/pgtable-3level.h
+++ b/arch/arm/include/asm/pgtable-3level.h
@@ -104,6 +104,14 @@
  */
 #define L_PGD_SWAPPER		(_AT(pgdval_t, 1) << 55)	/* swapper_pg_dir entry */
 
+/*
+ * 2-nd stage PTE definitions for LPAE.
+ */
+#define L_PTE2_READ		(_AT(pteval_t, 1) << 6)	/* HAP[0] */
+#define L_PTE2_WRITE		(_AT(pteval_t, 1) << 7)	/* HAP[1] */
+#define L_PTE2_NORM_WB		(_AT(pteval_t, 3) << 4)	/* MemAttr[3:2] */
+#define L_PTE2_INNER_WB		(_AT(pteval_t, 3) << 2)	/* MemAttr[1:0] */
+
 #ifndef __ASSEMBLY__
 
 #define pud_none(pud)		(!pud_val(pud))
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 4b72287..2561a8b 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -70,6 +70,7 @@ extern void __pgd_error(const char *file, int line, pgd_t);
 
 extern pgprot_t		pgprot_user;
 extern pgprot_t		pgprot_kernel;
+extern pgprot_t		pgprot_guest;
 
 #define _MOD_PROT(p, b)	__pgprot(pgprot_val(p) | (b))
 
@@ -83,6 +84,9 @@ extern pgprot_t		pgprot_kernel;
 #define PAGE_KERNEL		_MOD_PROT(pgprot_kernel, L_PTE_XN)
 #define PAGE_KERNEL_EXEC	pgprot_kernel
 #define PAGE_HYP		_MOD_PROT(pgprot_kernel, L_PTE_USER)
+#define PAGE_KVM_GUEST		_MOD_PROT(pgprot_guest, L_PTE2_READ | \
+					  L_PTE2_WRITE | L_PTE2_NORM_WB | \
+					  L_PTE2_INNER_WB)
 
 #define __PAGE_NONE		__pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
 #define __PAGE_SHARED		__pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index 94411a6..eb91da2 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -169,6 +169,9 @@ out:
  * Allocates the 1st level table only of size defined by PGD2_ORDER (can
  * support either full 40-bit input addresses or limited to 32-bit input
  * addresses). Clears the allocated pages.
+ *
+ * Note we don't need locking here as this is only called when the VM is
+ * destroyed, which can only be done once.
  */
 int kvm_alloc_stage2_pgd(struct kvm *kvm)
 {
@@ -230,6 +233,9 @@ static void free_stage2_ptes(pmd_t *pmd, unsigned long addr)
  * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
  * underlying level-2 and level-3 tables before freeing the actual level-1 table
  * and setting the struct pointer to NULL.
+ *
+ * Note we don't need locking here as this is only called when the VM is
+ * destroyed, which can only be done once.
  */
 void kvm_free_stage2_pgd(struct kvm *kvm)
 {
@@ -265,7 +271,126 @@ void kvm_free_stage2_pgd(struct kvm *kvm)
 	kvm->arch.pgd = NULL;
 }
 
+static int __user_mem_abort(struct kvm *kvm, phys_addr_t addr, pfn_t pfn)
+{
+	pgd_t *pgd;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *pte, new_pte;
+
+	/* Create 2nd stage page table mapping - Level 1 */
+	pgd = kvm->arch.pgd + pgd_index(addr);
+	pud = pud_offset(pgd, addr);
+	if (pud_none(*pud)) {
+		pmd = pmd_alloc_one(NULL, addr);
+		if (!pmd) {
+			put_page(pfn_to_page(pfn));
+			kvm_err("Cannot allocate 2nd stage pmd\n");
+			return -ENOMEM;
+		}
+		pud_populate(NULL, pud, pmd);
+		pmd += pmd_index(addr);
+	} else
+		pmd = pmd_offset(pud, addr);
+
+	/* Create 2nd stage page table mapping - Level 2 */
+	if (pmd_none(*pmd)) {
+		pte = pte_alloc_one_kernel(NULL, addr);
+		if (!pte) {
+			put_page(pfn_to_page(pfn));
+			kvm_err("Cannot allocate 2nd stage pte\n");
+			return -ENOMEM;
+		}
+		pmd_populate_kernel(NULL, pmd, pte);
+		pte += pte_index(addr);
+	} else
+		pte = pte_offset_kernel(pmd, addr);
+
+	/* Create 2nd stage page table mapping - Level 3 */
+	new_pte = pfn_pte(pfn, PAGE_KVM_GUEST);
+	set_pte_ext(pte, new_pte, 0);
+
+	return 0;
+}
+
+static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+			  gfn_t gfn, struct kvm_memory_slot *memslot)
+{
+	pfn_t pfn;
+	int ret;
+
+	pfn = gfn_to_pfn(vcpu->kvm, gfn);
+
+	if (is_error_pfn(pfn)) {
+		put_page(pfn_to_page(pfn));
+		kvm_err("Guest gfn %u (0x%08x) does not have \n"
+				"corresponding host mapping",
+				(unsigned int)gfn,
+				(unsigned int)gfn << PAGE_SHIFT);
+		return -EFAULT;
+	}
+
+	mutex_lock(&vcpu->kvm->arch.pgd_mutex);
+	ret = __user_mem_abort(vcpu->kvm, fault_ipa, pfn);
+	mutex_unlock(&vcpu->kvm->arch.pgd_mutex);
+
+	return ret;
+}
+
+#define HSR_ABT_FS	(0x3f)
+#define HPFAR_MASK	(~0xf)
+
+/**
+ * kvm_handle_guest_abort - handles all 2nd stage aborts
+ * @vcpu:	the VCPU pointer
+ * @run:	the kvm_run structure
+ *
+ * Any abort that gets to the host is almost guaranteed to be caused by a
+ * missing second stage translation table entry, which can mean that either the
+ * guest simply needs more memory and we must allocate an appropriate page or it
+ * can mean that the guest tried to access I/O memory, which is emulated by user
+ * space. The distinction is based on the IPA causing the fault and whether this
+ * memory region has been registered as standard RAM by user space.
+ */
 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
-	return -EINVAL;
+	unsigned long hsr_ec;
+	unsigned long fault_status;
+	phys_addr_t fault_ipa;
+	struct kvm_memory_slot *memslot = NULL;
+	bool is_iabt;
+	gfn_t gfn;
+
+	hsr_ec = vcpu->arch.hsr >> HSR_EC_SHIFT;
+	is_iabt = (hsr_ec == HSR_EC_IABT);
+
+	/* Check that the second stage fault is a translation fault */
+	fault_status = vcpu->arch.hsr & HSR_ABT_FS;
+	if ((fault_status & 0x3c) != 0x4) {
+		kvm_err("Unsupported fault status: %lx\n",
+				fault_status & 0x3c);
+		return -EFAULT;
+	}
+
+	fault_ipa = ((phys_addr_t)vcpu->arch.hpfar & HPFAR_MASK) << 8;
+
+	gfn = fault_ipa >> PAGE_SHIFT;
+	if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) {
+		if (is_iabt) {
+			kvm_err("Inst. abort on I/O address %08lx\n",
+				(unsigned long)fault_ipa);
+			return -EFAULT;
+		}
+
+		kvm_pr_unimpl("I/O address abort...");
+		return 0;
+	}
+
+	memslot = gfn_to_memslot(vcpu->kvm, gfn);
+	if (!memslot->user_alloc) {
+		kvm_err("non user-alloc memslots not supported\n");
+		return -EINVAL;
+	}
+
+	return user_mem_abort(vcpu, fault_ipa, gfn, memslot);
 }
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 94c5a0c..1a2df14 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -54,9 +54,11 @@ static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
 static unsigned int ecc_mask __initdata = 0;
 pgprot_t pgprot_user;
 pgprot_t pgprot_kernel;
+pgprot_t pgprot_guest;
 
 EXPORT_SYMBOL(pgprot_user);
 EXPORT_SYMBOL(pgprot_kernel);
+EXPORT_SYMBOL(pgprot_guest);
 
 struct cachepolicy {
 	const char	policy[16];
@@ -504,6 +506,7 @@ static void __init build_mem_type_table(void)
 	pgprot_user   = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
 	pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
 				 L_PTE_DIRTY | kern_pgprot);
+	pgprot_guest  = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG);
 
 	mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
 	mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 10/12] ARM: KVM: Handle I/O aborts
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (8 preceding siblings ...)
  2012-02-23  7:33 ` [PATCH v6 09/12] ARM: KVM: Handle guest faults in KVM Christoffer Dall
@ 2012-02-23  7:33 ` Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 11/12] ARM: KVM: Guest wait-for-interrupts (WFI) support Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 12/12] ARM: KVM: Handle CP15 CR9 accesses for L2CTLR emulation Christoffer Dall
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:33 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Christoffer Dall <c.dall@virtualopensystems.com>

When the guest accesses I/O memory this will create data abort
exceptions and they are handled by decoding the HSR information
(physical address, read/write, length, register) and forwarding reads
and writes to QEMU which performs the device emulation.

Certain classes of load/store operations do not support the syndrome
information provided in the HSR and we therefore must be able to fetch
the offending instruction from guest memory and decode it manually.

This requires changing the general flow somewhat since new calls to run
the VCPU must check if there's a pending MMIO load and perform the write
after userspace has made the data available.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/include/asm/kvm_emulate.h |    2 
 arch/arm/include/asm/kvm_host.h    |    1 
 arch/arm/include/asm/kvm_mmu.h     |    1 
 arch/arm/kvm/arm.c                 |    6 +
 arch/arm/kvm/emulate.c             |  275 ++++++++++++++++++++++++++++++++++++
 arch/arm/kvm/mmu.c                 |  153 ++++++++++++++++++++
 arch/arm/kvm/trace.h               |   21 +++
 7 files changed, 456 insertions(+), 3 deletions(-)

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 80fe35f..029f45f 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -46,6 +46,8 @@ int kvm_handle_cp14_load_store(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_handle_cp15_access(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run);
+int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+			unsigned long instr);
 
 /*
  * Return the SPSR for the specified mode of the virtual CPU.
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 72ba708..8002903 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -99,6 +99,7 @@ struct kvm_vcpu_arch {
 	u64 pc_ipa;		/* IPA for the current PC (VA to PA result) */
 
 	/* IO related fields */
+	bool mmio_sign_extend;	/* for byte/halfword loads */
 	u32 mmio_rd;
 
 	/* Interrupt related fields */
diff --git a/arch/arm/include/asm/kvm_mmu.h b/arch/arm/include/asm/kvm_mmu.h
index b142043..917edd7 100644
--- a/arch/arm/include/asm/kvm_mmu.h
+++ b/arch/arm/include/asm/kvm_mmu.h
@@ -36,6 +36,7 @@ void free_hyp_pmds(pgd_t *hyp_pgd);
 int kvm_alloc_stage2_pgd(struct kvm *kvm);
 void kvm_free_stage2_pgd(struct kvm *kvm);
 
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run);
 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run);
 
 #endif /* __ARM_KVM_MMU_H__ */
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 1566e9d..26fee60 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -425,6 +425,12 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	int ret = 0;
 	sigset_t sigsaved;
 
+	if (run->exit_reason == KVM_EXIT_MMIO) {
+		ret = kvm_handle_mmio_return(vcpu, vcpu->run);
+		if (ret)
+			return ret;
+	}
+
 	if (vcpu->sigset_active)
 		sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
 
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index ea6fa7e..77ccc2b 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -127,8 +127,30 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
 }
 
 /******************************************************************************
- * Co-processor emulation
+ * Utility functions common for all emulation code
+ *****************************************************************************/
+
+/*
+ * This one accepts a matrix where the first element is the
+ * bits as they must be, and the second element is the bitmask.
  */
+#define INSTR_NONE	-1
+static int kvm_instr_index(u32 instr, u32 table[][2], int table_entries)
+{
+	int i;
+	u32 mask;
+
+	for (i = 0; i < table_entries; i++) {
+		mask = table[i][1];
+		if ((table[i][0] & mask) == (instr & mask))
+			return i;
+	}
+	return INSTR_NONE;
+}
+
+/******************************************************************************
+ * Co-processor emulation
+ *****************************************************************************/
 
 struct coproc_params {
 	unsigned long CRm;
@@ -317,3 +339,254 @@ int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
 	return 0;
 }
+
+
+/******************************************************************************
+ * Load-Store instruction emulation
+ *****************************************************************************/
+
+/*
+ * Must be ordered with LOADS first and WRITES afterwards
+ * for easy distinction when doing MMIO.
+ */
+#define NUM_LD_INSTR  9
+enum INSTR_LS_INDEXES {
+	INSTR_LS_LDRBT, INSTR_LS_LDRT, INSTR_LS_LDR, INSTR_LS_LDRB,
+	INSTR_LS_LDRD, INSTR_LS_LDREX, INSTR_LS_LDRH, INSTR_LS_LDRSB,
+	INSTR_LS_LDRSH,
+	INSTR_LS_STRBT, INSTR_LS_STRT, INSTR_LS_STR, INSTR_LS_STRB,
+	INSTR_LS_STRD, INSTR_LS_STREX, INSTR_LS_STRH,
+	NUM_LS_INSTR
+};
+
+static u32 ls_instr[NUM_LS_INSTR][2] = {
+	{0x04700000, 0x0d700000}, /* LDRBT */
+	{0x04300000, 0x0d700000}, /* LDRT  */
+	{0x04100000, 0x0c500000}, /* LDR   */
+	{0x04500000, 0x0c500000}, /* LDRB  */
+	{0x000000d0, 0x0e1000f0}, /* LDRD  */
+	{0x01900090, 0x0ff000f0}, /* LDREX */
+	{0x001000b0, 0x0e1000f0}, /* LDRH  */
+	{0x001000d0, 0x0e1000f0}, /* LDRSB */
+	{0x001000f0, 0x0e1000f0}, /* LDRSH */
+	{0x04600000, 0x0d700000}, /* STRBT */
+	{0x04200000, 0x0d700000}, /* STRT  */
+	{0x04000000, 0x0c500000}, /* STR   */
+	{0x04400000, 0x0c500000}, /* STRB  */
+	{0x000000f0, 0x0e1000f0}, /* STRD  */
+	{0x01800090, 0x0ff000f0}, /* STREX */
+	{0x000000b0, 0x0e1000f0}  /* STRH  */
+};
+
+static inline int get_arm_ls_instr_index(u32 instr)
+{
+	return kvm_instr_index(instr, ls_instr, NUM_LS_INSTR);
+}
+
+/*
+ * Load-Store instruction decoding
+ */
+#define INSTR_LS_TYPE_BIT		26
+#define INSTR_LS_RD_MASK		0x0000f000
+#define INSTR_LS_RD_SHIFT		12
+#define INSTR_LS_RN_MASK		0x000f0000
+#define INSTR_LS_RN_SHIFT		16
+#define INSTR_LS_RM_MASK		0x0000000f
+#define INSTR_LS_OFFSET12_MASK		0x00000fff
+
+#define INSTR_LS_BIT_P			24
+#define INSTR_LS_BIT_U			23
+#define INSTR_LS_BIT_B			22
+#define INSTR_LS_BIT_W			21
+#define INSTR_LS_BIT_L			20
+#define INSTR_LS_BIT_S			 6
+#define INSTR_LS_BIT_H			 5
+
+/*
+ * ARM addressing mode defines
+ */
+#define OFFSET_IMM_MASK			0x0e000000
+#define OFFSET_IMM_VALUE		0x04000000
+#define OFFSET_REG_MASK			0x0e000ff0
+#define OFFSET_REG_VALUE		0x06000000
+#define OFFSET_SCALE_MASK		0x0e000010
+#define OFFSET_SCALE_VALUE		0x06000000
+
+#define SCALE_SHIFT_MASK		0x000000a0
+#define SCALE_SHIFT_SHIFT		5
+#define SCALE_SHIFT_LSL			0x0
+#define SCALE_SHIFT_LSR			0x1
+#define SCALE_SHIFT_ASR			0x2
+#define SCALE_SHIFT_ROR_RRX		0x3
+#define SCALE_SHIFT_IMM_MASK		0x00000f80
+#define SCALE_SHIFT_IMM_SHIFT		6
+
+#define PSR_BIT_C			29
+
+static unsigned long ls_word_calc_offset(struct kvm_vcpu *vcpu,
+					 unsigned long instr)
+{
+	int offset = 0;
+
+	if ((instr & OFFSET_IMM_MASK) == OFFSET_IMM_VALUE) {
+		/* Immediate offset/index */
+		offset = instr & INSTR_LS_OFFSET12_MASK;
+
+		if (!(instr & (1U << INSTR_LS_BIT_U)))
+			offset = -offset;
+	}
+
+	if ((instr & OFFSET_REG_MASK) == OFFSET_REG_VALUE) {
+		/* Register offset/index */
+		u8 rm = instr & INSTR_LS_RM_MASK;
+		offset = *vcpu_reg(vcpu, rm);
+
+		if (!(instr & (1U << INSTR_LS_BIT_P)))
+			offset = 0;
+	}
+
+	if ((instr & OFFSET_SCALE_MASK) == OFFSET_SCALE_VALUE) {
+		/* Scaled register offset */
+		u8 rm = instr & INSTR_LS_RM_MASK;
+		u8 shift = (instr & SCALE_SHIFT_MASK) >> SCALE_SHIFT_SHIFT;
+		u32 shift_imm = (instr & SCALE_SHIFT_IMM_MASK)
+				>> SCALE_SHIFT_IMM_SHIFT;
+		offset = *vcpu_reg(vcpu, rm);
+
+		switch (shift) {
+		case SCALE_SHIFT_LSL:
+			offset = offset << shift_imm;
+			break;
+		case SCALE_SHIFT_LSR:
+			if (shift_imm == 0)
+				offset = 0;
+			else
+				offset = ((u32)offset) >> shift_imm;
+			break;
+		case SCALE_SHIFT_ASR:
+			if (shift_imm == 0) {
+				if (offset & (1U << 31))
+					offset = 0xffffffff;
+				else
+					offset = 0;
+			} else {
+				/* Ensure arithmetic shift */
+				asm("mov %[r], %[op], ASR %[s]":
+				    [r] "=r" (offset) :
+				    [op] "r" (offset), [s] "r" (shift_imm));
+			}
+			break;
+		case SCALE_SHIFT_ROR_RRX:
+			if (shift_imm == 0) {
+				u32 C = (vcpu->arch.regs.cpsr &
+						(1U << PSR_BIT_C));
+				offset = (C << 31) | offset >> 1;
+			} else {
+				/* Ensure arithmetic shift */
+				asm("mov %[r], %[op], ASR %[s]":
+				    [r] "=r" (offset) :
+				    [op] "r" (offset), [s] "r" (shift_imm));
+			}
+			break;
+		}
+
+		if (instr & (1U << INSTR_LS_BIT_U))
+			return offset;
+		else
+			return -offset;
+	}
+
+	if (instr & (1U << INSTR_LS_BIT_U))
+		return offset;
+	else
+		return -offset;
+
+	BUG();
+}
+
+static int kvm_ls_length(struct kvm_vcpu *vcpu, u32 instr)
+{
+	int index;
+
+	index = get_arm_ls_instr_index(instr);
+
+	if (instr & (1U << INSTR_LS_TYPE_BIT)) {
+		/* LS word or unsigned byte */
+		if (instr & (1U << INSTR_LS_BIT_B))
+			return sizeof(unsigned char);
+		else
+			return sizeof(u32);
+	} else {
+		/* LS halfword, doubleword or signed byte */
+		u32 H = (instr & (1U << INSTR_LS_BIT_H));
+		u32 S = (instr & (1U << INSTR_LS_BIT_S));
+		u32 L = (instr & (1U << INSTR_LS_BIT_L));
+
+		if (!L && S) {
+			kvm_err("WARNING: d-word for MMIO\n");
+			return 2 * sizeof(u32);
+		} else if (L && S && !H)
+			return sizeof(char);
+		else
+			return sizeof(u16);
+	}
+
+	BUG();
+}
+
+/**
+ * kvm_emulate_mmio_ls - emulates load/store instructions made to I/O memory
+ * @vcpu:	The vcpu pointer
+ * @fault_ipa:	The IPA that caused the 2nd stage fault
+ * @instr:	The instruction that caused the fault
+ *
+ * Handles emulation of load/store instructions which cannot be emulated through
+ * information found in the HSR on faults. It is necessary in this case to
+ * simply decode the offending instruction in software and determine the
+ * required operands.
+ */
+int kvm_emulate_mmio_ls(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
+			unsigned long instr)
+{
+	unsigned long rd, rn, offset, len;
+	int index;
+	bool is_write;
+
+	trace_kvm_mmio_emulate(vcpu->arch.regs.pc, instr, vcpu->arch.regs.cpsr);
+
+	index = get_arm_ls_instr_index(instr);
+	if (index == INSTR_NONE) {
+		kvm_err("Unknown load/store instruction\n");
+		return -EINVAL;
+	}
+
+	is_write = (index < NUM_LD_INSTR) ? false : true;
+	rd = (instr & INSTR_LS_RD_MASK) >> INSTR_LS_RD_SHIFT;
+	len = kvm_ls_length(vcpu, instr);
+
+	vcpu->run->exit_reason = KVM_EXIT_MMIO;
+	vcpu->run->mmio.is_write = is_write;
+	vcpu->run->mmio.phys_addr = fault_ipa;
+	vcpu->run->mmio.len = len;
+	vcpu->arch.mmio_sign_extend = false;
+	vcpu->arch.mmio_rd = rd;
+
+	trace_kvm_mmio((is_write) ? KVM_TRACE_MMIO_WRITE :
+				    KVM_TRACE_MMIO_READ_UNSATISFIED,
+			len, fault_ipa, (is_write) ? *vcpu_reg(vcpu, rd) : 0);
+
+	/* Handle base register writeback */
+	if (!(instr & (1U << INSTR_LS_BIT_P)) ||
+	     (instr & (1U << INSTR_LS_BIT_W))) {
+		rn = (instr & INSTR_LS_RN_MASK) >> INSTR_LS_RN_SHIFT;
+		offset = ls_word_calc_offset(vcpu, instr);
+		*vcpu_reg(vcpu, rn) += offset;
+	}
+
+	/*
+	 * The MMIO instruction is emulated and should not be re-executed
+	 * in the guest. (XXX We don't support Thumb instructions yet).
+	 */
+	*vcpu_reg(vcpu, 15) += 4;
+	return 0;
+}
diff --git a/arch/arm/kvm/mmu.c b/arch/arm/kvm/mmu.c
index eb91da2..bbbba44 100644
--- a/arch/arm/kvm/mmu.c
+++ b/arch/arm/kvm/mmu.c
@@ -16,9 +16,13 @@
 
 #include <linux/mman.h>
 #include <linux/kvm_host.h>
+#include <trace/events/kvm.h>
 #include <asm/pgalloc.h>
 #include <asm/kvm_arm.h>
 #include <asm/kvm_mmu.h>
+#include <asm/kvm_emulate.h>
+
+#include "trace.h"
 
 pgd_t *kvm_hyp_pgd;
 DEFINE_MUTEX(kvm_hyp_pgd_mutex);
@@ -337,6 +341,150 @@ static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
 	return ret;
 }
 
+/**
+ * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation
+ * @vcpu: The VCPU pointer
+ * @run:  The VCPU run struct containing the mmio data
+ *
+ * This should only be called after returning from userspace for MMIO load
+ * emulation.
+ */
+int kvm_handle_mmio_return(struct kvm_vcpu *vcpu, struct kvm_run *run)
+{
+	int *dest;
+	unsigned int len;
+	int mask;
+
+	if (!run->mmio.is_write) {
+		dest = vcpu_reg(vcpu, vcpu->arch.mmio_rd);
+		memset(dest, 0, sizeof(int));
+
+		len = run->mmio.len;
+		if (len > 4)
+			return -EINVAL;
+
+		memcpy(dest, run->mmio.data, len);
+
+		trace_kvm_mmio(KVM_TRACE_MMIO_READ, len, run->mmio.phys_addr,
+				*((u64 *)run->mmio.data));
+
+		if (vcpu->arch.mmio_sign_extend && len < 4) {
+			mask = 1U << ((len * 8) - 1);
+			*dest = (*dest ^ mask) - mask;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * invalid_io_mem_abort -- Handle I/O aborts ISV bit is clear
+ *
+ * @vcpu:      The vcpu pointer
+ * @fault_ipa: The IPA that caused the 2nd stage fault
+ *
+ * Some load/store instructions cannot be emulated using the information
+ * presented in the HSR, for instance, register write-back instructions are not
+ * supported. We therefore need to fetch the instruction, decode it, and then
+ * emulate its behavior.
+ */
+static int invalid_io_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
+{
+	unsigned long instr;
+	phys_addr_t pc_ipa;
+
+	if (vcpu->arch.pc_ipa & (1U << 11)) {
+		/* LPAE PAR format */
+		pc_ipa = vcpu->arch.pc_ipa & PAGE_MASK & ((1ULL << 32) - 1);
+	} else {
+		/* VMSAv7 PAR format */
+		pc_ipa = vcpu->arch.pc_ipa & PAGE_MASK & ((1ULL << 40) - 1);
+	}
+	pc_ipa += vcpu->arch.regs.pc & ~PAGE_MASK;
+
+	if (kvm_read_guest(vcpu->kvm, pc_ipa, &instr, sizeof(instr))) {
+		kvm_err("Could not copy guest instruction\n");
+		return -EFAULT;
+	}
+
+	if (vcpu->arch.regs.cpsr & PSR_T_BIT) {
+		/* Need to decode thumb instructions as well */
+		return -EINVAL;
+	}
+
+	return kvm_emulate_mmio_ls(vcpu, fault_ipa, instr);
+}
+
+static int io_mem_abort(struct kvm_vcpu *vcpu, struct kvm_run *run,
+			phys_addr_t fault_ipa, struct kvm_memory_slot *memslot)
+{
+	unsigned long rd, len, instr_len;
+	bool is_write, sign_extend;
+
+	if (!(vcpu->arch.hsr & HSR_ISV))
+		return invalid_io_mem_abort(vcpu, fault_ipa);
+
+	if (((vcpu->arch.hsr >> 8) & 1)) {
+		kvm_err("Not supported, Cache operation on I/O addr.\n");
+		return -EFAULT;
+	}
+
+	if ((vcpu->arch.hsr >> 7) & 1) {
+		kvm_err("Translation table accesses I/O memory\n");
+		return -EFAULT;
+	}
+
+	switch ((vcpu->arch.hsr >> 22) & 0x3) {
+	case 0:
+		len = 1;
+		break;
+	case 1:
+		len = 2;
+		break;
+	case 2:
+		len = 4;
+		break;
+	default:
+		kvm_err("Invalid I/O abort\n");
+		return -EFAULT;
+	}
+
+	is_write = ((vcpu->arch.hsr >> 6) & 1);
+	sign_extend = ((vcpu->arch.hsr >> 21) & 1);
+	rd = (vcpu->arch.hsr >> 16) & 0xf;
+	BUG_ON(rd > 15);
+
+	if (rd == 15) {
+		kvm_err("I/O memory trying to read/write pc\n");
+		return -EFAULT;
+	}
+
+	/* Get instruction length in bytes */
+	instr_len = ((vcpu->arch.hsr >> 25) & 1) ? 4 : 2;
+
+	/* Export MMIO operations to user space */
+	run->exit_reason = KVM_EXIT_MMIO;
+	run->mmio.is_write = is_write;
+	run->mmio.phys_addr = fault_ipa;
+	run->mmio.len = len;
+	vcpu->arch.mmio_sign_extend = sign_extend;
+	vcpu->arch.mmio_rd = rd;
+
+	trace_kvm_mmio((is_write) ? KVM_TRACE_MMIO_WRITE :
+				    KVM_TRACE_MMIO_READ_UNSATISFIED,
+			len, fault_ipa, (is_write) ? *vcpu_reg(vcpu, rd) : 0);
+
+	if (is_write)
+		memcpy(run->mmio.data, vcpu_reg(vcpu, rd), len);
+
+	/*
+	 * The MMIO instruction is emulated and should not be re-executed
+	 * in the guest.
+	 */
+	*vcpu_reg(vcpu, 15) += instr_len;
+	return 0;
+}
+
 #define HSR_ABT_FS	(0x3f)
 #define HPFAR_MASK	(~0xf)
 
@@ -382,8 +530,9 @@ int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			return -EFAULT;
 		}
 
-		kvm_pr_unimpl("I/O address abort...");
-		return 0;
+		/* Adjust page offset */
+		fault_ipa += vcpu->arch.hdfar % PAGE_SIZE;
+		return io_mem_abort(vcpu, run, fault_ipa, memslot);
 	}
 
 	memslot = gfn_to_memslot(vcpu->kvm, gfn);
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index e474a0a..bd3a6cc 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -39,6 +39,27 @@ TRACE_EVENT(kvm_exit,
 	TP_printk("PC: 0x%08lx", __entry->vcpu_pc)
 );
 
+TRACE_EVENT(kvm_mmio_emulate,
+	TP_PROTO(unsigned long vcpu_pc, unsigned long instr,
+		 unsigned long cpsr),
+	TP_ARGS(vcpu_pc, instr, cpsr),
+
+	TP_STRUCT__entry(
+		__field(	unsigned long,	vcpu_pc		)
+		__field(	unsigned long,	instr		)
+		__field(	unsigned long,	cpsr		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_pc		= vcpu_pc;
+		__entry->vcpu_pc		= instr;
+		__entry->vcpu_pc		= cpsr;
+	),
+
+	TP_printk("Emulate MMIO at: 0x%08lx (instr: %08lx, cpsr: %08lx)",
+		  __entry->vcpu_pc, __entry->instr, __entry->cpsr)
+);
+
 /* Architecturally implementation defined CP15 register access */
 TRACE_EVENT(kvm_emulate_cp15_imp,
 	TP_PROTO(unsigned long Op1, unsigned long Rt1, unsigned long CRn,


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 11/12] ARM: KVM: Guest wait-for-interrupts (WFI) support
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (9 preceding siblings ...)
  2012-02-23  7:33 ` [PATCH v6 10/12] ARM: KVM: Handle I/O aborts Christoffer Dall
@ 2012-02-23  7:33 ` Christoffer Dall
  2012-02-23  7:33 ` [PATCH v6 12/12] ARM: KVM: Handle CP15 CR9 accesses for L2CTLR emulation Christoffer Dall
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:33 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

When the guest executes a WFI instruction the operation is trapped to
KVM, which emulates the instruction in software. There is no correlation
between a guest executing a WFI instruction and actually putting the
hardware into a low-power mode, since a KVM guest is essentially a
process and the WFI instruction can be seen as 'sleep' call from this
process. Therefore, we flag the VCPU to be in wait_for_interrupts mode
and call the main KVM function kvm_vcpu_block() function. This function
will put the thread on a wait-queue and call schedule.

When an interrupt comes in through KVM_IRQ_LINE (see previous patch) we
signal the VCPU thread and unflag the VCPU to no longer wait for
interrupts. All calls to kvm_arch_vcpu_ioctl_run() result in a call to
kvm_vcpu_block() as long as the VCPU is in wfi-mode.

Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
---
 arch/arm/kvm/arm.c     |   15 ++++++++++++++-
 arch/arm/kvm/emulate.c |   12 ++++++++++++
 arch/arm/kvm/trace.h   |   16 ++++++++++++++++
 3 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 26fee60..3772847 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -268,9 +268,17 @@ int kvm_arch_vcpu_ioctl_set_mpstate(struct kvm_vcpu *vcpu,
 	return -EINVAL;
 }
 
+/**
+ * kvm_arch_vcpu_runnable - determine if the vcpu can be scheduled
+ * @v:		The VCPU pointer
+ *
+ * If the guest CPU is not waiting for interrupts (or waiting and
+ * an interrupt is pending) then it is by definition runnable.
+ */
 int kvm_arch_vcpu_runnable(struct kvm_vcpu *v)
 {
-	return 0;
+	return !!v->arch.irq_lines ||
+		!v->arch.wait_for_interrupts;
 }
 
 int kvm_arch_vcpu_in_guest_mode(struct kvm_vcpu *v)
@@ -448,6 +456,9 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
 			break;
 		}
 
+		if (vcpu->arch.wait_for_interrupts)
+			kvm_vcpu_block(vcpu);
+
 		/*
 		 * Enter the guest
 		 */
@@ -520,6 +531,8 @@ static int kvm_arch_vm_ioctl_irq_line(struct kvm *kvm,
 	 * trigger a world-switch round on the running physical CPU to set the
 	 * virtual IRQ/FIQ fields in the HCR appropriately.
 	 */
+	if (irq_level->level)
+		vcpu->arch.wait_for_interrupts = 0;
 	kvm_vcpu_kick(vcpu);
 
 	return 0;
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index 77ccc2b..20269f8 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -335,8 +335,20 @@ unsupp_err_out:
 	return -EINVAL;
 }
 
+/**
+ * kvm_handle_wfi - handle a wait-for-interrupts instruction executed by a guest
+ * @vcpu:	the vcpu pointer
+ * @run:	the kvm_run structure pointer
+ *
+ * Simply sets the wait_for_interrupts flag on the vcpu structure, which will
+ * halt execution of world-switches and schedule other host processes until
+ * there is an incoming IRQ or FIQ to the VM.
+ */
 int kvm_handle_wfi(struct kvm_vcpu *vcpu, struct kvm_run *run)
 {
+	trace_kvm_wfi(vcpu->arch.regs.pc);
+	if (!vcpu->arch.irq_lines)
+		vcpu->arch.wait_for_interrupts = 1;
 	return 0;
 }
 
diff --git a/arch/arm/kvm/trace.h b/arch/arm/kvm/trace.h
index bd3a6cc..fc68394 100644
--- a/arch/arm/kvm/trace.h
+++ b/arch/arm/kvm/trace.h
@@ -90,6 +90,22 @@ TRACE_EVENT(kvm_emulate_cp15_imp,
 			__entry->CRm, __entry->Op2)
 );
 
+TRACE_EVENT(kvm_wfi,
+	TP_PROTO(unsigned long vcpu_pc),
+	TP_ARGS(vcpu_pc),
+
+	TP_STRUCT__entry(
+		__field(	unsigned long,	vcpu_pc		)
+	),
+
+	TP_fast_assign(
+		__entry->vcpu_pc		= vcpu_pc;
+	),
+
+	TP_printk("guest executed wfi at: 0x%08lx", __entry->vcpu_pc)
+);
+
+
 #endif /* _TRACE_KVM_H */
 
 #undef TRACE_INCLUDE_PATH


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* [PATCH v6 12/12] ARM: KVM: Handle CP15 CR9 accesses for L2CTLR emulation
  2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
                   ` (10 preceding siblings ...)
  2012-02-23  7:33 ` [PATCH v6 11/12] ARM: KVM: Guest wait-for-interrupts (WFI) support Christoffer Dall
@ 2012-02-23  7:33 ` Christoffer Dall
  11 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-23  7:33 UTC (permalink / raw)
  To: android-virt, kvm; +Cc: tech

From: Marc Zyngier <marc.zyngier@arm.com>

Note: This is an awful hack and will go away as soon as the emulation and
decoding code has been changed to a table-driven approach.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm/kvm/emulate.c |   36 ++++++++++++++++++++++++++++++++++++
 1 files changed, 36 insertions(+), 0 deletions(-)

diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index 20269f8..4f5f2de 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -206,6 +206,39 @@ int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
 }
 
 /**
+ * emulate_cp15_c9_access -- emulates cp15 accesses for CRn == 9
+ * @vcpu: The VCPU pointer
+ * @p:    The coprocessor parameters struct pointer holding trap inst. details
+ */
+static int emulate_cp15_c9_access(struct kvm_vcpu *vcpu,
+				  struct coproc_params *p)
+{
+	BUG_ON(p->CRn != 9);
+	BUG_ON(p->is_64bit);
+
+	if (p->CRm == 0 && p->Op1 == 1 && p->Op2 == 2) {
+		/* Emulate L2CTLR access */
+		u32 l2ctlr, ncores;
+
+		if (p->is_write)
+			return 0;
+
+		asm volatile("mrc p15, 1, %0, c9, c0, 2\n" : "=r" (l2ctlr));
+		l2ctlr &= ~(3 << 24);
+		ncores = atomic_read(&vcpu->kvm->online_vcpus) - 1;
+		l2ctlr |= (ncores & 3) << 24;
+		*vcpu_reg(vcpu, p->Rt1) = l2ctlr;
+
+		return 0;
+	}
+
+	/* hack alert!!! */
+	if (!p->is_write)
+		*vcpu_reg(vcpu, p->Rt1) = 0;
+	return 0;
+}
+
+/**
  * emulate_cp15_c10_access -- emulates cp15 accesses for CRn == 10
  * @vcpu: The VCPU pointer
  * @p:    The coprocessor parameters struct pointer holding trap inst. details
@@ -310,6 +343,9 @@ int kvm_handle_cp15_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
 		goto unsupp_err_out;
 
 	switch (params.CRn) {
+	case 9:
+		ret = emulate_cp15_c9_access(vcpu, &params);
+		break;
 	case 10:
 		ret = emulate_cp15_c10_access(vcpu, &params);
 		break;


^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-23  7:32 ` [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support Christoffer Dall
@ 2012-02-24  3:32   ` Rusty Russell
  2012-02-24  4:43     ` Christoffer Dall
  2012-03-11 21:41     ` Christoffer Dall
  0 siblings, 2 replies; 24+ messages in thread
From: Rusty Russell @ 2012-02-24  3:32 UTC (permalink / raw)
  To: Christoffer Dall, android-virt, kvm, Dave Martin; +Cc: tech

On Thu, 23 Feb 2012 02:32:26 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> From: Christoffer Dall <c.dall@virtualopensystems.com>
> 
> Targets KVM support for Cortex A-15 processors.
> 
> Contains no real functionality but all the framework components,
> make files, header files and some tracing functionality.
> 
> “Nothing to see here. Move along, move along..."
> 
> Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.
> 
> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
> ---
>  arch/arm/Kconfig                   |    2 
>  arch/arm/Makefile                  |    1 
>  arch/arm/include/asm/kvm.h         |   72 ++++++++++
>  arch/arm/include/asm/kvm_asm.h     |   28 ++++
>  arch/arm/include/asm/kvm_emulate.h |   92 +++++++++++++
>  arch/arm/include/asm/kvm_host.h    |  116 ++++++++++++++++
>  arch/arm/include/asm/kvm_para.h    |    9 +
>  arch/arm/include/asm/unified.h     |   12 ++
>  arch/arm/kvm/Kconfig               |   45 ++++++
>  arch/arm/kvm/Makefile              |   17 ++
>  arch/arm/kvm/arm.c                 |  256 ++++++++++++++++++++++++++++++++++++
>  arch/arm/kvm/emulate.c             |  121 +++++++++++++++++
>  arch/arm/kvm/exports.c             |   16 ++
>  arch/arm/kvm/guest.c               |  148 +++++++++++++++++++++
>  arch/arm/kvm/init.S                |   17 ++
>  arch/arm/kvm/interrupts.S          |   17 ++
>  arch/arm/kvm/mmu.c                 |   15 ++
>  arch/arm/kvm/trace.h               |   52 +++++++
>  arch/arm/mm/Kconfig                |    8 +
>  19 files changed, 1044 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/include/asm/kvm.h
>  create mode 100644 arch/arm/include/asm/kvm_asm.h
>  create mode 100644 arch/arm/include/asm/kvm_emulate.h
>  create mode 100644 arch/arm/include/asm/kvm_host.h
>  create mode 100644 arch/arm/include/asm/kvm_para.h
>  create mode 100644 arch/arm/kvm/Kconfig
>  create mode 100644 arch/arm/kvm/Makefile
>  create mode 100644 arch/arm/kvm/arm.c
>  create mode 100644 arch/arm/kvm/emulate.c
>  create mode 100644 arch/arm/kvm/exports.c
>  create mode 100644 arch/arm/kvm/guest.c
>  create mode 100644 arch/arm/kvm/init.S
>  create mode 100644 arch/arm/kvm/interrupts.S
>  create mode 100644 arch/arm/kvm/mmu.c
>  create mode 100644 arch/arm/kvm/trace.h
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index e12bc34..81aa08f 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -2263,3 +2263,5 @@ source "security/Kconfig"
>  source "crypto/Kconfig"
>  
>  source "lib/Kconfig"
> +
> +source "arch/arm/kvm/Kconfig"
> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
> index 40319d9..eca44e0 100644
> --- a/arch/arm/Makefile
> +++ b/arch/arm/Makefile
> @@ -253,6 +253,7 @@ core-$(CONFIG_VFP)		+= arch/arm/vfp/
>  
>  # If we have a machine-specific directory, then include it in the build.
>  core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
> +core-y 				+= arch/arm/kvm/
>  core-y				+= $(machdirs) $(platdirs)
>  
>  drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
> new file mode 100644
> index 0000000..544cb2a
> --- /dev/null
> +++ b/arch/arm/include/asm/kvm.h
> @@ -0,0 +1,72 @@
> +/*
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License, version 2, as
> + * published by the Free Software Foundation.
> + *
> + * 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.
> + *
> + */
> +
> +#ifndef __ARM_KVM_H__
> +#define __ARM_KVM_H__
> +
> +#include <asm/types.h>
> +
> +#define __KVM_HAVE_GUEST_DEBUG
> +
> +/*
> + * Modes used for short-hand mode determinition in the world-switch code and
> + * in emulation code.
> + *
> + * Note: These indices do NOT correspond to the value of the CPSR mode bits!
> + */
> +enum vcpu_modes {

Nitpick: s/vcpu_modes/vcpu_mode/ ?

...
> +static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)

static inline enum vcpu_mode vcpu_mode(struct kvm_vcpu *vcpu)...

> +{
> +	u8 modes_table[16] = {
> +		MODE_USR,	/* 0x0 */
> +		MODE_FIQ,	/* 0x1 */
> +		MODE_IRQ,	/* 0x2 */
> +		MODE_SVC,	/* 0x3 */
> +		0xf, 0xf, 0xf,
> +		MODE_ABT,	/* 0x7 */
> +		0xf, 0xf, 0xf,
> +		MODE_UND,	/* 0xb */
> +		0xf, 0xf, 0xf,
> +		MODE_SYS};	/* 0xf */
> +
> +	BUG_ON(modes_table[vcpu->arch.regs.cpsr & 0xf] == 0xf);
> +	return modes_table[vcpu->arch.regs.cpsr & 0xf];
> +}

Like much of your code, I find this far too readable.  How about:

enum vcpu_mode {
        MODE_USR,
        MODE_FIQ,
        MODE_IRQ,
        MODE_SVC,
        MODE_ABT,
        MODE_UND,
        MODE_SYS
};

static inline enum vcpu_mode vcpu_mode(const struct kvm_vcpu *vcpu)
{
        u8 mode = vcpu->arch.regs.cpsr & 0xf;
        return (mode & 3) + (mode >> 2);
}


> +/*
> + * Return the SPSR for the specified mode of the virtual CPU.
> + */
> +static inline u32 *kvm_vcpu_spsr(struct kvm_vcpu *vcpu, u32 mode)

s/u32/enum vcpu_mode/

> +{
> +	switch (mode) {
> +	case MODE_SVC:
> +		return &vcpu->arch.regs.svc_regs[2];
> +	case MODE_ABT:
> +		return &vcpu->arch.regs.svc_regs[2];
> +	case MODE_UND:
> +		return &vcpu->arch.regs.svc_regs[2];
> +	case MODE_IRQ:
> +		return &vcpu->arch.regs.svc_regs[2];

This reminds me: shouldn't these be:

	case MODE_ABT:
		return &vcpu->arch.regs.abt_regs[2];
	case MODE_UND:
		return &vcpu->arch.regs.und_regs[2];
	case MODE_IRQ:
		return &vcpu->arch.regs.irq_regs[2];

?

> +static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu)
> +{
> +	return &vcpu->arch.regs.cpsr;
> +}

In general, do you want accessors like this to all regs?  I'd like to
know, because injecting an undefined insn trap in the guest needs to
access the pc...

> +struct kvm_vcpu;
> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);

s/u32/enum vcpu_mode/

> +config KVM
> +	tristate "Kernel-based Virtual Machine (KVM) support"
> +	select PREEMPT_NOTIFIERS
> +	select ANON_INODES
> +	select KVM_ARM_HOST
> +	select KVM_MMIO
> +	depends on CPU_V7 && ARM_VIRT_EXT
> +	---help---
> +	  Support hosting virtualized guest machines. You will also
> +	  need to select one or more of the processor modules below.
> +
> +	  This module provides access to the hardware capabilities through
> +	  a character device node named /dev/kvm.
> +
> +	  If unsure, say N.
> +
> +config KVM_ARM_HOST
> +	bool "KVM host support for ARM cpus."
> +	depends on KVM
> +	depends on MMU
> +	depends on CPU_V7 && ARM_VIRT_EXT
> +	---help---
> +	  Provides host support for ARM processors.

I don't think KVM should select KVM_ARM_HOST (I assume there'll be a
KVM_ARM_GUEST one day).  Otherwise remove the prompt after 'bool' in
KVM_ARM_HOST.

> +/*
> + * Return a pointer to the register number valid in the specified mode of
> + * the virtual CPU.
> + */
> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
> +{
> +	BUG_ON(reg_num > 15);
> +	BUG_ON(mode > MODE_SYS);
> +
> +	return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
> +}

Hmm.... I tried to neaten this (untested).  Not sure if it's a win, your
call:

commit 7f99177bac6173968925f7329333e5bdf752be67
Author: Rusty Russell <rusty@rustcorp.com.au>
Date:   Fri Feb 24 13:37:44 2012 +1030

    ARM: KVM: neaten offset calculations.
    
    If we do this the C-correct way, we use fewer casts and it's a bit clearer.
    
    Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 73aece6..6f5b08f 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -84,7 +84,11 @@ enum cp15_regs {
 };
 
 struct kvm_vcpu_arch {
-	struct kvm_vcpu_regs regs;
+	/* We sometimes access these as an array for simplicity. */
+	union {
+		struct kvm_vcpu_regs regs;
+		u32 reg_array[sizeof(struct kvm_vcpu_regs) / sizeof(u32)];
+	};
 
 	/* System control coprocessor (cp15) */
 	u32 cp15[nr_cp15_regs];
diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
index 4f5f2de..108db38 100644
--- a/arch/arm/kvm/emulate.c
+++ b/arch/arm/kvm/emulate.c
@@ -22,8 +22,10 @@
 
 #include "trace.h"
 
-#define USR_REG_OFFSET(_reg) \
-	offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
+#define REG_OFFSET(_reg) \
+	(offsetof(struct kvm_vcpu_regs, _reg) / sizeof(u32))
+
+#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs[_num])
 
 static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 	/* FIQ Registers */
@@ -31,14 +33,14 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
 		USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7),
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r8 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r9 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[2]), /* r10 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[3]), /* r11 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[4]), /* r12 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[5]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.fiq_regs[6]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)		  /* r15 */
+		REG_OFFSET(fiq_regs[1]), /* r8 */
+		REG_OFFSET(fiq_regs[1]), /* r9 */
+		REG_OFFSET(fiq_regs[2]), /* r10 */
+		REG_OFFSET(fiq_regs[3]), /* r11 */
+		REG_OFFSET(fiq_regs[4]), /* r12 */
+		REG_OFFSET(fiq_regs[5]), /* r13 */
+		REG_OFFSET(fiq_regs[6]), /* r14 */
+		REG_OFFSET(pc)		 /* r15 */
 	},
 
 	/* IRQ Registers */
@@ -48,9 +50,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.irq_regs[0]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.irq_regs[1]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+		REG_OFFSET(irq_regs[0]), /* r13 */
+		REG_OFFSET(irq_regs[1]), /* r14 */
+		REG_OFFSET(pc)	         /* r15 */
 	},
 
 	/* SVC Registers */
@@ -60,9 +62,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.svc_regs[0]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.svc_regs[1]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)		  /* r15 */
+		REG_OFFSET(svc_regs[0]), /* r13 */
+		REG_OFFSET(svc_regs[1]), /* r14 */
+		REG_OFFSET(pc)		 /* r15 */
 	},
 
 	/* ABT Registers */
@@ -72,9 +74,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.abt_regs[0]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.abt_regs[1]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+		REG_OFFSET(abt_regs[0]), /* r13 */
+		REG_OFFSET(abt_regs[1]), /* r14 */
+		REG_OFFSET(pc)	         /* r15 */
 	},
 
 	/* UND Registers */
@@ -84,9 +86,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.und_regs[0]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.und_regs[1]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)	          /* r15 */
+		REG_OFFSET(und_regs[0]), /* r13 */
+		REG_OFFSET(und_regs[1]), /* r14 */
+		REG_OFFSET(pc)	         /* r15 */
 	},
 
 	/* USR Registers */
@@ -96,9 +98,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)	           /* r15 */
+		REG_OFFSET(usr_regs[13]), /* r13 */
+		REG_OFFSET(usr_regs[14]), /* r14 */
+		REG_OFFSET(pc)	          /* r15 */
 	},
 
 	/* SYS Registers */
@@ -108,9 +110,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
 		USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
 		USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
 		USR_REG_OFFSET(12),
-		offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
-		offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
-		offsetof(struct kvm_vcpu_arch, regs.pc)	           /* r15 */
+		REG_OFFSET(usr_regs[13]), /* r13 */
+		REG_OFFSET(usr_regs[14]), /* r14 */
+		REG_OFFSET(pc)	          /* r15 */
 	},
 };
 
@@ -123,7 +125,7 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
 	BUG_ON(reg_num > 15);
 	BUG_ON(mode > MODE_SYS);
 
-	return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
+	return &vcpu->arch.reg_array[vcpu_reg_offsets[mode][reg_num]];
 }
 
 /******************************************************************************

> +config ARM_VIRT_EXT
> +	bool "Support for ARM Virtualization Extensions"
> +	depends on ARM_LPAE
> +	help
> +	  Say Y if you have an ARMv7 processor supporting the ARM hardware
> +	  Virtualization extensions. KVM depends on this feature and will
> +	  not run without it being selected.
> +
>  config ARCH_PHYS_ADDR_T_64BIT
>  	def_bool ARM_LPAE

If you say Y here, you won't boot on a machine which hasn't got VIRT,
right?  That's changing, of course, with Dave's boot changes, but worth
mentioning either way I think.

Thanks,
Rusty.

^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping
  2012-02-23  7:32 ` [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping Christoffer Dall
@ 2012-02-24  3:33   ` Rusty Russell
  0 siblings, 0 replies; 24+ messages in thread
From: Rusty Russell @ 2012-02-24  3:33 UTC (permalink / raw)
  To: Christoffer Dall, android-virt, kvm; +Cc: tech

On Thu, 23 Feb 2012 02:32:33 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
> index 9c75ec4..c0adab0 100644
> --- a/arch/arm/kvm/guest.c
> +++ b/arch/arm/kvm/guest.c
> @@ -24,7 +24,6 @@
>  #include <asm/kvm_asm.h>
>  #include <asm/kvm_emulate.h>
>  
> -
>  struct kvm_stats_debugfs_item debugfs_entries[] = {
>  	{ NULL }
>  };

Cheers,
Rusty.

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-02-23  7:32 ` [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization Christoffer Dall
@ 2012-02-24  4:00   ` Rusty Russell
  2012-03-11 22:24     ` Christoffer Dall
  2012-03-05  1:12   ` Rusty Russell
  1 sibling, 1 reply; 24+ messages in thread
From: Rusty Russell @ 2012-02-24  4:00 UTC (permalink / raw)
  To: Christoffer Dall, android-virt, kvm; +Cc: tech

On Thu, 23 Feb 2012 02:32:39 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> +	/*
> +	 * Allocate stack pages for Hypervisor-mode
> +	 */
> +	for_each_possible_cpu(cpu)
> +		per_cpu(kvm_arm_hyp_stack_page, cpu) = NULL;

This is weird; we can't call this init function multiple times without
reloading the module.

> +	for_each_possible_cpu(cpu) {
> +		void *stack_page;
> +
> +		stack_page = (void *)__get_free_page(GFP_KERNEL);

Actually, if you change kvm_arm_hyp_stack_page to an unsigned long, and
your mapping functions to take unsigned long too, you can avoid many
casts.

Cheers,
Rusty.

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-24  3:32   ` Rusty Russell
@ 2012-02-24  4:43     ` Christoffer Dall
  2012-02-25  3:50       ` Rusty Russell
  2012-03-11 21:41     ` Christoffer Dall
  1 sibling, 1 reply; 24+ messages in thread
From: Christoffer Dall @ 2012-02-24  4:43 UTC (permalink / raw)
  To: Rusty Russell; +Cc: android-virt, kvm, Dave Martin, tech

On Thu, Feb 23, 2012 at 10:32 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Thu, 23 Feb 2012 02:32:26 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> From: Christoffer Dall <c.dall@virtualopensystems.com>
>>
>> Targets KVM support for Cortex A-15 processors.
>>
>> Contains no real functionality but all the framework components,
>> make files, header files and some tracing functionality.
>>
>> “Nothing to see here. Move along, move along..."
>>
>> Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.
>>
>> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
>> ---
>>  arch/arm/Kconfig                   |    2
>>  arch/arm/Makefile                  |    1
>>  arch/arm/include/asm/kvm.h         |   72 ++++++++++
>>  arch/arm/include/asm/kvm_asm.h     |   28 ++++
>>  arch/arm/include/asm/kvm_emulate.h |   92 +++++++++++++
>>  arch/arm/include/asm/kvm_host.h    |  116 ++++++++++++++++
>>  arch/arm/include/asm/kvm_para.h    |    9 +
>>  arch/arm/include/asm/unified.h     |   12 ++
>>  arch/arm/kvm/Kconfig               |   45 ++++++
>>  arch/arm/kvm/Makefile              |   17 ++
>>  arch/arm/kvm/arm.c                 |  256 ++++++++++++++++++++++++++++++++++++
>>  arch/arm/kvm/emulate.c             |  121 +++++++++++++++++
>>  arch/arm/kvm/exports.c             |   16 ++
>>  arch/arm/kvm/guest.c               |  148 +++++++++++++++++++++
>>  arch/arm/kvm/init.S                |   17 ++
>>  arch/arm/kvm/interrupts.S          |   17 ++
>>  arch/arm/kvm/mmu.c                 |   15 ++
>>  arch/arm/kvm/trace.h               |   52 +++++++
>>  arch/arm/mm/Kconfig                |    8 +
>>  19 files changed, 1044 insertions(+), 0 deletions(-)
>>  create mode 100644 arch/arm/include/asm/kvm.h
>>  create mode 100644 arch/arm/include/asm/kvm_asm.h
>>  create mode 100644 arch/arm/include/asm/kvm_emulate.h
>>  create mode 100644 arch/arm/include/asm/kvm_host.h
>>  create mode 100644 arch/arm/include/asm/kvm_para.h
>>  create mode 100644 arch/arm/kvm/Kconfig
>>  create mode 100644 arch/arm/kvm/Makefile
>>  create mode 100644 arch/arm/kvm/arm.c
>>  create mode 100644 arch/arm/kvm/emulate.c
>>  create mode 100644 arch/arm/kvm/exports.c
>>  create mode 100644 arch/arm/kvm/guest.c
>>  create mode 100644 arch/arm/kvm/init.S
>>  create mode 100644 arch/arm/kvm/interrupts.S
>>  create mode 100644 arch/arm/kvm/mmu.c
>>  create mode 100644 arch/arm/kvm/trace.h
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index e12bc34..81aa08f 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -2263,3 +2263,5 @@ source "security/Kconfig"
>>  source "crypto/Kconfig"
>>
>>  source "lib/Kconfig"
>> +
>> +source "arch/arm/kvm/Kconfig"
>> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
>> index 40319d9..eca44e0 100644
>> --- a/arch/arm/Makefile
>> +++ b/arch/arm/Makefile
>> @@ -253,6 +253,7 @@ core-$(CONFIG_VFP)                += arch/arm/vfp/
>>
>>  # If we have a machine-specific directory, then include it in the build.
>>  core-y                               += arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
>> +core-y                               += arch/arm/kvm/
>>  core-y                               += $(machdirs) $(platdirs)
>>
>>  drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
>> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
>> new file mode 100644
>> index 0000000..544cb2a
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm.h
>> @@ -0,0 +1,72 @@
>> +/*
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License, version 2, as
>> + * published by the Free Software Foundation.
>> + *
>> + * 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.
>> + *
>> + */
>> +
>> +#ifndef __ARM_KVM_H__
>> +#define __ARM_KVM_H__
>> +
>> +#include <asm/types.h>
>> +
>> +#define __KVM_HAVE_GUEST_DEBUG
>> +
>> +/*
>> + * Modes used for short-hand mode determinition in the world-switch code and
>> + * in emulation code.
>> + *
>> + * Note: These indices do NOT correspond to the value of the CPSR mode bits!
>> + */
>> +enum vcpu_modes {
>
> Nitpick: s/vcpu_modes/vcpu_mode/ ?
>
> ...
>> +static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)
>
> static inline enum vcpu_mode vcpu_mode(struct kvm_vcpu *vcpu)...
>
>> +{
>> +     u8 modes_table[16] = {
>> +             MODE_USR,       /* 0x0 */
>> +             MODE_FIQ,       /* 0x1 */
>> +             MODE_IRQ,       /* 0x2 */
>> +             MODE_SVC,       /* 0x3 */
>> +             0xf, 0xf, 0xf,
>> +             MODE_ABT,       /* 0x7 */
>> +             0xf, 0xf, 0xf,
>> +             MODE_UND,       /* 0xb */
>> +             0xf, 0xf, 0xf,
>> +             MODE_SYS};      /* 0xf */
>> +
>> +     BUG_ON(modes_table[vcpu->arch.regs.cpsr & 0xf] == 0xf);
>> +     return modes_table[vcpu->arch.regs.cpsr & 0xf];
>> +}
>
> Like much of your code, I find this far too readable.  How about:
>

"far too readable" - what does this mean?

> enum vcpu_mode {
>        MODE_USR,
>        MODE_FIQ,
>        MODE_IRQ,
>        MODE_SVC,
>        MODE_ABT,
>        MODE_UND,
>        MODE_SYS
> };
>
> static inline enum vcpu_mode vcpu_mode(const struct kvm_vcpu *vcpu)
> {
>        u8 mode = vcpu->arch.regs.cpsr & 0xf;
>        return (mode & 3) + (mode >> 2);
> }
>
>
>> +/*
>> + * Return the SPSR for the specified mode of the virtual CPU.
>> + */
>> +static inline u32 *kvm_vcpu_spsr(struct kvm_vcpu *vcpu, u32 mode)
>
> s/u32/enum vcpu_mode/
>
>> +{
>> +     switch (mode) {
>> +     case MODE_SVC:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_ABT:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_UND:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_IRQ:
>> +             return &vcpu->arch.regs.svc_regs[2];
>
> This reminds me: shouldn't these be:
>
>        case MODE_ABT:
>                return &vcpu->arch.regs.abt_regs[2];
>        case MODE_UND:
>                return &vcpu->arch.regs.und_regs[2];
>        case MODE_IRQ:
>                return &vcpu->arch.regs.irq_regs[2];
>
> ?
>
>> +static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu)
>> +{
>> +     return &vcpu->arch.regs.cpsr;
>> +}
>
> In general, do you want accessors like this to all regs?  I'd like to
> know, because injecting an undefined insn trap in the guest needs to
> access the pc...
>
>> +struct kvm_vcpu;
>> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
>
> s/u32/enum vcpu_mode/
>
>> +config KVM
>> +     tristate "Kernel-based Virtual Machine (KVM) support"
>> +     select PREEMPT_NOTIFIERS
>> +     select ANON_INODES
>> +     select KVM_ARM_HOST
>> +     select KVM_MMIO
>> +     depends on CPU_V7 && ARM_VIRT_EXT
>> +     ---help---
>> +       Support hosting virtualized guest machines. You will also
>> +       need to select one or more of the processor modules below.
>> +
>> +       This module provides access to the hardware capabilities through
>> +       a character device node named /dev/kvm.
>> +
>> +       If unsure, say N.
>> +
>> +config KVM_ARM_HOST
>> +     bool "KVM host support for ARM cpus."
>> +     depends on KVM
>> +     depends on MMU
>> +     depends on CPU_V7 && ARM_VIRT_EXT
>> +     ---help---
>> +       Provides host support for ARM processors.
>
> I don't think KVM should select KVM_ARM_HOST (I assume there'll be a
> KVM_ARM_GUEST one day).  Otherwise remove the prompt after 'bool' in
> KVM_ARM_HOST.
>
>> +/*
>> + * Return a pointer to the register number valid in the specified mode of
>> + * the virtual CPU.
>> + */
>> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
>> +{
>> +     BUG_ON(reg_num > 15);
>> +     BUG_ON(mode > MODE_SYS);
>> +
>> +     return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
>> +}
>
> Hmm.... I tried to neaten this (untested).  Not sure if it's a win, your
> call:
>
> commit 7f99177bac6173968925f7329333e5bdf752be67
> Author: Rusty Russell <rusty@rustcorp.com.au>
> Date:   Fri Feb 24 13:37:44 2012 +1030
>
>    ARM: KVM: neaten offset calculations.
>
>    If we do this the C-correct way, we use fewer casts and it's a bit clearer.
>
>    Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 73aece6..6f5b08f 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -84,7 +84,11 @@ enum cp15_regs {
>  };
>
>  struct kvm_vcpu_arch {
> -       struct kvm_vcpu_regs regs;
> +       /* We sometimes access these as an array for simplicity. */
> +       union {
> +               struct kvm_vcpu_regs regs;
> +               u32 reg_array[sizeof(struct kvm_vcpu_regs) / sizeof(u32)];
> +       };
>
>        /* System control coprocessor (cp15) */
>        u32 cp15[nr_cp15_regs];
> diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
> index 4f5f2de..108db38 100644
> --- a/arch/arm/kvm/emulate.c
> +++ b/arch/arm/kvm/emulate.c
> @@ -22,8 +22,10 @@
>
>  #include "trace.h"
>
> -#define USR_REG_OFFSET(_reg) \
> -       offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
> +#define REG_OFFSET(_reg) \
> +       (offsetof(struct kvm_vcpu_regs, _reg) / sizeof(u32))
> +
> +#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs[_num])
>
>  static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>        /* FIQ Registers */
> @@ -31,14 +33,14 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>                USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7),
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r8 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r9 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[2]), /* r10 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[3]), /* r11 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[4]), /* r12 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[5]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[6]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(fiq_regs[1]), /* r8 */
> +               REG_OFFSET(fiq_regs[1]), /* r9 */
> +               REG_OFFSET(fiq_regs[2]), /* r10 */
> +               REG_OFFSET(fiq_regs[3]), /* r11 */
> +               REG_OFFSET(fiq_regs[4]), /* r12 */
> +               REG_OFFSET(fiq_regs[5]), /* r13 */
> +               REG_OFFSET(fiq_regs[6]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* IRQ Registers */
> @@ -48,9 +50,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.irq_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.irq_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(irq_regs[0]), /* r13 */
> +               REG_OFFSET(irq_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* SVC Registers */
> @@ -60,9 +62,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.svc_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.svc_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(svc_regs[0]), /* r13 */
> +               REG_OFFSET(svc_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* ABT Registers */
> @@ -72,9 +74,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.abt_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.abt_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(abt_regs[0]), /* r13 */
> +               REG_OFFSET(abt_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* UND Registers */
> @@ -84,9 +86,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.und_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.und_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(und_regs[0]), /* r13 */
> +               REG_OFFSET(und_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* USR Registers */
> @@ -96,9 +98,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)            /* r15 */
> +               REG_OFFSET(usr_regs[13]), /* r13 */
> +               REG_OFFSET(usr_regs[14]), /* r14 */
> +               REG_OFFSET(pc)            /* r15 */
>        },
>
>        /* SYS Registers */
> @@ -108,9 +110,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)            /* r15 */
> +               REG_OFFSET(usr_regs[13]), /* r13 */
> +               REG_OFFSET(usr_regs[14]), /* r14 */
> +               REG_OFFSET(pc)            /* r15 */
>        },
>  };
>
> @@ -123,7 +125,7 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
>        BUG_ON(reg_num > 15);
>        BUG_ON(mode > MODE_SYS);
>
> -       return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
> +       return &vcpu->arch.reg_array[vcpu_reg_offsets[mode][reg_num]];
>  }
>
>  /******************************************************************************
>
>> +config ARM_VIRT_EXT
>> +     bool "Support for ARM Virtualization Extensions"
>> +     depends on ARM_LPAE
>> +     help
>> +       Say Y if you have an ARMv7 processor supporting the ARM hardware
>> +       Virtualization extensions. KVM depends on this feature and will
>> +       not run without it being selected.
>> +
>>  config ARCH_PHYS_ADDR_T_64BIT
>>       def_bool ARM_LPAE
>
> If you say Y here, you won't boot on a machine which hasn't got VIRT,
> right?  That's changing, of course, with Dave's boot changes, but worth
> mentioning either way I think.
>
> Thanks,
> Rusty.

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-24  4:43     ` Christoffer Dall
@ 2012-02-25  3:50       ` Rusty Russell
  2012-02-25 15:20         ` Christoffer Dall
  0 siblings, 1 reply; 24+ messages in thread
From: Rusty Russell @ 2012-02-25  3:50 UTC (permalink / raw)
  To: Christoffer Dall; +Cc: android-virt, kvm, Dave Martin, tech

On Thu, 23 Feb 2012 23:43:14 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> > Like much of your code, I find this far too readable.  How about:
> 
> "far too readable" - what does this mean?

It means I was joking with my suggestion.

I do this so often as I review patches just to keep my mind engaged.

Clearly, my humor failed here.
Rusty.

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-25  3:50       ` Rusty Russell
@ 2012-02-25 15:20         ` Christoffer Dall
  0 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-02-25 15:20 UTC (permalink / raw)
  To: Rusty Russell; +Cc: android-virt, kvm, Dave Martin, tech

On Fri, Feb 24, 2012 at 10:50 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Thu, 23 Feb 2012 23:43:14 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> > Like much of your code, I find this far too readable.  How about:
>>
>> "far too readable" - what does this mean?
>
> It means I was joking with my suggestion.
>
> I do this so often as I review patches just to keep my mind engaged.
>
> Clearly, my humor failed here.

lol, wow, I completely missed that. Thanks :)

Consider my senses tuned for next time around...

-Christoffer

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-02-23  7:32 ` [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization Christoffer Dall
  2012-02-24  4:00   ` Rusty Russell
@ 2012-03-05  1:12   ` Rusty Russell
  2012-03-05  2:13     ` Christoffer Dall
  1 sibling, 1 reply; 24+ messages in thread
From: Rusty Russell @ 2012-03-05  1:12 UTC (permalink / raw)
  To: Christoffer Dall, android-virt, kvm; +Cc: tech

On Thu, 23 Feb 2012 02:32:39 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> From: Christoffer Dall <c.dall@virtualopensystems.com>
> 
> +static void cpu_set_vector(void *vector)
> +{
> +	unsigned long vector_ptr;
> +	unsigned long smc_hyp_nr;
> +
> +	vector_ptr = (unsigned long)vector;
> +	smc_hyp_nr = SMCHYP_HVBAR_W;
> +
> +	/*
> +	 * Set the HVBAR
> +	 */
> +	asm volatile (
> +		"mov	r0, %[vector_ptr]\n\t"
> +		"mov	r7, %[smc_hyp_nr]\n\t"
> +		"smc	#0\n\t" : :
> +		[vector_ptr] "r" (vector_ptr),
> +		[smc_hyp_nr] "r" (smc_hyp_nr) :
> +		"r0", "r1");

Testing this recently, trying to get a kvm guest to boot.  No success
yet, but I did get another issue when I compiled the host non-SMP: you
need to mark r7 as clobbered here (on SMP we didn't clobber anything
important, but on UP it hit init_end_phys_addr and changed it to
0xffffffff and we died horribly in hyp_idmap_del().

Thanks,
Rusty.

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 3772847..146604a 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -585,7 +585,7 @@ static void cpu_set_vector(void *vector)
 		"smc	#0\n\t" : :
 		[vector_ptr] "r" (vector_ptr),
 		[smc_hyp_nr] "r" (smc_hyp_nr) :
-		"r0", "r1");
+		"r0", "r1", "r7");
 }
 
 static void cpu_init_hyp_mode(void *vector)

Cheers,
Rusty.

^ permalink raw reply related	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-03-05  1:12   ` Rusty Russell
@ 2012-03-05  2:13     ` Christoffer Dall
  0 siblings, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-03-05  2:13 UTC (permalink / raw)
  To: Rusty Russell; +Cc: android-virt, kvm, tech

On Sun, Mar 4, 2012 at 8:12 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Thu, 23 Feb 2012 02:32:39 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> From: Christoffer Dall <c.dall@virtualopensystems.com>
>>
>> +static void cpu_set_vector(void *vector)
>> +{
>> +     unsigned long vector_ptr;
>> +     unsigned long smc_hyp_nr;
>> +
>> +     vector_ptr = (unsigned long)vector;
>> +     smc_hyp_nr = SMCHYP_HVBAR_W;
>> +
>> +     /*
>> +      * Set the HVBAR
>> +      */
>> +     asm volatile (
>> +             "mov    r0, %[vector_ptr]\n\t"
>> +             "mov    r7, %[smc_hyp_nr]\n\t"
>> +             "smc    #0\n\t" : :
>> +             [vector_ptr] "r" (vector_ptr),
>> +             [smc_hyp_nr] "r" (smc_hyp_nr) :
>> +             "r0", "r1");
>
> Testing this recently, trying to get a kvm guest to boot.  No success
> yet, but I did get another issue when I compiled the host non-SMP: you
> need to mark r7 as clobbered here (on SMP we didn't clobber anything
> important, but on UP it hit init_end_phys_addr and changed it to
> 0xffffffff and we died horribly in hyp_idmap_del().
>

you're absolutely right. Nice catch. Thanks.

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support
  2012-02-24  3:32   ` Rusty Russell
  2012-02-24  4:43     ` Christoffer Dall
@ 2012-03-11 21:41     ` Christoffer Dall
  1 sibling, 0 replies; 24+ messages in thread
From: Christoffer Dall @ 2012-03-11 21:41 UTC (permalink / raw)
  To: Rusty Russell; +Cc: android-virt, kvm, Dave Martin, tech

On Thu, Feb 23, 2012 at 10:32 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Thu, 23 Feb 2012 02:32:26 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> From: Christoffer Dall <c.dall@virtualopensystems.com>
>>
>> Targets KVM support for Cortex A-15 processors.
>>
>> Contains no real functionality but all the framework components,
>> make files, header files and some tracing functionality.
>>
>> “Nothing to see here. Move along, move along..."
>>
>> Most functionality is in arch/arm/kvm/* or arch/arm/include/asm/kvm_*.h.
>>
>> Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
>> ---
>>  arch/arm/Kconfig                   |    2
>>  arch/arm/Makefile                  |    1
>>  arch/arm/include/asm/kvm.h         |   72 ++++++++++
>>  arch/arm/include/asm/kvm_asm.h     |   28 ++++
>>  arch/arm/include/asm/kvm_emulate.h |   92 +++++++++++++
>>  arch/arm/include/asm/kvm_host.h    |  116 ++++++++++++++++
>>  arch/arm/include/asm/kvm_para.h    |    9 +
>>  arch/arm/include/asm/unified.h     |   12 ++
>>  arch/arm/kvm/Kconfig               |   45 ++++++
>>  arch/arm/kvm/Makefile              |   17 ++
>>  arch/arm/kvm/arm.c                 |  256 ++++++++++++++++++++++++++++++++++++
>>  arch/arm/kvm/emulate.c             |  121 +++++++++++++++++
>>  arch/arm/kvm/exports.c             |   16 ++
>>  arch/arm/kvm/guest.c               |  148 +++++++++++++++++++++
>>  arch/arm/kvm/init.S                |   17 ++
>>  arch/arm/kvm/interrupts.S          |   17 ++
>>  arch/arm/kvm/mmu.c                 |   15 ++
>>  arch/arm/kvm/trace.h               |   52 +++++++
>>  arch/arm/mm/Kconfig                |    8 +
>>  19 files changed, 1044 insertions(+), 0 deletions(-)
>>  create mode 100644 arch/arm/include/asm/kvm.h
>>  create mode 100644 arch/arm/include/asm/kvm_asm.h
>>  create mode 100644 arch/arm/include/asm/kvm_emulate.h
>>  create mode 100644 arch/arm/include/asm/kvm_host.h
>>  create mode 100644 arch/arm/include/asm/kvm_para.h
>>  create mode 100644 arch/arm/kvm/Kconfig
>>  create mode 100644 arch/arm/kvm/Makefile
>>  create mode 100644 arch/arm/kvm/arm.c
>>  create mode 100644 arch/arm/kvm/emulate.c
>>  create mode 100644 arch/arm/kvm/exports.c
>>  create mode 100644 arch/arm/kvm/guest.c
>>  create mode 100644 arch/arm/kvm/init.S
>>  create mode 100644 arch/arm/kvm/interrupts.S
>>  create mode 100644 arch/arm/kvm/mmu.c
>>  create mode 100644 arch/arm/kvm/trace.h
>>
>> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
>> index e12bc34..81aa08f 100644
>> --- a/arch/arm/Kconfig
>> +++ b/arch/arm/Kconfig
>> @@ -2263,3 +2263,5 @@ source "security/Kconfig"
>>  source "crypto/Kconfig"
>>
>>  source "lib/Kconfig"
>> +
>> +source "arch/arm/kvm/Kconfig"
>> diff --git a/arch/arm/Makefile b/arch/arm/Makefile
>> index 40319d9..eca44e0 100644
>> --- a/arch/arm/Makefile
>> +++ b/arch/arm/Makefile
>> @@ -253,6 +253,7 @@ core-$(CONFIG_VFP)                += arch/arm/vfp/
>>
>>  # If we have a machine-specific directory, then include it in the build.
>>  core-y                               += arch/arm/kernel/ arch/arm/mm/ arch/arm/common/
>> +core-y                               += arch/arm/kvm/
>>  core-y                               += $(machdirs) $(platdirs)
>>
>>  drivers-$(CONFIG_OPROFILE)      += arch/arm/oprofile/
>> diff --git a/arch/arm/include/asm/kvm.h b/arch/arm/include/asm/kvm.h
>> new file mode 100644
>> index 0000000..544cb2a
>> --- /dev/null
>> +++ b/arch/arm/include/asm/kvm.h
>> @@ -0,0 +1,72 @@
>> +/*
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License, version 2, as
>> + * published by the Free Software Foundation.
>> + *
>> + * 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.
>> + *
>> + */
>> +
>> +#ifndef __ARM_KVM_H__
>> +#define __ARM_KVM_H__
>> +
>> +#include <asm/types.h>
>> +
>> +#define __KVM_HAVE_GUEST_DEBUG
>> +
>> +/*
>> + * Modes used for short-hand mode determinition in the world-switch code and
>> + * in emulation code.
>> + *
>> + * Note: These indices do NOT correspond to the value of the CPSR mode bits!
>> + */
>> +enum vcpu_modes {
>
> Nitpick: s/vcpu_modes/vcpu_mode/ ?
>
> ...
>> +static inline unsigned char vcpu_mode(struct kvm_vcpu *vcpu)
>
> static inline enum vcpu_mode vcpu_mode(struct kvm_vcpu *vcpu)...
>
>> +{
>> +     u8 modes_table[16] = {
>> +             MODE_USR,       /* 0x0 */
>> +             MODE_FIQ,       /* 0x1 */
>> +             MODE_IRQ,       /* 0x2 */
>> +             MODE_SVC,       /* 0x3 */
>> +             0xf, 0xf, 0xf,
>> +             MODE_ABT,       /* 0x7 */
>> +             0xf, 0xf, 0xf,
>> +             MODE_UND,       /* 0xb */
>> +             0xf, 0xf, 0xf,
>> +             MODE_SYS};      /* 0xf */
>> +
>> +     BUG_ON(modes_table[vcpu->arch.regs.cpsr & 0xf] == 0xf);
>> +     return modes_table[vcpu->arch.regs.cpsr & 0xf];
>> +}
>
> Like much of your code, I find this far too readable.  How about:
>
> enum vcpu_mode {
>        MODE_USR,
>        MODE_FIQ,
>        MODE_IRQ,
>        MODE_SVC,
>        MODE_ABT,
>        MODE_UND,
>        MODE_SYS
> };
>
> static inline enum vcpu_mode vcpu_mode(const struct kvm_vcpu *vcpu)
> {
>        u8 mode = vcpu->arch.regs.cpsr & 0xf;
>        return (mode & 3) + (mode >> 2);
> }
>
>
>> +/*
>> + * Return the SPSR for the specified mode of the virtual CPU.
>> + */
>> +static inline u32 *kvm_vcpu_spsr(struct kvm_vcpu *vcpu, u32 mode)
>
> s/u32/enum vcpu_mode/
>
>> +{
>> +     switch (mode) {
>> +     case MODE_SVC:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_ABT:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_UND:
>> +             return &vcpu->arch.regs.svc_regs[2];
>> +     case MODE_IRQ:
>> +             return &vcpu->arch.regs.svc_regs[2];
>
> This reminds me: shouldn't these be:
>
>        case MODE_ABT:
>                return &vcpu->arch.regs.abt_regs[2];
>        case MODE_UND:
>                return &vcpu->arch.regs.und_regs[2];
>        case MODE_IRQ:
>                return &vcpu->arch.regs.irq_regs[2];
>
> ?
>

yes, definitely should. thanks.

>> +static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu)
>> +{
>> +     return &vcpu->arch.regs.cpsr;
>> +}
>
> In general, do you want accessors like this to all regs?  I'd like to
> know, because injecting an undefined insn trap in the guest needs to
> access the pc...
>

hmm, not really, but I kind of like it for simplicity and it goes nice
with kvm_vcpu_spsr, which should be called vcpu_spsr in the same light
of things by the way. I would have no problem having a vcpu_pc()
accessor as well, that wraps around vcpu_reg.

>> +struct kvm_vcpu;
>> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode);
>
> s/u32/enum vcpu_mode/
>
>> +config KVM
>> +     tristate "Kernel-based Virtual Machine (KVM) support"
>> +     select PREEMPT_NOTIFIERS
>> +     select ANON_INODES
>> +     select KVM_ARM_HOST
>> +     select KVM_MMIO
>> +     depends on CPU_V7 && ARM_VIRT_EXT
>> +     ---help---
>> +       Support hosting virtualized guest machines. You will also
>> +       need to select one or more of the processor modules below.
>> +
>> +       This module provides access to the hardware capabilities through
>> +       a character device node named /dev/kvm.
>> +
>> +       If unsure, say N.
>> +
>> +config KVM_ARM_HOST
>> +     bool "KVM host support for ARM cpus."
>> +     depends on KVM
>> +     depends on MMU
>> +     depends on CPU_V7 && ARM_VIRT_EXT
>> +     ---help---
>> +       Provides host support for ARM processors.
>
> I don't think KVM should select KVM_ARM_HOST (I assume there'll be a
> KVM_ARM_GUEST one day).  Otherwise remove the prompt after 'bool' in
> KVM_ARM_HOST.
>

I see. I removed the select.

>> +/*
>> + * Return a pointer to the register number valid in the specified mode of
>> + * the virtual CPU.
>> + */
>> +u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
>> +{
>> +     BUG_ON(reg_num > 15);
>> +     BUG_ON(mode > MODE_SYS);
>> +
>> +     return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
>> +}
>
> Hmm.... I tried to neaten this (untested).  Not sure if it's a win, your
> call:
>

I like the macros and getting rid of the horrible casts. I am not sure
about the union in the struct though as people might have to grep for
both access names if they wish to see where something is modified and
such - and since it serves only that single access point. How about
creating that array in kvm_vcpu_reg function instead? I'll take your
newer patch and modify it and see where that takes me.

Thanks for reworking this.

> commit 7f99177bac6173968925f7329333e5bdf752be67
> Author: Rusty Russell <rusty@rustcorp.com.au>
> Date:   Fri Feb 24 13:37:44 2012 +1030
>
>    ARM: KVM: neaten offset calculations.
>
>    If we do this the C-correct way, we use fewer casts and it's a bit clearer.
>
>    Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
>
> diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
> index 73aece6..6f5b08f 100644
> --- a/arch/arm/include/asm/kvm_host.h
> +++ b/arch/arm/include/asm/kvm_host.h
> @@ -84,7 +84,11 @@ enum cp15_regs {
>  };
>
>  struct kvm_vcpu_arch {
> -       struct kvm_vcpu_regs regs;
> +       /* We sometimes access these as an array for simplicity. */
> +       union {
> +               struct kvm_vcpu_regs regs;
> +               u32 reg_array[sizeof(struct kvm_vcpu_regs) / sizeof(u32)];
> +       };
>
>        /* System control coprocessor (cp15) */
>        u32 cp15[nr_cp15_regs];
> diff --git a/arch/arm/kvm/emulate.c b/arch/arm/kvm/emulate.c
> index 4f5f2de..108db38 100644
> --- a/arch/arm/kvm/emulate.c
> +++ b/arch/arm/kvm/emulate.c
> @@ -22,8 +22,10 @@
>
>  #include "trace.h"
>
> -#define USR_REG_OFFSET(_reg) \
> -       offsetof(struct kvm_vcpu_arch, regs.usr_regs[_reg])
> +#define REG_OFFSET(_reg) \
> +       (offsetof(struct kvm_vcpu_regs, _reg) / sizeof(u32))
> +
> +#define USR_REG_OFFSET(_num) REG_OFFSET(usr_regs[_num])
>
>  static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>        /* FIQ Registers */
> @@ -31,14 +33,14 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(0), USR_REG_OFFSET(1), USR_REG_OFFSET(2),
>                USR_REG_OFFSET(3), USR_REG_OFFSET(4), USR_REG_OFFSET(5),
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7),
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r8 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[1]), /* r9 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[2]), /* r10 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[3]), /* r11 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[4]), /* r12 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[5]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.fiq_regs[6]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(fiq_regs[1]), /* r8 */
> +               REG_OFFSET(fiq_regs[1]), /* r9 */
> +               REG_OFFSET(fiq_regs[2]), /* r10 */
> +               REG_OFFSET(fiq_regs[3]), /* r11 */
> +               REG_OFFSET(fiq_regs[4]), /* r12 */
> +               REG_OFFSET(fiq_regs[5]), /* r13 */
> +               REG_OFFSET(fiq_regs[6]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* IRQ Registers */
> @@ -48,9 +50,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.irq_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.irq_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(irq_regs[0]), /* r13 */
> +               REG_OFFSET(irq_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* SVC Registers */
> @@ -60,9 +62,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.svc_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.svc_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(svc_regs[0]), /* r13 */
> +               REG_OFFSET(svc_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* ABT Registers */
> @@ -72,9 +74,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.abt_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.abt_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(abt_regs[0]), /* r13 */
> +               REG_OFFSET(abt_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* UND Registers */
> @@ -84,9 +86,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.und_regs[0]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.und_regs[1]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)           /* r15 */
> +               REG_OFFSET(und_regs[0]), /* r13 */
> +               REG_OFFSET(und_regs[1]), /* r14 */
> +               REG_OFFSET(pc)           /* r15 */
>        },
>
>        /* USR Registers */
> @@ -96,9 +98,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)            /* r15 */
> +               REG_OFFSET(usr_regs[13]), /* r13 */
> +               REG_OFFSET(usr_regs[14]), /* r14 */
> +               REG_OFFSET(pc)            /* r15 */
>        },
>
>        /* SYS Registers */
> @@ -108,9 +110,9 @@ static const unsigned long vcpu_reg_offsets[MODE_SYS + 1][16] = {
>                USR_REG_OFFSET(6), USR_REG_OFFSET(7), USR_REG_OFFSET(8),
>                USR_REG_OFFSET(9), USR_REG_OFFSET(10), USR_REG_OFFSET(11),
>                USR_REG_OFFSET(12),
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[13]), /* r13 */
> -               offsetof(struct kvm_vcpu_arch, regs.usr_regs[14]), /* r14 */
> -               offsetof(struct kvm_vcpu_arch, regs.pc)            /* r15 */
> +               REG_OFFSET(usr_regs[13]), /* r13 */
> +               REG_OFFSET(usr_regs[14]), /* r14 */
> +               REG_OFFSET(pc)            /* r15 */
>        },
>  };
>
> @@ -123,7 +125,7 @@ u32 *kvm_vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num, u32 mode)
>        BUG_ON(reg_num > 15);
>        BUG_ON(mode > MODE_SYS);
>
> -       return (u32 *)((void *)&vcpu->arch + vcpu_reg_offsets[mode][reg_num]);
> +       return &vcpu->arch.reg_array[vcpu_reg_offsets[mode][reg_num]];
>  }
>
>  /******************************************************************************
>
>> +config ARM_VIRT_EXT
>> +     bool "Support for ARM Virtualization Extensions"
>> +     depends on ARM_LPAE
>> +     help
>> +       Say Y if you have an ARMv7 processor supporting the ARM hardware
>> +       Virtualization extensions. KVM depends on this feature and will
>> +       not run without it being selected.
>> +
>>  config ARCH_PHYS_ADDR_T_64BIT
>>       def_bool ARM_LPAE
>
> If you say Y here, you won't boot on a machine which hasn't got VIRT,
> right?  That's changing, of course, with Dave's boot changes, but worth
> mentioning either way I think.
>

definitely. comment added.

-Christoffer

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-02-24  4:00   ` Rusty Russell
@ 2012-03-11 22:24     ` Christoffer Dall
  2012-03-13  3:20       ` Rusty Russell
  0 siblings, 1 reply; 24+ messages in thread
From: Christoffer Dall @ 2012-03-11 22:24 UTC (permalink / raw)
  To: Rusty Russell; +Cc: android-virt, kvm, tech

On Thu, Feb 23, 2012 at 11:00 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> On Thu, 23 Feb 2012 02:32:39 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
>> +     /*
>> +      * Allocate stack pages for Hypervisor-mode
>> +      */
>> +     for_each_possible_cpu(cpu)
>> +             per_cpu(kvm_arm_hyp_stack_page, cpu) = NULL;
>
> This is weird; we can't call this init function multiple times without
> reloading the module.
>

what you're saying is that static DEFINE_PER_CPU will still be
initialized to zero? I don't actually have experience with this, but I
assumed that the data..percpu section would not necessarily be zeroed
out when loading a module... Now I tried to look, but I couldn't
convince myself. Can you enlighten me?

>> +     for_each_possible_cpu(cpu) {
>> +             void *stack_page;
>> +
>> +             stack_page = (void *)__get_free_page(GFP_KERNEL);
>
> Actually, if you change kvm_arm_hyp_stack_page to an unsigned long, and
> your mapping functions to take unsigned long too, you can avoid many
> casts.
>
true, thanks.

-Christoffer

^ permalink raw reply	[flat|nested] 24+ messages in thread

* Re: [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization
  2012-03-11 22:24     ` Christoffer Dall
@ 2012-03-13  3:20       ` Rusty Russell
  0 siblings, 0 replies; 24+ messages in thread
From: Rusty Russell @ 2012-03-13  3:20 UTC (permalink / raw)
  To: Christoffer Dall; +Cc: android-virt, kvm, tech

On Sun, 11 Mar 2012 18:24:03 -0400, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> On Thu, Feb 23, 2012 at 11:00 PM, Rusty Russell <rusty@rustcorp.com.au> wrote:
> > On Thu, 23 Feb 2012 02:32:39 -0500, Christoffer Dall <c.dall@virtualopensystems.com> wrote:
> >> +     /*
> >> +      * Allocate stack pages for Hypervisor-mode
> >> +      */
> >> +     for_each_possible_cpu(cpu)
> >> +             per_cpu(kvm_arm_hyp_stack_page, cpu) = NULL;
> >
> > This is weird; we can't call this init function multiple times without
> > reloading the module.
> >
> 
> what you're saying is that static DEFINE_PER_CPU will still be
> initialized to zero? I don't actually have experience with this, but I
> assumed that the data..percpu section would not necessarily be zeroed
> out when loading a module... Now I tried to look, but I couldn't
> convince myself. Can you enlighten me?

Absolutely and definitely.  It's placed in a special section, and from
there copied into the per-cpu sections by the module loader but still
follows the C semantics of being zero-initialized.

Cheers,
Rusty.
-- 
  How could I marry someone with more hair than me?  http://baldalex.org

^ permalink raw reply	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2012-03-13  4:40 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-02-23  7:32 [PATCH v6 00/12] KVM/ARM Implementation Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 01/12] KVM: Introduce __KVM_HAVE_IRQ_LINE Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 02/12] ARM: KVM: Initial skeleton to compile KVM support Christoffer Dall
2012-02-24  3:32   ` Rusty Russell
2012-02-24  4:43     ` Christoffer Dall
2012-02-25  3:50       ` Rusty Russell
2012-02-25 15:20         ` Christoffer Dall
2012-03-11 21:41     ` Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 03/12] ARM: KVM: Hypervisor identity mapping Christoffer Dall
2012-02-24  3:33   ` Rusty Russell
2012-02-23  7:32 ` [PATCH v6 04/12] ARM: KVM: Hypervisor inititalization Christoffer Dall
2012-02-24  4:00   ` Rusty Russell
2012-03-11 22:24     ` Christoffer Dall
2012-03-13  3:20       ` Rusty Russell
2012-03-05  1:12   ` Rusty Russell
2012-03-05  2:13     ` Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 05/12] ARM: KVM: Memory virtualization setup Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 06/12] ARM: KVM: Inject IRQs and FIQs from userspace Christoffer Dall
2012-02-23  7:32 ` [PATCH v6 07/12] ARM: KVM: World-switch implementation Christoffer Dall
2012-02-23  7:33 ` [PATCH v6 08/12] ARM: KVM: Emulation framework and CP15 emulation Christoffer Dall
2012-02-23  7:33 ` [PATCH v6 09/12] ARM: KVM: Handle guest faults in KVM Christoffer Dall
2012-02-23  7:33 ` [PATCH v6 10/12] ARM: KVM: Handle I/O aborts Christoffer Dall
2012-02-23  7:33 ` [PATCH v6 11/12] ARM: KVM: Guest wait-for-interrupts (WFI) support Christoffer Dall
2012-02-23  7:33 ` [PATCH v6 12/12] ARM: KVM: Handle CP15 CR9 accesses for L2CTLR emulation Christoffer Dall

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