Re: [RFC PATCH 04/45] KVM: arm/arm64: vgic-new: Add data structure definitions

Christoffer Dall
2016-03-29T13:08:29Z

On Fri, Mar 25, 2016 at 02:04:27AM +0000, Andre Przywara wrote:
> From: Christoffer Dall <christoffer.dall@linaro.org>
>
> Add a new header file for the new and improved GIC implementation.
> The big change is that we now have a struct vgic_irq per IRQ instead
> of spreading all the information over various bitmaps.
>
> We include this new header conditionally from within the old header
> file for the time being to avoid touching all the users.
>
> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
> include/kvm/arm_vgic.h | 5 ++
> include/kvm/vgic/vgic.h | 198 ++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 203 insertions(+)
> create mode 100644 include/kvm/vgic/vgic.h
>
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 7656a46..db289a2 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -19,6 +19,10 @@
> #ifndef __ASM_ARM_KVM_VGIC_H
> #define __ASM_ARM_KVM_VGIC_H
>
> +#ifdef CONFIG_KVM_NEW_VGIC
> +#include <kvm/vgic/vgic.h>
> +#else
> +
> #include <linux/kernel.h>
> #include <linux/kvm.h>
> #include <linux/irqreturn.h>
> @@ -376,4 +380,5 @@ static inline int vgic_v3_probe(struct device_node *vgic_node,
> }
> #endif
>
> +#endif /* old VGIC include */
> #endif
> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
> new file mode 100644
> index 0000000..659f8b1
> --- /dev/null
> +++ b/include/kvm/vgic/vgic.h
> @@ -0,0 +1,198 @@
> +/*
> + * Copyright (C) 2015, 2016 ARM Ltd.
> + *
> + * 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 __ASM_ARM_KVM_VGIC_VGIC_H
> +#define __ASM_ARM_KVM_VGIC_VGIC_H
> +
> +#include <linux/kernel.h>
> +#include <linux/kvm.h>
> +#include <linux/irqreturn.h>
> +#include <linux/spinlock.h>
> +#include <linux/types.h>
> +#include <kvm/iodev.h>
> +
> +#define VGIC_V3_MAX_CPUS 255
> +#define VGIC_V2_MAX_CPUS 8
> +#define VGIC_NR_IRQS_LEGACY 256
> +#define VGIC_NR_SGIS 16
> +#define VGIC_NR_PPIS 16
> +#define VGIC_NR_PRIVATE_IRQS (VGIC_NR_SGIS + VGIC_NR_PPIS)
> +#define VGIC_MAX_PRIVATE (VGIC_NR_PRIVATE_IRQS - 1)
> +#define VGIC_MAX_SPI 1019
> +#define VGIC_MAX_RESERVED 1023
> +#define VGIC_MIN_LPI 8192
> +
> +enum vgic_type {
> + VGIC_V2, /* Good ol' GICv2 */
> + VGIC_V3, /* New fancy GICv3 */
> +};
> +
> +/* same for all guests, as depending only on the _host's_ GIC model */
> +struct vgic_global {
> + /* type of the host GIC */
> + enum vgic_type type;
> +
> + /* Physical address of vgic virtual cpu interface */
> + phys_addr_t vcpu_base;
> +
> + /* virtual control interface mapping */
> + void __iomem *vctrl_base;
> +
> + /* Number of implemented list registers */
> + int nr_lr;
> +
> + /* Maintenance IRQ number */
> + unsigned int maint_irq;
> +
> + /* maximum number of VCPUs allowed (GICv2 limits us to 8) */
> + int max_gic_vcpus;
> +
> + /* Only needed for the legacy KVM_CREATE_IRQCHIP */
> + bool can_emulate_gicv2;
> +};
> +
> +extern struct vgic_global kvm_vgic_global_state;
> +
> +#define VGIC_V2_MAX_LRS (1 << 6)
> +#define VGIC_V3_MAX_LRS 16
> +#define VGIC_V3_LR_INDEX(lr) (VGIC_V3_MAX_LRS - 1 - lr)
> +
> +enum vgic_irq_config {
> + VGIC_CONFIG_EDGE = 0,
> + VGIC_CONFIG_LEVEL
> +};
> +
> +struct vgic_irq {
> + spinlock_t irq_lock; /* Protects the content of the struct */
> + struct list_head ap_list;
> +
> + struct kvm_vcpu *vcpu; /* SGIs and PPIs: The VCPU
> + * SPIs and LPIs: The VCPU whose ap_list
> + * on which this is queued.
> + */
> +
> + struct kvm_vcpu *target_vcpu; /* The VCPU that this interrupt should
> + * be send to, as a result of the
> + * targets reg (v2) or the
> + * affinity reg (v3).
> + */
> +
> + u32 intid; /* Guest visible INTID */
> + bool pending;
> + bool line_level; /* Level only */
> + bool soft_pending; /* Level only */
> + bool active; /* not used for LPIs */
> + bool enabled;
> + bool hw; /* Tied to HW IRQ */
> + u32 hwintid; /* HW INTID number */
> + union {
> + u8 targets; /* GICv2 target VCPUs mask */
> + u32 mpidr; /* GICv3 target VCPU */
> + };
> + u8 source; /* GICv2 SGIs only */
> + u8 priority;
> + enum vgic_irq_config config; /* Level or edge */
> +};
> +
> +struct vgic_dist {
> + bool in_kernel;
> + bool ready;
> +
> + /* vGIC model the kernel emulates for the guest (GICv2 or GICv3) */
> + u32 vgic_model;
> +
> + int nr_spis;
> +
> + /* TODO: Consider moving to global state */
> + /* Virtual control interface mapping */
> + void __iomem *vctrl_base;
> +
> + /* base addresses in guest physical address space: */
> + gpa_t vgic_dist_base; /* distributor */
> + union {
> + /* either a GICv2 CPU interface */
> + gpa_t vgic_cpu_base;
> + /* or a number of GICv3 redistributor regions */
> + gpa_t vgic_redist_base;
> + };
> +
> + /* distributor enabled */
> + u32 enabled;
> +
> + struct vgic_irq *spis;
> +};
> +
> +struct vgic_v2_cpu_if {
> + u32 vgic_hcr;
> + u32 vgic_vmcr;
> + u32 vgic_misr; /* Saved only */
> + u64 vgic_eisr; /* Saved only */
> + u64 vgic_elrsr; /* Saved only */
> + u32 vgic_apr;
> + u32 vgic_lr[VGIC_V2_MAX_LRS];
> +};
> +
> +struct vgic_v3_cpu_if {
> +#ifdef CONFIG_KVM_ARM_VGIC_V3
> + u32 vgic_hcr;
> + u32 vgic_vmcr;
> + u32 vgic_sre; /* Restored only, change ignored */
> + 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 {
> + /* CPU vif control registers for world switch */
> + union {
> + struct vgic_v2_cpu_if vgic_v2;
> + struct vgic_v3_cpu_if vgic_v3;
> + };
> +
> + /* TODO: Move nr_lr to a global state */

what is our current plan and status about this TODO?

> + /* Number of list registers on this CPU */
> + int nr_lr;
> +
> + unsigned int used_lrs;
> + struct vgic_irq private_irqs[VGIC_NR_PRIVATE_IRQS];
> +
> + spinlock_t ap_list_lock; /* Protects the ap_list */
> +
> + /* list of IRQs for this VCPU to consider */

/*
* List of IRQs that this VCPU should consider because they are either
* Active or Pending (hence the name; AP list), or because they recently
* were one of the two and need to be migrated off this list to another
* VCPU.
*/

> + struct list_head ap_list_head;
> +};
> +
> +#define irqchip_in_kernel(k) (!!((k)->arch.vgic.in_kernel))
> +#define vgic_initialized(k) (false)
> +#define vgic_ready(k) ((k)->arch.vgic.ready)
> +#define vgic_valid_spi(k,i) (((i) >= VGIC_NR_PRIVATE_IRQS) && \
> + ((i) < (k)->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS))
> +
> +/**
> + * kvm_vgic_get_max_vcpus - Get the maximum number of VCPUs allowed by HW
> + *
> + * The host's GIC naturally limits the maximum amount of VCPUs a guest
> + * can use.
> + */
> +static inline int kvm_vgic_get_max_vcpus(void)
> +{
> + return kvm_vgic_global_state.max_gic_vcpus;
> +}
> +
> +#endif /* __ASM_ARM_KVM_VGIC_VGIC_H */
> --
> 2.7.3
>

Thanks,
-Christoffer