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* [PATCH v2 0/6] x86/kvm: add boot parameters for max vcpu configs
@ 2021-09-03 13:08 Juergen Gross
  2021-09-03 13:08 ` [PATCH v2 1/6] x86/kvm: remove non-x86 stuff from arch/x86/kvm/ioapic.h Juergen Gross
                   ` (5 more replies)
  0 siblings, 6 replies; 23+ messages in thread
From: Juergen Gross @ 2021-09-03 13:08 UTC (permalink / raw)
  To: kvm, x86, linux-kernel, linux-doc, linux-arm-kernel
  Cc: maz, ehabkost, Juergen Gross, Paolo Bonzini, Sean Christopherson,
	Vitaly Kuznetsov, Wanpeng Li, Jim Mattson, Joerg Roedel,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, H. Peter Anvin,
	Jonathan Corbet, James Morse, Alexandru Elisei, Suzuki K Poulose,
	Catalin Marinas, Will Deacon, kvmarm

In order to be able to have a single kernel for supporting even huge
numbers of vcpus per guest some arrays should be sized dynamically.

The easiest way to do that is to add boot parameters for the maximum
number of vcpus and to calculate the maximum vcpu-id from that using
either the host topology or a topology hint via another boot parameter.

This patch series is doing that for x86. The same scheme can be easily
adapted to other architectures, but I don't want to do that in the
first iteration.

In the long term I'd suggest to have a per-guest setting of the two
parameters allowing to spare some memory for smaller guests. OTOH this
would require new ioctl()s and respective qemu modifications, so I let
those away for now.

I've tested the series not to break normal guest operation and the new
parameters to be effective on x86. For Arm64 I did a compile test only.

Changes in V2:
- removed old patch 1, as already applied
- patch 1 (old patch 2) only for reference, as the patch is already in
  the kvm tree
- switch patch 2 (old patch 3) to calculate vcpu-id
- added patch 4

Juergen Gross (6):
  x86/kvm: remove non-x86 stuff from arch/x86/kvm/ioapic.h
  x86/kvm: add boot parameter for adding vcpu-id bits
  x86/kvm: introduce per cpu vcpu masks
  kvm: use kvfree() in kvm_arch_free_vm()
  kvm: allocate vcpu pointer array separately
  x86/kvm: add boot parameter for setting max number of vcpus per guest

 .../admin-guide/kernel-parameters.txt         | 25 ++++++
 arch/arm64/include/asm/kvm_host.h             |  1 -
 arch/arm64/kvm/arm.c                          | 23 ++++--
 arch/x86/include/asm/kvm_host.h               | 26 +++++--
 arch/x86/kvm/hyperv.c                         | 25 ++++--
 arch/x86/kvm/ioapic.c                         | 12 ++-
 arch/x86/kvm/ioapic.h                         |  8 +-
 arch/x86/kvm/irq_comm.c                       |  9 ++-
 arch/x86/kvm/x86.c                            | 78 ++++++++++++++++++-
 include/linux/kvm_host.h                      | 26 ++++++-
 10 files changed, 198 insertions(+), 35 deletions(-)

-- 
2.26.2


^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2021-09-28 16:48 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-09-03 13:08 [PATCH v2 0/6] x86/kvm: add boot parameters for max vcpu configs Juergen Gross
2021-09-03 13:08 ` [PATCH v2 1/6] x86/kvm: remove non-x86 stuff from arch/x86/kvm/ioapic.h Juergen Gross
2021-09-03 13:08 ` [PATCH v2 2/6] x86/kvm: add boot parameter for adding vcpu-id bits Juergen Gross
2021-09-03 13:43   ` Vitaly Kuznetsov
2021-09-03 13:53     ` Juergen Gross
2021-09-03 19:48   ` Eduardo Habkost
2021-09-06  4:46     ` Juergen Gross
2021-09-28 16:41   ` Paolo Bonzini
2021-09-03 13:08 ` [PATCH v2 3/6] x86/kvm: introduce per cpu vcpu masks Juergen Gross
2021-09-03 16:05   ` Eduardo Habkost
2021-09-06  4:34     ` Juergen Gross
2021-09-07 18:34   ` Eduardo Habkost
2021-09-08  8:41     ` Vitaly Kuznetsov
2021-09-03 13:08 ` [PATCH v2 4/6] kvm: use kvfree() in kvm_arch_free_vm() Juergen Gross
2021-09-28 16:48   ` Paolo Bonzini
2021-09-03 13:08 ` [PATCH v2 5/6] kvm: allocate vcpu pointer array separately Juergen Gross
2021-09-03 14:41   ` Marc Zyngier
2021-09-06  4:33     ` Juergen Gross
2021-09-06  9:46       ` Marc Zyngier
2021-09-09 20:28         ` Sean Christopherson
2021-09-03 13:08 ` [PATCH v2 6/6] x86/kvm: add boot parameter for setting max number of vcpus per guest Juergen Gross
2021-09-06  0:45   ` Yao Yuan
2021-09-06  4:47     ` Juergen Gross

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