From: James Morse <james.morse@arm.com>
Date: Tue, 25 Apr 2017 18:02:45 +0100
Subject: KVM: arm64: Restore host physical timer access on hyp_panic()
Patch-mainline: v4.13-rc1
Git-commit: e8ec032b182cd4841605de4fc297a8edffe55972
References: bsc#1077761

When KVM panics, it hurridly restores the host context and parachutes
into the host's panic() code. At some point panic() touches the physical
timer/counter. Unless we are an arm64 system with VHE, this traps back
to EL2. If we're lucky, we panic again.

Add a __timer_save_state() call to KVMs hyp_panic() path, this saves the
guest registers and disables the traps for the host.

Fixes: 53fd5b6487e4 ("arm64: KVM: Add panic handling")
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Alexander Graf <agraf@suse.de>
---
 arch/arm64/kvm/hyp/switch.c |    1 +
 1 file changed, 1 insertion(+)

--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -443,6 +443,7 @@
 
 		vcpu = (struct kvm_vcpu *)read_sysreg(tpidr_el2);
 		host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context);
+		__timer_save_state(vcpu);
 		__deactivate_traps(vcpu);
 		__deactivate_vm(vcpu);
 		__sysreg_restore_host_state(host_ctxt);