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

KVM SVM changes for 7.1

 - Fix and optimize IRQ window inhibit handling for AVIC (the tracking needs to
   be per-vCPU, e.g. so that KVM doesn't prematurely re-enable AVIC if multiple
   vCPUs have to-be-injected IRQs).

 - Fix an undefined behavior warning where a crafty userspace can read the
   "avic" module param before it's fully initialized.

 - Fix a (likely benign) bug in the "OS-visible workarounds" handling, where
   KVM could clobber state when enabling virtualization on multiple CPUs in
   parallel, and clean up and optimize the code.

 - Drop a WARN in KVM_MEMORY_ENCRYPT_REG_REGION where KVM complains about a
   "too large" size based purely on user input, and clean up and harden the
   related pinning code.

 - Disallow synchronizing a VMSA of an already-launched/encrypted vCPU, as
   doing so for an SNP guest will trigger an RMP violation #PF and crash the
   host.

 - Protect all of sev_mem_enc_register_region() with kvm->lock to ensure
   sev_guest() is stable for the entire of the function.

 - Lock all vCPUs when synchronizing VMSAs for SNP guests to ensure the VMSA
   page isn't actively being used.

 - Overhaul KVM's APIs for detecting SEV+ guests so that VM-scoped queries are
   required to hold kvm->lock (KVM has had multiple bugs due "is SEV?" checks
   becoming stale), enforced by lockdep.  Add and use vCPU-scoped APIs when
   possible/appropriate, as all checks that originate from a vCPU are
   guaranteed to be stable.

 - Convert a pile of kvm->lock SEV code to guard().

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d2ac8777c766..4c14aee1fb06 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1030,6 +1030,13 @@ static inline struct kvm_vcpu *kvm_get_vcpu_by_id(struct kvm *kvm, int id)
 	return NULL;
 }
 
+static inline bool kvm_is_vcpu_creation_in_progress(struct kvm *kvm)
+{
+	lockdep_assert_held(&kvm->lock);
+
+	return kvm->created_vcpus != atomic_read(&kvm->online_vcpus);
+}
+
 void kvm_destroy_vcpus(struct kvm *kvm);
 
 int kvm_trylock_all_vcpus(struct kvm *kvm);