[RFC PATCH 0/8] KVM: x86: svm: Enabling AVIC with in kernel irqchip

From: Suthikulpanit, Suravee
Date: Mon Feb 04 2019 - 09:41:58 EST

Currently, AMD AVIC can only be enabled when creating VM in irqchip
split mode, which is due to the following issues:

* AMD AVIC does not support ExtINT, which is required during booting
phase of Windows and FreeBSD VMs. This results in hanging in the
boot loaders.

* Untrap APIC EOI write for edge-trigger interrpt.
Please see 67034bb9dd5e ('KVM: SVM: Add irqchip_split() checks
before enabling AVIC') for more information.

This restriction makes AVIC difficult to enable since it depends on
the non-default QEMU's kernel_irqchip=split option. Therefore, this RFC
series tries to provide workaround for the issues above, and allow AVIC to
work with the option kernel_irqchip=on (QEMU default).

Patch 1 fixes AVIC deactivation.
Patch 2-6 introduces run-time AVIC acticate/deactivate support.
Patch 7 provide workaround for untrap APIC EOI.
Patch 8 removes the kernel irqchip split restriction.

This series has been tested booting Linux, Windows, and FreeBSD VMs
with kernel_irqchip=off/split/on.


Julian Stecklina (1):
KVM: i8254: Remove need for irq ack notifier

Suravee Suthikulpanit (7):
svm: Fix improper check when deactivate AVIC
KVM: x86: Add interface for run-time activate/de-activate APIC
KVM: x86: Add callback functions for handling APIC ID, DFR and LDR
svm: Add AMD AVIC handlers for APIC ID, DFR and LDR update
svm: Add support for APIC_ACCESS_PAGE_PRIVATE_MEMSLOT setup/destroy
svm: Temporary deactivate AVIC during ExtINT handling
svm: Allow AVIC with in-kernel irqchip mode

arch/x86/include/asm/kvm_host.h | 11 +++
arch/x86/kvm/i8254.c | 22 +-----
arch/x86/kvm/i8254.h | 2 -
arch/x86/kvm/lapic.c | 11 ++-
arch/x86/kvm/svm.c | 118 +++++++++++++++++++++++++++++---
arch/x86/kvm/x86.c | 36 ++++++++++
6 files changed, 164 insertions(+), 36 deletions(-)