Re: [Qemu-devel] [PATCH v6 7/9] hw/kvm/arm_gic: Implement support for KVM in-kernel ARM GIC

["Andreas Färber" <afaerber@suse.de>]

Am 22.02.2013 20:04, schrieb Peter Maydell:
> Implement support for using the KVM in-kernel GIC for ARM.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  hw/a15mpcore.c       |    8 ++-
>  hw/arm/Makefile.objs |    1 +
>  hw/kvm/arm_gic.c     |  169 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 177 insertions(+), 1 deletion(-)
>  create mode 100644 hw/kvm/arm_gic.c
> 
> diff --git a/hw/a15mpcore.c b/hw/a15mpcore.c
> index fe6c34c..97abe41 100644
> --- a/hw/a15mpcore.c
> +++ b/hw/a15mpcore.c
> @@ -19,6 +19,7 @@
>   */
>  
>  #include "sysbus.h"
> +#include "sysemu/kvm.h"
>  
>  /* A15MP private memory region.  */
>  
> @@ -40,8 +41,13 @@ static int a15mp_priv_init(SysBusDevice *dev)
>  {
>      A15MPPrivState *s = FROM_SYSBUS(A15MPPrivState, dev);
>      SysBusDevice *busdev;
> +    const char *gictype = "arm_gic";
>  
> -    s->gic = qdev_create(NULL, "arm_gic");
> +    if (kvm_irqchip_in_kernel()) {
> +        gictype = "kvm-arm-gic";
> +    }
> +
> +    s->gic = qdev_create(NULL, gictype);
>      qdev_prop_set_uint32(s->gic, "num-cpu", s->num_cpu);
>      qdev_prop_set_uint32(s->gic, "num-irq", s->num_irq);
>      qdev_prop_set_uint32(s->gic, "revision", 2);
> diff --git a/hw/arm/Makefile.objs b/hw/arm/Makefile.objs
> index 6d049e7..38b10a8 100644
> --- a/hw/arm/Makefile.objs
> +++ b/hw/arm/Makefile.objs
> @@ -31,5 +31,6 @@ obj-y += collie.o
>  obj-y += imx_serial.o imx_ccm.o imx_timer.o imx_avic.o
>  obj-y += kzm.o
>  obj-$(CONFIG_FDT) += ../device_tree.o
> +obj-$(CONFIG_KVM) += kvm/arm_gic.o
>  
>  obj-y := $(addprefix ../,$(obj-y))
> diff --git a/hw/kvm/arm_gic.c b/hw/kvm/arm_gic.c
> new file mode 100644
> index 0000000..c3b73c4
> --- /dev/null
> +++ b/hw/kvm/arm_gic.c
> @@ -0,0 +1,169 @@
> +/*
> + * ARM Generic Interrupt Controller using KVM in-kernel support
> + *
> + * Copyright (c) 2012 Linaro Limited
> + * Written by Peter Maydell
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License as published by
> + * the Free Software Foundation, either version 2 of the License, or
> + * (at your option) any later version.
> + *
> + * 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 "hw/sysbus.h"
> +#include "sysemu/kvm.h"
> +#include "kvm_arm.h"
> +#include "hw/arm_gic_internal.h"
> +
> +#define TYPE_KVM_ARM_GIC "kvm-arm-gic"
> +#define KVM_ARM_GIC(obj) \
> +     OBJECT_CHECK(GICState, (obj), TYPE_KVM_ARM_GIC)
> +#define KVM_ARM_GIC_CLASS(klass) \
> +     OBJECT_CLASS_CHECK(KVMARMGICClass, (klass), TYPE_KVM_ARM_GIC)
> +#define KVM_ARM_GIC_GET_CLASS(obj) \
> +     OBJECT_GET_CLASS(KVMARMGICClass, (obj), TYPE_KVM_ARM_GIC)
> +
> +typedef struct KVMARMGICClass {
> +    ARMGICCommonClass parent_class;
> +    int (*parent_init)(SysBusDevice *dev);
> +    void (*parent_reset)(DeviceState *dev);
> +} KVMARMGICClass;
> +
> +static void kvm_arm_gic_set_irq(void *opaque, int irq, int level)
> +{
> +    /* Meaning of the 'irq' parameter:
> +     *  [0..N-1] : external interrupts
> +     *  [N..N+31] : PPI (internal) interrupts for CPU 0
> +     *  [N+32..N+63] : PPI (internal interrupts for CPU 1
> +     *  ...
> +     * Convert this to the kernel's desired encoding, which
> +     * has separate fields in the irq number for type,
> +     * CPU number and interrupt number.
> +     */
> +    GICState *s = (GICState *)opaque;
> +    int kvm_irq, irqtype, cpu;
> +
> +    if (irq < (s->num_irq - GIC_INTERNAL)) {
> +        /* External interrupt. The kernel numbers these like the GIC
> +         * hardware, with external interrupt IDs starting after the
> +         * internal ones.
> +         */
> +        irqtype = KVM_ARM_IRQ_TYPE_SPI;
> +        cpu = 0;
> +        irq += GIC_INTERNAL;
> +    } else {
> +        /* Internal interrupt: decode into (cpu, interrupt id) */
> +        irqtype = KVM_ARM_IRQ_TYPE_PPI;
> +        irq -= (s->num_irq - GIC_INTERNAL);
> +        cpu = irq / GIC_INTERNAL;
> +        irq %= GIC_INTERNAL;
> +    }
> +    kvm_irq = (irqtype << KVM_ARM_IRQ_TYPE_SHIFT)
> +        | (cpu << KVM_ARM_IRQ_VCPU_SHIFT) | irq;
> +
> +    kvm_set_irq(kvm_state, kvm_irq, !!level);
> +}
> +
> +static void kvm_arm_gic_put(GICState *s)
> +{
> +    /* TODO: there isn't currently a kernel interface to set the GIC state */
> +}
> +
> +static void kvm_arm_gic_get(GICState *s)
> +{
> +    /* TODO: there isn't currently a kernel interface to get the GIC state */
> +}
> +
> +static void kvm_arm_gic_reset(DeviceState *dev)
> +{
> +    GICState *s = ARM_GIC_COMMON(dev);
> +    KVMARMGICClass *kgc = KVM_ARM_GIC_GET_CLASS(s);
> +    kgc->parent_reset(dev);
> +    kvm_arm_gic_put(s);
> +}
> +
> +static int kvm_arm_gic_init(SysBusDevice *dev)

Please make this a realize function ...

> +{
> +    /* Device instance init function for the GIC sysbus device */
> +    int i;
> +    GICState *s = FROM_SYSBUS(GICState, dev);

ARM_GIC_COMMON(dev)

> +    KVMARMGICClass *kgc = KVM_ARM_GIC_GET_CLASS(s);
> +
> +    kgc->parent_init(dev);

... and call sbc->init(dev) here as long as the base class is not updated.

> +
> +    i = s->num_irq - GIC_INTERNAL;
> +    /* For the GIC, also expose incoming GPIO lines for PPIs for each CPU.
> +     * GPIO array layout is thus:
> +     *  [0..N-1] SPIs
> +     *  [N..N+31] PPIs for CPU 0
> +     *  [N+32..N+63] PPIs for CPU 1
> +     *   ...
> +     */
> +    i += (GIC_INTERNAL * s->num_cpu);
> +    qdev_init_gpio_in(&s->busdev.qdev, kvm_arm_gic_set_irq, i);

DEVICE() and DeviceState *dev variable

> +    /* We never use our outbound IRQ lines but provide them so that
> +     * we maintain the same interface as the non-KVM GIC.
> +     */
> +    for (i = 0; i < s->num_cpu; i++) {
> +        sysbus_init_irq(&s->busdev, &s->parent_irq[i]);

SYS_BUS_DEVICE() and SysBusDevice *d variable

> +    }
> +    /* Distributor */

> +    memory_region_init_reservation(&s->iomem, "kvm-gic_dist", 0x1000);
> +    sysbus_init_mmio(dev, &s->iomem);

-> instance_init?

> +    kvm_arm_register_device(&s->iomem,
> +                            (KVM_ARM_DEVICE_VGIC_V2 << KVM_ARM_DEVICE_ID_SHIFT)
> +                            | KVM_VGIC_V2_ADDR_TYPE_DIST);
> +    /* CPU interface for current core. Unlike arm_gic, we don't
> +     * provide the "interface for core #N" memory regions, because
> +     * cores with a VGIC don't have those.
> +     */

> +    memory_region_init_reservation(&s->cpuiomem[0], "kvm-gic_cpu", 0x1000);
> +    sysbus_init_mmio(dev, &s->cpuiomem[0]);

-> instance_init?

> +    kvm_arm_register_device(&s->cpuiomem[0],
> +                            (KVM_ARM_DEVICE_VGIC_V2 << KVM_ARM_DEVICE_ID_SHIFT)
> +                            | KVM_VGIC_V2_ADDR_TYPE_CPU);
> +    /* TODO: we should tell the kernel at some point the address
> +     * of the private peripheral base. However we don't currently have
> +     * any convenient infrastructure to do that, and in any case the
> +     * kernel doesn't yet implement an ioctl to let us tell it.
> +     */
> +    return 0;
> +}
> +
> +static void kvm_arm_gic_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +    SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
> +    ARMGICCommonClass *agcc = ARM_GIC_COMMON_CLASS(klass);
> +    KVMARMGICClass *kgc = KVM_ARM_GIC_CLASS(klass);

Please separate variable definitions and rest of block by a white line,
here and elsewhere.

> +    agcc->pre_save = kvm_arm_gic_get;
> +    agcc->post_load = kvm_arm_gic_put;
> +    kgc->parent_init = sbc->init;
> +    kgc->parent_reset = dc->reset;
> +    sbc->init = kvm_arm_gic_init;
> +    dc->reset = kvm_arm_gic_reset;
> +    dc->no_user = 1;
> +}
> +
> +static const TypeInfo kvm_arm_gic_info = {
> +    .name = TYPE_KVM_ARM_GIC,
> +    .parent = TYPE_ARM_GIC_COMMON,
> +    .instance_size = sizeof(GICState),
> +    .class_init = kvm_arm_gic_class_init,
> +    .class_size = sizeof(KVMARMGICClass),
> +};
> +
> +static void kvm_arm_gic_register_types(void)
> +{
> +    type_register_static(&kvm_arm_gic_info);
> +}
> +
> +type_init(kvm_arm_gic_register_types)

Andreas

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