KVM: arm64: Restore host physical timer access on hyp_panic()

[ Upstream commit e8ec032b182cd4841605de4fc297a8edffe55972 ]

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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/kvm/hyp/switch.c b/arch/arm64/kvm/hyp/switch.c
index 0c848c1..9174ba9 100644 (file)
--- a/arch/arm64/kvm/hyp/switch.c
+++ b/arch/arm64/kvm/hyp/switch.c
@@ -404,6 +404,7 @@ void __hyp_text __noreturn __hyp_panic(void)
 
                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);