[PATCH v4 19/20] KVM: ARM: vgic: add the GICv3 backend

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

On Tue, May 20 2014 at  2:09:41 pm BST, Christoffer Dall <christoffer.dall@linaro.org> wrote:
> On Thu, May 15, 2014 at 06:58:38PM +0100, Marc Zyngier wrote:
>> Introduce the support code for emulating a GICv2 on top of GICv3
>> hardware.
>> 
>> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
>> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
>> ---
>>  include/kvm/arm_vgic.h |  28 ++++++
>>  virt/kvm/arm/vgic-v3.c | 225 +++++++++++++++++++++++++++++++++++++++++++++++++
>>  2 files changed, 253 insertions(+)
>>  create mode 100644 virt/kvm/arm/vgic-v3.c
>> 
>> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
>> index 65f1121..35b0c12 100644
>> --- a/include/kvm/arm_vgic.h
>> +++ b/include/kvm/arm_vgic.h
>> @@ -33,6 +33,7 @@
>>  #define VGIC_MAX_CPUS		KVM_MAX_VCPUS
>>  
>>  #define VGIC_V2_MAX_LRS		(1 << 6)
>> +#define VGIC_V3_MAX_LRS		16
>>  
>>  /* Sanity checks... */
>>  #if (VGIC_MAX_CPUS > 8)
>> @@ -72,6 +73,7 @@ struct kvm_vcpu;
>>  
>>  enum vgic_type {
>>  	VGIC_V2,		/* Good ol' GICv2 */
>> +	VGIC_V3,		/* New fancy GICv3 */
>>  };
>>  
>>  #define LR_STATE_PENDING	(1 << 0)
>> @@ -172,6 +174,19 @@ struct vgic_v2_cpu_if {
>>  	u32		vgic_lr[VGIC_V2_MAX_LRS];
>>  };
>>  
>> +struct vgic_v3_cpu_if {
>> +#ifdef CONFIG_ARM_GIC_V3
>> +	u32		vgic_hcr;
>> +	u32		vgic_vmcr;
>> +	u32		vgic_misr;	/* Saved only */
>> +	u32		vgic_eisr;	/* Saved only */
>> +	u32		vgic_elrsr;	/* Saved only */
>> +	u32		vgic_ap0r[4];
>> +	u32		vgic_ap1r[4];
>> +	u64		vgic_lr[VGIC_V3_MAX_LRS];
>> +#endif
>> +};
>> +
>>  struct vgic_cpu {
>>  #ifdef CONFIG_KVM_ARM_VGIC
>>  	/* per IRQ to LR mapping */
>> @@ -190,6 +205,7 @@ struct vgic_cpu {
>>  	/* CPU vif control registers for world switch */
>>  	union {
>>  		struct vgic_v2_cpu_if	vgic_v2;
>> +		struct vgic_v3_cpu_if	vgic_v3;
>>  	};
>>  #endif
>>  };
>> @@ -224,6 +240,18 @@ bool vgic_handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *run,
>>  int vgic_v2_probe(struct device_node *vgic_node,
>>  		  const struct vgic_ops **ops,
>>  		  const struct vgic_params **params);
>> +#ifdef CONFIG_ARM_GIC_V3
>> +int vgic_v3_probe(struct device_node *vgic_node,
>> +		  const struct vgic_ops **ops,
>> +		  const struct vgic_params **params);
>> +#else
>> +static inline int vgic_v3_probe(struct device_node *vgic_node,
>> +				const struct vgic_ops **ops,
>> +				const struct vgic_params **params)
>> +{
>> +	return -ENODEV;
>> +}
>> +#endif
>>  
>>  #else
>>  static inline int kvm_vgic_hyp_init(void)
>> diff --git a/virt/kvm/arm/vgic-v3.c b/virt/kvm/arm/vgic-v3.c
>> new file mode 100644
>> index 0000000..ecdec34
>> --- /dev/null
>> +++ b/virt/kvm/arm/vgic-v3.c
>> @@ -0,0 +1,225 @@
>> +/*
>> + * Copyright (C) 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/of.h>
>> +#include <linux/of_address.h>
>> +#include <linux/of_irq.h>
>> +
>> +#include <linux/irqchip/arm-gic-v3.h>
>> +
>> +#include <asm/kvm_emulate.h>
>> +#include <asm/kvm_arm.h>
>> +#include <asm/kvm_mmu.h>
>> +
>> +/* These are for GICv2 emulation only */
>> +#define GICH_LR_VIRTUALID		(0x3ffUL << 0)
>> +#define GICH_LR_PHYSID_CPUID_SHIFT	(10)
>> +#define GICH_LR_PHYSID_CPUID		(7UL << GICH_LR_PHYSID_CPUID_SHIFT)
>> +
>> +static u32 ich_vtr_el2;
>> +
>> +static struct vgic_lr vgic_v3_get_lr(const struct kvm_vcpu *vcpu, int lr)
>> +{
>> +	struct vgic_lr lr_desc;
>> +	u64 val = vcpu->arch.vgic_cpu.vgic_v3.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;
>> +
>> +	return lr_desc;
>> +}
>> +
>> +static void vgic_v3_set_lr(struct kvm_vcpu *vcpu, int lr,
>> +			   struct vgic_lr lr_desc)
>> +{
>> +	u64 lr_val = (((u32)lr_desc.source << GICH_LR_PHYSID_CPUID_SHIFT) |
>> +		      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;
>> +
>> +	vcpu->arch.vgic_cpu.vgic_v3.vgic_lr[lr] = lr_val;
>> +}
>> +
>> +static void vgic_v3_sync_lr_elrsr(struct kvm_vcpu *vcpu, int lr,
>> +				  struct vgic_lr lr_desc)
>> +{
>> +	if (!(lr_desc.state & LR_STATE_MASK))
>> +		vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr |= (1U << lr);
>> +}
>> +
>> +static u64 vgic_v3_get_elrsr(const struct kvm_vcpu *vcpu)
>> +{
>> +	return vcpu->arch.vgic_cpu.vgic_v3.vgic_elrsr;
>> +}
>> +
>> +static u64 vgic_v3_get_eisr(const struct kvm_vcpu *vcpu)
>> +{
>> +	return vcpu->arch.vgic_cpu.vgic_v3.vgic_eisr;
>> +}
>> +
>> +static u32 vgic_v3_get_interrupt_status(const struct kvm_vcpu *vcpu)
>> +{
>> +	u32 misr = vcpu->arch.vgic_cpu.vgic_v3.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_v3_get_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
>> +{
>> +	u32 vmcr = vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr;
>> +
>> +	vmcrp->ctlr = (vmcr & GICH_VMCR_CTLR_MASK) >> GICH_VMCR_CTLR_SHIFT;
>> +	vmcrp->abpr = (vmcr & GICH_VMCR_BPR1_MASK) >> GICH_VMCR_BPR1_SHIFT;
>> +	vmcrp->bpr  = (vmcr & GICH_VMCR_BPR0_MASK) >> GICH_VMCR_BPR0_SHIFT;
>> +	vmcrp->pmr  = (vmcr & GICH_VMCR_PMR_MASK) >> GICH_VMCR_PMR_SHIFT;
>> +}
>> +
>> +static void vgic_v3_enable_underflow(struct kvm_vcpu *vcpu)
>> +{
>> +	vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr |= GICH_HCR_UIE;
>> +}
>> +
>> +static void vgic_v3_disable_underflow(struct kvm_vcpu *vcpu)
>> +{
>> +	vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr &= ~GICH_HCR_UIE;
>> +}
>> +
>> +static void vgic_v3_set_vmcr(struct kvm_vcpu *vcpu, struct vgic_vmcr *vmcrp)
>> +{
>> +	u32 vmcr;
>> +
>> +	vmcr  = (vmcrp->ctlr << GICH_VMCR_CTLR_SHIFT) & GICH_VMCR_CTLR_MASK;
>> +	vmcr |= (vmcrp->abpr << GICH_VMCR_BPR1_SHIFT) & GICH_VMCR_BPR1_MASK;
>> +	vmcr |= (vmcrp->bpr << GICH_VMCR_BPR0_SHIFT) & GICH_VMCR_BPR0_MASK;
>> +	vmcr |= (vmcrp->pmr << GICH_VMCR_PMR_SHIFT) & GICH_VMCR_PMR_MASK;
>> +
>> +	vcpu->arch.vgic_cpu.vgic_v3.vgic_vmcr = vmcr;
>> +}
>> +
>> +static void vgic_v3_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_v3.vgic_vmcr = 0;
>> +
>> +	/* Get the show on the road... */
>> +	vcpu->arch.vgic_cpu.vgic_v3.vgic_hcr = GICH_HCR_EN;
>> +}
>> +
>> +static const struct vgic_ops vgic_v3_ops = {
>> +	.get_lr			= vgic_v3_get_lr,
>> +	.set_lr			= vgic_v3_set_lr,
>> +	.sync_lr_elrsr		= vgic_v3_sync_lr_elrsr,
>> +	.get_elrsr		= vgic_v3_get_elrsr,
>> +	.get_eisr		= vgic_v3_get_eisr,
>> +	.get_interrupt_status	= vgic_v3_get_interrupt_status,
>> +	.enable_underflow	= vgic_v3_enable_underflow,
>> +	.disable_underflow	= vgic_v3_disable_underflow,
>> +	.get_vmcr		= vgic_v3_get_vmcr,
>> +	.set_vmcr		= vgic_v3_set_vmcr,
>> +	.enable			= vgic_v3_enable,
>> +};
>> +
>> +static struct vgic_params vgic_v3_params;
>> +
>> +/**
>> + * vgic_v3_probe - probe for a GICv3 compatible interrupt controller in DT
>> + * @node:	pointer to the DT node
>> + * @ops: 	address of a pointer to the GICv3 operations
>> + * @params:	address of a pointer to HW-specific parameters
>> + *
>> + * Returns 0 if a GICv3 has been found, with the low level operations
>> + * in *ops and the HW parameters in *params. Returns an error code
>> + * otherwise.
>> + */
>> +int vgic_v3_probe(struct device_node *vgic_node,
>> +		  const struct vgic_ops **ops,
>> +		  const struct vgic_params **params)
>> +{
>> +	int ret = 0;
>> +	u32 gicv_idx;
>> +	struct resource vcpu_res;
>> +	struct vgic_params *vgic = &vgic_v3_params;
>> +
>> +	vgic->maint_irq = irq_of_parse_and_map(vgic_node, 0);
>> +	if (!vgic->maint_irq) {
>> +		kvm_err("error getting vgic maintenance irq from DT\n");
>> +		ret = -ENXIO;
>> +		goto out;
>> +	}
>> +
>> +	ich_vtr_el2 = kvm_call_hyp(__vgic_v3_get_ich_vtr_el2);
>
> it builds, but the function is still not here :(
>
> I think it would be nicer to move that little function into this patch.

Ah, good point. I was bound to mess something up. I'll move the little
sod over.

Thanks for the additionnal review!

	M.
-- 
Jazz is not dead. It just smells funny.