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

Christoffer Dall
2016-04-06T13:57:53Z

On Tue, Apr 05, 2016 at 10:10:09PM +0200, Christoffer Dall wrote:
> On Tue, Apr 05, 2016 at 02:34:42PM +0100, Andre Przywara wrote:
> > Hi,
> >
> > On 29/03/16 14:09, Christoffer Dall wrote:
> > > 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?
> >
> > The point is that the current HYP code is accessing this field. We do
> > have this field in the current "global" struct vgic_params there as
> > well, but this struct is (more or less) private to vgic-v2.c, so not
> > easily accessible from virt/kvm/arm/hyp/*.c.
> > So I suggest we keep this in here for the time being and eventually
> > remove it (and rework the save/restore code) once we get rid of the old
> > VGIC code.
> >
> Hmmm, I haven't tried it, but I don't understand why moving it now is
> difficult. I'd really like to avoid having a bunch of todo's lingering
> around and having duplicated state in the new code.
>
> I think I noticed a number of places in this patch series which refers
> tot he vgic_cpu->nr_lr instead of the global place already...
>
So I wrote a patch for this and it doesn't really look that bad. I'll
send it as part of a little prerequisite series later.

-Christoffer