4 files changed, 33 insertions, 2 deletions
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 3f5830b3ca3f..644d73956864 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -34,7 +34,7 @@
 #include <kvm/arm_vgic.h>
 #include <kvm/arm_arch_timer.h>
 
-#define KVM_VCPU_MAX_FEATURES 1
+#define KVM_VCPU_MAX_FEATURES 2
 
 /* We don't currently support large pages. */
 #define KVM_HPAGE_GFN_SHIFT(x)	0
diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
index 5b1110c49df5..5031f4263937 100644
--- a/arch/arm64/include/uapi/asm/kvm.h
+++ b/arch/arm64/include/uapi/asm/kvm.h
@@ -75,6 +75,7 @@ struct kvm_regs {
 #define KVM_VGIC_V2_CPU_SIZE		0x2000
 
 #define KVM_ARM_VCPU_POWER_OFF		0 /* CPU is started in OFF state */
+#define KVM_ARM_VCPU_EL1_32BIT		1 /* CPU running a 32bit VM */
 
 struct kvm_vcpu_init {
 	__u32 target;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 3d7518a7ebaa..2c3ff67a8ecb 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -99,6 +99,12 @@ static int set_core_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
 	if (off == KVM_REG_ARM_CORE_REG(regs.pstate)) {
 		u32 mode = (*(u32 *)valp) & COMPAT_PSR_MODE_MASK;
 		switch (mode) {
+		case COMPAT_PSR_MODE_USR:
+		case COMPAT_PSR_MODE_FIQ:
+		case COMPAT_PSR_MODE_IRQ:
+		case COMPAT_PSR_MODE_SVC:
+		case COMPAT_PSR_MODE_ABT:
+		case COMPAT_PSR_MODE_UND:
 		case PSR_MODE_EL0t:
 		case PSR_MODE_EL1t:
 		case PSR_MODE_EL1h:
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 766150ac76ed..70a7816535cd 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -38,16 +38,32 @@ static const struct kvm_regs default_regs_reset = {
 			PSR_F_BIT | PSR_D_BIT),
 };
 
+static const struct kvm_regs default_regs_reset32 = {
+	.regs.pstate = (COMPAT_PSR_MODE_SVC | COMPAT_PSR_A_BIT |
+			COMPAT_PSR_I_BIT | COMPAT_PSR_F_BIT),
+};
+
 static const struct kvm_irq_level default_vtimer_irq = {
 	.irq	= 27,
 	.level	= 1,
 };
 
+static bool cpu_has_32bit_el1(void)
+{
+	u64 pfr0;
+
+	pfr0 = read_cpuid(ID_AA64PFR0_EL1);
+	return !!(pfr0 & 0x20);
+}
+
 int kvm_arch_dev_ioctl_check_extension(long ext)
 {
 	int r;
 
 	switch (ext) {
+	case KVM_CAP_ARM_EL1_32BIT:
+		r = cpu_has_32bit_el1();
+		break;
 	default:
 		r = 0;
 	}
@@ -70,7 +86,15 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 
 	switch (vcpu->arch.target) {
 	default:
-		cpu_reset = &default_regs_reset;
+		if (test_bit(KVM_ARM_VCPU_EL1_32BIT, vcpu->arch.features)) {
+			if (!cpu_has_32bit_el1())
+				return -EINVAL;
+			cpu_reset = &default_regs_reset32;
+			vcpu->arch.hcr_el2 &= ~HCR_RW;
+		} else {
+			cpu_reset = &default_regs_reset;
+		}
+
 		cpu_vtimer_irq = &default_vtimer_irq;
 		break;
 	}