This started as a simple cleanup, and then I made the mistake of writing
a test to verify my changes to AVIC's handling of logical mode interrupts.
TL;DR: KVM's AVIC and optimized APIC map code doesn't correctly handle
various edge cases that are 100% architecturally legal, but are unlikely
to occur in most real world scenarios.
There are a variety of other fixes, but most of them are non-fatal.
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.
I'll post my KVM-Unit-Tests later this week (need to write quite a few
changelogs). The gist of the tests is to target multiple and non-existent
vCPUs in logical mode, and to target multiple vCPUs in physical mode by
aliasing vCPU0 and vCPU1 to the same physical ID.
Sean Christopherson (19):
KVM: SVM: Process ICR on AVIC IPI delivery failure due to invalid
target
KVM: SVM: Don't put/load AVIC when setting virtual APIC mode
Revert "KVM: SVM: Introduce hybrid-AVIC mode"
KVM: SVM: Replace "avic_mode" enum with "x2avic_enabled" boolean
KVM: SVM: Compute dest based on sender's x2APIC status for AVIC kick
KVM: SVM: Get x2APIC logical dest bitmap from ICRH[15:0], not
ICHR[31:16]
KVM: SVM: Drop buggy and redundant AVIC "single logical dest" check
KVM: SVM: Remove redundant cluster calculation that also creates a
shadow
KVM: SVM: Drop duplicate calcuation of AVIC/x2AVIC "logical index"
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: 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: Explicitly skip optimized logical map setup if vCPU's LDR==0
KVM: x86: Explicitly track all possibilities for APIC map's logical
modes
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"
Documentation/virt/kvm/x86/errata.rst | 11 ++
arch/x86/include/asm/kvm_host.h | 27 ++-
arch/x86/kvm/lapic.c | 100 ++++++++--
arch/x86/kvm/svm/avic.c | 273 ++++++++++++++------------
arch/x86/kvm/svm/svm.c | 2 +-
arch/x86/kvm/svm/svm.h | 9 +-
6 files changed, 260 insertions(+), 162 deletions(-)
base-commit: 372d07084593dc7a399bf9bee815711b1fb1bcf2
--
2.37.2.672.g94769d06f0-goog
