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Commit 96e5e670 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

ARM: KVM: Add VFP lazy save/restore handler 



Similar to the arm64 version, add the code that deals with VFP traps,
re-enabling VFP, save/restoring the registers and resuming the guest.

Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 89ef2b21

arch/arm/kvm/hyp/entry.S

+31 −0
Original line number Diff line number Diff line
@@ -66,5 +66,36 @@ ENTRY(__guest_exit) 
	bx	lr

ENDPROC(__guest_exit)



/*

 * If VFPv3 support is not available, then we will not switch the VFP

 * registers; however cp10 and cp11 accesses will still trap and fallback

 * to the regular coprocessor emulation code, which currently will

 * inject an undefined exception to the guest.

 */

#ifdef CONFIG_VFPv3

ENTRY(__vfp_guest_restore)

	push	{r3, r4, lr}



	@ NEON/VFP used.  Turn on VFP access.

	mrc	p15, 4, r1, c1, c1, 2		@ HCPTR

	bic	r1, r1, #(HCPTR_TCP(10) | HCPTR_TCP(11))

	mcr	p15, 4, r1, c1, c1, 2		@ HCPTR

	isb



	@ Switch VFP/NEON hardware state to the guest's

	mov	r4, r0

	ldr	r0, [r0, #VCPU_HOST_CTXT]

	add	r0, r0, #CPU_CTXT_VFP

	bl	__vfp_save_state

	add	r0, r4, #(VCPU_GUEST_CTXT + CPU_CTXT_VFP)

	bl	__vfp_restore_state



	pop	{r3, r4, lr}

	pop	{r0, r1, r2}

	clrex

	eret

ENDPROC(__vfp_guest_restore)

#endif



	.popsection