[PATCH v2 00/10] KVM: x86: Interrupt-based mechanism for async_pf 'page present' notifications

From: Vitaly Kuznetsov
Date: Mon May 25 2020 - 10:41:37 EST


Concerns were expressed around (ab)using #PF for KVM's async_pf mechanism,
it seems that re-using #PF exception for a PV mechanism wasn't a great
idea after all. The Grand Plan is to switch to using e.g. #VE for 'page
not present' events and normal APIC interrupts for 'page ready' events.
This series does the later.

Changes since v1:
- struct kvm_vcpu_pv_apf_data's fields renamed to 'flags' and 'token',
comments added [Vivek Goyal]
- 'type1/2' names for APF events dropped from everywhere [Vivek Goyal]
- kvm_arch_can_inject_async_page_present() renamed to
kvm_arch_can_dequeue_async_page_present [Vivek Goyal]
- 'KVM: x86: deprecate KVM_ASYNC_PF_SEND_ALWAYS' patch added.

v1: https://lore.kernel.org/kvm/20200511164752.2158645-1-vkuznets@xxxxxxxxxx/
QEMU patches for testing: https://github.com/vittyvk/qemu.git (async_pf2_v2 branch)

Vitaly Kuznetsov (10):
Revert "KVM: async_pf: Fix #DF due to inject "Page not Present" and
"Page Ready" exceptions simultaneously"
KVM: x86: extend struct kvm_vcpu_pv_apf_data with token info
KVM: rename kvm_arch_can_inject_async_page_present() to
kvm_arch_can_dequeue_async_page_present()
KVM: introduce kvm_read_guest_offset_cached()
KVM: x86: interrupt based APF 'page ready' event delivery
KVM: x86: acknowledgment mechanism for async pf page ready
notifications
KVM: x86: announce KVM_FEATURE_ASYNC_PF_INT
KVM: x86: Switch KVM guest to using interrupts for page ready APF
delivery
KVM: x86: drop KVM_PV_REASON_PAGE_READY case from
kvm_handle_page_fault()
KVM: x86: deprecate KVM_ASYNC_PF_SEND_ALWAYS

Documentation/virt/kvm/cpuid.rst | 6 ++
Documentation/virt/kvm/msr.rst | 120 +++++++++++++++------
arch/s390/include/asm/kvm_host.h | 4 +-
arch/s390/kvm/kvm-s390.c | 2 +-
arch/x86/entry/entry_32.S | 5 +
arch/x86/entry/entry_64.S | 5 +
arch/x86/include/asm/hardirq.h | 3 +
arch/x86/include/asm/irq_vectors.h | 6 +-
arch/x86/include/asm/kvm_host.h | 12 ++-
arch/x86/include/asm/kvm_para.h | 10 +-
arch/x86/include/uapi/asm/kvm_para.h | 19 +++-
arch/x86/kernel/irq.c | 9 ++
arch/x86/kernel/kvm.c | 62 +++++++----
arch/x86/kvm/cpuid.c | 3 +-
arch/x86/kvm/mmu/mmu.c | 19 ++--
arch/x86/kvm/svm/nested.c | 2 +-
arch/x86/kvm/svm/svm.c | 3 +-
arch/x86/kvm/vmx/nested.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 5 +-
arch/x86/kvm/x86.c | 149 ++++++++++++++++++---------
include/linux/kvm_host.h | 3 +
include/uapi/linux/kvm.h | 1 +
virt/kvm/async_pf.c | 12 ++-
virt/kvm/kvm_main.c | 19 +++-
24 files changed, 344 insertions(+), 137 deletions(-)

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2.25.4