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Commit c39798f4 authored by Marc Zyngier's avatar Marc Zyngier Committed by Christoffer Dall
Browse files

arm: KVM: Handle async aborts delivered while at HYP 



Just like for arm64, we can handle asynchronous aborts being
delivered at HYP while being caused by the guest. We use
the exact same method to catch such an abort, and soldier on.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
parent 435bca5f

arch/arm/kvm/hyp/entry.S

+31 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 
#include <linux/linkage.h>

#include <asm/asm-offsets.h>

#include <asm/kvm_arm.h>

#include <asm/kvm_asm.h>



	.arch_extension     virt
@@ -63,6 +64,36 @@ ENTRY(__guest_exit) 
	ldr	lr, [r0, #4]



	mov	r0, r1

	mrs	r1, SPSR

	mrs	r2, ELR_hyp

	mrc	p15, 4, r3, c5, c2, 0	@ HSR



	/*

	 * Force loads and stores to complete before unmasking aborts

	 * and forcing the delivery of the exception. This gives us a

	 * single instruction window, which the handler will try to

	 * match.

	 */

	dsb	sy

	cpsie	a



	.global	abort_guest_exit_start

abort_guest_exit_start:



	isb



	.global	abort_guest_exit_end

abort_guest_exit_end:



	/*

	 * If we took an abort, r0[31] will be set, and cmp will set

	 * the N bit in PSTATE.

	 */

	cmp	r0, #0

	msrmi	SPSR_cxsf, r1

	msrmi	ELR_hyp, r2

	mcrmi	p15, 4, r3, c5, c2, 0	@ HSR



	bx	lr

ENDPROC(__guest_exit)

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

+15 −1
Original line number Diff line number Diff line
@@ -81,7 +81,6 @@ __kvm_hyp_vector: 
	invalid_vector	hyp_undef	ARM_EXCEPTION_UNDEFINED

	invalid_vector	hyp_svc		ARM_EXCEPTION_SOFTWARE

	invalid_vector	hyp_pabt	ARM_EXCEPTION_PREF_ABORT

	invalid_vector	hyp_dabt	ARM_EXCEPTION_DATA_ABORT

	invalid_vector	hyp_fiq		ARM_EXCEPTION_FIQ



ENTRY(__hyp_do_panic)
@@ -164,6 +163,21 @@ hyp_irq: 
	load_vcpu r0			@ Load VCPU pointer to r0

	b	__guest_exit



hyp_dabt:

	push	{r0, r1}

	mrs	r0, ELR_hyp

	ldr	r1, =abort_guest_exit_start

THUMB(	add	r1, r1, #1)

	cmp	r0, r1

	ldrne	r1, =abort_guest_exit_end

THUMB(	addne	r1, r1, #1)

	cmpne	r0, r1

	pop	{r0, r1}

	bne	__hyp_panic



	orr	r0, r0, #(1 << ARM_EXIT_WITH_ABORT_BIT)

	eret



	.ltorg



	.popsection