[RFC PATCH 6/8] KVM: x86: Implement kvm_arch_{, pre_}vcpu_map_memory()

[isaku . yamahata]

From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>

Wire KVM_MAP_MEMORY ioctl to kvm_mmu_map_tdp_page() to populate guest
memory.

Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
 arch/x86/kvm/x86.c | 49 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 49 insertions(+)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 3b8cb69b04fa..6025c0e12d89 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4660,6 +4660,7 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
 	case KVM_CAP_VM_DISABLE_NX_HUGE_PAGES:
 	case KVM_CAP_IRQFD_RESAMPLE:
 	case KVM_CAP_MEMORY_FAULT_INFO:
+	case KVM_CAP_MAP_MEMORY:
 		r = 1;
 		break;
 	case KVM_CAP_EXIT_HYPERCALL:
@@ -5805,6 +5806,54 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 	}
 }
 
+int kvm_arch_vcpu_pre_map_memory(struct kvm_vcpu *vcpu)
+{
+	return kvm_mmu_reload(vcpu);
+}
+
+int kvm_arch_vcpu_map_memory(struct kvm_vcpu *vcpu,
+			     struct kvm_memory_mapping *mapping)
+{
+	u8 max_level, goal_level = PG_LEVEL_4K;
+	u32 error_code;
+	int r;
+
+	error_code = 0;
+	if (mapping->flags & KVM_MEMORY_MAPPING_FLAG_WRITE)
+		error_code |= PFERR_WRITE_MASK;
+	if (mapping->flags & KVM_MEMORY_MAPPING_FLAG_EXEC)
+		error_code |= PFERR_FETCH_MASK;
+	if (mapping->flags & KVM_MEMORY_MAPPING_FLAG_USER)
+		error_code |= PFERR_USER_MASK;
+	if (mapping->flags & KVM_MEMORY_MAPPING_FLAG_PRIVATE) {
+#ifdef PFERR_PRIVATE_ACCESS
+		error_code |= PFERR_PRIVATE_ACCESS;
+#else
+		return -OPNOTSUPP;
+#endif
+	}
+
+	if (IS_ALIGNED(mapping->base_gfn, KVM_PAGES_PER_HPAGE(PG_LEVEL_1G)) &&
+	    mapping->nr_pages >= KVM_PAGES_PER_HPAGE(PG_LEVEL_1G))
+		max_level = PG_LEVEL_1G;
+	else if (IS_ALIGNED(mapping->base_gfn, KVM_PAGES_PER_HPAGE(PG_LEVEL_2M)) &&
+		 mapping->nr_pages >= KVM_PAGES_PER_HPAGE(PG_LEVEL_2M))
+		max_level = PG_LEVEL_2M;
+	else
+		max_level = PG_LEVEL_4K;
+
+	r = kvm_mmu_map_page(vcpu, gfn_to_gpa(mapping->base_gfn), error_code,
+			     max_level, &goal_level);
+	if (r)
+		return r;
+
+	if (mapping->source)
+		mapping->source += KVM_HPAGE_SIZE(goal_level);
+	mapping->base_gfn += KVM_PAGES_PER_HPAGE(goal_level);
+	mapping->nr_pages -= KVM_PAGES_PER_HPAGE(goal_level);
+	return r;
+}
+
 long kvm_arch_vcpu_ioctl(struct file *filp,
 			 unsigned int ioctl, unsigned long arg)
 {
-- 
2.25.1