[PATCH v5 00/33] KVM: x86: AVIC and local APIC fixes+cleanups

Sean Christopherson
2023-01-06T01:13:35Z

Paolo,

This is a wholesale (and hopefully a drop-in) replacement for the patches
in `kvm-lapic-fix-and-cleanup`. The changes for " KVM: x86: Inhibit APIC
memslot if x2APIC and AVIC are enabled" in v5 are relatively minor, but it
led to multiple conflicts in later patches, i.e. a patch-to-be-squashed
wasn't going to work. Let me know if you've already done a lot of
massaging on your side, shouldn't be too difficult to generate patches to
go on top.

The first half or so patches fix semi-urgent, real-world relevant APICv
and AVIC bugs.

The second half fixes a variety of AVIC and optimized APIC map bugs
where KVM doesn't play nice with various edge cases that are
architecturally legal(ish), but are unlikely to occur in most real world
scenarios

v5:
- Fix even more bugs! [Greg]
- Collect reviews. [Maxim]
- Don't use an inhibit flag for hybrid AVIC. [Maxim]
- Fix an LDR cluster calc goof in the AVIC code. [Maxim]
- Drop a redundant "ldr == 0" check. [Maxim]
- Add helpers for logical vs. physical optimized map calcs. [Maxim]

v4:
- https://lore.kernel.org/all/20221001005915.2041642-1-seanjc@google.com
- Fix more bugs! [Alejandro]
- Delete APIC memslot to inhibit xAVIC acceleration when x2APIC is
enabled on AMD/SVM instead of using a "partial" inihbit. [Maxim]

v3:
- https://lore.kernel.org/all/20220920233134.940511-1-seanjc@google.com
- 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

Greg Edwards (1):
KVM: x86: Allow APICv APIC ID inhibit to be cleared

Sean Christopherson (31):
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 on xAPIC ID "change" if APIC is
disabled
KVM: x86: Don't inhibit APICv/AVIC if xAPIC ID mismatch is due to
32-bit ID
KVM: SVM: Don't put/load AVIC when setting virtual APIC mode
KVM: x86: Handle APICv updates for APIC "mode" changes via request
KVM: x86: Move APIC access page helper to common x86 code
KVM: x86: Inhibit APIC memslot if x2APIC and AVIC are enabled
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"
KVM: x86: Track required APICv inhibits with variable, not callback
KVM: x86: Add helpers to recalc physical vs. logical optimized APIC
maps

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-x86-ops.h | 1 -
arch/x86/include/asm/kvm_host.h | 52 +++-
arch/x86/kvm/lapic.c | 319 +++++++++++++++++-----
arch/x86/kvm/lapic.h | 2 +
arch/x86/kvm/svm/avic.c | 372 ++++++++++++--------------
arch/x86/kvm/svm/nested.c | 2 +-
arch/x86/kvm/svm/svm.c | 8 +-
arch/x86/kvm/svm/svm.h | 27 +-
arch/x86/kvm/vmx/vmx.c | 58 +---
arch/x86/kvm/x86.c | 29 +-
11 files changed, 524 insertions(+), 357 deletions(-)

base-commit: c04ec04c0d15a51aa33660be175ed978beb8de0c
--
2.39.0.314.g84b9a713c41-goog