arm/arm64: KVM: vgic: move reset initialization into vgic_init_maps()
VGIC initialization currently happens in three phases:
(1) kvm_vgic_create() (triggered by userspace GIC creation)
(2) vgic_init_maps() (triggered by userspace GIC register read/write
requests, or from kvm_vgic_init() if not already run)
(3) kvm_vgic_init() (triggered by first VM run)
We were doing initialization of some state to correspond with the
state of a freshly-reset GIC in kvm_vgic_init(); this is too late,
since it will overwrite changes made by userspace using the
register access APIs before the VM is run. Move this initialization
earlier, into the vgic_init_maps() phase.
This fixes a bug where QEMU could successfully restore a saved
VM state snapshot into a VM that had already been run, but could
not restore it "from cold" using the -loadvm command line option
(the symptoms being that the restored VM would run but interrupts
were ignored).
Finally rename vgic_init_maps to vgic_init and renamed kvm_vgic_init to
kvm_vgic_map_resources.
[ This patch is originally written by Peter Maydell, but I have
modified it somewhat heavily, renaming various bits and moving code
around. If something is broken, I am to be blamed. - Christoffer ]
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index da87c07..fa4b97c 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -428,11 +428,11 @@
vcpu->arch.has_run_once = true;
/*
- * Initialize the VGIC before running a vcpu the first time on
- * this VM.
+ * Map the VGIC hardware resources before running a vcpu the first
+ * time on this VM.
*/
if (unlikely(!vgic_initialized(vcpu->kvm))) {
- ret = kvm_vgic_init(vcpu->kvm);
+ ret = kvm_vgic_map_resources(vcpu->kvm);
if (ret)
return ret;
}