[PATCH v2 0/5] kvm: x86: better handling of optional kvm_x86_ops

From: Paolo Bonzini
Date: Mon Feb 14 2022 - 08:16:30 EST


This series is really two changes:

- patch 1 to 4 clean up optional kvm_x86_ops so that they are marked
in kvm-x86-ops.h and the non-optional ones WARN if used incorrectly.
As an additional outcome of the review, a few more uses of
static_call_cond are introduced.

- patch 5 allows to NULL a few kvm_x86_ops that return a value, by
using __static_call_ret0.

v1->v2:
- use KVM_X86_OP_OPTIONAL and KVM_X86_OP_OPTIONAL_RET0
- mark load_eoi_exitmap and set_virtual_apic_mode as optional
- fix module compilation of KVM

Paolo Bonzini (5):
KVM: x86: use static_call_cond for optional callbacks
KVM: x86: remove KVM_X86_OP_NULL and mark optional kvm_x86_ops
KVM: x86: warn on incorrectly NULL static calls
KVM: x86: make several AVIC callbacks optional
KVM: x86: allow defining return-0 static calls

arch/x86/include/asm/kvm-x86-ops.h | 104 +++++++++++++++--------------
arch/x86/include/asm/kvm_host.h | 11 ++-
arch/x86/kvm/lapic.c | 24 +++----
arch/x86/kvm/svm/avic.c | 23 -------
arch/x86/kvm/svm/svm.c | 30 ---------
arch/x86/kvm/svm/svm.h | 1 -
arch/x86/kvm/x86.c | 16 ++---
kernel/static_call.c | 1 +
8 files changed, 79 insertions(+), 131 deletions(-)

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2.31.1