linux-kernel - [PATCH v3 00/28] KVM: x86: AVIC and local APIC fixes+cleanups

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Message-ID: <20220920233134.940511-1-seanjc@google.com>
Date:   Tue, 20 Sep 2022 23:31:06 +0000
From:   Sean Christopherson <seanjc@...gle.com>
To:     Sean Christopherson <seanjc@...gle.com>,
        Paolo Bonzini <pbonzini@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Alejandro Jimenez <alejandro.j.jimenez@...cle.com>,
        Suravee Suthikulpanit <suravee.suthikulpanit@....com>,
        Maxim Levitsky <mlevitsk@...hat.com>,
        Li RongQing <lirongqing@...du.com>
Subject: [PATCH v3 00/28] KVM: x86: AVIC and local APIC fixes+cleanups

TL;DR: KVM's AVIC and optimized APIC map code doesn't correctly handle
various edge cases that are architecturally legal(ish), but are unlikely
to occur in most real world scenarios.

I have tested this heavily with KUT, but I haven't booted Windows and
don't have access to x2AVIC, so additional testing would be much
appreciated.

v3:
  - Collect reviews. [Paolo]
  - Drop "partial" x2APIC inhibit and instead delete the memslot.
    [Maxim, Suravee]
  - Skip logical mode updates for x2APIC, which just reuses the
    phys_map with some clever logic. [Suravee]
  - Add a fix for "nodecode write" traps. [Alejandro]

v2:
  - https://lore.kernel.org/all/20220903002254.2411750-1-seanjc@google.com
  - Collect reviews. [Li, Maxim]
  - Disable only MMIO access when x2APIC is enabled (instead of disabling
    all of AVIC). [Maxim]
  - Inhibit AVIC when logical IDs are aliased. [Maxim]
  - Tweak name of set_virtual_apic_mode() hook. [Maxim]
  - Straight up revert logical ID fastpath mess. [Maxim]
  - Reword changelog about skipping vCPU during logical setup. [Maxim]
  - Fix LDR updates on AVIC. [Maxim?]
  - Fix a nasty ISR caching bug.
  - Flush TLB when activating AVIC.

v1: https://lore.kernel.org/all/20220831003506.4117148-1-seanjc@google.com

Sean Christopherson (27):
  KVM: x86: Blindly get current x2APIC reg value on "nodecode write"
    traps
  KVM: x86: Purge "highest ISR" cache when updating APICv state
  KVM: SVM: Flush the "current" TLB when activating AVIC
  KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid
    target
  KVM: x86: Don't inhibit APICv/AVIC if xAPIC ID mismatch is due to
    32-bit ID
  KVM: x86: Move APIC access page helper to common x86 code
  KVM: x86: Inhibit APIC memslot if x2APIC and AVIC are enabled
  KVM: SVM: Don't put/load AVIC when setting virtual APIC mode
  KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean
  KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick
  Revert "KVM: SVM: Use target APIC ID to complete x2AVIC IRQs when
    possible"
  KVM: SVM: Document that vCPU ID == APIC ID in AVIC kick fastpatch
  KVM: SVM: Add helper to perform final AVIC "kick" of single vCPU
  KVM: x86: Explicitly skip optimized logical map setup if vCPU's LDR==0
  KVM: x86: Explicitly track all possibilities for APIC map's logical
    modes
  KVM: x86: Skip redundant x2APIC logical mode optimized cluster setup
  KVM: x86: Disable APIC logical map if logical ID covers multiple MDAs
  KVM: x86: Disable APIC logical map if vCPUs are aliased in logical
    mode
  KVM: x86: Honor architectural behavior for aliased 8-bit APIC IDs
  KVM: x86: Inhibit APICv/AVIC if the optimized physical map is disabled
  KVM: SVM: Inhibit AVIC if vCPUs are aliased in logical mode
  KVM: SVM: Always update local APIC on writes to logical dest register
  KVM: SVM: Update svm->ldr_reg cache even if LDR is "bad"
  KVM: SVM: Require logical ID to be power-of-2 for AVIC entry
  KVM: SVM: Handle multiple logical targets in AVIC kick fastpath
  KVM: SVM: Ignore writes to Remote Read Data on AVIC write traps
  Revert "KVM: SVM: Do not throw warning when calling avic_vcpu_load on
    a running vcpu"

Suravee Suthikulpanit (1):
  KVM: SVM: Fix x2APIC Logical ID calculation for
    avic_kick_target_vcpus_fast

 Documentation/virt/kvm/x86/errata.rst |  11 +
 arch/x86/include/asm/kvm_host.h       |  51 +++-
 arch/x86/kvm/lapic.c                  | 224 +++++++++++++---
 arch/x86/kvm/lapic.h                  |   2 +
 arch/x86/kvm/svm/avic.c               | 363 ++++++++++++--------------
 arch/x86/kvm/svm/svm.c                |   4 +-
 arch/x86/kvm/svm/svm.h                |  11 +-
 arch/x86/kvm/vmx/vmx.c                |  36 +--
 arch/x86/kvm/x86.c                    |   7 +
 9 files changed, 426 insertions(+), 283 deletions(-)


base-commit: 372d07084593dc7a399bf9bee815711b1fb1bcf2
-- 
2.37.3.968.ga6b4b080e4-goog