Bug 42760

Summary:	Raise number of supported CPUs
Product:	Sisyphus	Reporter:	Vitaly Chikunov <vt>
Component:	qemu	Assignee:	Alexey Shabalin <shaba>
Status:	NEW ---	QA Contact:	qa-sisyphus
Severity:	normal
Priority:	P5	CC:	glebfm, iv, shaba, vt
Version:	unstable
Hardware:	x86
OS:	Linux
See Also:	https://bugzilla.altlinux.org/show_bug.cgi?id=42694

Description Vitaly Chikunov 2022-05-13 22:58:22 MSK

+ qemu-system-x86_64 -smp cores=1111 ...
qemu-system-x86_64: Invalid SMP CPUs 1111. The max CPUs supported by machine 'pc-i440fx-6.2' is 255

+ qemu-system-x86_64 -M q35 -smp cores=1111 ...
qemu-system-x86_64: Invalid SMP CPUs 1111. The max CPUs supported by machine 'pc-q35-6.2' is 288

Comment 1 Vitaly Chikunov 2022-05-13 23:07:06 MSK

Возможно, больше 1024 поднимать не имеет смысла так как, на x86-64 есть ещё не изменяемый лимит

  #define KVM_MAX_VCPUS 1024

Comment 2 Vitaly Chikunov 2022-05-13 23:21:01 MSK

https://access.redhat.com/articles/rhel-kvm-limits
Intel 64 and AMD64: Red Hat Enterprise Linux 8 Server with KVM
Maximum number of virtual CPUs in virtualized guest 384

https://access.redhat.com/articles/906543
Virtual Machine Maximums:
710 for RHV 4.4 (710 for Q35 machines, 240 for PC machines)

Host Maximums:
Logical CPU cores or threads: 768