From: Christian Borntraeger <borntraeger@de.ibm.com>
To: "Sean Christopherson" <sean.j.christopherson@intel.com>,
"James Hogan" <jhogan@kernel.org>,
"Paul Mackerras" <paulus@ozlabs.org>,
"Janosch Frank" <frankja@linux.ibm.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Marc Zyngier" <maz@kernel.org>
Cc: David Hildenbrand <david@redhat.com>,
Cornelia Huck <cohuck@redhat.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>,
James Morse <james.morse@arm.com>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
linux-mips@vger.kernel.org, kvm-ppc@vger.kernel.org,
kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
Christoffer Dall <christoffer.dall@arm.com>
Subject: Re: [PATCH v3 00/15] KVM: Dynamically size memslot arrays
Date: Mon, 16 Dec 2019 09:25:24 +0100 [thread overview]
Message-ID: <ca928a38-4bc0-88cd-dc70-62aec8695c77@de.ibm.com> (raw)
In-Reply-To: <20191213200151.GF31552@linux.intel.com>
On 13.12.19 21:01, Sean Christopherson wrote:
> On Tue, Dec 03, 2019 at 02:14:33PM -0800, Sean Christopherson wrote:
>> On Thu, Oct 24, 2019 at 04:07:29PM -0700, Sean Christopherson wrote:
>>> The end goal of this series is to dynamically size the memslot array so
>>> that KVM allocates memory based on the number of memslots in use, as
>>> opposed to unconditionally allocating memory for the maximum number of
>>> memslots. On x86, each memslot consumes 88 bytes, and so with 2 address
>>> spaces of 512 memslots, each VM consumes ~90k bytes for the memslots.
>>> E.g. given a VM that uses a total of 30 memslots, dynamic sizing reduces
>>> the memory footprint from 90k to ~2.6k bytes.
>>>
>>> The changes required to support dynamic sizing are relatively small,
>>> e.g. are essentially contained in patches 14/15 and 15/15. Patches 1-13
>>> clean up the memslot code, which has gotten quite crusty, especially
>>> __kvm_set_memory_region(). The clean up is likely not strictly necessary
>>> to switch to dynamic sizing, but I didn't have a remotely reasonable
>>> level of confidence in the correctness of the dynamic sizing without first
>>> doing the clean up.
>>>
>>> Christoffer, I added your Tested-by to the patches that I was confident
>>> would be fully tested based on the desription of what you tested. Let me
>>> know if you disagree with any of 'em.
>>>
>>> v3:
>>> - Fix build errors on PPC and MIPS due to missed params during
>>> refactoring [kbuild test robot].
>>> - Rename the helpers for update_memslots() and add comments describing
>>> the new algorithm and how it interacts with searching [Paolo].
>>> - Remove the unnecessary and obnoxious warning regarding memslots being
>>> a flexible array [Paolo].
>>> - Fix typos in the changelog of patch 09/15 [Christoffer].
>>> - Collect tags [Christoffer].
>>>
>>> v2:
>>> - Split "Drop kvm_arch_create_memslot()" into three patches to move
>>> minor functional changes to standalone patches [Janosch].
>>> - Rebase to latest kvm/queue (f0574a1cea5b, "KVM: x86: fix ...")
>>> - Collect an Acked-by and a Reviewed-by
>>
>> Paolo, do you want me to rebase this to the latest kvm/queue?
>
> Ping.
>
> Applies cleanly on the current kvm/queue and nothing caught fire in
> testing (though I only re-tested the series as a whole).
Do you have the latest version somewhere on a branch? The version on the
list no longer applies cleanly.
next prev parent reply other threads:[~2019-12-16 8:25 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-24 23:07 [PATCH v3 00/15] KVM: Dynamically size memslot arrays Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 01/15] KVM: Reinstall old memslots if arch preparation fails Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 02/15] KVM: Don't free new memslot if allocation of said memslot fails Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 03/15] KVM: PPC: Move memslot memory allocation into prepare_memory_region() Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 04/15] KVM: x86: Allocate memslot resources during prepare_memory_region() Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 05/15] KVM: Drop kvm_arch_create_memslot() Sean Christopherson
2019-12-16 8:04 ` Christian Borntraeger
2019-10-24 23:07 ` [PATCH v3 06/15] KVM: Explicitly free allocated-but-unused dirty bitmap Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 07/15] KVM: Refactor error handling for setting memory region Sean Christopherson
2019-12-05 9:49 ` Philippe Mathieu-Daudé
2019-10-24 23:07 ` [PATCH v3 08/15] KVM: Move setting of memslot into helper routine Sean Christopherson
2019-12-05 9:54 ` Philippe Mathieu-Daudé
2019-10-24 23:07 ` [PATCH v3 09/15] KVM: Move memslot deletion to helper function Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 10/15] KVM: Simplify kvm_free_memslot() and all its descendents Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 11/15] KVM: Clean up local variable usage in __kvm_set_memory_region() Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 12/15] KVM: Provide common implementation for generic dirty log functions Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 13/15] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log() Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 14/15] KVM: Terminate memslot walks via used_slots Sean Christopherson
2019-10-24 23:07 ` [PATCH v3 15/15] KVM: Dynamically size memslot array based on number of used slots Sean Christopherson
2019-10-25 13:28 ` [PATCH v3 00/15] KVM: Dynamically size memslot arrays Christoffer Dall
2019-10-25 16:30 ` Marc Zyngier
2019-12-03 22:14 ` Sean Christopherson
2019-12-13 20:01 ` Sean Christopherson
2019-12-16 8:25 ` Christian Borntraeger [this message]
2019-12-17 17:55 ` Sean Christopherson
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