[PATCH v6 08/15] KVM: arm64: introduce new KVM ITS device
Marc Zyngier
marc.zyngier at arm.com
Wed Jun 22 08:23:18 PDT 2016
On 17/06/16 13:08, Andre Przywara wrote:
> Introduce a new KVM device that represents an ARM Interrupt Translation
> Service (ITS) controller. Since there can be multiple of this per guest,
> we can't piggy back on the existing GICv3 distributor device, but create
> a new type of KVM device.
> On the KVM_CREATE_DEVICE ioctl we malloc and initialize the ITS data
> structure and store the pointer in the kvm_device data.
> Upon an explicit init ioctl from userland (after having setup the MMIO
> address) we register the handlers with the kvm_io_bus framework.
> Any reference to an ITS thus has to go via MMIO accesses.
>
> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
> ---
> Documentation/virtual/kvm/devices/arm-vgic.txt | 25 +++--
> arch/arm/kvm/arm.c | 1 +
> arch/arm64/include/uapi/asm/kvm.h | 2 +
> include/kvm/vgic/vgic.h | 1 +
> include/uapi/linux/kvm.h | 2 +
> virt/kvm/arm/vgic/vgic-its.c | 131 ++++++++++++++++++++++++-
> virt/kvm/arm/vgic/vgic-kvm-device.c | 7 +-
> virt/kvm/arm/vgic/vgic-mmio-v3.c | 2 +-
> virt/kvm/arm/vgic/vgic.h | 8 ++
> 9 files changed, 168 insertions(+), 11 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt b/Documentation/virtual/kvm/devices/arm-vgic.txt
> index 59541d4..89182f8 100644
> --- a/Documentation/virtual/kvm/devices/arm-vgic.txt
> +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
> @@ -4,16 +4,22 @@ ARM Virtual Generic Interrupt Controller (VGIC)
> Device types supported:
> KVM_DEV_TYPE_ARM_VGIC_V2 ARM Generic Interrupt Controller v2.0
> KVM_DEV_TYPE_ARM_VGIC_V3 ARM Generic Interrupt Controller v3.0
> + KVM_DEV_TYPE_ARM_VGIC_ITS ARM Interrupt Translation Service Controller
>
> -Only one VGIC instance may be instantiated through either this API or the
> -legacy KVM_CREATE_IRQCHIP api. The created VGIC will act as the VM interrupt
> -controller, requiring emulated user-space devices to inject interrupts to the
> -VGIC instead of directly to CPUs.
> +Only one VGIC instance of the V2/V3 types above may be instantiated through
> +either this API or the legacy KVM_CREATE_IRQCHIP api. The created VGIC will
> +act as the VM interrupt controller, requiring emulated user-space devices to
> +inject interrupts to the VGIC instead of directly to CPUs.
>
> Creating a guest GICv3 device requires a host GICv3 as well.
> GICv3 implementations with hardware compatibility support allow a guest GICv2
> as well.
>
> +Creating a virtual ITS controller requires a host GICv3 (but does not depend
> +on having physical ITS controllers).
> +There can be multiple ITS controllers per guest, each of them has to have
> +a separate, non-overlapping MMIO region.
> +
> Groups:
> KVM_DEV_ARM_VGIC_GRP_ADDR
> Attributes:
> @@ -39,6 +45,13 @@ Groups:
> Only valid for KVM_DEV_TYPE_ARM_VGIC_V3.
> This address needs to be 64K aligned.
>
> + KVM_VGIC_V3_ADDR_TYPE_ITS (rw, 64-bit)
> + Base address in the guest physical address space of the GICv3 ITS
> + control register frame. The ITS allows MSI(-X) interrupts to be
> + injected into guests. This extension is optional. If the kernel
> + does not support the ITS, the call returns -ENODEV.
> + Only valid for KVM_DEV_TYPE_ARM_VGIC_ITS.
> + This address needs to be 64K aligned and the region covers 128K.
>
> KVM_DEV_ARM_VGIC_GRP_DIST_REGS
> Attributes:
> @@ -109,8 +122,8 @@ Groups:
> KVM_DEV_ARM_VGIC_GRP_CTRL
> Attributes:
> KVM_DEV_ARM_VGIC_CTRL_INIT
> - request the initialization of the VGIC, no additional parameter in
> - kvm_device_attr.addr.
> + request the initialization of the VGIC or ITS, no additional parameter
> + in kvm_device_attr.addr.
> Errors:
> -ENXIO: VGIC not properly configured as required prior to calling
> this attribute
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index a268c85..f4a953e 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -20,6 +20,7 @@
> #include <linux/errno.h>
> #include <linux/err.h>
> #include <linux/kvm_host.h>
> +#include <linux/list.h>
> #include <linux/module.h>
> #include <linux/vmalloc.h>
> #include <linux/fs.h>
> diff --git a/arch/arm64/include/uapi/asm/kvm.h b/arch/arm64/include/uapi/asm/kvm.h
> index f209ea1..f8c257b 100644
> --- a/arch/arm64/include/uapi/asm/kvm.h
> +++ b/arch/arm64/include/uapi/asm/kvm.h
> @@ -87,9 +87,11 @@ struct kvm_regs {
> /* Supported VGICv3 address types */
> #define KVM_VGIC_V3_ADDR_TYPE_DIST 2
> #define KVM_VGIC_V3_ADDR_TYPE_REDIST 3
> +#define KVM_VGIC_ITS_ADDR_TYPE 4
>
> #define KVM_VGIC_V3_DIST_SIZE SZ_64K
> #define KVM_VGIC_V3_REDIST_SIZE (2 * SZ_64K)
> +#define KVM_VGIC_V3_ITS_SIZE SZ_64K
>
> #define KVM_ARM_VCPU_POWER_OFF 0 /* CPU is started in OFF state */
> #define KVM_ARM_VCPU_EL1_32BIT 1 /* CPU running a 32bit VM */
> diff --git a/include/kvm/vgic/vgic.h b/include/kvm/vgic/vgic.h
> index a66ba9a..979d8c3 100644
> --- a/include/kvm/vgic/vgic.h
> +++ b/include/kvm/vgic/vgic.h
> @@ -158,6 +158,7 @@ struct vgic_dist {
>
> struct vgic_io_device dist_iodev;
>
> + bool has_its;
> /*
> * Contains the address of the LPI configuration table.
> * Since we report GICR_TYPER.CommonLPIAff as 0b00, we can share
> diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
> index 7de96f5..d8c4c32 100644
> --- a/include/uapi/linux/kvm.h
> +++ b/include/uapi/linux/kvm.h
> @@ -1077,6 +1077,8 @@ enum kvm_device_type {
> #define KVM_DEV_TYPE_FLIC KVM_DEV_TYPE_FLIC
> KVM_DEV_TYPE_ARM_VGIC_V3,
> #define KVM_DEV_TYPE_ARM_VGIC_V3 KVM_DEV_TYPE_ARM_VGIC_V3
> + KVM_DEV_TYPE_ARM_VGIC_ITS,
> +#define KVM_DEV_TYPE_ARM_VGIC_ITS KVM_DEV_TYPE_ARM_VGIC_ITS
> KVM_DEV_TYPE_MAX,
> };
>
> diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
> index c02d9df..4ae3c82 100644
> --- a/virt/kvm/arm/vgic/vgic-its.c
> +++ b/virt/kvm/arm/vgic/vgic-its.c
> @@ -21,6 +21,7 @@
> #include <linux/kvm.h>
> #include <linux/kvm_host.h>
> #include <linux/interrupt.h>
> +#include <linux/uaccess.h>
>
> #include <linux/irqchip/arm-gic-v3.h>
>
> @@ -81,7 +82,7 @@ struct vgic_register_region its_registers[] = {
> VGIC_ACCESS_32bit),
> };
>
> -int vits_register(struct kvm *kvm, struct vgic_its *its)
> +static int vits_register(struct kvm *kvm, struct vgic_its *its)
> {
> struct vgic_io_device *iodev = &its->iodev;
> int ret;
> @@ -100,8 +101,134 @@ int vits_register(struct kvm *kvm, struct vgic_its *its)
> return ret;
> }
>
> -void vits_destroy(struct kvm *kvm, struct vgic_its *its)
> +static void vits_destroy(struct kvm *kvm, struct vgic_its *its)
Maybe move these hunks to the previous patch?
> {
>
> its->enabled = false;
> }
> +
> +static int vgic_its_create(struct kvm_device *dev, u32 type)
> +{
> + struct vgic_its *its;
> +
> + if (type != KVM_DEV_TYPE_ARM_VGIC_ITS)
> + return -ENODEV;
> +
> + its = kzalloc(sizeof(struct vgic_its), GFP_KERNEL);
> + if (!its)
> + return -ENOMEM;
> +
> + its->vgic_its_base = VGIC_ADDR_UNDEF;
> +
> + dev->kvm->arch.vgic.has_its = true;
> + its->enabled = false;
> +
> + dev->private = its;
> +
> + return 0;
> +}
> +
> +static void vgic_its_destroy(struct kvm_device *dev)
> +{
> + struct vgic_its *its = dev->private;
> +
> + vits_destroy(dev->kvm, its);
If that's the only use of vits_destroy (and given that it is not really
doing much), can we inline it here (or alternatively get rid of it
altogether)?
> +
> + kfree(its);
> +}
> +
> +static int vgic_its_has_attr(struct kvm_device *dev,
> + struct kvm_device_attr *attr)
> +{
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_ADDR:
> + switch (attr->attr) {
> + case KVM_VGIC_ITS_ADDR_TYPE:
> + return 0;
> + }
> + break;
> + case KVM_DEV_ARM_VGIC_GRP_CTRL:
> + switch (attr->attr) {
> + case KVM_DEV_ARM_VGIC_CTRL_INIT:
> + return 0;
> + }
> + break;
> + }
> + return -ENXIO;
> +}
> +
> +static int vgic_its_set_attr(struct kvm_device *dev,
> + struct kvm_device_attr *attr)
> +{
> + struct vgic_its *its = dev->private;
> + int ret;
> +
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_ADDR: {
> + u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> + unsigned long type = (unsigned long)attr->attr;
> + u64 addr;
> +
> + if (type != KVM_VGIC_ITS_ADDR_TYPE)
> + return -ENODEV;
> +
> + if (copy_from_user(&addr, uaddr, sizeof(addr)))
> + return -EFAULT;
> +
> + ret = vgic_check_ioaddr(dev->kvm, &its->vgic_its_base,
> + addr, SZ_64K);
> + if (ret)
> + return ret;
> +
> + its->vgic_its_base = addr;
> +
> + return 0;
> + }
> + case KVM_DEV_ARM_VGIC_GRP_CTRL:
> + switch (attr->attr) {
> + case KVM_DEV_ARM_VGIC_CTRL_INIT:
> + return vits_register(dev->kvm, its);
> + }
> + break;
> + }
> + return -ENXIO;
> +}
> +
> +static int vgic_its_get_attr(struct kvm_device *dev,
> + struct kvm_device_attr *attr)
> +{
> + switch (attr->group) {
> + case KVM_DEV_ARM_VGIC_GRP_ADDR: {
> + struct vgic_its *its = dev->private;
> + u64 addr = its->vgic_its_base;
> + u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> + unsigned long type = (unsigned long)attr->attr;
> +
> + if (type != KVM_VGIC_ITS_ADDR_TYPE)
> + return -ENODEV;
> +
> + if (copy_to_user(uaddr, &addr, sizeof(addr)))
> + return -EFAULT;
> + break;
> + default:
> + return -ENXIO;
> + }
> + }
> +
> + return 0;
> +}
> +
> +struct kvm_device_ops kvm_arm_vgic_its_ops = {
> + .name = "kvm-arm-vgic-its",
> + .create = vgic_its_create,
> + .destroy = vgic_its_destroy,
> + .set_attr = vgic_its_set_attr,
> + .get_attr = vgic_its_get_attr,
> + .has_attr = vgic_its_has_attr,
> +};
> +
> +int kvm_vgic_register_its_device(void)
> +{
> + return kvm_register_device_ops(&kvm_arm_vgic_its_ops,
> + KVM_DEV_TYPE_ARM_VGIC_ITS);
> +}
> diff --git a/virt/kvm/arm/vgic/vgic-kvm-device.c b/virt/kvm/arm/vgic/vgic-kvm-device.c
> index 2f24f13..1813f93 100644
> --- a/virt/kvm/arm/vgic/vgic-kvm-device.c
> +++ b/virt/kvm/arm/vgic/vgic-kvm-device.c
> @@ -21,8 +21,8 @@
>
> /* common helpers */
>
> -static int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr,
> - phys_addr_t addr, phys_addr_t alignment)
> +int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr,
> + phys_addr_t addr, phys_addr_t alignment)
> {
> if (addr & ~KVM_PHYS_MASK)
> return -E2BIG;
> @@ -223,6 +223,9 @@ int kvm_register_vgic_device(unsigned long type)
> case KVM_DEV_TYPE_ARM_VGIC_V3:
> ret = kvm_register_device_ops(&kvm_arm_vgic_v3_ops,
> KVM_DEV_TYPE_ARM_VGIC_V3);
> + if (ret)
> + break;
> + ret = kvm_vgic_register_its_device();
> break;
> #endif
> }
> diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> index 4eee0d7..3a72308 100644
> --- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
> +++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
> @@ -49,7 +49,7 @@ bool vgic_has_its(struct kvm *kvm)
> if (dist->vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3)
> return false;
>
> - return false;
> + return dist->has_its;
> }
>
> static unsigned long vgic_mmio_read_v3_misc(struct kvm_vcpu *vcpu,
> diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
> index b09590d..24150f7 100644
> --- a/virt/kvm/arm/vgic/vgic.h
> +++ b/virt/kvm/arm/vgic/vgic.h
> @@ -46,6 +46,9 @@ static inline void vgic_put_irq(struct vgic_irq *irq)
> bool vgic_queue_irq_put(struct kvm *kvm, struct vgic_irq *irq);
> void vgic_kick_vcpus(struct kvm *kvm);
>
> +int vgic_check_ioaddr(struct kvm *kvm, phys_addr_t *ioaddr,
> + phys_addr_t addr, phys_addr_t alignment);
> +
> void vgic_v2_process_maintenance(struct kvm_vcpu *vcpu);
> void vgic_v2_fold_lr_state(struct kvm_vcpu *vcpu);
> void vgic_v2_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr);
> @@ -77,6 +80,7 @@ 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);
> +int kvm_vgic_register_its_device(void);
> #else
> static inline void vgic_v3_process_maintenance(struct kvm_vcpu *vcpu)
> {
> @@ -134,6 +138,10 @@ static inline bool vgic_has_its(struct kvm *kvm)
> return false;
> }
>
> +static inline int kvm_vgic_register_its_device(void)
> +{
> + return -ENODEV;
> +}
> #endif
>
> int kvm_register_vgic_device(unsigned long type);
>
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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