From 8f17f5e4698ee5e42c827e8905cf39cf61c482c2 Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Mon, 9 Oct 2017 21:43:50 +0200 Subject: KVM: arm64: Rework hyp_panic for VHE and non-VHE VHE actually doesn't rely on clearing the VTTBR when returning to the host kernel, and that is the current key mechanism of hyp_panic to figure out how to attempt to return to a state good enough to print a panic statement. Therefore, we split the hyp_panic function into two functions, a VHE and a non-VHE, keeping the non-VHE version intact, but changing the VHE behavior. The vttbr_el2 check on VHE doesn't really make that much sense, because the only situation where we can get here on VHE is when the hypervisor assembly code actually called into hyp_panic, which only happens when VBAR_EL2 has been set to the KVM exception vectors. On VHE, we can always safely disable the traps and restore the host registers at this point, so we simply do that unconditionally and call into the panic function directly. Acked-by: Marc Zyngier Reviewed-by: Andrew Jones Signed-off-by: Christoffer Dall Signed-off-by: Marc Zyngier --- arch/arm64/kvm/hyp/switch.c | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) (limited to 'arch/arm64/kvm/hyp') diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c index 46717da75643..579d9a263853 100644 --- a/arch/arm64/kvm/hyp/switch.c +++ b/arch/arm64/kvm/hyp/switch.c @@ -439,10 +439,20 @@ again: static const char __hyp_panic_string[] = "HYP panic:\nPS:%08llx PC:%016llx ESR:%08llx\nFAR:%016llx HPFAR:%016llx PAR:%016llx\nVCPU:%p\n"; static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par, - struct kvm_vcpu *vcpu) + struct kvm_cpu_context *__host_ctxt) { + struct kvm_vcpu *vcpu; unsigned long str_va; + vcpu = __host_ctxt->__hyp_running_vcpu; + + if (read_sysreg(vttbr_el2)) { + __timer_disable_traps(vcpu); + __deactivate_traps(vcpu); + __deactivate_vm(vcpu); + __sysreg_restore_host_state(__host_ctxt); + } + /* * Force the panic string to be loaded from the literal pool, * making sure it is a kernel address and not a PC-relative @@ -456,37 +466,31 @@ static void __hyp_text __hyp_call_panic_nvhe(u64 spsr, u64 elr, u64 par, read_sysreg(hpfar_el2), par, vcpu); } -static void __hyp_text __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par, - struct kvm_vcpu *vcpu) +static void __hyp_call_panic_vhe(u64 spsr, u64 elr, u64 par, + struct kvm_cpu_context *host_ctxt) { + struct kvm_vcpu *vcpu; + vcpu = host_ctxt->__hyp_running_vcpu; + + __deactivate_traps(vcpu); + __sysreg_restore_host_state(host_ctxt); + panic(__hyp_panic_string, spsr, elr, read_sysreg_el2(esr), read_sysreg_el2(far), read_sysreg(hpfar_el2), par, vcpu); } -static hyp_alternate_select(__hyp_call_panic, - __hyp_call_panic_nvhe, __hyp_call_panic_vhe, - ARM64_HAS_VIRT_HOST_EXTN); - void __hyp_text __noreturn hyp_panic(struct kvm_cpu_context *host_ctxt) { - struct kvm_vcpu *vcpu = NULL; - u64 spsr = read_sysreg_el2(spsr); u64 elr = read_sysreg_el2(elr); u64 par = read_sysreg(par_el1); - if (read_sysreg(vttbr_el2)) { - vcpu = host_ctxt->__hyp_running_vcpu; - __timer_disable_traps(vcpu); - __deactivate_traps(vcpu); - __deactivate_vm(vcpu); - __sysreg_restore_host_state(host_ctxt); - } - - /* Call panic for real */ - __hyp_call_panic()(spsr, elr, par, vcpu); + if (!has_vhe()) + __hyp_call_panic_nvhe(spsr, elr, par, host_ctxt); + else + __hyp_call_panic_vhe(spsr, elr, par, host_ctxt); unreachable(); } -- cgit v1.2.3