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Commit bc845e4f authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

ARM: KVM: Implement HVC_RESET_VECTORS stub hypercall in the init code 



In order to restore HYP mode to its original condition, KVM currently
implements __kvm_hyp_reset(). As we're moving towards a hyp-stub
defined API, it becomes necessary to implement HVC_RESET_VECTORS.

This patch adds the HVC_RESET_VECTORS hypercall to the KVM init
code, which so far lacked any form of hypercall support.

Tested-by: default avatarKeerthy <j-keerthy@ti.com>
Acked-by: default avatarRussell King <rmk+kernel@armlinux.org.uk>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 7d1bf4e0

arch/arm/include/asm/virt.h

+1 −0
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ static inline void sync_boot_mode(void) 


void __hyp_set_vectors(unsigned long phys_vector_base);

unsigned long __hyp_get_vectors(void);

void __hyp_reset_vectors(void);

#else

#define __boot_cpu_mode	(SVC_MODE)

#define sync_boot_mode()

arch/arm/kernel/hyp-stub.S

+1 −1
Original line number Diff line number Diff line
@@ -280,7 +280,7 @@ ENDPROC(__hyp_reset_vectors) 
#endif



.align 5

__hyp_stub_vectors:

ENTRY(__hyp_stub_vectors)

__hyp_stub_reset:	W(b)	.

__hyp_stub_und:		W(b)	.

__hyp_stub_svc:		W(b)	.

arch/arm/kvm/init.S

+27 −6
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <asm/kvm_asm.h>

#include <asm/kvm_arm.h>

#include <asm/kvm_mmu.h>

#include <asm/virt.h>



/********************************************************************

 * Hypervisor initialization
@@ -39,6 +40,10 @@ 
 * - Setup the page tables

 * - Enable the MMU

 * - Profit! (or eret, if you only care about the code).

 *

 * Another possibility is to get a HYP stub hypercall.

 * We discriminate between the two by checking if r0 contains a value

 * that is less than HVC_STUB_HCALL_NR.

 */



	.text
@@ -58,6 +63,10 @@ __kvm_hyp_init: 
	W(b)	.



__do_hyp_init:

	@ Check for a stub hypercall

	cmp	r0, #HVC_STUB_HCALL_NR

	blo	__kvm_handle_stub_hvc



	@ Set stack pointer

	mov	sp, r0
@@ -112,19 +121,31 @@ __do_hyp_init: 


	eret



	@ r0 : stub vectors address

ENTRY(__kvm_handle_stub_hvc)

	cmp	r0, #HVC_RESET_VECTORS

	bne	1f

ENTRY(__kvm_hyp_reset)

	/* We're now in idmap, disable MMU */

	mrc	p15, 4, r1, c1, c0, 0	@ HSCTLR

	ldr	r2, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I)

	bic	r1, r1, r2

	ldr	r0, =(HSCTLR_M | HSCTLR_A | HSCTLR_C | HSCTLR_I)

	bic	r1, r1, r0

	mcr	p15, 4, r1, c1, c0, 0	@ HSCTLR



	/* Install stub vectors */

	mcr	p15, 4, r0, c12, c0, 0	@ HVBAR

	isb

	/*

	 * Install stub vectors, using ardb's VA->PA trick.

	 */

0:	adr	r0, 0b					@ PA(0)

	movw	r1, #:lower16:__hyp_stub_vectors - 0b   @ VA(stub) - VA(0)

	movt	r1, #:upper16:__hyp_stub_vectors - 0b

	add	r1, r1, r0				@ PA(stub)

	mcr	p15, 4, r1, c12, c0, 0	@ HVBAR

	b	exit



1:	ldr	r0, =HVC_STUB_ERR



exit:

	eret

ENDPROC(__kvm_handle_stub_hvc)

ENDPROC(__kvm_hyp_reset)



	.ltorg