From: Oliver Upton <oliver.upton@linux.dev>
To: Anish Moorthy <amoorthy@google.com>
Cc: Sean Christopherson <seanjc@google.com>,
David Matlack <dmatlack@google.com>,
pbonzini@redhat.com, maz@kernel.org, jthoughton@google.com,
bgardon@google.com, ricarkol@google.com,
axelrasmussen@google.com, peterx@redhat.com, kvm@vger.kernel.org,
kvmarm@lists.linux.dev
Subject: Re: [PATCH v3 00/22] Improve scalability of KVM + userfaultfd live migration via annotated memory faults.
Date: Thu, 1 Jun 2023 22:43:24 +0000 [thread overview]
Message-ID: <ZHkfDCItA8HUxOG1@linux.dev> (raw)
In-Reply-To: <CAF7b7moF1URFC2yZXymPCwvDME8oJafCse12DSf0Rwo43JEDVg@mail.gmail.com>
On Tue, May 23, 2023 at 10:49:04AM -0700, Anish Moorthy wrote:
> On Wed, May 10, 2023 at 4:44 PM Anish Moorthy <amoorthy@google.com> wrote:
> >
> > On Wed, May 10, 2023 at 3:35 PM Sean Christopherson <seanjc@google.com> wrote:
> > >
> > > Yeah, when I speed read the series, several of the conversions stood out as being
> > > "wrong". My (potentially unstated) idea was that KVM would only signal
> > > KVM_EXIT_MEMORY_FAULT when the -EFAULT could be traced back to a user access,
> > > i.e. when the fault _might_ be resolvable by userspace.
> >
> > Sean, besides direct_map which other patches did you notice as needing
> > to be dropped/marked as unrecoverable errors?
>
> I tried going through on my own to try and identify the incorrect
> annotations: here's my read.
>
> Correct (or can easily be corrected)
> -----------------------------------------------
> - user_mem_abort
> Incorrect as is: the annotations in patch 19 are incorrect, as they
> cover an error-on-no-slot case and one more I don't fully understand:
That other case is a wart we endearingly refer to as MTE (Memory Tagging
Extension). You theoretically _could_ pop out an annotated exit here, as
userspace likely messed up the mapping (like PROT_MTE missing).
But I'm perfectly happy letting someone complain about it before we go
out of our way to annotate that one. So feel free to drop.
--
Thanks,
Oliver
prev parent reply other threads:[~2023-06-01 22:43 UTC|newest]
Thread overview: 105+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-12 21:34 [PATCH v3 00/22] Improve scalability of KVM + userfaultfd live migration via annotated memory faults Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 01/22] KVM: selftests: Allow many vCPUs and reader threads per UFFD in demand paging test Anish Moorthy
2023-04-19 13:51 ` Hoo Robert
2023-04-20 17:55 ` Anish Moorthy
2023-04-21 12:15 ` Robert Hoo
2023-04-21 16:21 ` Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 02/22] KVM: selftests: Use EPOLL in userfaultfd_util reader threads and signal errors via TEST_ASSERT Anish Moorthy
2023-04-19 13:36 ` Hoo Robert
2023-04-19 23:26 ` Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 03/22] KVM: Allow hva_pfn_fast() to resolve read-only faults Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 04/22] KVM: x86: Set vCPU exit reason to KVM_EXIT_UNKNOWN at the start of KVM_RUN Anish Moorthy
2023-05-02 17:17 ` Anish Moorthy
2023-05-02 18:51 ` Sean Christopherson
2023-05-02 19:49 ` Anish Moorthy
2023-05-02 20:41 ` Sean Christopherson
2023-05-02 21:46 ` Anish Moorthy
2023-05-02 22:31 ` Sean Christopherson
2023-04-12 21:34 ` [PATCH v3 05/22] KVM: Add KVM_CAP_MEMORY_FAULT_INFO Anish Moorthy
2023-04-19 13:57 ` Hoo Robert
2023-04-20 18:09 ` Anish Moorthy
2023-04-21 12:28 ` Robert Hoo
2023-06-01 19:52 ` Oliver Upton
2023-06-01 20:30 ` Anish Moorthy
2023-06-01 21:29 ` Oliver Upton
2023-07-04 10:10 ` Kautuk Consul
2023-04-12 21:34 ` [PATCH v3 06/22] KVM: Add docstrings to __kvm_write_guest_page() and __kvm_read_guest_page() Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 07/22] KVM: Annotate -EFAULTs from kvm_vcpu_write_guest_page() Anish Moorthy
2023-04-20 20:52 ` Peter Xu
2023-04-20 23:29 ` Anish Moorthy
2023-04-21 15:00 ` Peter Xu
2023-04-12 21:34 ` [PATCH v3 08/22] KVM: Annotate -EFAULTs from kvm_vcpu_read_guest_page() Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 09/22] KVM: Annotate -EFAULTs from kvm_vcpu_map() Anish Moorthy
2023-04-20 20:53 ` Peter Xu
2023-04-20 23:34 ` Anish Moorthy
2023-04-21 14:58 ` Peter Xu
2023-04-12 21:34 ` [PATCH v3 10/22] KVM: x86: Annotate -EFAULTs from kvm_mmu_page_fault() Anish Moorthy
2023-04-12 21:34 ` [PATCH v3 11/22] KVM: x86: Annotate -EFAULTs from setup_vmgexit_scratch() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 12/22] KVM: x86: Annotate -EFAULTs from kvm_handle_page_fault() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 13/22] KVM: x86: Annotate -EFAULTs from kvm_hv_get_assist_page() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 14/22] KVM: x86: Annotate -EFAULTs from kvm_pv_clock_pairing() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 15/22] KVM: x86: Annotate -EFAULTs from direct_map() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 16/22] KVM: x86: Annotate -EFAULTs from kvm_handle_error_pfn() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 17/22] KVM: Introduce KVM_CAP_ABSENT_MAPPING_FAULT without implementation Anish Moorthy
2023-04-19 14:00 ` Hoo Robert
2023-04-20 18:23 ` Anish Moorthy
2023-04-24 21:02 ` Sean Christopherson
2023-06-01 16:04 ` Oliver Upton
2023-06-01 18:19 ` Oliver Upton
2023-06-01 18:59 ` Sean Christopherson
2023-06-01 19:29 ` Oliver Upton
2023-06-01 19:34 ` Sean Christopherson
2023-04-12 21:35 ` [PATCH v3 18/22] KVM: x86: Implement KVM_CAP_ABSENT_MAPPING_FAULT Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 19/22] KVM: arm64: Annotate (some) -EFAULTs from user_mem_abort() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 20/22] KVM: arm64: Implement KVM_CAP_ABSENT_MAPPING_FAULT Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 21/22] KVM: selftests: Add memslot_flags parameter to memstress_create_vm() Anish Moorthy
2023-04-12 21:35 ` [PATCH v3 22/22] KVM: selftests: Handle memory fault exits in demand_paging_test Anish Moorthy
2023-04-19 14:09 ` Hoo Robert
2023-04-19 16:40 ` Anish Moorthy
2023-04-20 22:47 ` Anish Moorthy
2023-04-27 15:48 ` James Houghton
2023-05-01 18:01 ` Anish Moorthy
2023-04-19 19:55 ` [PATCH v3 00/22] Improve scalability of KVM + userfaultfd live migration via annotated memory faults Peter Xu
2023-04-19 20:15 ` Axel Rasmussen
2023-04-19 21:05 ` Peter Xu
2023-04-19 21:53 ` Anish Moorthy
2023-04-20 21:29 ` Peter Xu
2023-04-21 16:58 ` Anish Moorthy
2023-04-21 17:39 ` Nadav Amit
2023-04-24 17:54 ` Anish Moorthy
2023-04-24 19:44 ` Nadav Amit
2023-04-24 20:35 ` Sean Christopherson
2023-04-24 23:47 ` Nadav Amit
2023-04-25 0:26 ` Sean Christopherson
2023-04-25 0:37 ` Nadav Amit
2023-04-25 0:15 ` Anish Moorthy
2023-04-25 0:54 ` Nadav Amit
2023-04-27 16:38 ` James Houghton
2023-04-27 20:26 ` Peter Xu
2023-05-03 19:45 ` Anish Moorthy
2023-05-03 20:09 ` Sean Christopherson
2023-05-03 21:18 ` Peter Xu
2023-05-03 21:27 ` Peter Xu
2023-05-03 21:42 ` Sean Christopherson
2023-05-03 23:45 ` Peter Xu
2023-05-04 19:09 ` Peter Xu
2023-05-05 18:32 ` Anish Moorthy
2023-05-08 1:23 ` Peter Xu
2023-05-09 20:52 ` Anish Moorthy
2023-05-10 21:50 ` Peter Xu
2023-05-11 17:17 ` David Matlack
2023-05-11 17:33 ` Axel Rasmussen
2023-05-11 19:05 ` David Matlack
2023-05-11 19:45 ` Axel Rasmussen
2023-05-15 15:16 ` Peter Xu
2023-05-15 15:05 ` Peter Xu
2023-05-15 17:16 ` Anish Moorthy
2023-05-05 20:05 ` Nadav Amit
2023-05-08 1:12 ` Peter Xu
2023-04-20 23:42 ` Anish Moorthy
2023-05-09 22:19 ` David Matlack
2023-05-10 16:35 ` Anish Moorthy
2023-05-10 22:35 ` Sean Christopherson
2023-05-10 23:44 ` Anish Moorthy
2023-05-23 17:49 ` Anish Moorthy
2023-06-01 22:43 ` Oliver Upton [this message]
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