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authorKim Kibum <kb0929.kim@samsung.com>2012-04-29 16:59:19 +0900
committerKim Kibum <kb0929.kim@samsung.com>2012-04-29 16:59:19 +0900
commitc1775d1a93a77a57380a4ce87ac3a8f807c944b2 (patch)
treee1f233f2af38ee247a677082198dd3a69a12a5a1 /virt/kvm/coalesced_mmio.c
parent2c2dcd5ffef2e97176e6a55e45512177e55e6fb9 (diff)
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Diffstat (limited to 'virt/kvm/coalesced_mmio.c')
-rw-r--r--virt/kvm/coalesced_mmio.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
new file mode 100644
index 00000000..fc848756
--- /dev/null
+++ b/virt/kvm/coalesced_mmio.c
@@ -0,0 +1,191 @@
+/*
+ * KVM coalesced MMIO
+ *
+ * Copyright (c) 2008 Bull S.A.S.
+ * Copyright 2009 Red Hat, Inc. and/or its affiliates.
+ *
+ * Author: Laurent Vivier <Laurent.Vivier@bull.net>
+ *
+ */
+
+#include "iodev.h"
+
+#include <linux/kvm_host.h>
+#include <linux/slab.h>
+#include <linux/kvm.h>
+
+#include "coalesced_mmio.h"
+
+static inline struct kvm_coalesced_mmio_dev *to_mmio(struct kvm_io_device *dev)
+{
+ return container_of(dev, struct kvm_coalesced_mmio_dev, dev);
+}
+
+static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
+ gpa_t addr, int len)
+{
+ struct kvm_coalesced_mmio_zone *zone;
+ struct kvm_coalesced_mmio_ring *ring;
+ unsigned avail;
+ int i;
+
+ /* Are we able to batch it ? */
+
+ /* last is the first free entry
+ * check if we don't meet the first used entry
+ * there is always one unused entry in the buffer
+ */
+ ring = dev->kvm->coalesced_mmio_ring;
+ avail = (ring->first - ring->last - 1) % KVM_COALESCED_MMIO_MAX;
+ if (avail < KVM_MAX_VCPUS) {
+ /* full */
+ return 0;
+ }
+
+ /* is it in a batchable area ? */
+
+ for (i = 0; i < dev->nb_zones; i++) {
+ zone = &dev->zone[i];
+
+ /* (addr,len) is fully included in
+ * (zone->addr, zone->size)
+ */
+
+ if (zone->addr <= addr &&
+ addr + len <= zone->addr + zone->size)
+ return 1;
+ }
+ return 0;
+}
+
+static int coalesced_mmio_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
+{
+ struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
+ struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
+ if (!coalesced_mmio_in_range(dev, addr, len))
+ return -EOPNOTSUPP;
+
+ spin_lock(&dev->lock);
+
+ /* copy data in first free entry of the ring */
+
+ ring->coalesced_mmio[ring->last].phys_addr = addr;
+ ring->coalesced_mmio[ring->last].len = len;
+ memcpy(ring->coalesced_mmio[ring->last].data, val, len);
+ smp_wmb();
+ ring->last = (ring->last + 1) % KVM_COALESCED_MMIO_MAX;
+ spin_unlock(&dev->lock);
+ return 0;
+}
+
+static void coalesced_mmio_destructor(struct kvm_io_device *this)
+{
+ struct kvm_coalesced_mmio_dev *dev = to_mmio(this);
+
+ kfree(dev);
+}
+
+static const struct kvm_io_device_ops coalesced_mmio_ops = {
+ .write = coalesced_mmio_write,
+ .destructor = coalesced_mmio_destructor,
+};
+
+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)
+ goto out_free_page;
+ spin_lock_init(&dev->lock);
+ kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
+ dev->kvm = kvm;
+ kvm->coalesced_mmio_dev = dev;
+
+ mutex_lock(&kvm->slots_lock);
+ ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, &dev->dev);
+ mutex_unlock(&kvm->slots_lock);
+ if (ret < 0)
+ goto out_free_dev;
+
+ return ret;
+
+out_free_dev:
+ kvm->coalesced_mmio_dev = NULL;
+ kfree(dev);
+out_free_page:
+ kvm->coalesced_mmio_ring = NULL;
+ __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,
+ struct kvm_coalesced_mmio_zone *zone)
+{
+ struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;
+
+ if (dev == NULL)
+ return -ENXIO;
+
+ mutex_lock(&kvm->slots_lock);
+ if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
+ mutex_unlock(&kvm->slots_lock);
+ return -ENOBUFS;
+ }
+
+ dev->zone[dev->nb_zones] = *zone;
+ dev->nb_zones++;
+
+ mutex_unlock(&kvm->slots_lock);
+ return 0;
+}
+
+int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
+ struct kvm_coalesced_mmio_zone *zone)
+{
+ int i;
+ struct kvm_coalesced_mmio_dev *dev = kvm->coalesced_mmio_dev;
+ struct kvm_coalesced_mmio_zone *z;
+
+ if (dev == NULL)
+ return -ENXIO;
+
+ mutex_lock(&kvm->slots_lock);
+
+ i = dev->nb_zones;
+ while (i) {
+ z = &dev->zone[i - 1];
+
+ /* unregister all zones
+ * included in (zone->addr, zone->size)
+ */
+
+ if (zone->addr <= z->addr &&
+ z->addr + z->size <= zone->addr + zone->size) {
+ dev->nb_zones--;
+ *z = dev->zone[dev->nb_zones];
+ }
+ i--;
+ }
+
+ mutex_unlock(&kvm->slots_lock);
+
+ return 0;
+}