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Commit c36b6db5 authored by Marc Zyngier's avatar Marc Zyngier
Browse files

ARM: KVM: Add panic handling code 



Instead of spinning forever, let's "properly" handle any unexpected
exception ("properly" meaning "print a spat on the console and die").

This has proved useful quite a few times...

Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent bafc6c2a

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

+21 −7
Original line number Diff line number Diff line
@@ -75,15 +75,29 @@ __kvm_hyp_vector: 


.macro invalid_vector label, cause

	.align

\label:	b	.

\label:	mov	r0, #\cause

	b	__hyp_panic

.endm



	invalid_vector	hyp_reset

	invalid_vector	hyp_undef

	invalid_vector	hyp_svc

	invalid_vector	hyp_pabt

	invalid_vector	hyp_dabt

	invalid_vector	hyp_fiq

	invalid_vector	hyp_reset	ARM_EXCEPTION_RESET

	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)

	mrs	lr, cpsr

	bic	lr, lr, #MODE_MASK

	orr	lr, lr, #SVC_MODE

THUMB(	orr	lr, lr, #PSR_T_BIT	)

	msr	spsr_cxsf, lr

	ldr	lr, =panic

	msr	ELR_hyp, lr

	ldr	lr, =kvm_call_hyp

	clrex

	eret

ENDPROC(__hyp_do_panic)



hyp_hvc:

	/*

arch/arm/kvm/hyp/switch.c

+38 −0
Original line number Diff line number Diff line
@@ -192,3 +192,41 @@ static int __hyp_text __guest_run(struct kvm_vcpu *vcpu) 
}



__alias(__guest_run) int __weak __kvm_vcpu_run(struct kvm_vcpu *vcpu);



static const char * const __hyp_panic_string[] = {

	[ARM_EXCEPTION_RESET]      = "\nHYP panic: RST   PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_UNDEFINED]  = "\nHYP panic: UNDEF PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_SOFTWARE]   = "\nHYP panic: SVC   PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_PREF_ABORT] = "\nHYP panic: PABRT PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_DATA_ABORT] = "\nHYP panic: DABRT PC:%08x ADDR:%08x",

	[ARM_EXCEPTION_IRQ]        = "\nHYP panic: IRQ   PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_FIQ]        = "\nHYP panic: FIQ   PC:%08x CPSR:%08x",

	[ARM_EXCEPTION_HVC]        = "\nHYP panic: HVC   PC:%08x CPSR:%08x",

};



void __hyp_text __noreturn __hyp_panic(int cause)

{

	u32 elr = read_special(ELR_hyp);

	u32 val;



	if (cause == ARM_EXCEPTION_DATA_ABORT)

		val = read_sysreg(HDFAR);

	else

		val = read_special(SPSR);



	if (read_sysreg(VTTBR)) {

		struct kvm_vcpu *vcpu;

		struct kvm_cpu_context *host_ctxt;



		vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR);

		host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);

		__deactivate_traps(vcpu);

		__deactivate_vm(vcpu);

		__sysreg_restore_state(host_ctxt);

	}



	/* Call panic for real */

	__hyp_do_panic(__hyp_panic_string[cause], elr, val);



	unreachable();

}