From: James Morse james.morse@arm.com
[ Upstream commit d2e19368848ce6065daa785efca26faed54732b6 ]
When KVM panics, it hurridly restores the host context and parachutes into the host's panic() code. This looks like it was copied from arm64, the 32bit KVM panic code needs to restore the host's banked registers too.
At some point panic() touches the physical timer/counter, this will trap back to HYP. 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: c36b6db5f3e4 ("ARM: KVM: Add panic handling code") 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 --- arch/arm/kvm/hyp/switch.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm/kvm/hyp/switch.c b/arch/arm/kvm/hyp/switch.c index 624a510d31df..ebd2dd46adf7 100644 --- a/arch/arm/kvm/hyp/switch.c +++ b/arch/arm/kvm/hyp/switch.c @@ -237,8 +237,10 @@ void __hyp_text __noreturn __hyp_panic(int cause)
vcpu = (struct kvm_vcpu *)read_sysreg(HTPIDR); host_ctxt = kern_hyp_va(vcpu->arch.host_cpu_context); + __timer_save_state(vcpu); __deactivate_traps(vcpu); __deactivate_vm(vcpu); + __banked_restore_state(host_ctxt); __sysreg_restore_state(host_ctxt); }