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Re: [Xen-devel] [RFC PATCH 07/24] ARM: GICv3 ITS: introduce device mapping



On Wed, Sep 28, 2016 at 11:54 PM, Andre Przywara <andre.przywara@xxxxxxx> wrote:
> The ITS uses device IDs to map LPIs to a device. Dom0 will later use
> those IDs, which we directly pass on to the host.
> For this we have to map each device that Dom0 may request to a host
> ITS device with the same identifier.
> Allocate the respective memory and enter each device into a list to
> later be able to iterate over it or to easily teardown guests.
>
> Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
> ---
>  xen/arch/arm/gic-its.c        | 90 
> +++++++++++++++++++++++++++++++++++++++++++
>  xen/include/asm-arm/gic-its.h | 16 ++++++++
>  2 files changed, 106 insertions(+)
>
> diff --git a/xen/arch/arm/gic-its.c b/xen/arch/arm/gic-its.c
> index 2140e4a..bf1f5b5 100644
> --- a/xen/arch/arm/gic-its.c
> +++ b/xen/arch/arm/gic-its.c
> @@ -168,6 +168,94 @@ static int its_send_cmd_mapc(struct host_its *its, int 
> collection_id, int cpu)
>      return its_send_command(its, cmd);
>  }
>
> +static int its_send_cmd_mapd(struct host_its *its, uint32_t deviceid,
> +                             int size, uint64_t itt_addr, bool valid)
> +{
> +    uint64_t cmd[4];
> +
> +    cmd[0] = GITS_CMD_MAPD | ((uint64_t)deviceid << 32);
> +    cmd[1] = size & GENMASK(4, 0);
> +    cmd[2] = itt_addr & GENMASK(51, 8);
> +    if ( valid )
> +        cmd[2] |= BIT(63);
> +    cmd[3] = 0x00;
> +
> +    return its_send_command(its, cmd);
> +}
> +
> +int gicv3_its_map_device(struct host_its *hw_its, struct domain *d,
> +                         int devid, int bits, bool valid)
> +{
> +    void *itt_addr = NULL;
> +    struct its_devices *dev, *temp;
> +    bool reuse_dev = false;
> +
> +    list_for_each_entry_safe(dev, temp, &hw_its->its_devices, entry)
> +    {
> +        if ( (dev->d->domain_id != d->domain_id) || (dev->devid != devid) )
> +            continue;
> +
> +        its_send_cmd_mapd(hw_its, dev->devid, 0, 0, false);
> +        xfree(dev->itt_addr);
> +        if ( !valid )
> +        {
> +            xfree(dev);
    xfree() should be done after list_del()
> +            list_del(&dev->entry);
> +
> +            return 0;
> +        }
> +
> +        reuse_dev = true;
> +        break;
> +    }
> +
> +    if ( !valid )
> +        return 0;
> +
> +    itt_addr = _xmalloc(BIT(bits) * hw_its->itte_size, 256);
> +    if ( !itt_addr )
> +        return -ENOMEM;
> +
> +    if ( !reuse_dev )
> +    {
> +        dev = xmalloc(struct its_devices);
> +        if ( !dev )
> +            return -ENOMEM;
> +
> +        list_add_tail(&dev->entry, &hw_its->its_devices);
> +    }
> +
> +    dev->itt_addr = itt_addr;
> +    dev->d = d;
> +    dev->devid = devid;
> +
> +    return its_send_cmd_mapd(hw_its, devid, bits - 1,
> +                             itt_addr ? virt_to_maddr(itt_addr) : 0, true);
          check on itt_addr is redundant

> +}
> +
> +/* Removing any connections a domain had to any ITS in the system. */
> +int its_remove_domain(struct domain *d)
> +{
> +    struct host_its *its;
> +    struct its_devices *dev, *temp;
> +
> +    list_for_each_entry(its, &host_its_list, entry)
> +    {
> +        list_for_each_entry_safe(dev, temp, &its->its_devices, entry)
> +        {
> +            if ( dev->d->domain_id != d->domain_id )
> +                continue;
> +
> +            its_send_cmd_mapd(its, dev->devid, 0, 0, false);
> +            xfree(dev->itt_addr);
> +            xfree(dev);

xfree() should be done after list_del(
> +            list_del(&dev->entry);
> +        }
        This code is same as above. Can be moved to a separate function?

> +    }
> +
> +    return 0;
> +}
> +
>  /* Set up the (1:1) collection mapping for the given host CPU. */
>  void gicv3_its_setup_collection(int cpu)
>  {
> @@ -297,6 +385,7 @@ int gicv3_its_init(struct host_its *hw_its)
>
>      reg = readq_relaxed(hw_its->its_base + GITS_TYPER);
>      hw_its->pta = reg & GITS_TYPER_PTA;
> +    hw_its->itte_size = ((reg >> 4) & 0xf) + 1;
      can define a macro for these constants
>
>      for (i = 0; i < 8; i++)
>      {
> @@ -520,6 +609,7 @@ void gicv3_its_dt_init(const struct dt_device_node *node)
>          its_data->size = size;
>          its_data->dt_node = its;
>          spin_lock_init(&its_data->cmd_lock);
> +        INIT_LIST_HEAD(&its_data->its_devices);
>
>          printk("GICv3: Found ITS @0x%lx\n", addr);
>
> diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
> index 512a388..4e9841a 100644
> --- a/xen/include/asm-arm/gic-its.h
> +++ b/xen/include/asm-arm/gic-its.h
> @@ -79,6 +79,13 @@
>  #ifndef __ASSEMBLY__
>  #include <xen/device_tree.h>
>
> +struct its_devices {
> +    struct list_head entry;
> +    struct domain *d;
> +    void *itt_addr;
> +    int devid;
> +};
> +
>  /* data structure for each hardware ITS */
>  struct host_its {
>      struct list_head entry;
> @@ -88,6 +95,8 @@ struct host_its {
>      void __iomem *its_base;
>      spinlock_t cmd_lock;
>      void *cmd_buf;
> +    struct list_head its_devices;
> +    int itte_size;
>      bool pta;
>  };
>
> @@ -114,6 +123,13 @@ void gicv3_set_redist_addr(paddr_t address, int 
> redist_id);
>  /* Map a collection for this host CPU to each host ITS. */
>  void gicv3_its_setup_collection(int cpu);
>
> +/* Map a device on the host by allocating an ITT on the host (ITS).
> + * "bits" specifies how many events (interrupts) this device will need.
> + * Setting "valid" to false deallocates the device.
> + */
> +int gicv3_its_map_device(struct host_its *hw_its, struct domain *d,
> +                         int devid, int bits, bool valid);
> +
>  int gicv3_lpi_allocate_host_lpi(struct host_its *its,
>                                  uint32_t devid, uint32_t eventid,
>                                  struct vcpu *v, int virt_lpi);
> --
> 2.9.0
>
>
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> Xen-devel@xxxxxxxxxxxxx
> https://lists.xen.org/xen-devel

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