[PATCH v2 0/9] KVM: Move x86 init ops to separate struct

From: Sean Christopherson
Date: Tue Feb 18 2020 - 18:54:41 EST


The non-x86 part of this series is wholly contained in patch 01. Compared
to other recent kvm-wide changes, this one is very straightforward (famous
last words).

Like a few other architectures, e.g. PPC, x86 uses a set of global hooks
to call back into vendor code on demand. A handlful of the x86 hooks are
used only within the scope of kvm_init(). This series moves the init-only
hooks to a separate struct, partly to clean up the code a bit, but mainly
so that the runtime hooks can be made available only after the x86 vendor
has completed its ->hardware_setup(). While working on a different series
I spent a fair bit of time scratching my as to why a kvm_x86_ops wasn't
working, and eventually realized VMX's callback wasn't "ready" because the
vmcs_config hadn't yet been populated.

Due to lack of a cross-compiling setup, the non-x86 changes in patch 01
are untested.

The SVM changes in patch 02 are fairly well tested, e.g. fudged things
enough to ensure KVM didn't explode on a null pointer.

Patch 05 is a bit scary as a rogue dereference of kvm_x86_ops before
->hardware_setup() will crash KVM (maybe the kernel?). I didn't find any
obvious ways to use kvm_x86_ops on AMD, and tested on a few different
Intel CPUs, so I'm reasonably confident that there are no existing
violations.

v2:
- Rebase to kvm/queue, 2c2787938512 ("KVM: selftests: Stop ...")
- Collect tags. [Cornelia]
- Add a patch to make kvm_x86_ops its own instance and copy
{vmx,svm}_x86_ops by value, which saves a memory access on every
invocation of a kvm_x86_ops hook. [Paolo]
- Add patches to tag {vmx,svm}_x86_ops as __initdata after they're
copied by value.

Sean Christopherson (9):
KVM: Pass kvm_init()'s opaque param to additional arch funcs
KVM: x86: Move init-only kvm_x86_ops to separate struct
KVM: VMX: Move hardware_setup() definition below vmx_x86_ops
KVM: VMX: Configure runtime hooks using vmx_x86_ops
KVM: x86: Set kvm_x86_ops only after ->hardware_setup() completes
KVM: x86: Copy kvm_x86_ops by value to eliminate layer of indirection
KVM: x86: Drop __exit from kvm_x86_ops' hardware_unsetup()
KVM: VMX: Annotate vmx_x86_ops as __initdata
KVM: SVM: Annotate svm_x86_ops as __initdata

arch/mips/kvm/mips.c | 4 +-
arch/powerpc/kvm/powerpc.c | 4 +-
arch/s390/kvm/kvm-s390.c | 4 +-
arch/x86/include/asm/kvm_host.h | 35 +--
arch/x86/kvm/cpuid.c | 24 +-
arch/x86/kvm/hyperv.c | 8 +-
arch/x86/kvm/kvm_cache_regs.h | 10 +-
arch/x86/kvm/lapic.c | 30 +--
arch/x86/kvm/mmu.h | 4 +-
arch/x86/kvm/mmu/mmu.c | 38 ++--
arch/x86/kvm/pmu.c | 30 +--
arch/x86/kvm/pmu.h | 2 +-
arch/x86/kvm/svm.c | 21 +-
arch/x86/kvm/trace.h | 4 +-
arch/x86/kvm/vmx/nested.c | 17 +-
arch/x86/kvm/vmx/nested.h | 3 +-
arch/x86/kvm/vmx/pmu_intel.c | 2 +-
arch/x86/kvm/vmx/vmx.c | 353 +++++++++++++++--------------
arch/x86/kvm/x86.c | 384 ++++++++++++++++----------------
arch/x86/kvm/x86.h | 4 +-
include/linux/kvm_host.h | 4 +-
virt/kvm/arm/arm.c | 4 +-
virt/kvm/kvm_main.c | 18 +-
23 files changed, 519 insertions(+), 488 deletions(-)

--
2.24.1