Re: [PATCH v4 09/13] x86/hyperlaunch: add domain id parsing to domain config

[Alejandro Vallejo <agarciav@amd.com>]

On Sat Apr 19, 2025 at 12:08 AM BST, dmkhn wrote:
> On Thu, Apr 17, 2025 at 01:48:31PM +0100, Alejandro Vallejo wrote:
>> From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
>> 
>> Introduce the ability to specify the desired domain id for the domain
>> definition. The domain id will be populated in the domid property of the
>> domain node in the device tree configuration.
>> 
>> Signed-off-by: Daniel P. Smith <dpsmith@apertussolutions.com>
>> Signed-off-by: Alejandro Vallejo <agarciav@amd.com>
>> ---
>> v4:
>>   * Add missing newline
>>   * Adjusted printks
>>   * Checked domid node against list of outstanding domids.
>> ---
>>  xen/arch/x86/setup.c            |  5 ++--
>>  xen/common/domain-builder/fdt.c | 51 ++++++++++++++++++++++++++++++++-
>>  2 files changed, 53 insertions(+), 3 deletions(-)
>> 
>> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
>> index 76ceb5221f..04ad2d0937 100644
>> --- a/xen/arch/x86/setup.c
>> +++ b/xen/arch/x86/setup.c
>> @@ -1033,8 +1033,9 @@ static struct domain *__init create_dom0(struct boot_info *bi)
>>      if ( iommu_enabled )
>>          dom0_cfg.flags |= XEN_DOMCTL_CDF_iommu;
>> 
>> -    /* Create initial domain.  Not d0 for pvshim. */
>> -    bd->domid = get_initial_domain_id();
>> +    if ( bd->domid == DOMID_INVALID )
>> +        /* Create initial domain.  Not d0 for pvshim. */
>> +        bd->domid = get_initial_domain_id();
>>      d = domain_create(bd->domid, &dom0_cfg, pv_shim ? 0 : CDF_privileged);
>>      if ( IS_ERR(d) )
>>          panic("Error creating d%u: %ld\n", bd->domid, PTR_ERR(d));
>> diff --git a/xen/common/domain-builder/fdt.c b/xen/common/domain-builder/fdt.c
>> index c0f526a4ce..0d3c713041 100644
>> --- a/xen/common/domain-builder/fdt.c
>> +++ b/xen/common/domain-builder/fdt.c
>> @@ -2,6 +2,7 @@
>>  /*
>>   * Copyright (C) 2024, Apertus Solutions, LLC
>>   */
>> +#include <xen/domain.h>
>>  #include <xen/err.h>
>>  #include <xen/init.h>
>>  #include <xen/lib.h>
>> @@ -178,12 +179,54 @@ static int __init fdt_read_multiboot_module(const void *fdt, int node,
>>  static int __init process_domain_node(
>>      struct boot_info *bi, const void *fdt, int dom_node)
>>  {
>> -    int node;
>> +    int node, property;
>>      struct boot_domain *bd = &bi->domains[bi->nr_domains];
>>      const char *name = fdt_get_name(fdt, dom_node, NULL) ?: "unknown";
>>      int address_cells = fdt_address_cells(fdt, dom_node);
>>      int size_cells = fdt_size_cells(fdt, dom_node);
>> 
>> +    fdt_for_each_property_offset(property, fdt, dom_node)
>> +    {
>> +        const struct fdt_property *prop;
>> +        const char *prop_name;
>> +        int name_len, rc;
>> +
>> +        prop = fdt_get_property_by_offset(fdt, property, NULL);
>> +        if ( !prop )
>> +            continue; /* silently skip */
>> +
>> +        prop_name = fdt_get_string(fdt, fdt32_to_cpu(prop->nameoff), &name_len);
>> +
>> +        if ( !strncmp(prop_name, "domid", name_len) )
>> +        {
>> +            uint32_t val = DOMID_INVALID;
>> +
>> +            if ( (rc = fdt_prop_as_u32(prop, &val)) )
>> +            {
>> +                printk(XENLOG_ERR
>> +                       "  failed processing domain id for domain %s\n", name);
>> +                return rc;
>> +            }
>> +            if ( val >= DOMID_FIRST_RESERVED )
>> +            {
>> +                printk(XENLOG_ERR "  invalid domain id for domain %s\n", name);
>> +                return -EINVAL;
>> +            }
>> +
>> +            for ( unsigned int i = 0; i < bi->nr_domains; i++ )
>> +            {
>> +                if ( bi->domains[i].domid == val )
>> +                {
>> +                    printk(XENLOG_ERR "  duplicate id for domain %s\n", name);
>> +                    return -EINVAL;
>> +                }
>> +            }
>> +
>> +            bd->domid = val;
>> +            printk(XENLOG_INFO "  domid: %d\n", bd->domid);
>> +        }
>> +    }
>> +
>>      fdt_for_each_subnode(node, fdt, dom_node)
>>      {
>>          if ( !fdt_node_check_compatible(fdt, node, "multiboot,kernel") )
>> @@ -249,6 +292,12 @@ static int __init process_domain_node(
>>          return -ENODATA;
>>      }
>> 
>> +    if ( bd->domid == DOMID_INVALID )
>> +        bd->domid = get_initial_domain_id();
>> +    else if ( bd->domid != get_initial_domain_id() )
>> +        printk(XENLOG_WARNING
>> +               "Warning: Unsuported boot with missing initial domid\n");
>
> s/Unsuported/Unsupported/

Ack

>
> Also, add bd->domid to the printout?

Yes, I'll do a rundown of the error strings and ensure they have
identifying tokens.

Cheers,
Alejandro