Re: [PATCH v4 11/13] x86/hyperlaunch: add memory parsing to domain config

[Alejandro Vallejo <agarciav@xxxxxxx>]

On Sat Apr 19, 2025 at 12:21 AM BST, dmkhn wrote:
> On Thu, Apr 17, 2025 at 01:48:33PM +0100, Alejandro Vallejo wrote:
>> From: "Daniel P. Smith" <dpsmith@xxxxxxxxxxxxxxxxxxxx>
>> 
>> Add three properties, memory, mem-min, and mem-max, to the domain node device
>> tree parsing to define the memory allocation for a domain. All three fields 
>> are
>> expressed in kb and written as a u64 in the device tree entries.
>> 
>> Signed-off-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
>> Reviewed-by: Jason Andryuk <jason.andryuk@xxxxxxx>
>> Signed-off-by: Alejandro Vallejo <agarciav@xxxxxxx>
>> ---
>> Can't use KB() rather tha SZ_1K, as that's strictly for literals.
>
> Oh, that's right! Thanks!
>
>> 
>> v4:
>>   * Don't override fdt_prop_as_u64() rc on error.
>>   * Add separate printk statements for each memory prop error.
>>   * Fix bug setting up dom0_size, dom0_min_size and dom0_max_size
>>     * Was overriding dom0_size on all 3 paths.
>>   * Pre-initialise max_pages of all boot_domains to be LONG_MAX, just as
>>     dom0_max_size.
>>     * Eventually dom0_max_size drops out in the bigger series, so we
>>       need that logic to be correct.
>> ---
>>  xen/arch/x86/dom0_build.c              |  8 ++++++
>>  xen/arch/x86/include/asm/boot-domain.h |  4 +++
>>  xen/arch/x86/setup.c                   |  5 +++-
>>  xen/common/domain-builder/fdt.c        | 36 ++++++++++++++++++++++++++
>>  xen/include/xen/libfdt/libfdt-xen.h    | 10 +++++++
>>  5 files changed, 62 insertions(+), 1 deletion(-)
>> 
>> diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
>> index 0b467fd4a4..8db24dbc0a 100644
>> --- a/xen/arch/x86/dom0_build.c
>> +++ b/xen/arch/x86/dom0_build.c
>> @@ -627,6 +627,14 @@ int __init construct_dom0(const struct boot_domain *bd)
>> 
>>      process_pending_softirqs();
>> 
>> +    /* If param dom0_size was not set and HL config provided memory size */
>> +    if ( !get_memsize(&dom0_size, ULONG_MAX) && bd->mem_pages )
>> +        dom0_size.nr_pages = bd->mem_pages;
>> +    if ( !get_memsize(&dom0_min_size, ULONG_MAX) && bd->min_pages )
>> +        dom0_min_size.nr_pages = bd->min_pages;
>> +    if ( !get_memsize(&dom0_max_size, ULONG_MAX) && bd->max_pages )
>> +        dom0_max_size.nr_pages = bd->max_pages;
>> +
>>      if ( is_hvm_domain(d) )
>>          rc = dom0_construct_pvh(bd);
>>      else if ( is_pv_domain(d) )
>> diff --git a/xen/arch/x86/include/asm/boot-domain.h 
>> b/xen/arch/x86/include/asm/boot-domain.h
>> index e316d4bcde..fa8ea1cc66 100644
>> --- a/xen/arch/x86/include/asm/boot-domain.h
>> +++ b/xen/arch/x86/include/asm/boot-domain.h
>> @@ -18,6 +18,10 @@ struct boot_domain {
>>  #define BUILD_MODE_ENABLE_DM     (1 << 1) /* HVM    | PVH     */
>>      uint32_t mode;
>> 
>> +    unsigned long mem_pages;
>> +    unsigned long min_pages;
>> +    unsigned long max_pages;
>> +
>>      struct boot_module *kernel;
>>      struct boot_module *module;
>>      const char *cmdline;
>> diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
>> index 05e3d2cf2a..455dad454c 100644
>> --- a/xen/arch/x86/setup.c
>> +++ b/xen/arch/x86/setup.c
>> @@ -296,7 +296,10 @@ static const char *cmdline_cook(const char *p, const 
>> char *loader_name);
>>  struct boot_info __initdata xen_boot_info = {
>>      .loader = "unknown",
>>      .cmdline = "",
>> -    .domains = { [0 ... MAX_NR_BOOTDOMS - 1] = { .domid = DOMID_INVALID } },
>> +    .domains = { [0 ... MAX_NR_BOOTDOMS - 1] = {
>> +        .domid = DOMID_INVALID,
>> +        .max_pages = ULONG_MAX,
>> +    }},
>>  };
>> 
>>  static struct boot_info *__init multiboot_fill_boot_info(
>> diff --git a/xen/common/domain-builder/fdt.c 
>> b/xen/common/domain-builder/fdt.c
>> index 6809c7f917..90218d120a 100644
>> --- a/xen/common/domain-builder/fdt.c
>> +++ b/xen/common/domain-builder/fdt.c
>> @@ -7,6 +7,7 @@
>>  #include <xen/init.h>
>>  #include <xen/lib.h>
>>  #include <xen/libfdt/libfdt.h>
>> +#include <xen/sizes.h>
>> 
>>  #include <asm/bootinfo.h>
>>  #include <asm/page.h>
>> @@ -246,6 +247,41 @@ static int __init process_domain_node(
>>                     (bd->mode & BUILD_MODE_ENABLE_DM) ? "hvm" :
>>                                                         "pvh");
>>          }
>> +        else if ( strncmp(prop_name, "memory", name_len) == 0 )
>
> Use !strncmp(...) like in the below code?

Sure

>
>> +        {
>> +            uint64_t kb;
>> +            if ( (rc = fdt_prop_as_u64(prop, &kb)) )
>> +            {
>> +                printk(XENLOG_ERR "  bad \"memory\" prop on domain %s\n", 
>> name);
>> +                return rc;
>> +            }
>> +            bd->mem_pages = PFN_DOWN(kb * SZ_1K);
>> +            printk(XENLOG_ERR "  memory: %lu KiB\n", kb);
>> +        }
>> +        else if ( !strncmp(prop_name, "mem-min", name_len) )
>> +        {
>> +            uint64_t kb;
>> +            if ( (rc = fdt_prop_as_u64(prop, &kb)) )
>> +            {
>> +                printk(XENLOG_ERR
>> +                       "  bad \"mem-min\" prop on domain %s\n", name);
>> +                return rc;
>> +            }
>> +            bd->min_pages = PFN_DOWN(kb * SZ_1K);
>> +            printk(XENLOG_INFO "  min memory: %lu kb\n", kb);
>> +        }
>> +        else if ( !strncmp(prop_name, "mem-max", name_len) )
>> +        {
>> +            uint64_t kb;
>> +            if ( (rc = fdt_prop_as_u64(prop, &kb)) )
>> +            {
>> +                printk(XENLOG_ERR
>> +                       "  bad \"mem-max\" prop on domain %s\n", name);
>> +                return rc;
>> +            }
>> +            bd->max_pages = PFN_DOWN(kb * SZ_1K);
>> +            printk(XENLOG_INFO "  max memory: %lu KiB\n", kb);
>> +        }
>>      }
>> 
>>      fdt_for_each_subnode(node, fdt, dom_node)
>> diff --git a/xen/include/xen/libfdt/libfdt-xen.h 
>> b/xen/include/xen/libfdt/libfdt-xen.h
>> index afc76e7750..3054b48a83 100644
>> --- a/xen/include/xen/libfdt/libfdt-xen.h
>> +++ b/xen/include/xen/libfdt/libfdt-xen.h
>> @@ -24,6 +24,16 @@ static inline int __init fdt_prop_as_u32(
>>      return 0;
>>  }
>> 
>> +static inline int __init fdt_prop_as_u64(
>> +    const struct fdt_property *prop, uint64_t *val)
>> +{
>> +    if ( !prop || fdt32_to_cpu(prop->len) < sizeof(uint64_t) )
>> +        return -EINVAL;
>> +
>> +    *val = fdt64_to_cpu(*(const fdt64_t *)prop->data);
>> +    return 0;
>> +}
>
> Perhaps move the call to common/domain-builder/fdt.c?

Yes, all new additions to that header ought to have gone to fdt.c
instead. That was my original intent, but then didn't go through with
everything.

Cheers,
Alejandro