Previously, with AVIC, guest needs to disable x2APIC capability and
can only run in APIC mode to activate hardware-accelerated interrupt
virtualization. With x2AVIC, guest can run in x2APIC mode.
This feature is indicated by the CPUID Fn8000_000A EDX[14],
and it can be activated by setting bit 31 (enable AVIC) and
bit 30 (x2APIC mode) of VMCB offset 60h.
The mode of interrupt virtualization can dynamically change during runtime.
For example, when AVIC is enabled, the hypervisor currently keeps track of
the AVIC activation and set the VMCB bit 31 accordingly. With x2AVIC,
the guest OS can also switch between APIC and x2APIC modes during runtime.
The kvm_amd driver needs to also keep track and set the VMCB
bit 30 accordingly.
Besides, for x2AVIC, kvm_amd driver needs to disable interception for the
x2APIC MSR range to allow AVIC hardware to virtualize register accesses.
Testing:
* This series has been tested booting a Linux VM with x2APIC physical
and logical modes upto 512 vCPUs.
Regards,
Suravee
Changes from v1
(https://lore.kernel.org/lkml/20220405230855.15376-1-suravee.suthikulpanit@xxxxxxx/T/)
* Rebase to v5.18
* Patch 7/12: remove logic to check for x2AVIC feature.
Suravee Suthikulpanit (12):
x86/cpufeatures: Introduce x2AVIC CPUID bit
KVM: x86: lapic: Rename [GET/SET]_APIC_DEST_FIELD to
[GET/SET]_XAPIC_DEST_FIELD
KVM: SVM: Detect X2APIC virtualization (x2AVIC) support
KVM: SVM: Update max number of vCPUs supported for x2AVIC mode
KVM: SVM: Update avic_kick_target_vcpus to support 32-bit APIC ID
KVM: SVM: Do not support updating APIC ID when in x2APIC mode
KVM: SVM: Adding support for configuring x2APIC MSRs interception
KVM: SVM: Update AVIC settings when changing APIC mode
KVM: SVM: Introduce helper functions to (de)activate AVIC and x2AVIC
KVM: SVM: Do not throw warning when calling avic_vcpu_load on a
running vcpu
KVM: SVM: Do not inhibit APICv when x2APIC is present
kvm/x86: Remove APICV activate mode inconsistency check
arch/x86/hyperv/hv_apic.c | 2 +-
arch/x86/include/asm/apicdef.h | 4 +-
arch/x86/include/asm/cpufeatures.h | 1 +
arch/x86/include/asm/svm.h | 16 ++-
arch/x86/kernel/apic/apic.c | 2 +-
arch/x86/kernel/apic/ipi.c | 2 +-
arch/x86/kvm/lapic.c | 2 +-
arch/x86/kvm/svm/avic.c | 152 ++++++++++++++++++++++++++---
arch/x86/kvm/svm/svm.c | 55 ++++++-----
arch/x86/kvm/svm/svm.h | 7 +-
arch/x86/kvm/x86.c | 13 +--
11 files changed, 204 insertions(+), 52 deletions(-)
--
2.25.1
