arm64: KVM: Implement vgic-v2 save/restore

Implement the vgic-v2 save restore (mostly) as a direct translation
of the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

arch/arm64/kvm/Makefile

@@ -10,6 +10,7 @@ KVM=../../../virt/kvm
 ARM=../../../arch/arm/kvm
 
 obj-$(CONFIG_KVM_ARM_HOST) += kvm.o
+obj-$(CONFIG_KVM_ARM_HOST) += hyp/
 
 kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o $(KVM)/vfio.o
 kvm-$(CONFIG_KVM_ARM_HOST) += $(ARM)/arm.o $(ARM)/mmu.o $(ARM)/mmio.o

arch/arm64/kvm/hyp/Makefile

@@ -0,0 +1,5 @@
+#
+# Makefile for Kernel-based Virtual Machine module, HYP part
+#
+
+obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o

arch/arm64/kvm/hyp/hyp.h

@@ -29,5 +29,8 @@
 #define hyp_kern_va(v) (typeof(v))((unsigned long)(v) - HYP_PAGE_OFFSET \
 						      + PAGE_OFFSET)
 
+void __vgic_v2_save_state(struct kvm_vcpu *vcpu);
+void __vgic_v2_restore_state(struct kvm_vcpu *vcpu);
+
 #endif /* __ARM64_KVM_HYP_H__ */
 

arch/arm64/kvm/hyp/vgic-v2-sr.c

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2012-2015 - ARM Ltd
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/compiler.h>
+#include <linux/irqchip/arm-gic.h>
+#include <linux/kvm_host.h>
+
+#include <asm/kvm_mmu.h>
+
+#include "hyp.h"
+
+/* vcpu is already in the HYP VA space */
+void __hyp_text __vgic_v2_save_state(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+	struct vgic_dist *vgic = &kvm->arch.vgic;
+	void __iomem *base = kern_hyp_va(vgic->vctrl_base);
+	u32 eisr0, eisr1, elrsr0, elrsr1;
+	int i, nr_lr;
+
+	if (!base)
+		return;
+
+	nr_lr = vcpu->arch.vgic_cpu.nr_lr;
+	cpu_if->vgic_vmcr = readl_relaxed(base + GICH_VMCR);
+	cpu_if->vgic_misr = readl_relaxed(base + GICH_MISR);
+	eisr0  = readl_relaxed(base + GICH_EISR0);
+	elrsr0 = readl_relaxed(base + GICH_ELRSR0);
+	if (unlikely(nr_lr > 32)) {
+		eisr1  = readl_relaxed(base + GICH_EISR1);
+		elrsr1 = readl_relaxed(base + GICH_ELRSR1);
+	} else {
+		eisr1 = elrsr1 = 0;
+	}
+#ifdef CONFIG_CPU_BIG_ENDIAN
+	cpu_if->vgic_eisr  = ((u64)eisr0 << 32) | eisr1;
+	cpu_if->vgic_elrsr = ((u64)elrsr0 << 32) | elrsr1;
+#else
+	cpu_if->vgic_eisr  = ((u64)eisr1 << 32) | eisr0;
+	cpu_if->vgic_elrsr = ((u64)elrsr1 << 32) | elrsr0;
+#endif
+	cpu_if->vgic_apr    = readl_relaxed(base + GICH_APR);
+
+	writel_relaxed(0, base + GICH_HCR);
+
+	for (i = 0; i < nr_lr; i++)
+		cpu_if->vgic_lr[i] = readl_relaxed(base + GICH_LR0 + (i * 4));
+}
+
+/* vcpu is already in the HYP VA space */
+void __hyp_text __vgic_v2_restore_state(struct kvm_vcpu *vcpu)
+{
+	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
+	struct vgic_v2_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v2;
+	struct vgic_dist *vgic = &kvm->arch.vgic;
+	void __iomem *base = kern_hyp_va(vgic->vctrl_base);
+	int i, nr_lr;
+
+	if (!base)
+		return;
+
+	writel_relaxed(cpu_if->vgic_hcr, base + GICH_HCR);
+	writel_relaxed(cpu_if->vgic_vmcr, base + GICH_VMCR);
+	writel_relaxed(cpu_if->vgic_apr, base + GICH_APR);
+
+	nr_lr = vcpu->arch.vgic_cpu.nr_lr;
+	for (i = 0; i < nr_lr; i++)
+		writel_relaxed(cpu_if->vgic_lr[i], base + GICH_LR0 + (i * 4));
+}