[PATCH RESEND v2 3/8] KVM: arm-vgic: Set base addr through device API

Marc Zyngier maz at misterjones.org
Wed Oct 23 11:10:42 EDT 2013


On 2013-10-22 10:08, Christoffer Dall wrote:
> Support setting the distributor and cpu interface base addresses in 
> the
> VM physical address space through the KVM_{SET,GET}_DEVICE_ATTR API
> in addition to the ARM specific API.
>
> This has the added benefit of being able to share more code in user
> space and do things in a uniform maner.

                                    manner?

> Also deprecate the older API at the same time, but backwards
> compatibility will be maintained.
>
> Signed-off-by: Christoffer Dall <christoffer.dall at linaro.org>
> Reviewed-by: Alexander Graf <agraf at suse.de>
> ---
>  Documentation/virtual/kvm/api.txt              |    6 +-
>  Documentation/virtual/kvm/devices/arm-vgic.txt |   11 +++
>  arch/arm/include/uapi/asm/kvm.h                |    9 +++
>  arch/arm/kvm/arm.c                             |    2 +-
>  include/kvm/arm_vgic.h                         |    2 +-
>  virt/kvm/arm/vgic.c                            |   90
> ++++++++++++++++++++----
>  6 files changed, 105 insertions(+), 15 deletions(-)
>
> diff --git a/Documentation/virtual/kvm/api.txt
> b/Documentation/virtual/kvm/api.txt
> index 858aecf..d68b6c2 100644
> --- a/Documentation/virtual/kvm/api.txt
> +++ b/Documentation/virtual/kvm/api.txt
> @@ -2324,7 +2324,7 @@ This ioctl returns the guest registers that are
> supported for the
>  KVM_GET_ONE_REG/KVM_SET_ONE_REG calls.
>
>
> -4.84 KVM_ARM_SET_DEVICE_ADDR
> +4.84 KVM_ARM_SET_DEVICE_ADDR (deprecated)
>
>  Capability: KVM_CAP_ARM_SET_DEVICE_ADDR
>  Architectures: arm, arm64
> @@ -2362,6 +2362,10 @@ must be called after calling
> KVM_CREATE_IRQCHIP, but before calling
>  KVM_RUN on any of the VCPUs.  Calling this ioctl twice for any of 
> the
>  base addresses will return -EEXIST.
>
> +Note, this IOCTL is deprecated and the more flexible 
> SET/GET_DEVICE_ATTR API
> +should be used instead.
> +
> +
>  4.85 KVM_PPC_RTAS_DEFINE_TOKEN
>
>  Capability: KVM_CAP_PPC_RTAS
> diff --git a/Documentation/virtual/kvm/devices/arm-vgic.txt
> b/Documentation/virtual/kvm/devices/arm-vgic.txt
> index 38f27f7..c9febb2 100644
> --- a/Documentation/virtual/kvm/devices/arm-vgic.txt
> +++ b/Documentation/virtual/kvm/devices/arm-vgic.txt
> @@ -8,3 +8,14 @@ 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.
> +
> +Groups:
> +  KVM_DEV_ARM_VGIC_GRP_ADDR
> +  Attributes:
> +    KVM_VGIC_V2_ADDR_TYPE_DIST (rw, 64-bit)
> +      Base address in the guest physical address space of the GIC
> distributor
> +      register mappings.
> +
> +    KVM_VGIC_V2_ADDR_TYPE_CPU (rw, 64-bit)
> +      Base address in the guest physical address space of the GIC
> virtual cpu
> +      interface register mappings.
> diff --git a/arch/arm/include/uapi/asm/kvm.h
> b/arch/arm/include/uapi/asm/kvm.h
> index 1c85102..587f1ae 100644
> --- a/arch/arm/include/uapi/asm/kvm.h
> +++ b/arch/arm/include/uapi/asm/kvm.h
> @@ -142,6 +142,15 @@ struct kvm_arch_memory_slot {
>  #define KVM_REG_ARM_VFP_FPINST		0x1009
>  #define KVM_REG_ARM_VFP_FPINST2		0x100A
>
> +/* Device Control API: ARM VGIC */
> +#define KVM_DEV_ARM_VGIC_GRP_ADDR	0
> +#define KVM_DEV_ARM_VGIC_GRP_DIST_REGS	1
> +#define KVM_DEV_ARM_VGIC_GRP_CPU_REGS	2
> +#define   KVM_DEV_ARM_VGIC_CPUID_SHIFT	32
> +#define   KVM_DEV_ARM_VGIC_CPUID_MASK	(0xffULL <<
> KVM_DEV_ARM_VGIC_CPUID_SHIFT)
> +#define   KVM_DEV_ARM_VGIC_OFFSET_SHIFT	0
> +#define   KVM_DEV_ARM_VGIC_OFFSET_MASK	(0xffffffffULL <<
> KVM_DEV_ARM_VGIC_OFFSET_SHIFT)
> +
>  /* KVM_IRQ_LINE irq field index values */
>  #define KVM_ARM_IRQ_TYPE_SHIFT		24
>  #define KVM_ARM_IRQ_TYPE_MASK		0xff
> diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
> index ab96af2..3ecee45 100644
> --- a/arch/arm/kvm/arm.c
> +++ b/arch/arm/kvm/arm.c
> @@ -773,7 +773,7 @@ static int kvm_vm_ioctl_set_device_addr(struct 
> kvm *kvm,
>  	case KVM_ARM_DEVICE_VGIC_V2:
>  		if (!vgic_present)
>  			return -ENXIO;
> -		return kvm_vgic_set_addr(kvm, type, dev_addr->addr);
> +		return kvm_vgic_addr(kvm, type, &dev_addr->addr, true);
>  	default:
>  		return -ENODEV;
>  	}
> diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h
> index 7e2d158..be85127 100644
> --- a/include/kvm/arm_vgic.h
> +++ b/include/kvm/arm_vgic.h
> @@ -144,7 +144,7 @@ struct kvm_run;
>  struct kvm_exit_mmio;
>
>  #ifdef CONFIG_KVM_ARM_VGIC
> -int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 
> addr);
> +int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr,
> bool write);
>  int kvm_vgic_hyp_init(void);
>  int kvm_vgic_init(struct kvm *kvm);
>  int kvm_vgic_create(struct kvm *kvm);
> diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
> index 79a8bae..d9c0fc5 100644
> --- a/virt/kvm/arm/vgic.c
> +++ b/virt/kvm/arm/vgic.c
> @@ -1479,6 +1479,12 @@ static int vgic_ioaddr_assign(struct kvm *kvm,
> phys_addr_t *ioaddr,
>  {
>  	int ret;
>
> +	if (addr & ~KVM_PHYS_MASK)
> +		return -E2BIG;
> +
> +	if (addr & (SZ_4K - 1))
> +		return -EINVAL;
> +
>  	if (!IS_VGIC_ADDR_UNDEF(*ioaddr))
>  		return -EEXIST;
>  	if (addr + size < addr)
> @@ -1491,26 +1497,41 @@ static int vgic_ioaddr_assign(struct kvm
> *kvm, phys_addr_t *ioaddr,
>  	return ret;
>  }
>
> -int kvm_vgic_set_addr(struct kvm *kvm, unsigned long type, u64 addr)
> +/**
> + * kvm_vgic_addr - set or get vgic VM base addresses
> + * @kvm:   pointer to the vm struct
> + * @type:  the VGIC addr type, one of KVM_VGIC_V2_ADDR_TYPE_XXX
> + * @addr:  pointer to address value
> + * @write: if true set the address in the VM address space, if false
> read the
> + *          address
> + *
> + * Set or get the vgic base addresses for the distributor and the
> virtual CPU
> + * interface in the VM physical address space.  These addresses are
> properties
> + * of the emulated core/SoC and therefore user space initially knows 
> this
> + * information.
> + */
> +int kvm_vgic_addr(struct kvm *kvm, unsigned long type, u64 *addr,
> bool write)
>  {
>  	int r = 0;
>  	struct vgic_dist *vgic = &kvm->arch.vgic;
>
> -	if (addr & ~KVM_PHYS_MASK)
> -		return -E2BIG;
> -
> -	if (addr & (SZ_4K - 1))
> -		return -EINVAL;
> -
>  	mutex_lock(&kvm->lock);
>  	switch (type) {
>  	case KVM_VGIC_V2_ADDR_TYPE_DIST:
> -		r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base,
> -				       addr, KVM_VGIC_V2_DIST_SIZE);
> +		if (write) {
> +			r = vgic_ioaddr_assign(kvm, &vgic->vgic_dist_base,
> +					       *addr, KVM_VGIC_V2_DIST_SIZE);
> +		} else {
> +			*addr = vgic->vgic_dist_base;
> +		}
>  		break;
>  	case KVM_VGIC_V2_ADDR_TYPE_CPU:
> -		r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base,
> -				       addr, KVM_VGIC_V2_CPU_SIZE);
> +		if (write) {
> +			r = vgic_ioaddr_assign(kvm, &vgic->vgic_cpu_base,
> +					       *addr, KVM_VGIC_V2_CPU_SIZE);
> +		} else {
> +			*addr = vgic->vgic_cpu_base;
> +		}
>  		break;
>  	default:
>  		r = -ENODEV;
> @@ -1522,16 +1543,61 @@ int kvm_vgic_set_addr(struct kvm *kvm,
> unsigned long type, u64 addr)
>
>  static int vgic_set_attr(struct kvm_device *dev, struct
> kvm_device_attr *attr)
>  {
> +	int r;
> +
> +	switch (attr->group) {
> +	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		u64 addr;
> +		unsigned long type = (unsigned long)attr->attr;
> +
> +		if (copy_from_user(&addr, uaddr, sizeof(addr)))
> +			return -EFAULT;
> +
> +		r = kvm_vgic_addr(dev->kvm, type, &addr, true);
> +		return (r == -ENODEV) ? -ENXIO : r;
> +	}
> +	}
> +
>  	return -ENXIO;
>  }
>
>  static int vgic_get_attr(struct kvm_device *dev, struct
> kvm_device_attr *attr)
>  {
> -	return -ENXIO;
> +	int r = ENXIO;

Shouldn't this be a negative number?

> +	switch (attr->group) {
> +	case KVM_DEV_ARM_VGIC_GRP_ADDR: {
> +		u64 __user *uaddr = (u64 __user *)(long)attr->addr;
> +		u64 addr;
> +		unsigned long type = (unsigned long)attr->attr;
> +
> +		r = kvm_vgic_addr(dev->kvm, type, &addr, false);
> +		if (r)
> +			return (r == -ENODEV) ? -ENXIO : r;
> +
> +		r = 0;

Isn't r already zero at this point?

> +		if (copy_to_user(uaddr, &addr, sizeof(addr)))
> +			return -EFAULT;
> +	}
> +	}
> +
> +	return r;
>  }
>
>  static int vgic_has_attr(struct kvm_device *dev, struct
> kvm_device_attr *attr)
>  {
> +	phys_addr_t offset;
> +
> +	switch (attr->group) {
> +	case KVM_DEV_ARM_VGIC_GRP_ADDR:
> +		switch (attr->attr) {
> +		case KVM_VGIC_V2_ADDR_TYPE_DIST:
> +		case KVM_VGIC_V2_ADDR_TYPE_CPU:
> +			return 0;
> +		}
> +		break;
> +	}
>  	return -ENXIO;
>  }

Cheers,

         M.
-- 
Who you jivin' with that Cosmik Debris?



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