Re: [PATCH v3 05/23] xen/arm: vsmmuv3: Add dummy support for virtual SMMUv3 for guests

[Luca Fancellu <Luca.Fancellu@xxxxxxx>]

Hi Milan,


> 
> diff --git a/xen/drivers/passthrough/arm/viommu.c 
> b/xen/drivers/passthrough/arm/viommu.c
> index 7ab6061e34..53ae46349a 100644
> --- a/xen/drivers/passthrough/arm/viommu.c
> +++ b/xen/drivers/passthrough/arm/viommu.c
> @@ -2,12 +2,42 @@
> 
> #include <xen/errno.h>
> #include <xen/init.h>
> +#include <xen/irq.h>
> #include <xen/types.h>
> 
> #include <asm/viommu.h>
> 
> +/* List of all host IOMMUs */
> +LIST_HEAD(host_iommu_list);
> +
> const struct viommu_desc __read_mostly *cur_viommu;
> 
> +/* Common function for adding to host_iommu_list */
> +void add_to_host_iommu_list(paddr_t addr, paddr_t size,
> +                            const struct dt_device_node *node)
> +{
> +    struct host_iommu *iommu_data;
> +
> +    iommu_data = xzalloc(struct host_iommu);
> +    if ( !iommu_data )
> +        panic("vIOMMU: Cannot allocate memory for host IOMMU data\n");
> +
> +    iommu_data->addr = addr;
> +    iommu_data->size = size;
> +    iommu_data->dt_node = node;
> +    iommu_data->irq = platform_get_irq(node, 0);
> +    if ( iommu_data->irq < 0 )
> +    {
> +        gdprintk(XENLOG_ERR,
> +                 "vIOMMU: Cannot find a valid IOMMU irq\n");

We need to free iommu_data here

> +        return;
> +    }
> +
> +    printk("vIOMMU: Found IOMMU @0x%"PRIx64"\n", addr);
> +
> +    list_add_tail(&iommu_data->entry, &host_iommu_list);
> +}
> +
> int domain_viommu_init(struct domain *d, uint16_t viommu_type)
> {
>     if ( viommu_type == XEN_DOMCTL_CONFIG_VIOMMU_NONE )
> diff --git a/xen/drivers/passthrough/arm/vsmmu-v3.c 
> b/xen/drivers/passthrough/arm/vsmmu-v3.c
> new file mode 100644
> index 0000000000..6b4009e5ef
> --- /dev/null
> +++ b/xen/drivers/passthrough/arm/vsmmu-v3.c
> @@ -0,0 +1,124 @@
> +/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
> +
> +#include <xen/param.h>
> +#include <xen/sched.h>
> +#include <asm/mmio.h>
> +#include <asm/viommu.h>
> +
> +/* Struct to hold the vIOMMU ops and vIOMMU type */
> +extern const struct viommu_desc __read_mostly *cur_viommu;
> +
> +struct virt_smmu {
> +    struct      domain *d;
> +    struct      list_head viommu_list;
> +};
> +
> +static int vsmmuv3_mmio_write(struct vcpu *v, mmio_info_t *info,
> +                              register_t r, void *priv)
> +{
> +    return IO_HANDLED;
> +}
> +
> +static int vsmmuv3_mmio_read(struct vcpu *v, mmio_info_t *info,
> +                             register_t *r, void *priv)
> +{
> +    return IO_HANDLED;

If this has to be treated for now as RAZ, being a dummy implementation,
I would add *r = 0;

> +}
> +
> +static const struct mmio_handler_ops vsmmuv3_mmio_handler = {
> +    .read  = vsmmuv3_mmio_read,
> +    .write = vsmmuv3_mmio_write,
> +};
> +
> +static int vsmmuv3_init_single(struct domain *d, paddr_t addr, paddr_t size)
> +{
> +    struct virt_smmu *smmu;
> +
> +    smmu = xzalloc(struct virt_smmu);
> +    if ( !smmu )
> +        return -ENOMEM;
> +
> +    smmu->d = d;
> +
> +    register_mmio_handler(d, &vsmmuv3_mmio_handler, addr, size, smmu);
> +
> +    /* Register the vIOMMU to be able to clean it up later. */
> +    list_add_tail(&smmu->viommu_list, &d->arch.viommu_list);
> +
> +    return 0;
> +}
> +
> +int domain_vsmmuv3_init(struct domain *d)
> +{
> +    int ret;
> +    INIT_LIST_HEAD(&d->arch.viommu_list);
> +
> +    if ( is_hardware_domain(d) )
> +    {
> +        struct host_iommu *hw_iommu;
> +
> +        list_for_each_entry(hw_iommu, &host_iommu_list, entry)
> +        {
> +            ret = vsmmuv3_init_single(d, hw_iommu->addr, hw_iommu->size);
> +            if ( ret )
> +                return ret;
> +        }
> +    }
> +    else
> +    {
> +        ret = vsmmuv3_init_single(d, GUEST_VSMMUV3_BASE, GUEST_VSMMUV3_SIZE);
> +        if ( ret )
> +            return ret;
> +    }
> +
> +    return 0;
> +}
> +
> +int vsmmuv3_relinquish_resources(struct domain *d)
> +{
> +    struct virt_smmu *pos, *temp;
> +
> +    /* Cope with unitialized vIOMMU */

Typo s/unitialized/uninitialized/


Cheers,
Luca