[PATCH v2 19/30] arm64: KVM: Plug the VGIC

[marc.zyngier@arm.com (Marc Zyngier)]

Add support for the in-kernel GIC emulation. The include file
is a complete duplicate of the 32bit one - something to fix
at one point.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 arch/arm64/include/asm/kvm_vgic.h | 156 ++++++++++++++++++++++++++++++++++++++
 arch/arm64/kvm/hyp.S              |  88 +++++++++++++++++++++
 2 files changed, 244 insertions(+)
 create mode 100644 arch/arm64/include/asm/kvm_vgic.h

diff --git a/arch/arm64/include/asm/kvm_vgic.h b/arch/arm64/include/asm/kvm_vgic.h
new file mode 100644
index 0000000..f353f22
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_vgic.h
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2012 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/>.
+ */
+
+#ifndef __ARM64_KVM_VGIC_H
+#define __ARM64_KVM_VGIC_H
+
+#include <linux/kernel.h>
+#include <linux/kvm.h>
+#include <linux/irqreturn.h>
+#include <linux/spinlock.h>
+#include <linux/types.h>
+#include <linux/irqchip/arm-gic.h>
+
+#define VGIC_NR_IRQS		128
+#define VGIC_NR_SGIS		16
+#define VGIC_NR_PPIS		16
+#define VGIC_NR_PRIVATE_IRQS	(VGIC_NR_SGIS + VGIC_NR_PPIS)
+#define VGIC_NR_SHARED_IRQS	(VGIC_NR_IRQS - VGIC_NR_PRIVATE_IRQS)
+#define VGIC_MAX_CPUS		KVM_MAX_VCPUS
+
+/* Sanity checks... */
+#if (VGIC_MAX_CPUS > 8)
+#error	Invalid number of CPU interfaces
+#endif
+
+#if (VGIC_NR_IRQS & 31)
+#error "VGIC_NR_IRQS must be a multiple of 32"
+#endif
+
+#if (VGIC_NR_IRQS > 1024)
+#error "VGIC_NR_IRQS must be <= 1024"
+#endif
+
+/*
+ * The GIC distributor registers describing interrupts have two parts:
+ * - 32 per-CPU interrupts (SGI + PPI)
+ * - a bunch of shared interrupts (SPI)
+ */
+struct vgic_bitmap {
+	union {
+		u32 reg[VGIC_NR_PRIVATE_IRQS / 32];
+		DECLARE_BITMAP(reg_ul, VGIC_NR_PRIVATE_IRQS);
+	} percpu[VGIC_MAX_CPUS];
+	union {
+		u32 reg[VGIC_NR_SHARED_IRQS / 32];
+		DECLARE_BITMAP(reg_ul, VGIC_NR_SHARED_IRQS);
+	} shared;
+};
+
+struct vgic_bytemap {
+	u32 percpu[VGIC_MAX_CPUS][VGIC_NR_PRIVATE_IRQS / 4];
+	u32 shared[VGIC_NR_SHARED_IRQS  / 4];
+};
+
+struct vgic_dist {
+	spinlock_t		lock;
+	bool			ready;
+
+	/* Virtual control interface mapping */
+	void __iomem		*vctrl_base;
+
+	/* Distributor and vcpu interface mapping in the guest */
+	phys_addr_t		vgic_dist_base;
+	phys_addr_t		vgic_cpu_base;
+
+	/* Distributor enabled */
+	u32			enabled;
+
+	/* Interrupt enabled (one bit per IRQ) */
+	struct vgic_bitmap	irq_enabled;
+
+	/* Interrupt 'pin' level */
+	struct vgic_bitmap	irq_state;
+
+	/* Level-triggered interrupt in progress */
+	struct vgic_bitmap	irq_active;
+
+	/* Interrupt priority. Not used yet. */
+	struct vgic_bytemap	irq_priority;
+
+	/* Level/edge triggered */
+	struct vgic_bitmap	irq_cfg;
+
+	/* Source CPU per SGI and target CPU */
+	u8			irq_sgi_sources[VGIC_MAX_CPUS][16];
+
+	/* Target CPU for each IRQ */
+	u8			irq_spi_cpu[VGIC_NR_SHARED_IRQS];
+	struct vgic_bitmap	irq_spi_target[VGIC_MAX_CPUS];
+
+	/* Bitmap indicating which CPU has something pending */
+	unsigned long		irq_pending_on_cpu;
+};
+
+struct vgic_cpu {
+	/* per IRQ to LR mapping */
+	u8		vgic_irq_lr_map[VGIC_NR_IRQS];
+
+	/* Pending interrupts on this VCPU */
+	DECLARE_BITMAP(	pending_percpu, VGIC_NR_PRIVATE_IRQS);
+	DECLARE_BITMAP(	pending_shared, VGIC_NR_SHARED_IRQS);
+
+	/* Bitmap of used/free list registers */
+	DECLARE_BITMAP(	lr_used, 64);
+
+	/* Number of list registers on this CPU */
+	int		nr_lr;
+
+	/* CPU vif control registers for world switch */
+	u32		vgic_hcr;
+	u32		vgic_vmcr;
+	u32		vgic_misr;	/* Saved only */
+	u32		vgic_eisr[2];	/* Saved only */
+	u32		vgic_elrsr[2];	/* Saved only */
+	u32		vgic_apr;
+	u32		vgic_lr[64];	/* A15 has only 4... */
+};
+
+#define LR_EMPTY	0xff
+
+struct kvm;
+struct kvm_vcpu;
+struct kvm_run;
+struct kvm_exit_mmio;
+
+int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr);
+int kvm_vgic_hyp_init(void);
+int kvm_vgic_init(struct kvm *kvm);
+int kvm_vgic_create(struct kvm *kvm);
+int kvm_vgic_vcpu_init(struct kvm_vcpu *vcpu);
+void kvm_vgic_flush_hwstate(struct kvm_vcpu *vcpu);
+void kvm_vgic_sync_hwstate(struct kvm_vcpu *vcpu);
+int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num,
+			bool level);
+int kvm_vgic_vcpu_pending_irq(struct kvm_vcpu *vcpu);
+bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
+		      struct kvm_exit_mmio *mmio);
+
+#define irqchip_in_kernel(k)	(!!((k)->arch.vgic.vctrl_base))
+#define vgic_initialized(k)	((k)->arch.vgic.ready)
+
+#endif
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 9ebc67a..b2ace90 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -306,6 +306,90 @@ __kvm_hyp_code_start:
 	msr	vttbr_el2, xzr
 .endm
 
+/*
+ * Save the VGIC CPU state into memory
+ * x0: Register pointing to VCPU struct
+ * Do not corrupt x1!!!
+ */
+.macro save_vgic_state
+	/* Get VGIC VCTRL base into x2 */
+	ldr	x2, [x0, #VCPU_KVM]
+	kern_hyp_va	x2
+	ldr	x2, [x2, #KVM_VGIC_VCTRL]
+	kern_hyp_va	x2
+	cbz	x2, 2f		// disabled
+
+	/* Compute the address of struct vgic_cpu */
+	add	x3, x0, #VCPU_VGIC_CPU
+
+	/* Save all interesting registers */
+	ldr	w4, [x2, #GICH_HCR]
+	ldr	w5, [x2, #GICH_VMCR]
+	ldr	w6, [x2, #GICH_MISR]
+	ldr	w7, [x2, #GICH_EISR0]
+	ldr	w8, [x2, #GICH_EISR1]
+	ldr	w9, [x2, #GICH_ELRSR0]
+	ldr	w10, [x2, #GICH_ELRSR1]
+	ldr	w11, [x2, #GICH_APR]
+
+	str	w4, [x3, #VGIC_CPU_HCR]
+	str	w5, [x3, #VGIC_CPU_VMCR]
+	str	w6, [x3, #VGIC_CPU_MISR]
+	str	w7, [x3, #VGIC_CPU_EISR]
+	str	w8, [x3, #(VGIC_CPU_EISR + 4)]
+	str	w9, [x3, #VGIC_CPU_ELRSR]
+	str	w10, [x3, #(VGIC_CPU_ELRSR + 4)]
+	str	w11, [x3, #VGIC_CPU_APR]
+
+	/* Clear GICH_HCR */
+	str	wzr, [x2, #GICH_HCR]
+
+	/* Save list registers */
+	add	x2, x2, #GICH_LR0
+	ldr	w4, [x3, #VGIC_CPU_NR_LR]
+	add	x3, x3, #VGIC_CPU_LR
+1:	ldr	w5, [x2], #4
+	str	w5, [x3], #4
+	sub	w4, w4, #1
+	cbnz	w4, 1b
+2:
+.endm
+
+/*
+ * Restore the VGIC CPU state from memory
+ * x0: Register pointing to VCPU struct
+ */
+.macro restore_vgic_state
+	/* Get VGIC VCTRL base into x2 */
+	ldr	x2, [x0, #VCPU_KVM]
+	kern_hyp_va	x2
+	ldr	x2, [x2, #KVM_VGIC_VCTRL]
+	kern_hyp_va	x2
+	cbz	x2, 2f		// disabled
+
+	/* Compute the address of struct vgic_cpu */
+	add	x3, x0, #VCPU_VGIC_CPU
+
+	/* We only restore a minimal set of registers */
+	ldr	w4, [x3, #VGIC_CPU_HCR]
+	ldr	w5, [x3, #VGIC_CPU_VMCR]
+	ldr	w6, [x3, #VGIC_CPU_APR]
+
+	str	w4, [x2, #GICH_HCR]
+	str	w5, [x2, #GICH_VMCR]
+	str	w6, [x2, #GICH_APR]
+
+	/* Restore list registers */
+	add	x2, x2, #GICH_LR0
+	ldr	w4, [x3, #VGIC_CPU_NR_LR]
+	add	x3, x3, #VGIC_CPU_LR
+1:	ldr	w5, [x3], #4
+	str	w5, [x2], #4
+	sub	w4, w4, #1
+	cbnz	w4, 1b
+2:
+.endm
+
 __save_sysregs:
 	save_sysregs
 	ret
@@ -348,6 +432,8 @@ ENTRY(__kvm_vcpu_run)
 	activate_traps
 	activate_vm
 
+	restore_vgic_state
+
 	// Guest context
 	add	x2, x0, #VCPU_CONTEXT
 
@@ -370,6 +456,8 @@ __kvm_vcpu_return:
 	bl __save_fpsimd
 	bl __save_sysregs
 
+	save_vgic_state
+
 	deactivate_traps
 	deactivate_vm
 
-- 
1.8.1.4