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

[dmkhn@proton.me]

On Thu, Apr 17, 2025 at 01:48:33PM +0100, Alejandro Vallejo wrote:
> From: "Daniel P. Smith" <dpsmith@apertussolutions.com>
> 
> 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@apertussolutions.com>
> Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
> Signed-off-by: Alejandro Vallejo <agarciav@amd.com>
> ---
> 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?

> +        {
> +            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?

> +
>  static inline bool __init fdt_get_prop_offset(
>      const void *fdt, int node, const char *pname, unsigned long *poffset)
>  {
> --
> 2.43.0
> 
>