On Tuesday, April 8th, 2025 at 9:07 AM, Alejandro Vallejo <agarc...@amd.com>
wrote:
>
>
> From: "Daniel P. Smith" dpsm...@apertussolutions.com
>
>
> Introduce the `cpus` property, named as such for dom0less compatibility, that
> represents the maximum number of vpcus to allocate for a domain. In the device
> tree, it will be encoded as a u32 value.
>
> Signed-off-by: Daniel P. Smith dpsm...@apertussolutions.com
>
> Reviewed-by: Jason Andryuk jason.andr...@amd.com
>
> ---
> xen/arch/x86/dom0_build.c | 3 +++
> xen/arch/x86/domain-builder/fdt.c | 11 +++++++++++
> xen/arch/x86/include/asm/boot-domain.h | 2 ++
> 3 files changed, 16 insertions(+)
>
> diff --git a/xen/arch/x86/dom0_build.c b/xen/arch/x86/dom0_build.c
> index 36fb090643..7b3e31a08f 100644
> --- a/xen/arch/x86/dom0_build.c
> +++ b/xen/arch/x86/dom0_build.c
> @@ -635,6 +635,9 @@ int __init construct_dom0(const struct boot_domain *bd)
> if ( !get_memsize(&dom0_max_size, LONG_MAX) && bd->max_pages )
>
> dom0_size.nr_pages = bd->max_pages;
>
>
> + if ( opt_dom0_max_vcpus_max == UINT_MAX && bd->max_vcpus )
>
> + opt_dom0_max_vcpus_max = bd->max_vcpus;
>
> +
> if ( is_hvm_domain(d) )
> rc = dom0_construct_pvh(bd);
> else if ( is_pv_domain(d) )
> diff --git a/xen/arch/x86/domain-builder/fdt.c
> b/xen/arch/x86/domain-builder/fdt.c
> index 338b4838c2..5fcb767bdd 100644
> --- a/xen/arch/x86/domain-builder/fdt.c
> +++ b/xen/arch/x86/domain-builder/fdt.c
> @@ -246,6 +246,17 @@ static int __init process_domain_node(
> bd->max_pages = PFN_DOWN(kb * SZ_1K);
>
> printk(" max memory: %ld kb\n", kb);
> }
> + else if ( strncmp(prop_name, "cpus", name_len) == 0 )
> + {
> + uint32_t val = UINT_MAX;
> + if ( fdt_prop_as_u32(prop, &val) != 0 )
> + {
> + printk(" failed processing max_vcpus for domain %s\n", name);
Suggest adding XENLOG_ERR to the error message.
> + return -EINVAL;
> + }
> + bd->max_vcpus = val;
>
> + printk(" max vcpus: %d\n", bd->max_vcpus);
>
> + }
> }
>
> fdt_for_each_subnode(node, fdt, dom_node)
> diff --git a/xen/arch/x86/include/asm/boot-domain.h
> b/xen/arch/x86/include/asm/boot-domain.h
> index fa8ea1cc66..969c02a6ea 100644
> --- a/xen/arch/x86/include/asm/boot-domain.h
> +++ b/xen/arch/x86/include/asm/boot-domain.h
> @@ -22,6 +22,8 @@ struct boot_domain {
> unsigned long min_pages;
> unsigned long max_pages;
>
> + unsigned int max_vcpus;
> +
> struct boot_module *kernel;
> struct boot_module *module;
> const char *cmdline;
> --
> 2.43.0
