KVM: Drop kvm_arch_create_memslot()

Remove kvm_arch_create_memslot() now that all arch implementations are effectively nops. Removing kvm_arch_create_memslot() eliminates the possibility for arch specific code to allocate memory prior to setting a memslot, which sets the stage for simplifying kvm_free_memslot(). Cc: Janosch Frank <[email protected]> Acked-by: Christian Borntraeger <[email protected]> Reviewed-by: Peter Xu <[email protected]> Signed-off-by: Sean Christopherson <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
kawasaki · Mar 16, 2020 · 414de7a · 414de7a
1 parent 0dab98b
commit 414de7a
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Showing 7 changed files with 7 additions and 46 deletions.
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
@@ -188,12 +188,6 @@ long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,
 	return -ENOIOCTLCMD;
 }
 
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages)
-{
-	return 0;
-}
-
 void kvm_arch_flush_shadow_all(struct kvm *kvm)
 {
 	/* Flush whole GPA */

diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
@@ -691,12 +691,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 	kvmppc_core_free_memslot(kvm, free, dont);
 }
 
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages)
-{
-	return 0;
-}
-
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot,
 				   const struct kvm_userspace_memory_region *mem,

diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
@@ -4507,12 +4507,6 @@ vm_fault_t kvm_arch_vcpu_fault(struct kvm_vcpu *vcpu, struct vm_fault *vmf)
 	return VM_FAULT_SIGBUS;
 }
 
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages)
-{
-	return 0;
-}
-
 /* Section: memory related */
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				   struct kvm_memory_slot *memslot,

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
@@ -9873,12 +9873,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 	kvm_page_track_free_memslot(free, dont);
 }
 
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages)
-{
-	return 0;
-}
-
 static int kvm_alloc_memslot_metadata(struct kvm_memory_slot *slot,
 				      unsigned long npages)
 {

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
@@ -671,8 +671,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
 			    const struct kvm_userspace_memory_region *mem);
 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 			   struct kvm_memory_slot *dont);
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages);
 void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen);
 int kvm_arch_prepare_memory_region(struct kvm *kvm,
 				struct kvm_memory_slot *memslot,

diff --git a/virt/kvm/arm/mmu.c b/virt/kvm/arm/mmu.c
@@ -2354,12 +2354,6 @@ void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
 {
 }
 
-int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
-			    unsigned long npages)
-{
-	return 0;
-}
-
 void kvm_arch_memslots_updated(struct kvm *kvm, u64 gen)
 {
 }

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
@@ -1040,12 +1040,13 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	new.base_gfn = base_gfn;
 	new.npages = npages;
 	new.flags = mem->flags;
+	new.userspace_addr = mem->userspace_addr;
 
 	if (npages) {
 		if (!old.npages)
 			change = KVM_MR_CREATE;
 		else { /* Modify an existing slot. */
-			if ((mem->userspace_addr != old.userspace_addr) ||
+			if ((new.userspace_addr != old.userspace_addr) ||
 			    (npages != old.npages) ||
 			    ((new.flags ^ old.flags) & KVM_MEM_READONLY))
 				goto out;
@@ -1080,22 +1081,14 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		}
 	}
 
-	/* Free page dirty bitmap if unneeded */
-	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
-		new.dirty_bitmap = NULL;
-
 	r = -ENOMEM;
-	if (change == KVM_MR_CREATE) {
-		new.userspace_addr = mem->userspace_addr;
 
-		if (kvm_arch_create_memslot(kvm, &new, npages))
-			goto out;
-	}
-
-	/* Allocate page dirty bitmap if needed */
-	if ((new.flags & KVM_MEM_LOG_DIRTY_PAGES) && !new.dirty_bitmap) {
+	/* Allocate/free page dirty bitmap as needed */
+	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
+		new.dirty_bitmap = NULL;
+	else if (!new.dirty_bitmap) {
 		if (kvm_create_dirty_bitmap(&new) < 0)
-			goto out_free;
+			goto out;
 	}
 
 	slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT);