KVM: x86: Rename kvm_x86_ops' gmem_invalidate() to gmem_make_shared()

Rename kvm_x86_ops's gmem_invalidate() hook to gmem_make_shared(), as the
hook doesn't invalidate anything, and so that KVM doesn't need to add yet
another vendor callback to support "convert to shared" once in-place
conversion comes along.

Opportunistically wrap the ops declarations with a GMEM_RECLAIM guard so
that attempting to wire up a .gmem_make_shared() hook without selecting
CONFIG_HAVE_KVM_ARCH_GMEM_RECLAIM will result in a build failure.

No functional change intended.

Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com>
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Reviewed-by: Fuad Tabba <fuad.tabba@linux.dev>
Link: https://patch.msgid.link/20260723210811.72720-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

6 files changed, 10 insertions, 6 deletions

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index 736129db272a..210cb95d0a0b 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -149,7 +149,9 @@ KVM_X86_OP_OPTIONAL(alloc_apic_backing_page)
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
 KVM_X86_OP_OPTIONAL_RET0(gmem_prepare)
 #endif
-KVM_X86_OP_OPTIONAL(gmem_invalidate)
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_RECLAIM
+KVM_X86_OP_OPTIONAL(gmem_make_shared)
+#endif
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
 KVM_X86_OP_OPTIONAL(gmem_invalidate_range)
 #endif
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index ef20f0e12193..693be16abd95 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1906,7 +1906,9 @@ struct kvm_x86_ops {
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
 	int (*gmem_prepare)(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
 #endif
-	void (*gmem_invalidate)(kvm_pfn_t pfn, kvm_pfn_t nr_pages);
+#ifdef CONFIG_HAVE_KVM_ARCH_GMEM_RECLAIM
+	void (*gmem_make_shared)(kvm_pfn_t pfn, kvm_pfn_t nr_pages);
+#endif
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
 	void (*gmem_invalidate_range)(struct kvm *kvm, struct kvm_gfn_range *range);
 #endif
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 5a5e8342c4fe..4c46081889a6 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5159,7 +5159,7 @@ int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
 	return 0;
 }
 
-void sev_gmem_invalidate(kvm_pfn_t pfn, kvm_pfn_t nr_pages)
+void sev_gmem_make_shared(kvm_pfn_t pfn, kvm_pfn_t nr_pages)
 {
 	kvm_pfn_t end = pfn + nr_pages;
 
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index dd51df74c2dc..44c3af6f71d8 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -5451,7 +5451,7 @@ struct kvm_x86_ops svm_x86_ops __initdata = {
 	.vm_move_enc_context_from = sev_vm_move_enc_context_from,
 
 	.gmem_prepare = sev_gmem_prepare,
-	.gmem_invalidate = sev_gmem_invalidate,
+	.gmem_make_shared = sev_gmem_make_shared,
 	.gmem_invalidate_range = sev_gmem_invalidate_range,
 	.gmem_max_mapping_level = sev_gmem_max_mapping_level,
 #endif
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 2180d03bb0a6..51e3494e7802 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -1010,7 +1010,7 @@ int sev_dev_get_attr(u32 group, u64 attr, u64 *val);
 extern unsigned int max_sev_asid;
 void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code);
 int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
-void sev_gmem_invalidate(kvm_pfn_t pfn, kvm_pfn_t nr_pages);
+void sev_gmem_make_shared(kvm_pfn_t pfn, kvm_pfn_t nr_pages);
 void sev_gmem_invalidate_range(struct kvm *kvm, struct kvm_gfn_range *range);
 int sev_gmem_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn, bool is_private);
 struct vmcb_save_area *sev_decrypt_vmsa(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index befba27672c7..0075815acdd5 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10599,7 +10599,7 @@ int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_ord
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_RECLAIM
 void kvm_arch_gmem_reclaim(kvm_pfn_t pfn, kvm_pfn_t nr_pages)
 {
-	kvm_x86_call(gmem_invalidate)(pfn, nr_pages);
+	kvm_x86_call(gmem_make_shared)(pfn, nr_pages);
 }
 #endif