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Commit fd0e0c61 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm64: hyp-stub: Implement HVC_RESET_VECTORS stub hypercall 



Let's define a new stub hypercall that resets the HYP configuration
to its default: hyp-stub vectors, and MMU disabled.

Of course, for the hyp-stub itself, this is a trivial no-op.
Hypervisors will have a bit more work to do.

Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <cdall@linaro.org>
parent 810c86ee

arch/arm64/include/asm/virt.h

+9 −0
Original line number Diff line number Diff line
@@ -44,6 +44,14 @@ 
 */

#define HVC_SOFT_RESTART 2



/*

 * HVC_RESET_VECTORS - Restore the vectors to the original HYP stubs

 */

#define HVC_RESET_VECTORS 3



/* Max number of HYP stub hypercalls */

#define HVC_STUB_HCALL_NR 4



/* Error returned when an invalid stub number is passed into x0 */

#define HVC_STUB_ERR	0xbadca11
@@ -70,6 +78,7 @@ extern u32 __boot_cpu_mode[2]; 


void __hyp_set_vectors(phys_addr_t phys_vector_base);

phys_addr_t __hyp_get_vectors(void);

void __hyp_reset_vectors(void);



/* Reports the availability of HYP mode */

static inline bool is_hyp_mode_available(void)

arch/arm64/kernel/hyp-stub.S

+10 −1
Original line number Diff line number Diff line
@@ -73,8 +73,11 @@ el1_sync: 
	mov	x1, x3

	br	x4				// no return



3:	cmp	x0, #HVC_RESET_VECTORS

	beq	9f				// Nothing to reset!



	/* Someone called kvm_call_hyp() against the hyp-stub... */

3:	ldr	x0, =HVC_STUB_ERR

	ldr	x0, =HVC_STUB_ERR



9:	eret

ENDPROC(el1_sync)
@@ -127,3 +130,9 @@ ENTRY(__hyp_set_vectors) 
	hvc	#0

	ret

ENDPROC(__hyp_set_vectors)



ENTRY(__hyp_reset_vectors)

	mov	x0, #HVC_RESET_VECTORS

	hvc	#0

	ret

ENDPROC(__hyp_reset_vectors)