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Commit 8331c23c authored by Eric Auger's avatar Eric Auger Committed by Christoffer Dall
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KVM: arm64: vgic-its: Implement vgic_its_has_attr_regs and attr_regs_access 



This patch implements vgic_its_has_attr_regs and vgic_its_attr_regs_access
upon the MMIO framework. VGIC ITS KVM device KVM_DEV_ARM_VGIC_GRP_ITS_REGS
group becomes functional.

At least GITS_CREADR and GITS_IIDR require to differentiate a guest write
action from a user access. As such let's introduce a new uaccess_its_write
vgic_register_region callback.

Signed-off-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarChristoffer Dall <cdall@linaro.org>
Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent dfc99f85

virt/kvm/arm/vgic/vgic-its.c

+77 −2
Original line number Diff line number Diff line
@@ -1469,14 +1469,89 @@ static void vgic_its_destroy(struct kvm_device *kvm_dev) 
int vgic_its_has_attr_regs(struct kvm_device *dev,

			   struct kvm_device_attr *attr)

{

	const struct vgic_register_region *region;

	gpa_t offset = attr->attr;

	int align;



	align = (offset < GITS_TYPER) || (offset >= GITS_PIDR4) ? 0x3 : 0x7;



	if (offset & align)

		return -EINVAL;



	region = vgic_find_mmio_region(its_registers,

				       ARRAY_SIZE(its_registers),

				       offset);

	if (!region)

		return -ENXIO;



	return 0;

}



int vgic_its_attr_regs_access(struct kvm_device *dev,

			      struct kvm_device_attr *attr,

			      u64 *reg, bool is_write)

{

	return -ENXIO;

	const struct vgic_register_region *region;

	struct vgic_its *its;

	gpa_t addr, offset;

	unsigned int len;

	int align, ret = 0;



	its = dev->private;

	offset = attr->attr;



	/*

	 * Although the spec supports upper/lower 32-bit accesses to

	 * 64-bit ITS registers, the userspace ABI requires 64-bit

	 * accesses to all 64-bit wide registers. We therefore only

	 * support 32-bit accesses to GITS_CTLR, GITS_IIDR and GITS ID

	 * registers

	 */

	if ((offset < GITS_TYPER) || (offset >= GITS_PIDR4))

		align = 0x3;

	else

		align = 0x7;



	if (offset & align)

		return -EINVAL;



	mutex_lock(&dev->kvm->lock);



	if (IS_VGIC_ADDR_UNDEF(its->vgic_its_base)) {

		ret = -ENXIO;

		goto out;

	}



	region = vgic_find_mmio_region(its_registers,

				       ARRAY_SIZE(its_registers),

				       offset);

	if (!region) {

		ret = -ENXIO;

		goto out;

	}



	if (!lock_all_vcpus(dev->kvm)) {

		ret = -EBUSY;

		goto out;

	}



	addr = its->vgic_its_base + offset;



	len = region->access_flags & VGIC_ACCESS_64bit ? 8 : 4;



	if (is_write) {

		if (region->uaccess_its_write)

			ret = region->uaccess_its_write(dev->kvm, its, addr,

							len, *reg);

		else

			region->its_write(dev->kvm, its, addr, len, *reg);

	} else {

		*reg = region->its_read(dev->kvm, its, addr, len);

	}

	unlock_all_vcpus(dev->kvm);

out:

	mutex_unlock(&dev->kvm->lock);

	return ret;

}



static int vgic_its_has_attr(struct kvm_device *dev,

virt/kvm/arm/vgic/vgic-mmio.h

+7 −2
Original line number Diff line number Diff line
@@ -36,8 +36,13 @@ struct vgic_register_region { 
	};

	unsigned long (*uaccess_read)(struct kvm_vcpu *vcpu, gpa_t addr,

				      unsigned int len);

	union {

		void (*uaccess_write)(struct kvm_vcpu *vcpu, gpa_t addr,

				      unsigned int len, unsigned long val);

		int (*uaccess_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;