Merge tag 'kvm-x86-vmxon-7.1' of https://github.com/kvm-x86/linux into HEAD

KVM x86 VMXON and EFER.SVME extraction for 7.1

Move _only_ VMXON+VMXOFF and EFER.SVME toggling out of KVM (versus all of VMX
and SVM enabling) out of KVM and into the core kernel so that non-KVM TDX
enabling, e.g. for trusted I/O, can make SEAMCALLs without needing to ensure
KVM is fully loaded.

TIO isn't a hypervisor, and isn't trying to be a hypervisor. Specifically, TIO
should _never_ have it's own VMCSes (that are visible to the host; the
TDX-Module has it's own VMCSes to do SEAMCALL/SEAMRET), and so there is simply
no reason to move that functionality out of KVM.

With that out of the way, dealing with VMXON/VMXOFF and EFER.SVME is a fairly
simple refcounting game.

1 files changed, 7 insertions, 9 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 34b373bb5bd0..d2ac8777c766 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1629,6 +1629,13 @@ static inline void kvm_create_vcpu_debugfs(struct kvm_vcpu *vcpu) {}
 
 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
 /*
+ * kvm_arch_shutdown() is invoked immediately prior to forcefully disabling
+ * hardware virtualization on all CPUs via IPI function calls (in preparation
+ * for shutdown or reboot), e.g. to allow arch code to prepare for disabling
+ * virtualization while KVM may be actively running vCPUs.
+ */
+void kvm_arch_shutdown(void);
+/*
  * kvm_arch_{enable,disable}_virtualization() are called on one CPU, under
  * kvm_usage_lock, immediately after/before 0=>1 and 1=>0 transitions of
  * kvm_usage_count, i.e. at the beginning of the generic hardware enabling
@@ -2301,7 +2308,6 @@ static inline bool kvm_check_request(int req, struct kvm_vcpu *vcpu)
 
 #ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
 extern bool enable_virt_at_load;
-extern bool kvm_rebooting;
 #endif
 
 extern unsigned int halt_poll_ns;
@@ -2596,12 +2602,4 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu,
 				    struct kvm_pre_fault_memory *range);
 #endif
 
-#ifdef CONFIG_KVM_GENERIC_HARDWARE_ENABLING
-int kvm_enable_virtualization(void);
-void kvm_disable_virtualization(void);
-#else
-static inline int kvm_enable_virtualization(void) { return 0; }
-static inline void kvm_disable_virtualization(void) { }
-#endif
-
 #endif