KVM: arm/arm64: The GIC is dead, long live the GIC

I don't think any single piece of the KVM/ARM code ever generated
as much hatred as the GIC emulation.

It was written by someone who had zero experience in modeling
hardware (me), was riddled with design flaws, should have been
scrapped and rewritten from scratch long before having a remote
chance of reaching mainline, and yet we supported it for a good
three years. No need to mention the names of those who suffered,
the git log is singing their praises.

Thankfully, we now have a much more maintainable implementation,
and we can safely put the grumpy old GIC to rest.

Fellow hackers, please raise your glass in memory of the GIC:

	The GIC is dead, long live the GIC!

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 0 insertions, 274 deletions

diff --git a/virt/kvm/arm/vgic-v2.c b/virt/kvm/arm/vgic-v2.c
deleted file mode 100644
index 334cd7a89106..000000000000
--- a/virt/kvm/arm/vgic-v2.c
+++ /dev/null
@@ -1,274 +0,0 @@
-/*
- * Copyright (C) 2012,2013 ARM Limited, All Rights Reserved.
- * 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/cpu.h>
-#include <linux/kvm.h>
-#include <linux/kvm_host.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-
-#include <linux/irqchip/arm-gic.h>
-
-#include <asm/kvm_emulate.h>
-#include <asm/kvm_arm.h>
-#include <asm/kvm_mmu.h>
-
-static struct vgic_lr vgic_v2_get_lr(const struct kvm_vcpu *vcpu, int lr)
-{
-	struct vgic_lr lr_desc;
-	u32 val = vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr];
-
-	lr_desc.irq	= val & GICH_LR_VIRTUALID;
-	if (lr_desc.irq <= 15)
-		lr_desc.source	= (val >> GICH_LR_PHYSID_CPUID_SHIFT) & 0x7;
-	else
-		lr_desc.source = 0;
-	lr_desc.state	= 0;
-
-	if (val & GICH_LR_PENDING_BIT)
-		lr_desc.state |= LR_STATE_PENDING;
-	if (val & GICH_LR_ACTIVE_BIT)
-		lr_desc.state |= LR_STATE_ACTIVE;
-	if (val & GICH_LR_EOI)
-		lr_desc.state |= LR_EOI_INT;
-	if (val & GICH_LR_HW) {
-		lr_desc.state |= LR_HW;
-		lr_desc.hwirq = (val & GICH_LR_PHYSID_CPUID) >> GICH_LR_PHYSID_CPUID_SHIFT;
-	}
-
-	return lr_desc;
-}
-
-static void vgic_v2_set_lr(struct kvm_vcpu *vcpu, int lr,
-			   struct vgic_lr lr_desc)
-{
-	u32 lr_val;
-
-	lr_val = lr_desc.irq;
-
-	if (lr_desc.state & LR_STATE_PENDING)
-		lr_val |= GICH_LR_PENDING_BIT;
-	if (lr_desc.state & LR_STATE_ACTIVE)
-		lr_val |= GICH_LR_ACTIVE_BIT;
-	if (lr_desc.state & LR_EOI_INT)
-		lr_val |= GICH_LR_EOI;
-
-	if (lr_desc.state & LR_HW) {
-		lr_val |= GICH_LR_HW;
-		lr_val |= (u32)lr_desc.hwirq << GICH_LR_PHYSID_CPUID_SHIFT;
-	}
-
-	if (lr_desc.irq < VGIC_NR_SGIS)
-		lr_val |= (lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT);
-
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_lr[lr] = lr_val;
-
-	if (!(lr_desc.state & LR_STATE_MASK))
-		vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr |= (1ULL << lr);
-	else
-		vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr &= ~(1ULL << lr);
-}
-
-static u64 vgic_v2_get_elrsr(const struct kvm_vcpu *vcpu)
-{
-	return vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr;
-}
-
-static u64 vgic_v2_get_eisr(const struct kvm_vcpu *vcpu)
-{
-	return vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr;
-}
-
-static void vgic_v2_clear_eisr(struct kvm_vcpu *vcpu)
-{
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_eisr = 0;
-}
-
-static u32 vgic_v2_get_interrupt_status(const struct kvm_vcpu *vcpu)
-{
-	u32 misr = vcpu->arch.vgic_cpu.vgic_v2.vgic_misr;
-	u32 ret = 0;
-
-	if (misr & GICH_MISR_EOI)
-		ret |= INT_STATUS_EOI;
-	if (misr & GICH_MISR_U)
-		ret |= INT_STATUS_UNDERFLOW;
-
-	return ret;
-}
-
-static void vgic_v2_enable_underflow(struct kvm_vcpu *vcpu)
-{
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr |= GICH_HCR_UIE;
-}
-
-static void vgic_v2_disable_underflow(struct kvm_vcpu *vcpu)
-{
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr &= ~GICH_HCR_UIE;
-}
-
-static void vgic_v2_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
-{
-	u32 vmcr = vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr;
-
-	vmcrp->ctlr = (vmcr & GICH_VMCR_CTRL_MASK) >> GICH_VMCR_CTRL_SHIFT;
-	vmcrp->abpr = (vmcr & GICH_VMCR_ALIAS_BINPOINT_MASK) >> GICH_VMCR_ALIAS_BINPOINT_SHIFT;
-	vmcrp->bpr  = (vmcr & GICH_VMCR_BINPOINT_MASK) >> GICH_VMCR_BINPOINT_SHIFT;
-	vmcrp->pmr  = (vmcr & GICH_VMCR_PRIMASK_MASK) >> GICH_VMCR_PRIMASK_SHIFT;
-}
-
-static void vgic_v2_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
-{
-	u32 vmcr;
-
-	vmcr  = (vmcrp->ctlr << GICH_VMCR_CTRL_SHIFT) & GICH_VMCR_CTRL_MASK;
-	vmcr |= (vmcrp->abpr << GICH_VMCR_ALIAS_BINPOINT_SHIFT) & GICH_VMCR_ALIAS_BINPOINT_MASK;
-	vmcr |= (vmcrp->bpr << GICH_VMCR_BINPOINT_SHIFT) & GICH_VMCR_BINPOINT_MASK;
-	vmcr |= (vmcrp->pmr << GICH_VMCR_PRIMASK_SHIFT) & GICH_VMCR_PRIMASK_MASK;
-
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = vmcr;
-}
-
-static void vgic_v2_enable(struct kvm_vcpu *vcpu)
-{
-	/*
-	 * By forcing VMCR to zero, the GIC will restore the binary
-	 * points to their reset values. Anything else resets to zero
-	 * anyway.
-	 */
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_vmcr = 0;
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_elrsr = ~0;
-
-	/* Get the show on the road... */
-	vcpu->arch.vgic_cpu.vgic_v2.vgic_hcr = GICH_HCR_EN;
-}
-
-static const struct vgic_ops vgic_v2_ops = {
-	.get_lr			= vgic_v2_get_lr,
-	.set_lr			= vgic_v2_set_lr,
-	.get_elrsr		= vgic_v2_get_elrsr,
-	.get_eisr		= vgic_v2_get_eisr,
-	.clear_eisr		= vgic_v2_clear_eisr,
-	.get_interrupt_status	= vgic_v2_get_interrupt_status,
-	.enable_underflow	= vgic_v2_enable_underflow,
-	.disable_underflow	= vgic_v2_disable_underflow,
-	.get_vmcr		= vgic_v2_get_vmcr,
-	.set_vmcr		= vgic_v2_set_vmcr,
-	.enable			= vgic_v2_enable,
-};
-
-struct vgic_params __section(.hyp.text) vgic_v2_params;
-
-static void vgic_cpu_init_lrs(void *params)
-{
-	struct vgic_params *vgic = params;
-	int i;
-
-	for (i = 0; i < vgic->nr_lr; i++)
-		writel_relaxed(0, vgic->vctrl_base + GICH_LR0 + (i * 4));
-}
-
-/**
- * vgic_v2_probe - probe for a GICv2 compatible interrupt controller
- * @gic_kvm_info:	pointer to the GIC description
- * @ops:		address of a pointer to the GICv2 operations
- * @params:		address of a pointer to HW-specific parameters
- *
- * Returns 0 if a GICv2 has been found, with the low level operations
- * in *ops and the HW parameters in *params. Returns an error code
- * otherwise.
- */
-int vgic_v2_probe(const struct gic_kvm_info *gic_kvm_info,
-		   const struct vgic_ops **ops,
-		   const struct vgic_params **params)
-{
-	int ret;
-	struct vgic_params *vgic = &vgic_v2_params;
-	const struct resource *vctrl_res = &gic_kvm_info->vctrl;
-	const struct resource *vcpu_res = &gic_kvm_info->vcpu;
-
-	memset(vgic, 0, sizeof(*vgic));
-
-	if (!gic_kvm_info->maint_irq) {
-		kvm_err("error getting vgic maintenance irq\n");
-		ret = -ENXIO;
-		goto out;
-	}
-	vgic->maint_irq = gic_kvm_info->maint_irq;
-
-	if (!gic_kvm_info->vctrl.start) {
-		kvm_err("GICH not present in the firmware table\n");
-		ret = -ENXIO;
-		goto out;
-	}
-
-	vgic->vctrl_base = ioremap(gic_kvm_info->vctrl.start,
-				   resource_size(&gic_kvm_info->vctrl));
-	if (!vgic->vctrl_base) {
-		kvm_err("Cannot ioremap GICH\n");
-		ret = -ENOMEM;
-		goto out;
-	}
-
-	vgic->nr_lr = readl_relaxed(vgic->vctrl_base + GICH_VTR);
-	vgic->nr_lr = (vgic->nr_lr & 0x3f) + 1;
-
-	ret = create_hyp_io_mappings(vgic->vctrl_base,
-				     vgic->vctrl_base + resource_size(vctrl_res),
-				     vctrl_res->start);
-	if (ret) {
-		kvm_err("Cannot map VCTRL into hyp\n");
-		goto out_unmap;
-	}
-
-	if (!PAGE_ALIGNED(vcpu_res->start)) {
-		kvm_err("GICV physical address 0x%llx not page aligned\n",
-			(unsigned long long)vcpu_res->start);
-		ret = -ENXIO;
-		goto out_unmap;
-	}
-
-	if (!PAGE_ALIGNED(resource_size(vcpu_res))) {
-		kvm_err("GICV size 0x%llx not a multiple of page size 0x%lx\n",
-			(unsigned long long)resource_size(vcpu_res),
-			PAGE_SIZE);
-		ret = -ENXIO;
-		goto out_unmap;
-	}
-
-	vgic->can_emulate_gicv2 = true;
-	kvm_register_device_ops(&kvm_arm_vgic_v2_ops, KVM_DEV_TYPE_ARM_VGIC_V2);
-
-	vgic->vcpu_base = vcpu_res->start;
-
-	kvm_info("GICH base=0x%llx, GICV base=0x%llx, IRQ=%d\n",
-		 gic_kvm_info->vctrl.start, vgic->vcpu_base, vgic->maint_irq);
-
-	vgic->type = VGIC_V2;
-	vgic->max_gic_vcpus = VGIC_V2_MAX_CPUS;
-
-	on_each_cpu(vgic_cpu_init_lrs, vgic, 1);
-
-	*ops = &vgic_v2_ops;
-	*params = vgic;
-	goto out;
-
-out_unmap:
-	iounmap(vgic->vctrl_base);
-out:
-	return ret;
-}