On Mon, 9 May 2022 18:41:17 +0700 "Suthikulpanit, Suravee" <suravee.suthikulpa...@amd.com> wrote:
> Igor, > > On 5/9/2022 2:12 PM, Igor Mammedov wrote: > > On Wed, 4 May 2022 08:16:39 -0500 > > Suravee Suthikulpanit<suravee.suthikulpa...@amd.com> wrote: > > > >> This is the maximum number of vCPU supported by > >> the AMD x2APIC virtualization. > >> > >> Signed-off-by: Suravee Suthikulpanit<suravee.suthikulpa...@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 302288342a..e82b1c690d 100644 > >> --- a/hw/i386/pc_q35.c > >> +++ b/hw/i386/pc_q35.c > >> @@ -357,7 +357,7 @@ 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; > > Maybe we should bump it to KVM VCPU maximum, > > Grepping through the Linux kernel source, the KVM_MAX_VCPUS macro is defined > per architecture. > AFAICT, the absolute maximum is for x86, which is 1024. Does that sound about > right? yep > > and make sure we error out if asked for combination of > > hardware/irqchip is not usable. > > Could you please elaborate on this part? I meant that is you start with large VCPU number but accelerator/irqchip can't create correct (usable) VM, QEMU should exit with error. > Thanks, > Suravee >