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From: Pavel Fedin <p.fedin@samsung.com>
To: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: 'Christoffer Dall' <christoffer.dall@linaro.org>,
	'Marc Zyngier' <marc.zyngier@arm.com>
Subject: [PATCH] KVM: arm64: Decode basic HYP fault information
Date: Tue, 11 Aug 2015 10:34:07 +0300	[thread overview]
Message-ID: <00aa01d0d408$1ba96ea0$52fc4be0$@samsung.com> (raw)

Print exception vector name, exception class and PC translated to EL1 virtual
address. Significantly aids debugging HYP crashes without special means like
JTAG.

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
---
 arch/arm64/kvm/handle_exit.c | 30 +++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp.S         | 46 +++++++++++++++++---------------------------
 2 files changed, 48 insertions(+), 28 deletions(-)

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 29b184a..4d70d64 100644
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -136,3 +136,33 @@ int handle_exit(struct kvm_vcpu *vcpu, struct kvm_run *run,
 		return 0;
 	}
 }
+
+static const char *const hyp_faults[] = {
+	"EL2t Synchronous",
+	"EL2t IRQ",
+	"EL2t FIQ",
+	"EL2t Error",
+	"EL2h Synchronous",
+	"EL2h IRQ",
+	"EL2h FIQ",
+	"EL2h Error",
+	"EL1 Synchronous",
+	"EL1 IRQ",
+	"EL1 FIQ",
+	"EL1 Error"
+};
+
+void kvm_hyp_panic(unsigned long vector, unsigned int spsr, unsigned long pc,
+		   unsigned int esr, unsigned long far, unsigned long hpfar,
+		   unsigned long par, struct kvm_vcpu *vcpu)
+{
+	pr_emerg("Unhandled HYP exception %s on VCPU %p\n",
+		hyp_faults[vector], vcpu);
+	pr_emerg("PC : %016lx SPSR : %08x         ESR: %08x\n", pc, spsr, esr);
+	pr_emerg("FAR: %016lx HPFAR: %016lx PAR: %016lx\n", far, hpfar, par);
+
+	pr_emerg("Exception class: %02x Translated PC: %016lx\n",
+		esr >> ESR_ELx_EC_SHIFT, pc - HYP_PAGE_OFFSET + PAGE_OFFSET);
+
+	panic("HYP panic");
+}
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index c81eaaf..62785cd 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -1060,13 +1060,11 @@ __kvm_hyp_panic:
 	ldr	x2, [x0, #VCPU_HOST_CONTEXT]
 	kern_hyp_va x2
 
+	mov	x0, lr
 	bl __restore_sysregs
+	mov	lr, x0
 
-1:	adr	x0, __hyp_panic_str
-	adr	x1, 2f
-	ldp	x2, x3, [x1]
-	sub	x0, x0, x2
-	add	x0, x0, x3
+1:	mov	x0, lr
 	mrs	x1, spsr_el2
 	mrs	x2, elr_el2
 	mrs	x3, esr_el2
@@ -1078,20 +1076,11 @@ __kvm_hyp_panic:
 	mov	lr, #(PSR_F_BIT | PSR_I_BIT | PSR_A_BIT | PSR_D_BIT |\
 		      PSR_MODE_EL1h)
 	msr	spsr_el2, lr
-	ldr	lr, =panic
+	ldr	lr, =kvm_hyp_panic
 	msr	elr_el2, lr
 	eret
-
-	.align	3
-2:	.quad	HYP_PAGE_OFFSET
-	.quad	PAGE_OFFSET
 ENDPROC(__kvm_hyp_panic)
 
-__hyp_panic_str:
-	.ascii	"HYP panic:\nPS:%08x PC:%p ESR:%p\nFAR:%p HPFAR:%p PAR:%p\nVCPU:%p\n\0"
-
-	.align	2
-
 /*
  * u64 kvm_call_hyp(void *hypfn, ...);
  *
@@ -1115,26 +1104,27 @@ ENTRY(kvm_call_hyp)
 	ret
 ENDPROC(kvm_call_hyp)
 
-.macro invalid_vector	label, target
+.macro invalid_vector	label, N, target
 	.align	2
 \label:
+	mov lr, #\N
 	b \target
 ENDPROC(\label)
 .endm
 
 	/* None of these should ever happen */
-	invalid_vector	el2t_sync_invalid, __kvm_hyp_panic
-	invalid_vector	el2t_irq_invalid, __kvm_hyp_panic
-	invalid_vector	el2t_fiq_invalid, __kvm_hyp_panic
-	invalid_vector	el2t_error_invalid, __kvm_hyp_panic
-	invalid_vector	el2h_sync_invalid, __kvm_hyp_panic
-	invalid_vector	el2h_irq_invalid, __kvm_hyp_panic
-	invalid_vector	el2h_fiq_invalid, __kvm_hyp_panic
-	invalid_vector	el2h_error_invalid, __kvm_hyp_panic
-	invalid_vector	el1_sync_invalid, __kvm_hyp_panic
-	invalid_vector	el1_irq_invalid, __kvm_hyp_panic
-	invalid_vector	el1_fiq_invalid, __kvm_hyp_panic
-	invalid_vector	el1_error_invalid, __kvm_hyp_panic
+	invalid_vector	el2t_sync_invalid, 0, __kvm_hyp_panic
+	invalid_vector	el2t_irq_invalid, 1, __kvm_hyp_panic
+	invalid_vector	el2t_fiq_invalid, 2, __kvm_hyp_panic
+	invalid_vector	el2t_error_invalid, 3, __kvm_hyp_panic
+	invalid_vector	el2h_sync_invalid, 4, __kvm_hyp_panic
+	invalid_vector	el2h_irq_invalid, 5, __kvm_hyp_panic
+	invalid_vector	el2h_fiq_invalid, 6, __kvm_hyp_panic
+	invalid_vector	el2h_error_invalid, 7, __kvm_hyp_panic
+	invalid_vector	el1_sync_invalid, 8, __kvm_hyp_panic
+	invalid_vector	el1_irq_invalid, 9, __kvm_hyp_panic
+	invalid_vector	el1_fiq_invalid, 10, __kvm_hyp_panic
+	invalid_vector	el1_error_invalid, 11, __kvm_hyp_panic
 
 el1_sync:					// Guest trapped into EL2
 	push	x0, x1
-- 
2.4.4


Kind regards,
Pavel Fedin
Expert Engineer
Samsung Electronics Research center Russia




             reply	other threads:[~2015-08-11  7:34 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-08-11  7:34 Pavel Fedin [this message]
2015-08-30 17:44 ` [PATCH] KVM: arm64: Decode basic HYP fault information Christoffer Dall
2015-08-31  6:33   ` Pavel Fedin
2015-08-31  9:49     ` Christoffer Dall
2015-08-31  9:59       ` Pavel Fedin

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