KVM: ARM: Initial skeleton to compile KVM support

Targets KVM support for Cortex A-15 processors.

Contains all the framework components, make files, header files, some
tracing functionality, and basic user space API.

Only supported core is Cortex-A15 for now.

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

Reviewed-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>

Documentation/virtual/kvm/api.txt

@@ -293,7 +293,7 @@ kvm_run' (see below).
 4.11 KVM_GET_REGS
 
 Capability: basic
-Architectures: all
+Architectures: all except ARM
 Type: vcpu ioctl
 Parameters: struct kvm_regs (out)
 Returns: 0 on success, -1 on error
@@ -314,7 +314,7 @@ struct kvm_regs {
 4.12 KVM_SET_REGS
 
 Capability: basic
-Architectures: all
+Architectures: all except ARM
 Type: vcpu ioctl
 Parameters: struct kvm_regs (in)
 Returns: 0 on success, -1 on error
@@ -600,15 +600,16 @@ struct kvm_fpu {
 4.24 KVM_CREATE_IRQCHIP
 
 Capability: KVM_CAP_IRQCHIP
-Architectures: x86, ia64
+Architectures: x86, ia64, ARM
 Type: vm ioctl
 Parameters: none
 Returns: 0 on success, -1 on error
 
 Creates an interrupt controller model in the kernel.  On x86, creates a virtual
 ioapic, a virtual PIC (two PICs, nested), and sets up future vcpus to have a
 local APIC.  IRQ routing for GSIs 0-15 is set to both PIC and IOAPIC; GSI 16-23
-only go to the IOAPIC.  On ia64, a IOSAPIC is created.
+only go to the IOAPIC.  On ia64, a IOSAPIC is created. On ARM, a GIC is
+created.
 
 
 4.25 KVM_IRQ_LINE
@@ -1775,6 +1776,14 @@ registers, find a list below:
   PPC   | KVM_REG_PPC_VPA_DTL   | 128
   PPC   | KVM_REG_PPC_EPCR	| 32
 
+ARM registers are mapped using the lower 32 bits.  The upper 16 of that
+is the register group type, or coprocessor number:
+
+ARM core registers have the following id bit patterns:
+  0x4002 0000 0010 <index into the kvm_regs struct:16>
+
+
+
 4.69 KVM_GET_ONE_REG
 
 Capability: KVM_CAP_ONE_REG
@@ -2127,6 +2136,46 @@ written, then `n_invalid' invalid entries, invalidating any previously
 valid entries found.
 
 
+4.77 KVM_ARM_VCPU_INIT
+
+Capability: basic
+Architectures: arm
+Type: vcpu ioctl
+Parameters: struct struct kvm_vcpu_init (in)
+Returns: 0 on success; -1 on error
+Errors:
+  EINVAL:    the target is unknown, or the combination of features is invalid.
+  ENOENT:    a features bit specified is unknown.
+
+This tells KVM what type of CPU to present to the guest, and what
+optional features it should have.  This will cause a reset of the cpu
+registers to their initial values.  If this is not called, KVM_RUN will
+return ENOEXEC for that vcpu.
+
+Note that because some registers reflect machine topology, all vcpus
+should be created before this ioctl is invoked.
+
+
+4.78 KVM_GET_REG_LIST
+
+Capability: basic
+Architectures: arm
+Type: vcpu ioctl
+Parameters: struct kvm_reg_list (in/out)
+Returns: 0 on success; -1 on error
+Errors:
+  E2BIG:     the reg index list is too big to fit in the array specified by
+             the user (the number required will be written into n).
+
+struct kvm_reg_list {
+	__u64 n; /* number of registers in reg[] */
+	__u64 reg[0];
+};
+
+This ioctl returns the guest registers that are supported for the
+KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
+
+
 5. The kvm_run structure
 ------------------------
 

arch/arm/Kconfig

@@ -2322,3 +2322,5 @@ source "security/Kconfig"
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
+
+source "arch/arm/kvm/Kconfig"

arch/arm/Makefile

@@ -252,6 +252,7 @@ core-$(CONFIG_FPE_NWFPE)	+= arch/arm/nwfpe/
 core-$(CONFIG_FPE_FASTFPE)	+= $(FASTFPE_OBJ)
 core-$(CONFIG_VFP)		+= arch/arm/vfp/
 core-$(CONFIG_XEN)		+= arch/arm/xen/
+core-$(CONFIG_KVM_ARM_HOST) 	+= arch/arm/kvm/
 
 # If we have a machine-specific directory, then include it in the build.
 core-y				+= arch/arm/kernel/ arch/arm/mm/ arch/arm/common/

arch/arm/include/asm/kvm_arm.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * 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_ARM_H__
+#define __ARM_KVM_ARM_H__
+
+#include <linux/types.h>
+
+#endif /* __ARM_KVM_ARM_H__ */

arch/arm/include/asm/kvm_asm.h

@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * 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__
+
+/* 0 is reserved as an invalid value. */
+#define c0_MPIDR	1	/* MultiProcessor ID Register */
+#define c0_CSSELR	2	/* Cache Size Selection Register */
+#define c1_SCTLR	3	/* System Control Register */
+#define c1_ACTLR	4	/* Auxilliary Control Register */
+#define c1_CPACR	5	/* Coprocessor Access Control */
+#define c2_TTBR0	6	/* Translation Table Base Register 0 */
+#define c2_TTBR0_high	7	/* TTBR0 top 32 bits */
+#define c2_TTBR1	8	/* Translation Table Base Register 1 */
+#define c2_TTBR1_high	9	/* TTBR1 top 32 bits */
+#define c2_TTBCR	10	/* Translation Table Base Control R. */
+#define c3_DACR		11	/* Domain Access Control Register */
+#define c5_DFSR		12	/* Data Fault Status Register */
+#define c5_IFSR		13	/* Instruction Fault Status Register */
+#define c5_ADFSR	14	/* Auxilary Data Fault Status R */
+#define c5_AIFSR	15	/* Auxilary Instrunction Fault Status R */
+#define c6_DFAR		16	/* Data Fault Address Register */
+#define c6_IFAR		17	/* Instruction Fault Address Register */
+#define c9_L2CTLR	18	/* Cortex A15 L2 Control Register */
+#define c10_PRRR	19	/* Primary Region Remap Register */
+#define c10_NMRR	20	/* Normal Memory Remap Register */
+#define c12_VBAR	21	/* Vector Base Address Register */
+#define c13_CID		22	/* Context ID Register */
+#define c13_TID_URW	23	/* Thread ID, User R/W */
+#define c13_TID_URO	24	/* Thread ID, User R/O */
+#define c13_TID_PRIV	25	/* Thread ID, Privileged */
+#define NR_CP15_REGS	26	/* Number of regs (incl. invalid) */
+
+#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__ */

arch/arm/include/asm/kvm_coproc.h

@@ -0,0 +1,24 @@
+/*
+ * Copyright (C) 2012 Rusty Russell IBM Corporation
+ *
+ * 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_COPROC_H__
+#define __ARM_KVM_COPROC_H__
+#include <linux/kvm_host.h>
+
+void kvm_reset_coprocs(struct kvm_vcpu *vcpu);
+
+#endif /* __ARM_KVM_COPROC_H__ */

arch/arm/include/asm/kvm_emulate.h

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * 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 *vcpu_reg(struct kvm_vcpu *vcpu, u8 reg_num);
+u32 *vcpu_spsr(struct kvm_vcpu *vcpu);
+
+static inline u32 *vcpu_pc(struct kvm_vcpu *vcpu)
+{
+	return (u32 *)&vcpu->arch.regs.usr_regs.ARM_pc;
+}
+
+static inline u32 *vcpu_cpsr(struct kvm_vcpu *vcpu)
+{
+	return (u32 *)&vcpu->arch.regs.usr_regs.ARM_cpsr;
+}
+
+static inline bool mode_has_spsr(struct kvm_vcpu *vcpu)
+{
+	unsigned long cpsr_mode = vcpu->arch.regs.usr_regs.ARM_cpsr & MODE_MASK;
+	return (cpsr_mode > USR_MODE && cpsr_mode < SYSTEM_MODE);
+}
+
+static inline bool vcpu_mode_priv(struct kvm_vcpu *vcpu)
+{
+	unsigned long cpsr_mode = vcpu->arch.regs.usr_regs.ARM_cpsr & MODE_MASK;
+	return cpsr_mode > USR_MODE;;
+}
+
+#endif /* __ARM_KVM_EMULATE_H__ */

arch/arm/include/asm/kvm_host.h

@@ -0,0 +1,114 @@
+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Author: Christoffer Dall <c.dall@virtualopensystems.com>
+ *
+ * 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__
+
+#include <asm/kvm.h>
+#include <asm/kvm_asm.h>
+
+#define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
+#define KVM_MEMORY_SLOTS 32
+#define KVM_PRIVATE_MEM_SLOTS 4
+#define KVM_COALESCED_MMIO_PAGE_OFFSET 1
+
+#define KVM_VCPU_MAX_FEATURES 0
+
+/* 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);
+int kvm_target_cpu(void);
+int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
+void kvm_reset_coprocs(struct kvm_vcpu *vcpu);
+
+struct kvm_arch {
+	/* VTTBR value associated with below pgd and vmid */
+	u64    vttbr;
+
+	/*
+	 * Anything that is not used directly from assembly code goes
+	 * here.
+	 */
+
+	/* The VMID generation used for the virt. memory system */
+	u64    vmid_gen;
+	u32    vmid;
+
+	/* Stage-2 page table */
+	pgd_t *pgd;
+};
+
+#define KVM_NR_MEM_OBJS     40
+
+/*
+ * We don't want allocation failures within the mmu code, so we preallocate
+ * enough memory for a single page fault in a cache.
+ */
+struct kvm_mmu_memory_cache {
+	int nobjs;
+	void *objects[KVM_NR_MEM_OBJS];
+};
+
+struct kvm_vcpu_arch {
+	struct kvm_regs regs;
+
+	int target; /* Processor target */
+	DECLARE_BITMAP(features, KVM_VCPU_MAX_FEATURES);
+
+	/* System control coprocessor (cp15) */
+	u32 cp15[NR_CP15_REGS];
+
+	/* The CPU type we expose to the VM */
+	u32 midr;
+
+	/* Exception Information */
+	u32 hsr;		/* Hyp Syndrome Register */
+	u32 hxfar;		/* Hyp Data/Inst Fault Address Register */
+	u32 hpfar;		/* Hyp IPA Fault Address Register */
+
+	/* Interrupt related fields */
+	u32 irq_lines;		/* IRQ and FIQ levels */
+
+	/* Hyp exception information */
+	u32 hyp_pc;		/* PC when exception was taken from Hyp mode */
+
+	/* Cache some mmu pages needed inside spinlock regions */
+	struct kvm_mmu_memory_cache mmu_page_cache;
+};
+
+struct kvm_vm_stat {
+	u32 remote_tlb_flush;
+};
+
+struct kvm_vcpu_stat {
+	u32 halt_wakeup;
+};
+
+struct kvm_vcpu_init;
+int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
+			const struct kvm_vcpu_init *init);
+unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu);
+int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *indices);
+struct kvm_one_reg;
+int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
+int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg);
+#endif /* __ARM_KVM_HOST_H__ */