Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

arch/arm/include/asm/kvm_host.h

@@ -218,6 +218,15 @@ static inline void __cpu_init_stage2(void)
 {
 }
 
+static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+					phys_addr_t phys_idmap_start)
+{
+	/*
+	 * TODO
+	 * kvm_call_reset(boot_pgd_ptr, phys_idmap_start);
+	 */
+}
+
 static inline int kvm_arch_dev_ioctl_check_extension(long ext)
 {
 	return 0;
@@ -230,7 +239,6 @@ void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot);
 
 struct kvm_vcpu *kvm_mpidr_to_vcpu(struct kvm *kvm, unsigned long mpidr);
 
-static inline void kvm_arch_hardware_disable(void) {}
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}

arch/arm/include/asm/kvm_mmu.h

@@ -66,6 +66,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
 phys_addr_t kvm_mmu_get_httbr(void);
 phys_addr_t kvm_mmu_get_boot_httbr(void);
 phys_addr_t kvm_get_idmap_vector(void);
+phys_addr_t kvm_get_idmap_start(void);
 int kvm_mmu_init(void);
 void kvm_clear_hyp_idmap(void);
 

arch/arm/kvm/arm.c

@@ -16,7 +16,6 @@
  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
-#include <linux/cpu.h>
 #include <linux/cpu_pm.h>
 #include <linux/errno.h>
 #include <linux/err.h>
@@ -65,6 +64,8 @@ static DEFINE_SPINLOCK(kvm_vmid_lock);
 
 static bool vgic_present;
 
+static DEFINE_PER_CPU(unsigned char, kvm_arm_hardware_enabled);
+
 static void kvm_arm_set_running_vcpu(struct kvm_vcpu *vcpu)
 {
 	BUG_ON(preemptible());
@@ -89,11 +90,6 @@ struct kvm_vcpu * __percpu *kvm_get_running_vcpus(void)
 	return &kvm_arm_running_vcpu;
 }
 
-int kvm_arch_hardware_enable(void)
-{
-	return 0;
-}
-
 int kvm_arch_vcpu_should_kick(struct kvm_vcpu *vcpu)
 {
 	return kvm_vcpu_exiting_guest_mode(vcpu) == IN_GUEST_MODE;
@@ -987,37 +983,92 @@ static void cpu_init_hyp_mode(void *dummy)
 	kvm_arm_init_debug();
 }
 
-static int hyp_init_cpu_notify(struct notifier_block *self,
+static void cpu_hyp_reinit(void)
-			       unsigned long action, void *cpu)
 {
-	switch (action) {
+	if (is_kernel_in_hyp_mode()) {
-	case CPU_STARTING:
+		/*
-	case CPU_STARTING_FROZEN:
+		 * __cpu_init_stage2() is safe to call even if the PM
+		 * event was cancelled before the CPU was reset.
+		 */
+		__cpu_init_stage2();
+	} else {
 		if (__hyp_get_vectors() == hyp_default_vectors)
 			cpu_init_hyp_mode(NULL);
-		break;
+	}
 }
 
-	return NOTIFY_OK;
+static void cpu_hyp_reset(void)
+{
+	phys_addr_t boot_pgd_ptr;
+	phys_addr_t phys_idmap_start;
+
+	if (!is_kernel_in_hyp_mode()) {
+		boot_pgd_ptr = kvm_mmu_get_boot_httbr();
+		phys_idmap_start = kvm_get_idmap_start();
+
+		__cpu_reset_hyp_mode(boot_pgd_ptr, phys_idmap_start);
+	}
 }
 
-static struct notifier_block hyp_init_cpu_nb = {
+static void _kvm_arch_hardware_enable(void *discard)
-	.notifier_call = hyp_init_cpu_notify,
+{
-};
+	if (!__this_cpu_read(kvm_arm_hardware_enabled)) {
+		cpu_hyp_reinit();
+		__this_cpu_write(kvm_arm_hardware_enabled, 1);
+	}
+}
+
+int kvm_arch_hardware_enable(void)
+{
+	_kvm_arch_hardware_enable(NULL);
+	return 0;
+}
+
+static void _kvm_arch_hardware_disable(void *discard)
+{
+	if (__this_cpu_read(kvm_arm_hardware_enabled)) {
+		cpu_hyp_reset();
+		__this_cpu_write(kvm_arm_hardware_enabled, 0);
+	}
+}
+
+void kvm_arch_hardware_disable(void)
+{
+	_kvm_arch_hardware_disable(NULL);
+}
 
 #ifdef CONFIG_CPU_PM
 static int hyp_init_cpu_pm_notifier(struct notifier_block *self,
 				    unsigned long cmd,
 				    void *v)
 {
-	if (cmd == CPU_PM_EXIT &&
+	/*
-	    __hyp_get_vectors() == hyp_default_vectors) {
+	 * kvm_arm_hardware_enabled is left with its old value over
-		cpu_init_hyp_mode(NULL);
+	 * PM_ENTER->PM_EXIT. It is used to indicate PM_EXIT should
-		return NOTIFY_OK;
+	 * re-enable hyp.
-	}
+	 */
+	switch (cmd) {
+	case CPU_PM_ENTER:
+		if (__this_cpu_read(kvm_arm_hardware_enabled))
+			/*
+			 * don't update kvm_arm_hardware_enabled here
+			 * so that the hardware will be re-enabled
+			 * when we resume. See below.
+			 */
+			cpu_hyp_reset();
 
+		return NOTIFY_OK;
+	case CPU_PM_EXIT:
+		if (__this_cpu_read(kvm_arm_hardware_enabled))
+			/* The hardware was enabled before suspend. */
+			cpu_hyp_reinit();
+
+		return NOTIFY_OK;
+
+	default:
 		return NOTIFY_DONE;
 	}
+}
 
 static struct notifier_block hyp_init_cpu_pm_nb = {
 	.notifier_call = hyp_init_cpu_pm_notifier,
@@ -1033,6 +1084,91 @@ static inline void hyp_cpu_pm_init(void)
 }
 #endif
 
+static void teardown_common_resources(void)
+{
+	free_percpu(kvm_host_cpu_state);
+}
+
+static int init_common_resources(void)
+{
+	kvm_host_cpu_state = alloc_percpu(kvm_cpu_context_t);
+	if (!kvm_host_cpu_state) {
+		kvm_err("Cannot allocate host CPU state\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static int init_subsystems(void)
+{
+	int err = 0;
+
+	/*
+	 * Enable hardware so that subsystem initialisation can access EL2.
+	 */
+	on_each_cpu(_kvm_arch_hardware_enable, NULL, 1);
+
+	/*
+	 * Register CPU lower-power notifier
+	 */
+	hyp_cpu_pm_init();
+
+	/*
+	 * Init HYP view of VGIC
+	 */
+	err = kvm_vgic_hyp_init();
+	switch (err) {
+	case 0:
+		vgic_present = true;
+		break;
+	case -ENODEV:
+	case -ENXIO:
+		vgic_present = false;
+		err = 0;
+		break;
+	default:
+		goto out;
+	}
+
+	/*
+	 * Init HYP architected timer support
+	 */
+	err = kvm_timer_hyp_init();
+	if (err)
+		goto out;
+
+	kvm_perf_init();
+	kvm_coproc_table_init();
+
+out:
+	on_each_cpu(_kvm_arch_hardware_disable, NULL, 1);
+
+	return err;
+}
+
+static void teardown_hyp_mode(void)
+{
+	int cpu;
+
+	if (is_kernel_in_hyp_mode())
+		return;
+
+	free_hyp_pgds();
+	for_each_possible_cpu(cpu)
+		free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
+}
+
+static int init_vhe_mode(void)
+{
+	/* set size of VMID supported by CPU */
+	kvm_vmid_bits = kvm_get_vmid_bits();
+	kvm_info("%d-bit VMID\n", kvm_vmid_bits);
+
+	kvm_info("VHE mode initialized successfully\n");
+	return 0;
+}
+
 /**
  * Inits Hyp-mode on all online CPUs
  */
@@ -1063,7 +1199,7 @@ static int init_hyp_mode(void)
 		stack_page = __get_free_page(GFP_KERNEL);
 		if (!stack_page) {
 			err = -ENOMEM;
-			goto out_free_stack_pages;
+			goto out_err;
 		}
 
 		per_cpu(kvm_arm_hyp_stack_page, cpu) = stack_page;
@@ -1076,13 +1212,14 @@ static int init_hyp_mode(void)
 				  kvm_ksym_ref(__kvm_hyp_code_end));
 	if (err) {
 		kvm_err("Cannot map world-switch code\n");
-		goto out_free_mappings;
+		goto out_err;
 	}
 
-	err = create_hyp_mappings(__start_rodata, __end_rodata);
+	err = create_hyp_mappings(kvm_ksym_ref(__start_rodata),
+				  kvm_ksym_ref(__end_rodata));
 	if (err) {
 		kvm_err("Cannot map rodata section\n");
-		goto out_free_mappings;
+		goto out_err;
 	}
 
 	/*
@@ -1094,20 +1231,10 @@ static int init_hyp_mode(void)
 
 		if (err) {
 			kvm_err("Cannot map hyp stack\n");
-			goto out_free_mappings;
+			goto out_err;
 		}
 	}
 
-	/*
-	 * Map the host CPU structures
-	 */
-	kvm_host_cpu_state = alloc_percpu(kvm_cpu_context_t);
-	if (!kvm_host_cpu_state) {
-		err = -ENOMEM;
-		kvm_err("Cannot allocate host CPU state\n");
-		goto out_free_mappings;
-	}
-
 	for_each_possible_cpu(cpu) {
 		kvm_cpu_context_t *cpu_ctxt;
 
@@ -1116,44 +1243,14 @@ static int init_hyp_mode(void)
 
 		if (err) {
 			kvm_err("Cannot map host CPU state: %d\n", err);
-			goto out_free_context;
+			goto out_err;
 		}
 	}
 
-	/*
-	 * Execute the init code on each CPU.
-	 */
-	on_each_cpu(cpu_init_hyp_mode, NULL, 1);
-
-	/*
-	 * Init HYP view of VGIC
-	 */
-	err = kvm_vgic_hyp_init();
-	switch (err) {
-	case 0:
-		vgic_present = true;
-		break;
-	case -ENODEV:
-	case -ENXIO:
-		vgic_present = false;
-		break;
-	default:
-		goto out_free_context;
-	}
-
-	/*
-	 * Init HYP architected timer support
-	 */
-	err = kvm_timer_hyp_init();
-	if (err)
-		goto out_free_context;
-
 #ifndef CONFIG_HOTPLUG_CPU
 	free_boot_hyp_pgd();
 #endif
 
-	kvm_perf_init();
-
 	/* set size of VMID supported by CPU */
 	kvm_vmid_bits = kvm_get_vmid_bits();
 	kvm_info("%d-bit VMID\n", kvm_vmid_bits);
@@ -1161,14 +1258,9 @@ static int init_hyp_mode(void)
 	kvm_info("Hyp mode initialized successfully\n");
 
 	return 0;
-out_free_context:
+
-	free_percpu(kvm_host_cpu_state);
-out_free_mappings:
-	free_hyp_pgds();
-out_free_stack_pages:
-	for_each_possible_cpu(cpu)
-		free_page(per_cpu(kvm_arm_hyp_stack_page, cpu));
 out_err:
+	teardown_hyp_mode();
 	kvm_err("error initializing Hyp mode: %d\n", err);
 	return err;
 }
@@ -1212,26 +1304,27 @@ int kvm_arch_init(void *opaque)
 		}
 	}
 
-	cpu_notifier_register_begin();
+	err = init_common_resources();
+	if (err)
+		return err;
 
+	if (is_kernel_in_hyp_mode())
+		err = init_vhe_mode();
+	else
 		err = init_hyp_mode();
 	if (err)
 		goto out_err;
 
-	err = __register_cpu_notifier(&hyp_init_cpu_nb);
+	err = init_subsystems();
-	if (err) {
+	if (err)
-		kvm_err("Cannot register HYP init CPU notifier (%d)\n", err);
+		goto out_hyp;
-		goto out_err;
-	}
 
-	cpu_notifier_register_done();
-
-	hyp_cpu_pm_init();
-
-	kvm_coproc_table_init();
 	return 0;
+
+out_hyp:
+	teardown_hyp_mode();
 out_err:
-	cpu_notifier_register_done();
+	teardown_common_resources();
 	return err;
 }
 

arch/arm/kvm/mmu.c

@@ -28,6 +28,7 @@
 #include <asm/kvm_mmio.h>
 #include <asm/kvm_asm.h>
 #include <asm/kvm_emulate.h>
+#include <asm/virt.h>
 
 #include "trace.h"
 
@@ -598,6 +599,9 @@ int create_hyp_mappings(void *from, void *to)
 	unsigned long start = KERN_TO_HYP((unsigned long)from);
 	unsigned long end = KERN_TO_HYP((unsigned long)to);
 
+	if (is_kernel_in_hyp_mode())
+		return 0;
+
 	start = start & PAGE_MASK;
 	end = PAGE_ALIGN(end);
 
@@ -630,6 +634,9 @@ int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
 	unsigned long start = KERN_TO_HYP((unsigned long)from);
 	unsigned long end = KERN_TO_HYP((unsigned long)to);
 
+	if (is_kernel_in_hyp_mode())
+		return 0;
+
 	/* Check for a valid kernel IO mapping */
 	if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
 		return -EINVAL;
@@ -1648,6 +1655,11 @@ phys_addr_t kvm_get_idmap_vector(void)
 	return hyp_idmap_vector;
 }
 
+phys_addr_t kvm_get_idmap_start(void)
+{
+	return hyp_idmap_start;
+}
+
 int kvm_mmu_init(void)
 {
 	int err;

arch/arm64/include/asm/kvm_asm.h

@@ -22,6 +22,8 @@
 
 #define ARM_EXCEPTION_IRQ	  0
 #define ARM_EXCEPTION_TRAP	  1
+/* The hyp-stub will return this for any kvm_call_hyp() call */
+#define ARM_EXCEPTION_HYP_GONE	  2
 
 #define KVM_ARM64_DEBUG_DIRTY_SHIFT	0
 #define KVM_ARM64_DEBUG_DIRTY		(1 << KVM_ARM64_DEBUG_DIRTY_SHIFT)
@@ -29,11 +31,27 @@
 #define kvm_ksym_ref(sym)		phys_to_virt((u64)&sym - kimage_voffset)
 
 #ifndef __ASSEMBLY__
+#if __GNUC__ > 4
+#define kvm_ksym_shift			(PAGE_OFFSET - KIMAGE_VADDR)
+#else
+/*
+ * GCC versions 4.9 and older will fold the constant below into the addend of
+ * the reference to 'sym' above if kvm_ksym_shift is declared static or if the
+ * constant is used directly. However, since we use the small code model for
+ * the core kernel, the reference to 'sym' will be emitted as a adrp/add pair,
+ * with a +/- 4 GB range, resulting in linker relocation errors if the shift
+ * is sufficiently large. So prevent the compiler from folding the shift into
+ * the addend, by making the shift a variable with external linkage.
+ */
+__weak u64 kvm_ksym_shift = PAGE_OFFSET - KIMAGE_VADDR;
+#endif
+
 struct kvm;
 struct kvm_vcpu;
 
 extern char __kvm_hyp_init[];
 extern char __kvm_hyp_init_end[];
+extern char __kvm_hyp_reset[];
 
 extern char __kvm_hyp_vector[];
 

arch/arm64/include/asm/kvm_host.h

@@ -44,6 +44,7 @@
 int __attribute_const__ kvm_target_cpu(void);
 int kvm_reset_vcpu(struct kvm_vcpu *vcpu);
 int kvm_arch_dev_ioctl_check_extension(long ext);
+phys_addr_t kvm_hyp_reset_entry(void);
 
 struct kvm_arch {
 	/* The VMID generation used for the virt. memory system */
@@ -330,7 +331,17 @@ static inline void __cpu_init_stage2(void)
 {
 }
 
-static inline void kvm_arch_hardware_disable(void) {}
+static inline void __cpu_reset_hyp_mode(phys_addr_t boot_pgd_ptr,
+					phys_addr_t phys_idmap_start)
+{
+	/*
+	 * Call reset code, and switch back to stub hyp vectors.
+	 * Uses __kvm_call_hyp() to avoid kaslr's kvm_ksym_ref() translation.
+	 */
+	__kvm_call_hyp((void *)kvm_hyp_reset_entry(),
+		       boot_pgd_ptr, phys_idmap_start);
+}
+
 static inline void kvm_arch_hardware_unsetup(void) {}
 static inline void kvm_arch_sync_events(struct kvm *kvm) {}
 static inline void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu) {}

arch/arm64/include/asm/kvm_mmu.h

@@ -99,6 +99,7 @@ void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu);
 phys_addr_t kvm_mmu_get_httbr(void);
 phys_addr_t kvm_mmu_get_boot_httbr(void);
 phys_addr_t kvm_get_idmap_vector(void);
+phys_addr_t kvm_get_idmap_start(void);
 int kvm_mmu_init(void);
 void kvm_clear_hyp_idmap(void);
 

arch/arm64/include/asm/virt.h

@@ -18,6 +18,22 @@
 #ifndef __ASM__VIRT_H
 #define __ASM__VIRT_H
 
+/*
+ * The arm64 hcall implementation uses x0 to specify the hcall type. A value
+ * less than 0xfff indicates a special hcall, such as get/set vector.
+ * Any other value is used as a pointer to the function to call.
+ */
+
+/* HVC_GET_VECTORS - Return the value of the vbar_el2 register. */
+#define HVC_GET_VECTORS 0
+
+/*
+ * HVC_SET_VECTORS - Set the value of the vbar_el2 register.
+ *
+ * @x1: Physical address of the new vector table.
+ */
+#define HVC_SET_VECTORS 1
+
 #define BOOT_CPU_MODE_EL1	(0xe11)
 #define BOOT_CPU_MODE_EL2	(0xe12)
 

arch/arm64/kernel/hyp-stub.S

@@ -22,6 +22,8 @@
 #include <linux/irqchip/arm-gic-v3.h>
 
 #include <asm/assembler.h>
+#include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
 #include <asm/ptrace.h>
 #include <asm/virt.h>
 
@@ -53,15 +55,26 @@ ENDPROC(__hyp_stub_vectors)
 	.align 11
 
 el1_sync:
-	mrs	x1, esr_el2
+	mrs	x30, esr_el2
-	lsr	x1, x1, #26
+	lsr	x30, x30, #ESR_ELx_EC_SHIFT
-	cmp	x1, #0x16
+
-	b.ne	2f				// Not an HVC trap
+	cmp	x30, #ESR_ELx_EC_HVC64
-	cbz	x0, 1f
+	b.ne	9f				// Not an HVC trap
-	msr	vbar_el2, x0			// Set vbar_el2
+
-	b	2f
+	cmp	x0, #HVC_GET_VECTORS
-1:	mrs	x0, vbar_el2			// Return vbar_el2
+	b.ne	1f
-2:	eret
+	mrs	x0, vbar_el2
+	b	9f
+
+1:	cmp	x0, #HVC_SET_VECTORS
+	b.ne	2f
+	msr	vbar_el2, x1
+	b	9f
+
+	/* Someone called kvm_call_hyp() against the hyp-stub... */
+2:	mov     x0, #ARM_EXCEPTION_HYP_GONE
+
+9:	eret
 ENDPROC(el1_sync)
 
 .macro invalid_vector	label
@@ -101,10 +114,18 @@ ENDPROC(\label)
  */
 
 ENTRY(__hyp_get_vectors)
-	mov	x0, xzr
+	str	lr, [sp, #-16]!
-	// fall through
+	mov	x0, #HVC_GET_VECTORS
-ENTRY(__hyp_set_vectors)
 	hvc	#0
+	ldr	lr, [sp], #16
 	ret
 ENDPROC(__hyp_get_vectors)
+
+ENTRY(__hyp_set_vectors)
+	str	lr, [sp, #-16]!
+	mov	x1, x0
+	mov	x0, #HVC_SET_VECTORS
+	hvc	#0
+	ldr	lr, [sp], #16
+	ret
 ENDPROC(__hyp_set_vectors)

arch/arm64/kvm/handle_exit.c

@@ -183,6 +183,13 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		exit_handler = kvm_get_exit_handler(vcpu);
 
 		return exit_handler(vcpu, run);
+	case ARM_EXCEPTION_HYP_GONE:
+		/*
+		 * EL2 has been reset to the hyp-stub. This happens when a guest
+		 * is pre-empted by kvm_reboot()'s shutdown call.
+		 */
+		run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+		return 0;
 	default:
 		kvm_pr_unimpl("Unsupported exception type: %d",
 			      exception_index);

arch/arm64/kvm/hyp-init.S

@@ -152,6 +152,44 @@ merged:
 	eret
 ENDPROC(__kvm_hyp_init)
 
+	/*
+	 * x0: HYP boot pgd
+	 * x1: HYP phys_idmap_start
+	 */
+ENTRY(__kvm_hyp_reset)
+	/* We're in trampoline code in VA, switch back to boot page tables */
+	msr	ttbr0_el2, x0
+	isb
+
+	/* Ensure the PA branch doesn't find a stale tlb entry or stale code. */
+	ic	iallu
+	tlbi	alle2
+	dsb	sy
+	isb
+
+	/* Branch into PA space */
+	adr	x0, 1f
+	bfi	x1, x0, #0, #PAGE_SHIFT
+	br	x1
+
+	/* We're now in idmap, disable MMU */
+1:	mrs	x0, sctlr_el2
+	ldr	x1, =SCTLR_ELx_FLAGS
+	bic	x0, x0, x1		// Clear SCTL_M and etc
+	msr	sctlr_el2, x0
+	isb
+
+	/* Invalidate the old TLBs */
+	tlbi	alle2
+	dsb	sy
+
+	/* Install stub vectors */
+	adr_l	x0, __hyp_stub_vectors
+	msr	vbar_el2, x0
+
+	eret
+ENDPROC(__kvm_hyp_reset)
+
 	.ltorg
 
 	.popsection

arch/arm64/kvm/hyp.S

@@ -35,16 +35,21 @@
  * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c).  Return values are
  * passed in x0.
  *
- * A function pointer with a value of 0 has a special meaning, and is
+ * A function pointer with a value less than 0xfff has a special meaning,
- * used to implement __hyp_get_vectors in the same way as in
+ * and is used to implement __hyp_get_vectors in the same way as in
  * arch/arm64/kernel/hyp_stub.S.
+ * HVC behaves as a 'bl' call and will clobber lr.
  */
 ENTRY(__kvm_call_hyp)
 alternative_if_not ARM64_HAS_VIRT_HOST_EXTN
+	str     lr, [sp, #-16]!
 	hvc	#0
+	ldr     lr, [sp], #16
 	ret
 alternative_else
 	b	__vhe_hyp_call
 	nop
+	nop
+	nop
 alternative_endif
 ENDPROC(__kvm_call_hyp)

arch/arm64/kvm/hyp/hyp-entry.S

@@ -43,19 +43,17 @@
 	 * Shuffle the parameters before calling the function
 	 * pointed to in x0. Assumes parameters in x[1,2,3].
 	 */
-	sub	sp, sp, #16
-	str	lr, [sp]
 	mov	lr, x0
 	mov	x0, x1
 	mov	x1, x2
 	mov	x2, x3
 	blr	lr
-	ldr	lr, [sp]
-	add	sp, sp, #16
 .endm
 
 ENTRY(__vhe_hyp_call)
+	str	lr, [sp, #-16]!
 	do_el2_call
+	ldr	lr, [sp], #16
 	/*
 	 * We used to rely on having an exception return to get
 	 * an implicit isb. In the E2H case, we don't have it anymore.
@@ -81,8 +79,8 @@ el1_sync:				// Guest trapped into EL2
 	/* Here, we're pretty sure the host called HVC. */
 	restore_x0_to_x3
 
-	/* Check for __hyp_get_vectors */
+	cmp	x0, #HVC_GET_VECTORS
-	cbnz	x0, 1f
+	b.ne	1f
 	mrs	x0, vbar_el2
 	b	2f
 

arch/arm64/kvm/reset.c

@@ -29,7 +29,9 @@
 #include <asm/cputype.h>
 #include <asm/ptrace.h>
 #include <asm/kvm_arm.h>
+#include <asm/kvm_asm.h>
 #include <asm/kvm_coproc.h>
+#include <asm/kvm_mmu.h>
 
 /*
  * ARMv8 Reset Values
@@ -123,3 +125,15 @@ int kvm_reset_vcpu(struct kvm_vcpu *vcpu)
 	/* Reset timer */
 	return kvm_timer_vcpu_reset(vcpu, cpu_vtimer_irq);
 }
+
+extern char __hyp_idmap_text_start[];
+
+phys_addr_t kvm_hyp_reset_entry(void)
+{
+	unsigned long offset;
+
+	offset = (unsigned long)__kvm_hyp_reset
+		 - ((unsigned long)__hyp_idmap_text_start & PAGE_MASK);
+
+	return TRAMPOLINE_VA + offset;
+}