Re: [RFC PATCH 00/13] Introducing AMD x2APIC Virtualization (x2AVIC) support.

["Suthikulpanit, Suravee" <suravee.suthikulpanit@xxxxxxx>]

On 2/21/2022 9:19 AM, Suravee Suthikulpanit wrote:
> Testing:
>    * This series has been tested booting a Linux VM with x2APIC physical
>      and logical modes upto 511 vCPUs.

Update:
  * This series has been tested booting a Linux VM with x2APIC physical
    and logical modes upto 512 vCPUs with the following change in QEMU:

diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
index 797e09500b..282036df98 100644
--- a/hw/i386/pc_q35.c
+++ b/hw/i386/pc_q35.c
@@ -352,7 +352,7 @@ 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 = 512;
 }

Regards,
Suravee