KVM: Simplify coalesced mmio initialization

- add destructor function - move related allocation into constructor - add stubs for !CONFIG_KVM_MMIO Signed-off-by: Avi Kivity <avi@redhat.com>

KVM: Simplify coalesced mmio initialization
- add destructor function - move related allocation into constructor - add stubs for !CONFIG_KVM_MMIO Signed-off-by: Avi Kivity <avi@redhat.com>
Avi Kivity · Marcelo Tosatti
1 parent 50eb2a3cd0
Showing 3 changed files with 34 additions and 8 deletions Side-by-side Diff
virt/kvm/coalesced_mmio.c
virt/kvm/coalesced_mmio.h
virt/kvm/kvm_main.c
@@ -92,11 +92,19 @@
 int kvm_coalesced_mmio_init(struct kvm *kvm)
 {
 	struct kvm_coalesced_mmio_dev *dev;
+	struct page *page;
 	int ret;
  
+	ret = -ENOMEM;
+	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+	if (!page)
+		goto out_err;
+	kvm->coalesced_mmio_ring = page_address(page);
+
+	ret = -ENOMEM;
 	dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
 	if (!dev)
-		return -ENOMEM;
+		goto out_free_page;
 	spin_lock_init(&dev->lock);
 	kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
 	dev->kvm = kvm;
  
@@ -104,9 +112,22 @@
  
 	ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
 	if (ret < 0)
-		kfree(dev);
+		goto out_free_dev;
  
 	return ret;
+
+out_free_dev:
+	kfree(dev);
+out_free_page:
+	__free_page(page);
+out_err:
+	return ret;
+}
+
+void kvm_coalesced_mmio_free(struct kvm *kvm)
+{
+	if (kvm->coalesced_mmio_ring)
+		free_page((unsigned long)kvm->coalesced_mmio_ring);
 }
  
 int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
@@ -10,6 +10,8 @@
  *
  */
  
+#ifdef CONFIG_KVM_MMIO
+
 #define KVM_COALESCED_MMIO_ZONE_MAX 100
  
 struct kvm_coalesced_mmio_dev {
  
@@ -21,10 +23,18 @@
 };
  
 int kvm_coalesced_mmio_init(struct kvm *kvm);
+void kvm_coalesced_mmio_free(struct kvm *kvm);
 int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
                                        struct kvm_coalesced_mmio_zone *zone);
 int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
                                          struct kvm_coalesced_mmio_zone *zone);
+
+#else
+
+static inline int kvm_coalesced_mmio_init(struct kvm *kvm) { return 0; }
+static inline void kvm_coalesced_mmio_free(struct kvm *kvm) { }
+
+#endif
  
 #endif
@@ -51,9 +51,7 @@
 #include <asm/pgtable.h>
 #include <asm-generic/bitops/le.h>
  
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
 #include "coalesced_mmio.h"
-#endif
  
 #define CREATE_TRACE_POINTS
 #include <trace/events/kvm.h>
@@ -468,10 +466,7 @@
 	kvm_free_irq_routing(kvm);
 	kvm_io_bus_destroy(&kvm->pio_bus);
 	kvm_io_bus_destroy(&kvm->mmio_bus);
-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
-	if (kvm->coalesced_mmio_ring != NULL)
-		free_page((unsigned long)kvm->coalesced_mmio_ring);
-#endif
+	kvm_coalesced_mmio_free(kvm);
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
 #else
...	...	@@ -92,11 +92,19 @@
92	92	int kvm_coalesced_mmio_init(struct kvm *kvm)
93	93	{
94	94	struct kvm_coalesced_mmio_dev *dev;
	95	+ struct page *page;
95	96	int ret;
96	97
	98	+ ret = -ENOMEM;
	99	+ page = alloc_page(GFP_KERNEL \| __GFP_ZERO);
	100	+ if (!page)
	101	+ goto out_err;
	102	+ kvm->coalesced_mmio_ring = page_address(page);
	103	+
	104	+ ret = -ENOMEM;
97	105	dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
98	106	if (!dev)
99		- return -ENOMEM;
	107	+ goto out_free_page;
100	108	spin_lock_init(&dev->lock);
101	109	kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
102	110	dev->kvm = kvm;
103	111
...	...	@@ -104,9 +112,22 @@
104	112
105	113	ret = kvm_io_bus_register_dev(kvm, &kvm->mmio_bus, &dev->dev);
106	114	if (ret < 0)
107		- kfree(dev);
	115	+ goto out_free_dev;
108	116
109	117	return ret;
	118	+
	119	+out_free_dev:
	120	+ kfree(dev);
	121	+out_free_page:
	122	+ __free_page(page);
	123	+out_err:
	124	+ return ret;
	125	+}
	126	+
	127	+void kvm_coalesced_mmio_free(struct kvm *kvm)
	128	+{
	129	+ if (kvm->coalesced_mmio_ring)
	130	+ free_page((unsigned long)kvm->coalesced_mmio_ring);
110	131	}
111	132
112	133	int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
...	...	@@ -10,6 +10,8 @@
10	10	*
11	11	*/
12	12
	13	+#ifdef CONFIG_KVM_MMIO
	14	+
13	15	#define KVM_COALESCED_MMIO_ZONE_MAX 100
14	16
15	17	struct kvm_coalesced_mmio_dev {
16	18
...	...	@@ -21,10 +23,18 @@
21	23	};
22	24
23	25	int kvm_coalesced_mmio_init(struct kvm *kvm);
	26	+void kvm_coalesced_mmio_free(struct kvm *kvm);
24	27	int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
25	28	struct kvm_coalesced_mmio_zone *zone);
26	29	int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
27	30	struct kvm_coalesced_mmio_zone *zone);
	31	+
	32	+#else
	33	+
	34	+static inline int kvm_coalesced_mmio_init(struct kvm *kvm) { return 0; }
	35	+static inline void kvm_coalesced_mmio_free(struct kvm *kvm) { }
	36	+
	37	+#endif
28	38
29	39	#endif
...	...	@@ -51,9 +51,7 @@
51	51	#include <asm/pgtable.h>
52	52	#include <asm-generic/bitops/le.h>
53	53
54		-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
55	54	#include "coalesced_mmio.h"
56		-#endif
57	55
58	56	#define CREATE_TRACE_POINTS
59	57	#include <trace/events/kvm.h>
...	...	@@ -468,10 +466,7 @@
468	466	kvm_free_irq_routing(kvm);
469	467	kvm_io_bus_destroy(&kvm->pio_bus);
470	468	kvm_io_bus_destroy(&kvm->mmio_bus);
471		-#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
472		- if (kvm->coalesced_mmio_ring != NULL)
473		- free_page((unsigned long)kvm->coalesced_mmio_ring);
474		-#endif
	469	+ kvm_coalesced_mmio_free(kvm);
475	470	#if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
476	471	mmu_notifier_unregister(&kvm->mmu_notifier, kvm->mm);
477	472	#else