[PATCH v4 13/18] KVM: guest_memfd: Pass GPA, not GFN, to prepare() hook

[Sean Christopherson <seanjc@google.com>]

Pass a GPA instead of a GFN to kvm_arch_gmem_prepare() so that the GFN/GPA
can be made optional in the future, i.e. so that guest_memfd can pass
INVALID_GPA.  This will allow reworking the hook into a general .convert()
hook, i.e. so that it can be used for both "make private" and "make shared"
operations, at which point guest_memfd may not have a corresponding GFN,
e.g. when converting memory back to a shared state when a folio is freed.

Opportunistically swap the ordering of @pfn and @gpa params for
kvm_x86_ops.gmem_prepare() to match that of kvm_arch_gmem_prepare().

No functional change intended.

Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/kvm_host.h | 2 +-
 arch/x86/kvm/svm/sev.c          | 3 ++-
 arch/x86/kvm/svm/svm.h          | 2 +-
 arch/x86/kvm/x86.c              | 4 ++--
 include/linux/kvm_host.h        | 2 +-
 virt/kvm/guest_memfd.c          | 2 +-
 6 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 1f8ef0e1566a..24a7a9e6910a 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1904,7 +1904,7 @@ struct kvm_x86_ops {
 	gva_t (*get_untagged_addr)(struct kvm_vcpu *vcpu, gva_t gva, unsigned int flags);
 	void *(*alloc_apic_backing_page)(struct kvm_vcpu *vcpu);
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
-	int (*gmem_prepare)(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);
+	int (*gmem_prepare)(struct kvm *kvm, gpa_t gpa, kvm_pfn_t pfn, int max_order);
 #endif
 	void (*gmem_invalidate)(kvm_pfn_t start, kvm_pfn_t end);
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_INVALIDATE
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index a7584b7ed6dc..dfe93679a832 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -5112,9 +5112,10 @@ static bool is_large_rmp_possible(struct kvm *kvm, kvm_pfn_t pfn, int order)
 	return false;
 }
 
-int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)
+int sev_gmem_prepare(struct kvm *kvm, gpa_t gpa, kvm_pfn_t pfn, int max_order)
 {
 	struct kvm_sev_info *sev = to_kvm_sev_info(kvm);
+	gfn_t gfn = gpa_to_gfn(gpa);
 	kvm_pfn_t pfn_aligned;
 	gfn_t gfn_aligned;
 	int level, rc;
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 130205defffa..58390df36af0 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -1009,7 +1009,7 @@ int sev_cpu_init(struct svm_cpu_data *sd);
 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);
+int sev_gmem_prepare(struct kvm *kvm, gpa_t gpa, kvm_pfn_t pfn, int max_order);
 void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end);
 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);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5a5fd6211d23..cc1404bef8cb 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -10590,9 +10590,9 @@ bool kvm_arch_supports_gmem_init_shared(struct kvm *kvm)
 }
 
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
-int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_order)
+int kvm_arch_gmem_prepare(struct kvm *kvm, gpa_t gpa, kvm_pfn_t pfn, int max_order)
 {
-	return kvm_x86_call(gmem_prepare)(kvm, pfn, gfn, max_order);
+	return kvm_x86_call(gmem_prepare)(kvm, gpa, pfn, max_order);
 }
 #endif
 
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index c00fc1740ce5..542e5d50849e 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -2573,7 +2573,7 @@ static inline int kvm_gmem_get_pfn(struct kvm *kvm,
 #endif /* CONFIG_KVM_GUEST_MEMFD */
 
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
-int kvm_arch_gmem_prepare(struct kvm *kvm, gfn_t gfn, kvm_pfn_t pfn, int max_order);
+int kvm_arch_gmem_prepare(struct kvm *kvm, gpa_t gpa, kvm_pfn_t pfn, int max_order);
 #endif
 
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_POPULATE
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 659b8dbe0b30..7ad656e30f9f 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -66,7 +66,7 @@ static int __kvm_gmem_prepare_folio(struct kvm *kvm, struct kvm_memory_slot *slo
 #ifdef CONFIG_HAVE_KVM_ARCH_GMEM_PREPARE
 	kvm_pfn_t pfn = folio_file_pfn(folio, index);
 	gfn_t gfn = slot->base_gfn + index - slot->gmem.pgoff;
-	int rc = kvm_arch_gmem_prepare(kvm, gfn, pfn, folio_order(folio));
+	int rc = kvm_arch_gmem_prepare(kvm, gfn_to_gpa(gfn), pfn, folio_order(folio));
 	if (rc) {
 		pr_warn_ratelimited("gmem: Failed to prepare folio for index %lx GFN %llx PFN %llx error %d.\n",
 				    index, gfn, pfn, rc);
-- 
2.55.0.795.g602f6c329a-goog