From c36b6db5f3e4c1bd21659aee8e67226352d254ae Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 6 Jan 2016 09:12:42 +0000 Subject: [PATCH] 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: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm/kvm/hyp/hyp-entry.S | 28 +++++++++++++++++++------- arch/arm/kvm/hyp/switch.c | 38 ++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+), 7 deletions(-) diff --git a/arch/arm/kvm/hyp/hyp-entry.S b/arch/arm/kvm/hyp/hyp-entry.S index 1b4aa02fd364..54a8d67ad980 100644 --- a/arch/arm/kvm/hyp/hyp-entry.S +++ b/arch/arm/kvm/hyp/hyp-entry.S @@ -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: /* diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c index 0dd0ba33b8a7..abbe90b5f2ff 100644 --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -192,3 +192,41 @@ again: } __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(); +} -- 2.20.1