ARM: KVM: Support vgic-v3

This patch allows to build and use vgic-v3 in 32-bit mode.

Unfortunately, it can not be split in several steps without extra
stubs to keep patches independent and bisectable.  For instance,
virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling
access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre
to be already defined.

It is how support has been done:

* handle SGI requests from the guest

* report configured SRE on access to GICv3 cpu interface from the guest

* required vgic-v3 macros are provided via uapi.h

* static keys are used to select GIC backend

* to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with
  the static inlines

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
diff --git a/arch/arm/kvm/coproc.c b/arch/arm/kvm/coproc.c
index 1bb2b79..3e5e419 100644
--- a/arch/arm/kvm/coproc.c
+++ b/arch/arm/kvm/coproc.c
@@ -228,6 +228,35 @@
 	return true;
 }
 
+static bool access_gic_sgi(struct kvm_vcpu *vcpu,
+			   const struct coproc_params *p,
+			   const struct coproc_reg *r)
+{
+	u64 reg;
+
+	if (!p->is_write)
+		return read_from_write_only(vcpu, p);
+
+	reg = (u64)*vcpu_reg(vcpu, p->Rt2) << 32;
+	reg |= *vcpu_reg(vcpu, p->Rt1) ;
+
+	vgic_v3_dispatch_sgi(vcpu, reg);
+
+	return true;
+}
+
+static bool access_gic_sre(struct kvm_vcpu *vcpu,
+			   const struct coproc_params *p,
+			   const struct coproc_reg *r)
+{
+	if (p->is_write)
+		return ignore_write(vcpu, p);
+
+	*vcpu_reg(vcpu, p->Rt1) = vcpu->arch.vgic_cpu.vgic_v3.vgic_sre;
+
+	return true;
+}
+
 /*
  * We could trap ID_DFR0 and tell the guest we don't support performance
  * monitoring.  Unfortunately the patch to make the kernel check ID_DFR0 was
@@ -361,10 +390,16 @@
 	{ CRn(10), CRm( 3), Op1( 0), Op2( 1), is32,
 			access_vm_reg, reset_unknown, c10_AMAIR1},
 
+	/* ICC_SGI1R */
+	{ CRm64(12), Op1( 0), is64, access_gic_sgi},
+
 	/* VBAR: swapped by interrupt.S. */
 	{ CRn(12), CRm( 0), Op1( 0), Op2( 0), is32,
 			NULL, reset_val, c12_VBAR, 0x00000000 },
 
+	/* ICC_SRE */
+	{ CRn(12), CRm(12), Op1( 0), Op2(5), is32, access_gic_sre },
+
 	/* CONTEXTIDR/TPIDRURW/TPIDRURO/TPIDRPRW: swapped by interrupt.S. */
 	{ CRn(13), CRm( 0), Op1( 0), Op2( 1), is32,
 			access_vm_reg, reset_val, c13_CID, 0x00000000 },