Merge tag 'kvm-arm-for-3.13-1' of git://git.linaro.org/people/cdall/linux-kvm-arm into next

Updates for KVM/ARM including cpu=host and Cortex-A7 support

Documentation/virtual/kvm/api.txt

@@ -2304,7 +2304,31 @@ Possible features:
 	  Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only).
 
 
-4.83 KVM_GET_REG_LIST
+4.83 KVM_ARM_PREFERRED_TARGET
+
+Capability: basic
+Architectures: arm, arm64
+Type: vm ioctl
+Parameters: struct struct kvm_vcpu_init (out)
+Returns: 0 on success; -1 on error
+Errors:
+  ENODEV:    no preferred target available for the host
+
+This queries KVM for preferred CPU target type which can be emulated
+by KVM on underlying host.
+
+The ioctl returns struct kvm_vcpu_init instance containing information
+about preferred CPU target type and recommended features for it.  The
+kvm_vcpu_init->features bitmap returned will have feature bits set if
+the preferred target recommends setting these features, but this is
+not mandatory.
+
+The information returned by this ioctl can be used to prepare an instance
+of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in
+in VCPU matching underlying host.
+
+
+4.84 KVM_GET_REG_LIST
 
 Capability: basic
 Architectures: arm, arm64
@@ -2323,8 +2347,7 @@ struct kvm_reg_list {
 This ioctl returns the guest registers that are supported for the
 KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
 
-
-4.84 KVM_ARM_SET_DEVICE_ADDR
+4.85 KVM_ARM_SET_DEVICE_ADDR
 
 Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
 Architectures: arm, arm64
@@ -2362,7 +2385,7 @@ must be called after calling KVM_CREATE_IRQCHIP, but before calling
 KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of the
 base addresses will return -EEXIST.
 
-4.85 KVM_PPC_RTAS_DEFINE_TOKEN
+4.86 KVM_PPC_RTAS_DEFINE_TOKEN
 
 Capability: KVM_CAP_PPC_RTAS
 Architectures: ppc

arch/arm/include/asm/kvm_arm.h

@@ -95,12 +95,12 @@
 #define TTBCR_IRGN1	(3 << 24)
 #define TTBCR_EPD1	(1 << 23)
 #define TTBCR_A1	(1 << 22)
-#define TTBCR_T1SZ	(3 << 16)
+#define TTBCR_T1SZ	(7 << 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 TTBCR_T0SZ	(7 << 0)
 #define HTCR_MASK	(TTBCR_T0SZ | TTBCR_IRGN0 | TTBCR_ORGN0 | TTBCR_SH0)
 
 /* Hyp System Trap Register */

arch/arm/include/asm/kvm_asm.h

@@ -39,7 +39,7 @@
 #define c6_IFAR		17	/* Instruction Fault Address Register */
 #define c7_PAR		18	/* Physical Address Register */
 #define c7_PAR_high	19	/* PAR top 32 bits */
-#define c9_L2CTLR	20	/* Cortex A15 L2 Control Register */
+#define c9_L2CTLR	20	/* Cortex A15/A7 L2 Control Register */
 #define c10_PRRR	21	/* Primary Region Remap Register */
 #define c10_NMRR	22	/* Normal Memory Remap Register */
 #define c12_VBAR	23	/* Vector Base Address Register */

arch/arm/include/asm/kvm_host.h

@@ -149,6 +149,7 @@ struct kvm_vcpu_stat {
 struct kvm_vcpu_init;
 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 			const struct kvm_vcpu_init *init);
+int kvm_vcpu_preferred_target(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;

arch/arm/include/uapi/asm/kvm.h

@@ -63,7 +63,8 @@ struct kvm_regs {
 
 /* Supported Processor Types */
 #define KVM_ARM_TARGET_CORTEX_A15	0
-#define KVM_ARM_NUM_TARGETS		1
+#define KVM_ARM_TARGET_CORTEX_A7	1
+#define KVM_ARM_NUM_TARGETS		2
 
 /* KVM_ARM_SET_DEVICE_ADDR ioctl id encoding */
 #define KVM_ARM_DEVICE_TYPE_SHIFT	0

arch/arm/kvm/Makefile

@@ -19,6 +19,6 @@ kvm-arm-y = $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o
 
 obj-y += kvm-arm.o init.o interrupts.o
 obj-y += arm.o handle_exit.o guest.o mmu.o emulate.o reset.o
-obj-y += coproc.o coproc_a15.o mmio.o psci.o perf.o
+obj-y += coproc.o coproc_a15.o coproc_a7.o mmio.o psci.o perf.o
 obj-$(CONFIG_KVM_ARM_VGIC) += $(KVM)/arm/vgic.o
 obj-$(CONFIG_KVM_ARM_TIMER) += $(KVM)/arm/arch_timer.o

arch/arm/kvm/arm.c

@@ -797,6 +797,19 @@ long kvm_arch_vm_ioctl(struct file *filp,
 			return -EFAULT;
 		return kvm_vm_ioctl_set_device_addr(kvm, &dev_addr);
 	}
+	case KVM_ARM_PREFERRED_TARGET: {
+		int err;
+		struct kvm_vcpu_init init;
+
+		err = kvm_vcpu_preferred_target(&init);
+		if (err)
+			return err;
+
+		if (copy_to_user(argp, &init, sizeof(init)))
+			return -EFAULT;
+
+		return 0;
+	}
 	default:
 		return -EINVAL;
 	}

arch/arm/kvm/coproc.c

@@ -71,6 +71,92 @@ int kvm_handle_cp14_access(struct kvm_vcpu *vcpu, struct kvm_run *run)
 	return 1;
 }
 
+static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
+{
+	/*
+	 * Compute guest MPIDR. No need to mess around with different clusters
+	 * but we read the 'U' bit from the underlying hardware directly.
+	 */
+	vcpu->arch.cp15[c0_MPIDR] = (read_cpuid_mpidr() & MPIDR_SMP_BITMASK)
+					| vcpu->vcpu_id;
+}
+
+/* TRM entries A7:4.3.31 A15:4.3.28 - RO WI */
+static bool access_actlr(struct kvm_vcpu *vcpu,
+			 const struct coproc_params *p,
+			 const struct coproc_reg *r)
+{
+	if (p->is_write)
+		return ignore_write(vcpu, p);
+
+	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c1_ACTLR];
+	return true;
+}
+
+/* TRM entries A7:4.3.56, A15:4.3.60 - R/O. */
+static bool access_cbar(struct kvm_vcpu *vcpu,
+			const struct coproc_params *p,
+			const struct coproc_reg *r)
+{
+	if (p->is_write)
+		return write_to_read_only(vcpu, p);
+	return read_zero(vcpu, p);
+}
+
+/* TRM entries A7:4.3.49, A15:4.3.48 - R/O WI */
+static bool access_l2ctlr(struct kvm_vcpu *vcpu,
+			  const struct coproc_params *p,
+			  const struct coproc_reg *r)
+{
+	if (p->is_write)
+		return ignore_write(vcpu, p);
+
+	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c9_L2CTLR];
+	return true;
+}
+
+static void reset_l2ctlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
+{
+	u32 l2ctlr, ncores;
+
+	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->arch.cp15[c9_L2CTLR] = l2ctlr;
+}
+
+static void reset_actlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
+{
+	u32 actlr;
+
+	/* ACTLR contains SMP bit: make sure you create all cpus first! */
+	asm volatile("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
+	/* Make the SMP bit consistent with the guest configuration */
+	if (atomic_read(&vcpu->kvm->online_vcpus) > 1)
+		actlr |= 1U << 6;
+	else
+		actlr &= ~(1U << 6);
+
+	vcpu->arch.cp15[c1_ACTLR] = actlr;
+}
+
+/*
+ * TRM entries: A7:4.3.50, A15:4.3.49
+ * R/O WI (even if NSACR.NS_L2ERR, a write of 1 is ignored).
+ */
+static bool access_l2ectlr(struct kvm_vcpu *vcpu,
+			   const struct coproc_params *p,
+			   const struct coproc_reg *r)
+{
+	if (p->is_write)
+		return ignore_write(vcpu, p);
+
+	*vcpu_reg(vcpu, p->Rt1) = 0;
+	return true;
+}
+
 /* See note at ARM ARM B1.14.4 */
 static bool access_dcsw(struct kvm_vcpu *vcpu,
 			const struct coproc_params *p,
@@ -153,10 +239,22 @@ static bool pm_fake(struct kvm_vcpu *vcpu,
  *            registers preceding 32-bit ones.
  */
 static const struct coproc_reg cp15_regs[] = {
+	/* MPIDR: we use VMPIDR for guest access. */
+	{ CRn( 0), CRm( 0), Op1( 0), Op2( 5), is32,
+			NULL, reset_mpidr, c0_MPIDR },
+
 	/* CSSELR: swapped by interrupt.S. */
 	{ CRn( 0), CRm( 0), Op1( 2), Op2( 0), is32,
 			NULL, reset_unknown, c0_CSSELR },
 
+	/* ACTLR: trapped by HCR.TAC bit. */
+	{ CRn( 1), CRm( 0), Op1( 0), Op2( 1), is32,
+			access_actlr, reset_actlr, c1_ACTLR },
+
+	/* CPACR: swapped by interrupt.S. */
+	{ CRn( 1), CRm( 0), Op1( 0), Op2( 2), is32,
+			NULL, reset_val, c1_CPACR, 0x00000000 },
+
 	/* TTBR0/TTBR1: swapped by interrupt.S. */
 	{ CRm64( 2), Op1( 0), is64, NULL, reset_unknown64, c2_TTBR0 },
 	{ CRm64( 2), Op1( 1), is64, NULL, reset_unknown64, c2_TTBR1 },
@@ -194,6 +292,13 @@ static const struct coproc_reg cp15_regs[] = {
 	{ CRn( 7), CRm( 6), Op1( 0), Op2( 2), is32, access_dcsw},
 	{ CRn( 7), CRm(10), Op1( 0), Op2( 2), is32, access_dcsw},
 	{ CRn( 7), CRm(14), Op1( 0), Op2( 2), is32, access_dcsw},
+	/*
+	 * L2CTLR access (guest wants to know #CPUs).
+	 */
+	{ CRn( 9), CRm( 0), Op1( 1), Op2( 2), is32,
+			access_l2ctlr, reset_l2ctlr, c9_L2CTLR },
+	{ CRn( 9), CRm( 0), Op1( 1), Op2( 3), is32, access_l2ectlr},
+
 	/*
 	 * Dummy performance monitor implementation.
 	 */
@@ -234,6 +339,9 @@ static const struct coproc_reg cp15_regs[] = {
 	/* CNTKCTL: swapped by interrupt.S. */
 	{ CRn(14), CRm( 1), Op1( 0), Op2( 0), is32,
 			NULL, reset_val, c14_CNTKCTL, 0x00000000 },
+
+	/* The Configuration Base Address Register. */
+	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
 };
 
 /* Target specific emulation tables */
@@ -241,6 +349,12 @@ static struct kvm_coproc_target_table *target_tables[KVM_ARM_NUM_TARGETS];
 
 void kvm_register_target_coproc_table(struct kvm_coproc_target_table *table)
 {
+	unsigned int i;
+
+	for (i = 1; i < table->num; i++)
+		BUG_ON(cmp_reg(&table->table[i-1],
+			       &table->table[i]) >= 0);
+
 	target_tables[table->target] = table;
 }
 

arch/arm/kvm/coproc_a15.c

@@ -17,101 +17,12 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 #include <linux/kvm_host.h>
-#include <asm/cputype.h>
-#include <asm/kvm_arm.h>
-#include <asm/kvm_host.h>
-#include <asm/kvm_emulate.h>
 #include <asm/kvm_coproc.h>
+#include <asm/kvm_emulate.h>
 #include <linux/init.h>
 
-static void reset_mpidr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
-{
-	/*
-	 * Compute guest MPIDR:
-	 * (Even if we present only one VCPU to the guest on an SMP
-	 * host we don't set the U bit in the MPIDR, or vice versa, as
-	 * revealing the underlying hardware properties is likely to
-	 * be the best choice).
-	 */
-	vcpu->arch.cp15[c0_MPIDR] = (read_cpuid_mpidr() & ~MPIDR_LEVEL_MASK)
-		| (vcpu->vcpu_id & MPIDR_LEVEL_MASK);
-}
-
 #include "coproc.h"
 
-/* A15 TRM 4.3.28: RO WI */
-static bool access_actlr(struct kvm_vcpu *vcpu,
-			 const struct coproc_params *p,
-			 const struct coproc_reg *r)
-{
-	if (p->is_write)
-		return ignore_write(vcpu, p);
-
-	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c1_ACTLR];
-	return true;
-}
-
-/* A15 TRM 4.3.60: R/O. */
-static bool access_cbar(struct kvm_vcpu *vcpu,
-			const struct coproc_params *p,
-			const struct coproc_reg *r)
-{
-	if (p->is_write)
-		return write_to_read_only(vcpu, p);
-	return read_zero(vcpu, p);
-}
-
-/* A15 TRM 4.3.48: R/O WI. */
-static bool access_l2ctlr(struct kvm_vcpu *vcpu,
-			  const struct coproc_params *p,
-			  const struct coproc_reg *r)
-{
-	if (p->is_write)
-		return ignore_write(vcpu, p);
-
-	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.cp15[c9_L2CTLR];
-	return true;
-}
-
-static void reset_l2ctlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
-{
-	u32 l2ctlr, ncores;
-
-	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->arch.cp15[c9_L2CTLR] = l2ctlr;
-}
-
-static void reset_actlr(struct kvm_vcpu *vcpu, const struct coproc_reg *r)
-{
-	u32 actlr;
-
-	/* ACTLR contains SMP bit: make sure you create all cpus first! */
-	asm volatile("mrc p15, 0, %0, c1, c0, 1\n" : "=r" (actlr));
-	/* Make the SMP bit consistent with the guest configuration */
-	if (atomic_read(&vcpu->kvm->online_vcpus) > 1)
-		actlr |= 1U << 6;
-	else
-		actlr &= ~(1U << 6);
-
-	vcpu->arch.cp15[c1_ACTLR] = actlr;
-}
-
-/* A15 TRM 4.3.49: R/O WI (even if NSACR.NS_L2ERR, a write of 1 is ignored). */
-static bool access_l2ectlr(struct kvm_vcpu *vcpu,
-			   const struct coproc_params *p,
-			   const struct coproc_reg *r)
-{
-	if (p->is_write)
-		return ignore_write(vcpu, p);
-
-	*vcpu_reg(vcpu, p->Rt1) = 0;
-	return true;
-}
-
 /*
  * A15-specific CP15 registers.
  * CRn denotes the primary register number, but is copied to the CRm in the
@@ -121,29 +32,9 @@ static bool access_l2ectlr(struct kvm_vcpu *vcpu,
  *            registers preceding 32-bit ones.
  */
 static const struct coproc_reg a15_regs[] = {
-	/* MPIDR: we use VMPIDR for guest access. */
-	{ CRn( 0), CRm( 0), Op1( 0), Op2( 5), is32,
-			NULL, reset_mpidr, c0_MPIDR },
-
 	/* SCTLR: swapped by interrupt.S. */
 	{ CRn( 1), CRm( 0), Op1( 0), Op2( 0), is32,
 			NULL, reset_val, c1_SCTLR, 0x00C50078 },
-	/* ACTLR: trapped by HCR.TAC bit. */
-	{ CRn( 1), CRm( 0), Op1( 0), Op2( 1), is32,
-			access_actlr, reset_actlr, c1_ACTLR },
-	/* CPACR: swapped by interrupt.S. */
-	{ CRn( 1), CRm( 0), Op1( 0), Op2( 2), is32,
-			NULL, reset_val, c1_CPACR, 0x00000000 },
-
-	/*
-	 * L2CTLR access (guest wants to know #CPUs).
-	 */
-	{ CRn( 9), CRm( 0), Op1( 1), Op2( 2), is32,
-			access_l2ctlr, reset_l2ctlr, c9_L2CTLR },
-	{ CRn( 9), CRm( 0), Op1( 1), Op2( 3), is32, access_l2ectlr},
-
-	/* The Configuration Base Address Register. */
-	{ CRn(15), CRm( 0), Op1( 4), Op2( 0), is32, access_cbar},
 };
 
 static struct kvm_coproc_target_table a15_target_table = {
@@ -154,12 +45,6 @@ static struct kvm_coproc_target_table a15_target_table = {
 
 static int __init coproc_a15_init(void)
 {
-	unsigned int i;
-
-	for (i = 1; i < ARRAY_SIZE(a15_regs); i++)
-		BUG_ON(cmp_reg(&a15_regs[i-1],
-			       &a15_regs[i]) >= 0);
-
 	kvm_register_target_coproc_table(&a15_target_table);
 	return 0;
 }

arch/arm/kvm/coproc_a7.c

+/*
+ * Copyright (C) 2012 - Virtual Open Systems and Columbia University
+ * Copyright (C) 2013 - ARM Ltd
+ *
+ * Authors: Rusty Russell <rusty@rustcorp.au>
+ *          Christoffer Dall <c.dall@virtualopensystems.com>
+ *          Jonathan Austin <jonathan.austin@arm.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.
+ */
+#include <linux/kvm_host.h>
+#include <asm/kvm_coproc.h>
+#include <asm/kvm_emulate.h>
+#include <linux/init.h>
+
+#include "coproc.h"
+
+/*
+ * Cortex-A7 specific CP15 registers.
+ * CRn denotes the primary register number, but is copied to the CRm in the
+ * user space API for 64-bit register access in line with the terminology used
+ * in the ARM ARM.
+ * Important: Must be sorted ascending by CRn, CRM, Op1, Op2 and with 64-bit
+ *            registers preceding 32-bit ones.
+ */
+static const struct coproc_reg a7_regs[] = {
+	/* SCTLR: swapped by interrupt.S. */
+	{ CRn( 1), CRm( 0), Op1( 0), Op2( 0), is32,
+			NULL, reset_val, c1_SCTLR, 0x00C50878 },
+};
+
+static struct kvm_coproc_target_table a7_target_table = {
+	.target = KVM_ARM_TARGET_CORTEX_A7,
+	.table = a7_regs,
+	.num = ARRAY_SIZE(a7_regs),
+};
+
+static int __init coproc_a7_init(void)
+{
+	kvm_register_target_coproc_table(&a7_target_table);
+	return 0;
+}
+late_initcall(coproc_a7_init);

arch/arm/kvm/emulate.c

@@ -354,7 +354,7 @@ static void inject_abt(struct kvm_vcpu *vcpu, bool is_pabt, unsigned long addr)
 	*vcpu_pc(vcpu) = exc_vector_base(vcpu) + vect_offset;
 
 	if (is_pabt) {
-		/* Set DFAR and DFSR */
+		/* Set IFAR and IFSR */
 		vcpu->arch.cp15[c6_IFAR] = addr;
 		is_lpae = (vcpu->arch.cp15[c2_TTBCR] >> 31);
 		/* Always give debug fault for now - should give guest a clue */

arch/arm/kvm/guest.c

@@ -190,6 +190,8 @@ int __attribute_const__ kvm_target_cpu(void)
 		return -EINVAL;
 
 	switch (part_number) {
+	case ARM_CPU_PART_CORTEX_A7:
+		return KVM_ARM_TARGET_CORTEX_A7;
 	case ARM_CPU_PART_CORTEX_A15:
 		return KVM_ARM_TARGET_CORTEX_A15;
 	default:
@@ -202,7 +204,7 @@ int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 {
 	unsigned int i;
 
-	/* We can only do a cortex A15 for now. */
+	/* We can only cope with guest==host and only on A15/A7 (for now). */
 	if (init->target != kvm_target_cpu())
 		return -EINVAL;
 
@@ -222,6 +224,26 @@ int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 	return kvm_reset_vcpu(vcpu);
 }
 
+int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
+{
+	int target = kvm_target_cpu();
+
+	if (target < 0)
+		return -ENODEV;
+
+	memset(init, 0, sizeof(*init));
+
+	/*
+	 * For now, we don't return any features.
+	 * In future, we might use features to return target
+	 * specific features available for the preferred
+	 * target type.
+	 */
+	init->target = (__u32)target;
+
+	return 0;
+}
+
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
 	return -EINVAL;

arch/arm/kvm/reset.c

@@ -30,16 +30,16 @@
 #include <kvm/arm_arch_timer.h>
 
 /******************************************************************************
- * Cortex-A15 Reset Values
+ * Cortex-A15 and Cortex-A7 Reset Values
  */
 
-static const int a15_max_cpu_idx = 3;
+static const int cortexa_max_cpu_idx = 3;
 
-static struct kvm_regs a15_regs_reset = {
+static struct kvm_regs cortexa_regs_reset = {
 	.usr_regs.ARM_cpsr = SVC_MODE | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT,
 };
 
-static const struct kvm_irq_level a15_vtimer_irq = {
+static const struct kvm_irq_level cortexa_vtimer_irq = {
 	{ .irq = 27 },
 	.level = 1,
 };
@@ -62,12 +62,13 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 	const struct kvm_irq_level *cpu_vtimer_irq;
 
 	switch (vcpu->arch.target) {
+	case KVM_ARM_TARGET_CORTEX_A7:
 	case KVM_ARM_TARGET_CORTEX_A15:
-		if (vcpu->vcpu_id > a15_max_cpu_idx)
+		if (vcpu->vcpu_id > cortexa_max_cpu_idx)
 			return -EINVAL;
-		cpu_reset = &a15_regs_reset;
+		cpu_reset = &cortexa_regs_reset;
 		vcpu->arch.midr = read_cpuid_id();
-		cpu_vtimer_irq = &a15_vtimer_irq;
+		cpu_vtimer_irq = &cortexa_vtimer_irq;
 		break;
 	default:
 		return -ENODEV;

arch/arm64/include/asm/kvm_host.h

@@ -146,6 +146,7 @@ struct kvm_vcpu_stat {
 struct kvm_vcpu_init;
 int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 			const struct kvm_vcpu_init *init);
+int kvm_vcpu_preferred_target(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;

arch/arm64/kvm/guest.c

@@ -248,6 +248,26 @@ int kvm_vcpu_set_target(struct kvm_vcpu *vcpu,
 	return kvm_reset_vcpu(vcpu);
 }
 
+int kvm_vcpu_preferred_target(struct kvm_vcpu_init *init)
+{
+	int target = kvm_target_cpu();
+
+	if (target < 0)
+		return -ENODEV;
+
+	memset(init, 0, sizeof(*init));
+
+	/*
+	 * For now, we don't return any features.
+	 * In future, we might use features to return target
+	 * specific features available for the preferred
+	 * target type.
+	 */
+	init->target = (__u32)target;
+
+	return 0;
+}
+
 int kvm_arch_vcpu_ioctl_get_fpu(struct kvm_vcpu *vcpu, struct kvm_fpu *fpu)
 {
 	return -EINVAL;

include/uapi/linux/kvm.h

@@ -1012,6 +1012,7 @@ struct kvm_s390_ucas_mapping {
 /* VM is being stopped by host */
 #define KVM_KVMCLOCK_CTRL	  _IO(KVMIO,   0xad)
 #define KVM_ARM_VCPU_INIT	  _IOW(KVMIO,  0xae, struct kvm_vcpu_init)
+#define KVM_ARM_PREFERRED_TARGET  _IOR(KVMIO,  0xaf, struct kvm_vcpu_init)
 #define KVM_GET_REG_LIST	  _IOWR(KVMIO, 0xb0, struct kvm_reg_list)
 
 #define KVM_DEV_ASSIGN_ENABLE_IOMMU	(1 << 0)