arm/arm64: KVM: add opaque private pointer to MMIO data

For a GICv2 there is always only one (v)CPU involved: the one that
does the access. On a GICv3 the access to a CPU redistributor is
memory-mapped, but not banked, so the (v)CPU affected is determined by
looking at the MMIO address region being accessed.
To allow passing the affected CPU into the accessors later, extend
struct kvm_exit_mmio to add an opaque private pointer parameter.
The current GICv2 emulation just does not use it.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

arch/arm/include/asm/kvm_mmio.h

@@ -37,6 +37,7 @@ struct kvm_exit_mmio {
 	u8		data[8];
 	u32		len;
 	bool		is_write;
+	void		*private;
 };
 
 static inline void kvm_prepare_mmio(struct kvm_run *run,

arch/arm64/include/asm/kvm_mmio.h

@@ -40,6 +40,7 @@ struct kvm_exit_mmio {
 	u8		data[8];
 	u32		len;
 	bool		is_write;
+	void		*private;
 };
 
 static inline void kvm_prepare_mmio(struct kvm_run *run,

virt/kvm/arm/vgic.c

@@ -709,6 +709,7 @@ static bool call_range_handler(struct kvm_vcpu *vcpu,
 
 	mmio32.len = 4;
 	mmio32.is_write = mmio->is_write;
+	mmio32.private = mmio->private;
 
 	mmio32.phys_addr = mmio->phys_addr + 4;
 	if (mmio->is_write)