[v2,0/8] KVM: x86: allow compiling out SMM support

Message

Paolo Bonzini Sept. 29, 2022, 5:20 p.m. UTC

Some users of KVM implement the UEFI variable store through a paravirtual device
that does not require the "SMM lockbox" component of edk2; allow them to
compile out system management mode, which is not a full implementation
especially in how it interacts with nested virtualization.

In order to limit the number and especially the size of the #ifdefs,
the first 4 patches move most SMM code to a completely new file in
arch/x86/kvm.  Patch 5 is the main change to introduce the Kconfig
symbol and key smm.c's compilation off it; patches 6-8 instead eliminate
other bits of SMM code that remain outside smm.c, the last one being
"optional" as it is a bit into diminishing returns land.

Paolo

Paolo Bonzini (8):
  KVM: x86: start moving SMM-related functions to new files
  KVM: x86: move SMM entry to a new file
  KVM: x86: move SMM exit to a new file
  KVM: x86: do not go through ctxt->ops when emulating rsm
  KVM: allow compiling out SMM support
  KVM: x86: compile out vendor-specific code if SMM is disabled
  KVM: x86: remove SMRAM address space if SMM is not supported
  KVM: x86: do not define KVM_REQ_SMI if SMM disabled

 arch/x86/include/asm/kvm-x86-ops.h            |   2 +
 arch/x86/include/asm/kvm_host.h               |  24 +-
 arch/x86/kvm/Kconfig                          |  11 +
 arch/x86/kvm/Makefile                         |   1 +
 arch/x86/kvm/emulate.c                        | 355 +----------
 arch/x86/kvm/kvm_cache_regs.h                 |   5 -
 arch/x86/kvm/kvm_emulate.h                    |  47 +-
 arch/x86/kvm/lapic.c                          |  14 +-
 arch/x86/kvm/lapic.h                          |   7 +-
 arch/x86/kvm/mmu/mmu.c                        |   1 +
 arch/x86/kvm/smm.c                            | 573 ++++++++++++++++++
 arch/x86/kvm/smm.h                            |  38 ++
 arch/x86/kvm/svm/nested.c                     |   3 +
 arch/x86/kvm/svm/svm.c                        |  11 +-
 arch/x86/kvm/vmx/nested.c                     |   1 +
 arch/x86/kvm/vmx/vmx.c                        |   7 +
 arch/x86/kvm/x86.c                            | 353 +----------
 tools/testing/selftests/kvm/x86_64/smm_test.c |   2 +
 18 files changed, 737 insertions(+), 718 deletions(-)
 create mode 100644 arch/x86/kvm/smm.c
 create mode 100644 arch/x86/kvm/smm.h