Re: [PATCH v5 0/8] KVM: x86: Add CMCI and UCNA emulation

Paolo Bonzini
2022-06-23T18:23:57Z

On 6/10/22 19:11, Jue Wang wrote:
> This patch series implement emulation for Corrected Machine Check
> Interrupt (CMCI) signaling and UnCorrectable No Action required (UCNA)
> error injection.
>
> UCNA errors signaled via CMCI allow a guest to be notified as soon as
> uncorrectable memory errors get detected by some background threads,
> e.g., threads that migrate guest memory across hosts or threads that
> constantly scan system memory for errors [1].
>
> Upon receiving UCNAs, guest kernel isolates the poisoned pages which may
> still be free, preventing future accesses that may cause fatal MCEs.
>
> 1. https://lore.kernel.org/linux-mm/8eceffc0-01e8-2a55-6eb9-b26faa9e3caf@intel.com/t/
>
>
> Patch 1-3 clean up KVM APIC LVT logic in preparation to adding APIC_LVTCMCI.
>
> Patch 4 adds APIC_LVTCMCI emulation.
>
> Patch 5 updates mce_banks to use array allocation api.
>
> Patch 6 adds emulation for MSR_IA32_MCx_CTL2 registers that provide per
> bank control of CMCI signaling.
>
> Patch 7 enables MCG_CMCI_P and handles injected UCNA errors.
>
> Patch 8 adds a KVM self test that validates UCNA injection and CMCI
> emulation.
>
> v5 changes
> - Incorporate feedback from David Matlack <dmatlack@google.com>
> - Rewrite the change log to be more concise and accurate.
> - Removes several duplicated checks in UCNA injection code.
> - Add test cases that validate CMCI emulation to self test.
>
> v4 changes
> - Incorporate feedback from David Matlack <dmatlack@google.com>
> - Rewrite the change logs to be more descriptive.
> - Add a KVM self test.
>
> v3 changes
> - Incorporate feedback from Sean Christopherson <seanjc@google.com>
> - Split clean up to KVM APIC LVT logic to 3 patches.
> - Put the clean up of mce_array allocation in a separate patch.
> - Base the MCi_CTL2 register emulation on Sean's clean up and fix
> series [2]
> - Fix bugs around MCi_CTL2 register offset validation and the free of
> mci_ctl2_banks array.
> - Rewrite the change log with more details in architectural information
> about CMCI, UCNA and MCG_CMCI_P.
> - Fix various comments and wrapping style.
>
> 2. https://lore.kernel.org/lkml/20220512222716.4112548-1-seanjc@google.com/T/
>
> v2 chanegs
> - Incorporate feedback from Sean Christopherson <seanjc@google.com>
> - Split the single patch into 4:
> 1). clean up KVM APIC LVT logic
> 2). add CMCI emulation to lapic
> 3). add emulation of MSR_IA32_MCx_CTL2
> 4). enable MCG_CMCI_P and handle injected UCNAs
> - Fix various style issues.
>
> Jue Wang (8):
> KVM: x86: Make APIC_VERSION capture only the magic 0x14UL.
> KVM: x86: Fill apic_lvt_mask with enums / explicit entries.
> KVM: x86: Add APIC_LVTx() macro.
> KVM: x86: Add Corrected Machine Check Interrupt (CMCI) emulation to
> lapic.
> KVM: x86: Use kcalloc to allocate the mce_banks array.
> KVM: x86: Add emulation for MSR_IA32_MCx_CTL2 MSRs.
> KVM: x86: Enable CMCI capability by default and handle injected UCNA
> errors
> KVM: selftests: Add a self test for CMCI and UCNA emulations.
>
> arch/x86/include/asm/kvm_host.h | 1 +
> arch/x86/kvm/lapic.c | 66 ++--
> arch/x86/kvm/lapic.h | 16 +-
> arch/x86/kvm/vmx/vmx.c | 1 +
> arch/x86/kvm/x86.c | 178 ++++++---
> tools/testing/selftests/kvm/.gitignore | 1 +
> tools/testing/selftests/kvm/Makefile | 1 +
> .../selftests/kvm/include/x86_64/apic.h | 1 +
> .../selftests/kvm/include/x86_64/mce.h | 25 ++
> .../selftests/kvm/include/x86_64/processor.h | 1 +
> .../selftests/kvm/lib/x86_64/processor.c | 2 +-
> .../kvm/x86_64/ucna_injection_test.c | 347 ++++++++++++++++++
> 12 files changed, 573 insertions(+), 67 deletions(-)
> create mode 100644 tools/testing/selftests/kvm/include/x86_64/mce.h
> create mode 100644 tools/testing/selftests/kvm/x86_64/ucna_injection_test.c
>

Queued, thanks. The test of course required some changes to adapt to
the new API.

Paolo