Re: [PATCH v3 15/16] x86/hyperlaunch: add max vcpu parsing of hyperlaunch device tree

[Alejandro Vallejo <agarciav@amd.com>]

On Wed Apr 9, 2025 at 11:33 PM BST, Denis Mukhin wrote:
> On Tuesday, April 8th, 2025 at 9:07 AM, Alejandro Vallejo <agarciav@amd.com> wrote:
>
>> 
>> 
>> From: "Daniel P. Smith" dpsmith@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 dpsmith@apertussolutions.com
>> 
>> Reviewed-by: Jason Andryuk jason.andryuk@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.

And XENLOG_INFO to the one below.

Ack.

Cheers,
Alejandro