1 files changed, 87 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
new file mode 100644
index 000000000..bd1bab551
--- /dev/null
+++ b/arch/arm64/kvm/hyp/vgic-v2-cpuif-proxy.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ */
+
+#include <linux/compiler.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/kvm_host.h>
+#include <linux/swab.h>
+
+#include <asm/kvm_emulate.h>
+#include <asm/kvm_hyp.h>
+#include <asm/kvm_mmu.h>
+
+static bool __is_be(struct kvm_vcpu *vcpu)
+{
+	if (vcpu_mode_is_32bit(vcpu))
+		return !!(read_sysreg_el2(SYS_SPSR) & PSR_AA32_E_BIT);
+
+	return !!(read_sysreg(SCTLR_EL1) & SCTLR_ELx_EE);
+}
+
+/*
+ * __vgic_v2_perform_cpuif_access -- perform a GICV access on behalf of the
+ *				     guest.
+ *
+ * @vcpu: the offending vcpu
+ *
+ * Returns:
+ *  1: GICV access successfully performed
+ *  0: Not a GICV access
+ * -1: Illegal GICV access successfully performed
+ */
+int __vgic_v2_perform_cpuif_access(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+	struct vgic_dist *vgic = &kvm->arch.vgic;
+	phys_addr_t fault_ipa;
+	void __iomem *addr;
+	int rd;
+
+	/* Build the full address */
+	fault_ipa  = kvm_vcpu_get_fault_ipa(vcpu);
+	fault_ipa |= kvm_vcpu_get_hfar(vcpu) & GENMASK(11, 0);
+
+	/* If not for GICV, move on */
+	if (fault_ipa <  vgic->vgic_cpu_base ||
+	    fault_ipa >= (vgic->vgic_cpu_base + KVM_VGIC_V2_CPU_SIZE))
+		return 0;
+
+	/* Reject anything but a 32bit access */
+	if (kvm_vcpu_dabt_get_as(vcpu) != sizeof(u32)) {
+		__kvm_skip_instr(vcpu);
+		return -1;
+	}
+
+	/* Not aligned? Don't bother */
+	if (fault_ipa & 3) {
+		__kvm_skip_instr(vcpu);
+		return -1;
+	}
+
+	rd = kvm_vcpu_dabt_get_rd(vcpu);
+	addr  = hyp_symbol_addr(kvm_vgic_global_state)->vcpu_hyp_va;
+	addr += fault_ipa - vgic->vgic_cpu_base;
+
+	if (kvm_vcpu_dabt_iswrite(vcpu)) {
+		u32 data = vcpu_get_reg(vcpu, rd);
+		if (__is_be(vcpu)) {
+			/* guest pre-swabbed data, undo this for writel() */
+			data = __kvm_swab32(data);
+		}
+		writel_relaxed(data, addr);
+	} else {
+		u32 data = readl_relaxed(addr);
+		if (__is_be(vcpu)) {
+			/* guest expects swabbed data */
+			data = __kvm_swab32(data);
+		}
+		vcpu_set_reg(vcpu, rd, data);
+	}
+
+	__kvm_skip_instr(vcpu);
+
+	return 1;
+}