linux/arch/x86
Linus Torvalds 3f749befb0 x86: kvm: fix build error
The cpu_emergency_register_virt_callback() function is used
unconditionally by the x86 kvm code, but it is declared (and defined)
conditionally:

  #if IS_ENABLED(CONFIG_KVM_INTEL) || IS_ENABLED(CONFIG_KVM_AMD)
  void cpu_emergency_register_virt_callback(cpu_emergency_virt_cb *callback);
  ...

leading to a build error when neither KVM_INTEL nor KVM_AMD support is
enabled:

  arch/x86/kvm/x86.c: In function ‘kvm_arch_enable_virtualization’:
  arch/x86/kvm/x86.c:12517:9: error: implicit declaration of function ‘cpu_emergency_register_virt_callback’ [-Wimplicit-function-declaration]
  12517 |         cpu_emergency_register_virt_callback(kvm_x86_ops.emergency_disable_virtualization_cpu);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  arch/x86/kvm/x86.c: In function ‘kvm_arch_disable_virtualization’:
  arch/x86/kvm/x86.c:12522:9: error: implicit declaration of function ‘cpu_emergency_unregister_virt_callback’ [-Wimplicit-function-declaration]
  12522 |         cpu_emergency_unregister_virt_callback(kvm_x86_ops.emergency_disable_virtualization_cpu);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fix the build by defining empty helper functions the same way the old
cpu_emergency_disable_virtualization() function was dealt with for the
same situation.

Maybe we could instead have made the call sites conditional, since the
callers (kvm_arch_{en,dis}able_virtualization()) have an empty weak
fallback.  I'll leave that to the kvm people to argue about, this at
least gets the build going for that particular config.

Fixes: 590b09b1d8 ("KVM: x86: Register "emergency disable" callbacks when virt is enabled")
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Kai Huang <kai.huang@intel.com>
Cc: Chao Gao <chao.gao@intel.com>
Cc: Farrah Chen <farrah.chen@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2024-09-29 14:47:33 -07:00
..
boot
coco x86/tdx: Fix "in-kernel MMIO" check 2024-09-26 09:45:04 -07:00
configs
crypto
entry Random number generator updates for Linux 6.12-rc1. 2024-09-18 15:26:31 +02:00
events Performance events changes for v6.12: 2024-09-18 15:03:58 +02:00
hyperv hyperv-next for v6.12 2024-09-19 08:15:30 +02:00
ia32
include x86: kvm: fix build error 2024-09-29 14:47:33 -07:00
kernel x86: 2024-09-28 09:20:14 -07:00
kvm x86: 2024-09-28 09:20:14 -07:00
lib Merge branch 'locking/core' into locking/urgent, to pick up pending commits 2024-09-29 08:57:18 +02:00
math-emu
mm x86: 2024-09-28 09:20:14 -07:00
net
pci
platform xen: branch for v6.12-rc1a 2024-09-27 09:55:30 -07:00
power
purgatory
ras
realmode
tools
um This pull request contains the following changes for UML: 2024-09-27 12:48:48 -07:00
video
virt
xen xen: branch for v6.12-rc1a 2024-09-27 09:55:30 -07:00
.gitignore
Kbuild
Kconfig ALong with the usual shower of singleton patches, notable patch series in 2024-09-21 07:29:05 -07:00
Kconfig.assembler
Kconfig.cpu
Kconfig.debug
Makefile
Makefile_32.cpu
Makefile.postlink
Makefile.um