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From: Marc Zyngier <maz@kernel.org>
To: kvm@vger.kernel.org, linux-mips@vger.kernel.org,
	kvmarm@lists.cs.columbia.edu, linuxppc-dev@lists.ozlabs.org
Cc: Juergen Gross <jgross@suse.com>,
	Huacai Chen <chenhuacai@kernel.org>,
	Janosch Frank <frankja@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Sean Christopherson <seanjc@google.com>,
	Anup Patel <anup.patel@wdc.com>,
	David Hildenbrand <david@redhat.com>,
	Nicholas Piggin <npiggin@gmail.com>,
	Atish Patra <atish.patra@wdc.com>,
	Aleksandar Markovic <aleksandar.qemu.devel@gmail.com>,
	Paul Mackerras <paulus@samba.org>,
	James Morse <james.morse@arm.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	kernel-team@android.com,
	Claudio Imbrenda <imbrenda@linux.ibm.com>,
	Alexandru Elisei <alexandru.elisei@arm.com>,
	Suzuki K Poulose <suzuki.poulose@arm.com>
Subject: [PATCH 0/5] KVM: Turn the vcpu array into an xarray
Date: Fri,  5 Nov 2021 19:20:56 +0000	[thread overview]
Message-ID: <20211105192101.3862492-1-maz@kernel.org> (raw)

The kvm structure is pretty large. A large portion of it is the vcpu
array, which is 4kB on x86_64 and arm64 as they deal with 512 vcpu
VMs. Of course, hardly anyone runs VMs this big, so this is often a
net waste of memory and cache locality.

A possible approach is to turn the fixed-size array into an xarray,
which results in a net code deletion after a bit of cleanup.

This series is on top of the current linux/master as it touches the
RISC-V implementation. Only tested on arm64.

Marc Zyngier (5):
  KVM: Move wiping of the kvm->vcpus array to common code
  KVM: mips: Use kvm_get_vcpu() instead of open-coded access
  KVM: s390: Use kvm_get_vcpu() instead of open-coded access
  KVM: x86: Use kvm_get_vcpu() instead of open-coded access
  KVM: Convert the kvm->vcpus array to a xarray

 arch/arm64/kvm/arm.c           | 10 +---------
 arch/mips/kvm/loongson_ipi.c   |  4 ++--
 arch/mips/kvm/mips.c           | 23 ++---------------------
 arch/powerpc/kvm/powerpc.c     | 10 +---------
 arch/riscv/kvm/vm.c            | 10 +---------
 arch/s390/kvm/kvm-s390.c       | 26 ++++++--------------------
 arch/x86/kvm/vmx/posted_intr.c |  2 +-
 arch/x86/kvm/x86.c             |  9 +--------
 include/linux/kvm_host.h       |  7 ++++---
 virt/kvm/kvm_main.c            | 33 ++++++++++++++++++++++++++-------
 10 files changed, 45 insertions(+), 89 deletions(-)

-- 
2.30.2


             reply	other threads:[~2021-11-05 19:22 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-11-05 19:20 Marc Zyngier [this message]
2021-11-05 19:20 ` [PATCH 1/5] KVM: Move wiping of the kvm->vcpus array to common code Marc Zyngier
2021-11-05 20:12   ` Sean Christopherson
2021-11-06 11:17     ` Marc Zyngier
2021-11-16 13:49       ` Paolo Bonzini
2021-11-08 12:12   ` Claudio Imbrenda
2021-11-05 19:20 ` [PATCH 2/5] KVM: mips: Use kvm_get_vcpu() instead of open-coded access Marc Zyngier
2021-11-06 15:56   ` Philippe Mathieu-Daudé
2021-11-05 19:20 ` [PATCH 3/5] KVM: s390: " Marc Zyngier
2021-11-08 12:13   ` Claudio Imbrenda
2021-11-05 19:21 ` [PATCH 4/5] KVM: x86: " Marc Zyngier
2021-11-05 20:03   ` Sean Christopherson
2021-11-16 14:04     ` Paolo Bonzini
2021-11-16 16:07       ` Sean Christopherson
2021-11-16 16:48         ` Paolo Bonzini
2021-11-05 19:21 ` [PATCH 5/5] KVM: Convert the kvm->vcpus array to a xarray Marc Zyngier
2021-11-05 20:21   ` Sean Christopherson
2021-11-06 11:48     ` Marc Zyngier
2021-11-08  8:23       ` Marc Zyngier
2021-11-16 14:13 ` [PATCH 0/5] KVM: Turn the vcpu array into an xarray Juergen Gross
2021-11-16 14:21   ` Paolo Bonzini
2021-11-16 14:54     ` Juergen Gross
2021-11-16 15:03 ` Paolo Bonzini
2021-11-16 15:40   ` Marc Zyngier

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