[PATCH v6 07/15] KVM: arm64: introduce ITS emulation file with MMIO framework
Andre Przywara
andre.przywara at arm.com
Wed Jun 22 08:03:40 PDT 2016
Hi,
On 22/06/16 15:48, Marc Zyngier wrote:
> On 17/06/16 13:08, Andre Przywara wrote:
>> The ARM GICv3 ITS emulation code goes into a separate file, but needs
>> to be connected to the GICv3 emulation, of which it is an option.
>> The ITS MMIO handlers require the respective ITS pointer to be passed in,
>> so we amend the existing VGIC MMIO framework to let it cope with that.
>> Also we introduce the basic ITS data structure and initialize it, but
>> don't return any success yet, as we are not yet ready for the show.
>>
>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>> ---
>> arch/arm64/kvm/Makefile | 1 +
>> include/kvm/vgic/vgic.h | 13 ++++-
>> include/linux/irqchip/arm-gic-v3.h | 1 +
>> virt/kvm/arm/vgic/vgic-its.c | 107 +++++++++++++++++++++++++++++++++++++
>> virt/kvm/arm/vgic/vgic-mmio-v3.c | 38 ++++++++++++-
>> virt/kvm/arm/vgic/vgic-mmio.c | 25 ++++++---
>> virt/kvm/arm/vgic/vgic-mmio.h | 4 ++
>> virt/kvm/arm/vgic/vgic.h | 7 +++
>> 8 files changed, 187 insertions(+), 9 deletions(-)
>> create mode 100644 virt/kvm/arm/vgic/vgic-its.c
>>
>> diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
>> index a7a958c..2755d17 100644
>> --- a/arch/arm64/kvm/Makefile
>> +++ b/arch/arm64/kvm/Makefile
>> @@ -30,6 +30,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio.o
>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v2.o
>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-mmio-v3.o
>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-kvm-device.o
>> +kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic-its.o
>> else
>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic.o
>> kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic-v2.o
>> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
>> index dc7f2fd..a66ba9a 100644
>> --- a/include/kvm/vgic/vgic.h
>> +++ b/include/kvm/vgic/vgic.h
>> @@ -111,12 +111,23 @@ struct vgic_register_region;
>>
>> struct vgic_io_device {
>> gpa_t base_addr;
>> - struct kvm_vcpu *redist_vcpu;
>> + union {
>> + struct kvm_vcpu *redist_vcpu;
>> + struct vgic_its *its;
>> + };
>> const struct vgic_register_region *regions;
>> int nr_regions;
>> struct kvm_io_device dev;
>> };
>>
>> +struct vgic_its {
>> + /* The base address of the ITS control register frame */
>> + gpa_t vgic_its_base;
>> +
>> + bool enabled;
>> + struct vgic_io_device iodev;
>> +};
>
> You may want to move this definition before struct vgic_io_device, some
> compilers are more picky than some others.
Mmh, I just see that this is actually circular here.
So shall I add an opaque declaration for struct vgic_its above?
>
>> +
>> struct vgic_dist {
>> bool in_kernel;
>> bool ready;
>> diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
>> index 64e8c70..92d5da8 100644
>> --- a/include/linux/irqchip/arm-gic-v3.h
>> +++ b/include/linux/irqchip/arm-gic-v3.h
>> @@ -176,6 +176,7 @@
>> #define GITS_CWRITER 0x0088
>> #define GITS_CREADR 0x0090
>> #define GITS_BASER 0x0100
>> +#define GITS_IDREGS_BASE 0xffd0
>
> Please make all the changes to the core GIC code in a separate patch,
> which I can pick independently.
Sure.
>
>> #define GITS_PIDR2 GICR_PIDR2
>>
>> #define GITS_TRANSLATER 0x10040
>> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
>> new file mode 100644
>> index 0000000..c02d9df
>> --- /dev/null
>> +++ b/virt/kvm/arm/vgic/vgic-its.c
>> @@ -0,0 +1,107 @@
>> +/*
>> + * GICv3 ITS emulation
>> + *
>> + * Copyright (C) 2015,2016 ARM Ltd.
>> + * Author: Andre Przywara <andre.przywara at 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/irqchip/arm-gic-v3.h>
>> +
>> +#include <asm/kvm_emulate.h>
>> +#include <asm/kvm_arm.h>
>> +#include <asm/kvm_mmu.h>
>> +
>> +#include "vgic.h"
>> +#include "vgic-mmio.h"
>> +
>> +#define REGISTER_ITS_DESC(off, rd, wr, length, acc) \
>> +{ \
>> + .reg_offset = off, \
>> + .len = length, \
>> + .access_flags = acc, \
>> + .read = NULL, \
>> + .write = NULL, \
>> + .its_read = rd, \
>> + .its_write = wr, \
>
> Meh. That's not very nice... Why can't they be a union?
We can, but we would need another differentiator then (as you suggested
below).
>> +}
>> +
>> +static unsigned long its_mmio_read_raz(struct kvm *kvm, struct vgic_its *its,
>> + gpa_t addr, unsigned int len)
>> +{
>> + return 0;
>> +}
>> +
>> +static void its_mmio_write_wi(struct kvm *kvm, struct vgic_its *its,
>> + gpa_t addr, unsigned int len, unsigned long val)
>> +{
>> + /* Ignore */
>> +}
>> +
>> +struct vgic_register_region its_registers[] = {
>
> Shouldn't this be static?
Indeed, looks like a rebase artefact (I had the registration in another
file during some rework attempts).
>
>> + REGISTER_ITS_DESC(GITS_CTLR,
>> + its_mmio_read_raz, its_mmio_write_wi, 4,
>> + VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_IIDR,
>> + its_mmio_read_raz, its_mmio_write_wi, 4,
>> + VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_TYPER,
>> + its_mmio_read_raz, its_mmio_write_wi, 8,
>> + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_CBASER,
>> + its_mmio_read_raz, its_mmio_write_wi, 8,
>> + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_CWRITER,
>> + its_mmio_read_raz, its_mmio_write_wi, 8,
>> + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_CREADR,
>> + its_mmio_read_raz, its_mmio_write_wi, 8,
>> + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_BASER,
>> + its_mmio_read_raz, its_mmio_write_wi, 0x40,
>> + VGIC_ACCESS_64bit | VGIC_ACCESS_32bit),
>> + REGISTER_ITS_DESC(GITS_IDREGS_BASE,
>> + its_mmio_read_raz, its_mmio_write_wi, 0x30,
>> + VGIC_ACCESS_32bit),
>> +};
>> +
>> +int vits_register(struct kvm *kvm, struct vgic_its *its)
>> +{
>> + struct vgic_io_device *iodev = &its->iodev;
>> + int ret;
>> +
>> + iodev->regions = its_registers;
>> + iodev->nr_regions = ARRAY_SIZE(its_registers);
>> + kvm_iodevice_init(&iodev->dev, &kvm_io_gic_ops);
>> +
>> + iodev->base_addr = its->vgic_its_base;
>> + iodev->its = its;
>> + mutex_lock(&kvm->slots_lock);
>> + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, iodev->base_addr,
>> + SZ_64K, &iodev->dev);
>> + mutex_unlock(&kvm->slots_lock);
>> +
>> + return ret;
>> +}
>> +
>> +void vits_destroy(struct kvm *kvm, struct vgic_its *its)
>> +{
>> +
>> + its->enabled = false;
>> +}
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> index 8cd7190..4eee0d7 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
>> @@ -42,6 +42,16 @@ static u64 update_64bit_reg(u64 reg, unsigned int offset, unsigned int len,
>> return reg | ((u64)val << lower);
>> }
>>
>> +bool vgic_has_its(struct kvm *kvm)
>> +{
>> + struct vgic_dist *dist = &kvm->arch.vgic;
>> +
>> + if (dist->vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3)
>> + return false;
>> +
>> + return false;
>> +}
>> +
>> static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
>> gpa_t addr, unsigned int len)
>> {
>> @@ -126,6 +136,32 @@ static void vgic_mmio_write_irouter(struct kvm_vcpu *vcpu,
>> vgic_put_irq(irq);
>> }
>>
>> +static unsigned long vgic_mmio_read_v3r_ctlr(struct kvm_vcpu *vcpu,
>> + gpa_t addr, unsigned int len)
>> +{
>> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>> +
>> + return vgic_cpu->lpis_enabled ? GICR_CTLR_ENABLE_LPIS : 0;
>> +}
>> +
>> +
>> +static void vgic_mmio_write_v3r_ctlr(struct kvm_vcpu *vcpu,
>> + gpa_t addr, unsigned int len,
>> + unsigned long val)
>> +{
>> + struct vgic_cpu *vgic_cpu = &vcpu->arch.vgic_cpu;
>> + bool was_enabled = vgic_cpu->lpis_enabled;
>> +
>> + if (!vgic_has_its(vcpu->kvm))
>> + return;
>> +
>> + vgic_cpu->lpis_enabled = val & GICR_CTLR_ENABLE_LPIS;
>> +
>> + if (!was_enabled && vgic_cpu->lpis_enabled) {
>> + /* Eventually do something */
>> + }
>> +}
>> +
>> static unsigned long vgic_mmio_read_v3r_typer(struct kvm_vcpu *vcpu,
>> gpa_t addr, unsigned int len)
>> {
>> @@ -325,7 +361,7 @@ static const struct vgic_register_region vgic_v3_dist_registers[] = {
>>
>> static const struct vgic_register_region vgic_v3_rdbase_registers[] = {
>> REGISTER_DESC_WITH_LENGTH(GICR_CTLR,
>> - vgic_mmio_read_raz, vgic_mmio_write_wi, 4,
>> + vgic_mmio_read_v3r_ctlr, vgic_mmio_write_v3r_ctlr, 4,
>> VGIC_ACCESS_32bit),
>> REGISTER_DESC_WITH_LENGTH(GICR_IIDR,
>> vgic_mmio_read_v3r_iidr, vgic_mmio_write_wi, 4,
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio.c b/virt/kvm/arm/vgic/vgic-mmio.c
>> index 4050c1c..c98a4fd 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio.c
>> +++ b/virt/kvm/arm/vgic/vgic-mmio.c
>> @@ -461,8 +461,7 @@ static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
>> {
>> struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
>> const struct vgic_register_region *region;
>> - struct kvm_vcpu *r_vcpu;
>> - unsigned long data;
>> + unsigned long data = 0;
>>
>> region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
>> addr - iodev->base_addr);
>> @@ -471,8 +470,15 @@ static int dispatch_mmio_read(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
>> return 0;
>> }
>>
>> - r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
>> - data = region->read(r_vcpu, addr, len);
>> + if (region->read) {
>> + struct kvm_vcpu *r_vcpu;
>> +
>> + r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
>> + data = region->read(r_vcpu, addr, len);
>> + } else if (region->its_read) {
>> + data = region->its_read(vcpu->kvm, iodev->its, addr, len);
>> + }
>
> I'd rather have a flag somewhere that allows us to identify the type of
> device we're dealing with. You could have something like:
>
> enum iodev_type {
> IODEV_VGIC_DISTRIBUTOR,
> IODEV_VGIC_REDISTRIBUTOR,
> IODEV_VGIC_ITS,
> };
>
> assign the type to each region we have, and then have something like:
>
> switch (region->iodev_type) {
> case IODEV_VGIC_DISTRIBUTOR:
> data = region->read(vcpu, addr, len);
> break;
> case IODEV_VGIC_REDISTRIBUTOR:
> data = region->read(iodev->redist_vcpu, addr, len);
> break;
> case IODEV_VGIC_ITS:
> data = region->its_read(vcpu->kvm, iodev->its, addr, len);
> break;
> }
>
> It would make it extensible *and* readable.
Agreed, will fix it.
Cheers,
Andre.
>> +
>> vgic_data_host_to_mmio_bus(val, len, data);
>> return 0;
>> }
>> @@ -482,7 +488,6 @@ static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
>> {
>> struct vgic_io_device *iodev = kvm_to_vgic_iodev(dev);
>> const struct vgic_register_region *region;
>> - struct kvm_vcpu *r_vcpu;
>> unsigned long data = vgic_data_mmio_bus_to_host(val, len);
>>
>> region = vgic_find_mmio_region(iodev->regions, iodev->nr_regions,
>> @@ -493,8 +498,14 @@ static int dispatch_mmio_write(struct kvm_vcpu *vcpu, struct kvm_io_device *dev,
>> if (!check_region(region, addr, len))
>> return 0;
>>
>> - r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
>> - region->write(r_vcpu, addr, len, data);
>> + if (region->write) {
>> + struct kvm_vcpu *r_vcpu;
>> +
>> + r_vcpu = iodev->redist_vcpu ? iodev->redist_vcpu : vcpu;
>> + region->write(r_vcpu, addr, len, data);
>> + } else if (region->its_write) {
>> + region->its_write(vcpu->kvm, iodev->its, addr, len, data);
>> + }
>
> Same here.
>
>> return 0;
>> }
>>
>> diff --git a/virt/kvm/arm/vgic/vgic-mmio.h b/virt/kvm/arm/vgic/vgic-mmio.h
>> index 8509014..6dfc2f0 100644
>> --- a/virt/kvm/arm/vgic/vgic-mmio.h
>> +++ b/virt/kvm/arm/vgic/vgic-mmio.h
>> @@ -25,6 +25,10 @@ struct vgic_register_region {
>> unsigned int len);
>> void (*write)(struct kvm_vcpu *vcpu, gpa_t addr, unsigned int len,
>> unsigned long val);
>> + unsigned long (*its_read)(struct kvm *kvm, struct vgic_its *its,
>> + gpa_t addr, unsigned int len);
>> + void (*its_write)(struct kvm *kvm, struct vgic_its *its,
>> + gpa_t addr, unsigned int len, unsigned long val);
>> };
>>
>> extern struct kvm_io_device_ops kvm_io_gic_ops;
>> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
>> index fa2d225..b09590d 100644
>> --- a/virt/kvm/arm/vgic/vgic.h
>> +++ b/virt/kvm/arm/vgic/vgic.h
>> @@ -76,6 +76,7 @@ void vgic_v3_enable(struct kvm_vcpu *vcpu);
>> int vgic_v3_probe(const struct gic_kvm_info *info);
>> int vgic_v3_map_resources(struct kvm *kvm);
>> int vgic_register_redist_iodevs(struct kvm *kvm, gpa_t dist_base_address);
>> +bool vgic_has_its(struct kvm *kvm);
>> #else
>> static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
>> {
>> @@ -127,6 +128,12 @@ static inline int vgic_register_redist_iodevs(struct kvm *kvm,
>> {
>> return -ENODEV;
>> }
>> +
>> +static inline bool vgic_has_its(struct kvm *kvm)
>> +{
>> + return false;
>> +}
>> +
>> #endif
>>
>> int kvm_register_vgic_device(unsigned long type);
>>
>
> Thanks,
>
> M.
>
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