Re: [PATCH v4 3/3] pc: q35: Bump max_cpus to 1024

[Igor Mammedov]

On Mon, 5 Jun 2023 16:39:06 -0500
Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> wrote:

> Since KVM_MAX_VCPUS is currently defined to 1024 for x86 as shown in
> arch/x86/include/asm/kvm_host.h, update QEMU limits to the same number.
> 
> In case KVM could not support the specified number of vcpus, QEMU would
> return the following error message:
> 
>   qemu-system-x86_64: kvm_init_vcpu: kvm_get_vcpu failed (xxx): Invalid 
> argument
> 
> Cc: Igor Mammedov <imammedo@redhat.com>
> Cc: Daniel P. Berrangé <berrange@redhat.com>
> Cc: Michael S. Tsirkin <mst@redhat.com>
> Cc: Julia Suvorova <jusual@redhat.com>
> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
> ---
>  hw/i386/pc_q35.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> index 371cca7484..bd862add94 100644
> --- a/hw/i386/pc_q35.c
> +++ b/hw/i386/pc_q35.c
> @@ -365,7 +365,7 @@ static void pc_q35_machine_options(MachineClass *m)
>      machine_class_allow_dynamic_sysbus_dev(m, TYPE_INTEL_IOMMU_DEVICE);
>      machine_class_allow_dynamic_sysbus_dev(m, TYPE_RAMFB_DEVICE);
>      machine_class_allow_dynamic_sysbus_dev(m, TYPE_VMBUS_BRIDGE);
> -    m->max_cpus = 288;
> +    m->max_cpus = 1024;

did you forgot to preserve value for older machine types?
use commit 00d0f9fd6602a2 as reference 

>  }
>
>  static void pc_q35_8_1_machine_options(MachineClass *m)