From: Sean Christopherson <seanjc@google.com>
To: Sean Christopherson <seanjc@google.com>,
oliver.upton@linux.dev, maz@kernel.org, kvm@vger.kernel.org,
kvmarm@lists.linux.dev, Anish Moorthy <amoorthy@google.com>
Cc: robert.hoo.linux@gmail.com, jthoughton@google.com,
dmatlack@google.com, axelrasmussen@google.com,
peterx@redhat.com, nadav.amit@gmail.com,
isaku.yamahata@gmail.com, kconsul@linux.vnet.ibm.com
Subject: Re: [PATCH v7 00/14] Improve KVM + userfaultfd performance via KVM_EXIT_MEMORY_FAULTs on stage-2 faults
Date: Tue, 9 Apr 2024 17:19:46 -0700 [thread overview]
Message-ID: <171270376781.1586271.10159724514702496320.b4-ty@google.com> (raw)
In-Reply-To: <20240215235405.368539-1-amoorthy@google.com>
On Thu, 15 Feb 2024 23:53:51 +0000, Anish Moorthy wrote:
> This series adds an option to cause stage-2 fault handlers to
> KVM_MEMORY_FAULT_EXIT when they would otherwise be required to fault in
> the userspace mappings. Doing so allows userspace to receive stage-2
> faults directly from KVM_RUN instead of through userfaultfd, which
> suffers from serious contention issues as the number of vCPUs scales.
>
> Support for the new option (KVM_CAP_EXIT_ON_MISSING) is added to the
> demand_paging_test, which demonstrates the scalability improvements:
> the following data was collected using [2] on an x86 machine with 256
> cores.
>
> [...]
Applied 1,2, and 4 to kvm-x86 generic, and 10-12 to kvm-x86 selftests.
I skipped all KVM_CAP_EXIT_ON_MISSING as per our decision to hold off until we
see the KVM userfault stuff. I skipped the docs patch because it would require
more massaging than I wanted to do when applying. And lastly, I skipped the
"Add memslot_flags parameter to memstress_create_vm()" patch because it would be
dead code without the exit-on-missing usage.
Please take a look at the selftests commits in particular, as I did a decent
amount of massaging when applying.
Thanks!
[01/14] KVM: Clarify meaning of hva_to_pfn()'s 'atomic' parameter
https://github.com/kvm-x86/linux/commit/ed2f049fc144
[02/14] KVM: Add function comments for __kvm_read/write_guest_page()
https://github.com/kvm-x86/linux/commit/a3bd2f7ead6d
...
[04/14] KVM: Simplify error handling in __gfn_to_pfn_memslot()
https://github.com/kvm-x86/linux/commit/f588557ac4ac
...
[10/14] KVM: selftests: Report per-vcpu demand paging rate from demand paging test
https://github.com/kvm-x86/linux/commit/2ca76c12c48b
[11/14] KVM: selftests: Allow many vCPUs and reader threads per UFFD in demand paging test
https://github.com/kvm-x86/linux/commit/df4ec5aada9d
[12/14] KVM: selftests: Use EPOLL in userfaultfd_util reader threads
https://github.com/kvm-x86/linux/commit/0cba6442e9e2
--
https://github.com/kvm-x86/linux/tree/next
next prev parent reply other threads:[~2024-04-10 0:21 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-15 23:53 [PATCH v7 00/14] Improve KVM + userfaultfd performance via KVM_EXIT_MEMORY_FAULTs on stage-2 faults Anish Moorthy
2024-02-15 23:53 ` [PATCH v7 01/14] KVM: Clarify meaning of hva_to_pfn()'s 'atomic' parameter Anish Moorthy
2024-02-15 23:53 ` [PATCH v7 02/14] KVM: Add function comments for __kvm_read/write_guest_page() Anish Moorthy
2024-02-15 23:53 ` [PATCH v7 03/14] KVM: Documentation: Make note of the KVM_MEM_GUEST_MEMFD memslot flag Anish Moorthy
2024-04-09 22:47 ` Sean Christopherson
2024-02-15 23:53 ` [PATCH v7 04/14] KVM: Simplify error handling in __gfn_to_pfn_memslot() Anish Moorthy
2024-04-09 22:44 ` Sean Christopherson
2024-02-15 23:53 ` [PATCH v7 05/14] KVM: Define and communicate KVM_EXIT_MEMORY_FAULT RWX flags to userspace Anish Moorthy
2024-02-15 23:53 ` [PATCH v7 06/14] KVM: Add memslot flag to let userspace force an exit on missing hva mappings Anish Moorthy
2024-03-08 22:07 ` Sean Christopherson
2024-03-09 0:46 ` David Matlack
2024-03-11 4:45 ` Oliver Upton
2024-03-11 16:20 ` David Matlack
2024-03-11 16:36 ` Sean Christopherson
2024-03-11 17:08 ` Anish Moorthy
2024-03-11 21:21 ` Oliver Upton
2024-02-15 23:53 ` [PATCH v7 07/14] KVM: x86: Enable KVM_CAP_EXIT_ON_MISSING and annotate EFAULTs from stage-2 fault handler Anish Moorthy
2024-02-15 23:53 ` [PATCH v7 08/14] KVM: arm64: Enable KVM_CAP_MEMORY_FAULT_INFO and annotate fault in the " Anish Moorthy
2024-03-04 20:00 ` Oliver Upton
2024-03-04 20:10 ` Oliver Upton
2024-03-04 20:32 ` Sean Christopherson
2024-03-04 21:03 ` Oliver Upton
2024-03-04 22:49 ` Sean Christopherson
2024-03-05 1:01 ` Oliver Upton
2024-03-05 15:39 ` Sean Christopherson
2024-02-15 23:54 ` [PATCH v7 09/14] KVM: arm64: Implement and advertise KVM_CAP_EXIT_ON_MISSING Anish Moorthy
2024-02-15 23:54 ` [PATCH v7 10/14] KVM: selftests: Report per-vcpu demand paging rate from demand paging test Anish Moorthy
2024-04-09 22:49 ` Sean Christopherson
2024-02-15 23:54 ` [PATCH v7 11/14] KVM: selftests: Allow many vCPUs and reader threads per UFFD in " Anish Moorthy
2024-04-09 22:58 ` Sean Christopherson
2024-02-15 23:54 ` [PATCH v7 12/14] KVM: selftests: Use EPOLL in userfaultfd_util reader threads and signal errors via TEST_ASSERT Anish Moorthy
2024-02-15 23:54 ` [PATCH v7 13/14] KVM: selftests: Add memslot_flags parameter to memstress_create_vm() Anish Moorthy
2024-02-15 23:54 ` [PATCH v7 14/14] KVM: selftests: Handle memory fault exits in demand_paging_test Anish Moorthy
2024-02-16 7:36 ` [PATCH v7 00/14] Improve KVM + userfaultfd performance via KVM_EXIT_MEMORY_FAULTs on stage-2 faults Gupta, Pankaj
2024-02-16 20:00 ` Anish Moorthy
2024-02-16 23:40 ` Axel Rasmussen
2024-02-21 7:35 ` Gupta, Pankaj
2024-04-10 0:19 ` Sean Christopherson [this message]
2024-05-07 17:38 ` Anish Moorthy
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