qemu/hw/i386
Ani Sinha e4e98c7eeb pc: q35: Bump max_cpus to 4096 vcpus
Since commit f10a570b093e6 ("KVM: x86: Add CONFIG_KVM_MAX_NR_VCPUS to allow up to 4096 vCPUs")
Linux kernel can support upto a maximum number of 4096 vcpus when MAXSMP is
enabled in the kernel. At present, QEMU has been tested to correctly boot a
linux guest with 4096 vcpus using the current edk2 upstream master branch that
has the fixes corresponding to the following two PRs:

https://github.com/tianocore/edk2/pull/5410
https://github.com/tianocore/edk2/pull/5418

The changes merged into edk2 with the above PRs will be in the upcoming 2024-05
release. With current seabios firmware, it boots fine with 4096 vcpus already.
So bump up the value max_cpus to 4096 for q35 machines versions 9 and newer.
Q35 machines versions 8.2 and older continue to support 1024 maximum vcpus
as before for compatibility reasons.

If KVM is not able to support the specified number of vcpus, QEMU would
return the following error messages:

$ ./qemu-system-x86_64 -cpu host -accel kvm -machine q35 -smp 1728
qemu-system-x86_64: -accel kvm: warning: Number of SMP cpus requested (1728) exceeds the recommended cpus supported by KVM (12)
qemu-system-x86_64: -accel kvm: warning: Number of hotpluggable cpus requested (1728) exceeds the recommended cpus supported by KVM (12)
Number of SMP cpus requested (1728) exceeds the maximum cpus supported by KVM (1024)

Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Julia Suvorova <jusual@redhat.com>
Cc: kraxel@redhat.com
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Ani Sinha <anisinha@redhat.com>
Message-Id: <20240228143351.3967-1-anisinha@redhat.com>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2024-03-12 17:56:55 -04:00
..
kvm hw/i386/pc: Rename "bus" attribute to "pcibus" 2024-02-27 09:37:30 +01:00
xen hw/xen/hvm: Get target page size at runtime 2024-03-09 18:51:45 +01:00
acpi-build.c hw/i386/pc: Rename "bus" attribute to "pcibus" 2024-02-27 09:37:30 +01:00
acpi-build.h hw/acpi/ich9: Enable ACPI PCI hot-plug 2021-07-16 04:33:35 -04:00
acpi-common.c Misc HW patch queue 2024-02-22 15:44:29 +00:00
acpi-common.h hw/i386/acpi: Declare pc_madt_cpu_entry() in 'acpi-common.h' 2024-02-20 20:34:21 +03:00
acpi-microvm.c hw/i386/acpi-microvm.c: Use common function to add virtio in DSDT 2024-01-10 18:47:46 +10:00
acpi-microvm.h microvm/acpi: add minimal acpi support 2020-09-17 14:16:19 +02:00
amd_iommu-stub.c amd_iommu: report x2APIC support to the operating system 2024-02-14 06:09:32 -05:00
amd_iommu.c hw/i386/pc: Rename "bus" attribute to "pcibus" 2024-02-27 09:37:30 +01:00
amd_iommu.h amd_iommu: report x2APIC support to the operating system 2024-02-14 06:09:32 -05:00
e820_memory_layout.c hw/i386/e820: remove legacy reserved entries for e820 2022-11-02 06:56:31 -04:00
e820_memory_layout.h hw/i386/e820: remove legacy reserved entries for e820 2022-11-02 06:56:31 -04:00
fw_cfg.c hw/i386/pc: Defer smbios_set_defaults() to machine_done 2024-02-22 12:47:40 +01:00
fw_cfg.h hw/i386/pc: Defer smbios_set_defaults() to machine_done 2024-02-22 12:47:40 +01:00
intel_iommu.c hw/i386/pc: Rename "bus" attribute to "pcibus" 2024-02-27 09:37:30 +01:00
intel_iommu_internal.h intel-iommu: Report interrupt remapping faults, fix return value 2023-10-22 05:18:17 -04:00
Kconfig hw/i386: Activate IOMMUFD for q35 machines 2023-12-19 19:03:38 +01:00
meson.build hw/i386: Rename kvmvapic.c -> vapic.c 2024-03-09 18:51:45 +01:00
microvm-dt.c hw/rtc/mc146818rtc: QOM'ify io_base offset 2022-06-11 11:44:50 +02:00
microvm-dt.h microvm: add device tree support. 2021-11-02 17:24:17 +01:00
microvm.c hw/i386/x86: Let ioapic_init_gsi() take parent as pointer 2024-02-27 09:37:30 +01:00
multiboot.c bulk: Rename TARGET_FMT_plx -> HWADDR_FMT_plx 2023-01-18 11:14:34 +01:00
multiboot.h target/i386: use DMA-enabled multiboot ROM for new-enough QEMU machine types 2021-11-02 15:57:27 +01:00
pc.c vl, pc: turn -no-fd-bootchk into a machine property 2024-02-28 00:23:36 +01:00
pc_piix.c hw/i386/pc: Have pc_init_isa() pass a NULL pci_type argument 2024-03-09 18:51:45 +01:00
pc_q35.c pc: q35: Bump max_cpus to 4096 vcpus 2024-03-12 17:56:55 -04:00
pc_sysfw.c hw/i386/pc_sysfw: Use qdev_is_realized() instead of QOM API 2024-02-22 12:47:40 +01:00
pc_sysfw_ovmf-stubs.c hw/i386: Introduce X86_FW_OVMF Kconfig symbol 2021-07-14 22:28:58 +02:00
pc_sysfw_ovmf.c hw/i386: Replace magic number with field length calculation 2022-03-06 05:08:23 -05:00
port92.c hw/i386/port92: Add missing 'hw/isa/isa.h' header 2024-02-20 20:34:21 +03:00
sgx-epc.c Mark remaining global TypeInfo instances as const 2022-02-21 13:30:20 +00:00
sgx-stub.c target/i386: the sgx_epc_get_section stub is reachable 2023-12-31 09:11:27 +01:00
sgx.c hw/i386/sgx: Use QDev API 2024-02-27 09:37:30 +01:00
trace-events vmmouse: replace DPRINTF with tracing 2023-09-12 10:37:01 +04:00
trace.h trace: switch position of headers to what Meson requires 2020-08-21 06:18:24 -04:00
vapic.c hw/i386: Rename kvmvapic.c -> vapic.c 2024-03-09 18:51:45 +01:00
vmmouse.c hw/i386: Constify VMState 2023-12-29 11:17:30 +11:00
vmport.c Do not include cpu.h if it's not really necessary 2021-05-02 17:24:51 +02:00
x86-iommu-stub.c hw/i386/pc: Remove x86_iommu_get_type() 2021-11-01 18:49:10 -04:00
x86-iommu.c hw/i386/pc: Rename "bus" attribute to "pcibus" 2024-02-27 09:37:30 +01:00
x86.c hw/i386/x86: Let ioapic_init_gsi() take parent as pointer 2024-02-27 09:37:30 +01:00