From: Paolo Bonzini <pbonzini@redhat.com>
To: Ben Gardon <bgardon@google.com>,
linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: Peter Xu <peterx@redhat.com>,
Sean Christopherson <seanjc@google.com>,
David Matlack <dmatlack@google.com>,
Jim Mattson <jmattson@google.com>,
David Dunn <daviddunn@google.com>,
Jing Zhang <jingzhangos@google.com>,
Junaid Shahid <junaids@google.com>
Subject: Re: [PATCH v2 0/9] KVM: x86/MMU: Optimize disabling dirty logging
Date: Fri, 25 Mar 2022 13:00:27 +0100 [thread overview]
Message-ID: <dba0ecc8-90ae-975f-7a27-3049d6951ba0@redhat.com> (raw)
In-Reply-To: <20220321224358.1305530-1-bgardon@google.com>
On 3/21/22 23:43, Ben Gardon wrote:
> Currently disabling dirty logging with the TDP MMU is extremely slow.
> On a 96 vCPU / 96G VM it takes ~256 seconds to disable dirty logging
> with the TDP MMU, as opposed to ~4 seconds with the legacy MMU. This
> series optimizes TLB flushes and introduces in-place large page
> promotion, to bring the disable dirty log time down to ~3 seconds.
>
> Testing:
> Ran KVM selftests and kvm-unit-tests on an Intel Haswell. This
> series introduced no new failures.
Thanks, looks good. The one change I'd make is to just place the
outcome of build_tdp_shadow_zero_bits_mask() in a global (say
tdp_shadow_zero_check) at kvm_configure_mmu() time. The
tdp_max_root_level works as a conservative choice for the second
argument of build_tdp_shadow_zero_bits_mask().
No need to do anything though, I'll handle this later in 5.19 time (and
first merge my changes that factor out the constant part of
vcpu->arch.root_mmu initialization, since this is part of the same ideas).
Paolo
next prev parent reply other threads:[~2022-03-25 12:00 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-21 22:43 [PATCH v2 0/9] KVM: x86/MMU: Optimize disabling dirty logging Ben Gardon
2022-03-21 22:43 ` [PATCH v2 1/9] KVM: x86/mmu: Move implementation of make_spte to a helper Ben Gardon
2022-03-21 22:43 ` [PATCH v2 2/9] KVM: x86/mmu: Factor mt_mask out of __make_spte Ben Gardon
2022-03-21 22:43 ` [PATCH v2 3/9] KVM: x86/mmu: Factor shadow_zero_check " Ben Gardon
2022-04-12 15:52 ` Sean Christopherson
2022-03-21 22:43 ` [PATCH v2 4/9] KVM: x86/mmu: Replace vcpu argument with kvm pointer in make_spte Ben Gardon
2022-03-21 22:43 ` [PATCH v2 5/9] KVM: x86/mmu: Factor out the meat of reset_tdp_shadow_zero_bits_mask Ben Gardon
2022-04-12 15:46 ` Sean Christopherson
2022-04-21 18:50 ` Ben Gardon
2022-04-21 19:09 ` Ben Gardon
2022-03-21 22:43 ` [PATCH v2 6/9] KVM: x86/mmu: Factor out part of vmx_get_mt_mask which does not depend on vcpu Ben Gardon
2022-03-28 18:04 ` David Matlack
2022-03-21 22:43 ` [PATCH v2 7/9] KVM: x86/mmu: Add try_get_mt_mask to x86_ops Ben Gardon
2022-04-11 23:00 ` Sean Christopherson
2022-04-11 23:24 ` Ben Gardon
2022-04-11 23:33 ` Sean Christopherson
2022-04-12 19:30 ` Sean Christopherson
2022-03-21 22:43 ` [PATCH v2 8/9] KVM: x86/mmu: Make kvm_is_mmio_pfn usable outside of spte.c Ben Gardon
2022-04-12 19:39 ` Sean Christopherson
2022-03-21 22:43 ` [PATCH v2 9/9] KVM: x86/mmu: Promote pages in-place when disabling dirty logging Ben Gardon
2022-03-28 17:45 ` David Matlack
2022-03-28 18:07 ` Ben Gardon
2022-03-28 18:20 ` David Matlack
2022-07-12 23:21 ` Sean Christopherson
2022-07-13 16:20 ` Sean Christopherson
2022-03-28 18:21 ` David Matlack
2022-04-12 16:43 ` Sean Christopherson
2022-04-25 18:09 ` Ben Gardon
2022-03-25 12:00 ` Paolo Bonzini [this message]
2022-07-12 1:37 ` [PATCH v2 0/9] KVM: x86/MMU: Optimize " Sean Christopherson
2022-07-14 7:55 ` Paolo Bonzini
2022-07-14 15:27 ` Sean Christopherson
2022-03-28 17:49 ` David Matlack
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