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-rw-r--r--virt/kvm/coalesced_mmio.c156
-rw-r--r--virt/kvm/coalesced_mmio.h23
-rw-r--r--virt/kvm/kvm_main.c57
3 files changed, 236 insertions, 0 deletions
diff --git a/virt/kvm/coalesced_mmio.c b/virt/kvm/coalesced_mmio.c
new file mode 100644
index 00000000000..5ae620d32fa
--- /dev/null
+++ b/virt/kvm/coalesced_mmio.c
@@ -0,0 +1,156 @@
+/*
+ * KVM coalesced MMIO
+ *
+ * Copyright (c) 2008 Bull S.A.S.
+ *
+ * Author: Laurent Vivier <Laurent.Vivier@bull.net>
+ *
+ */
+
+#include "iodev.h"
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+
+#include "coalesced_mmio.h"
+
+static int coalesced_mmio_in_range(struct kvm_io_device *this,
+ gpa_t addr, int len, int is_write)
+{
+ struct kvm_coalesced_mmio_dev *dev =
+ (struct kvm_coalesced_mmio_dev*)this->private;
+ struct kvm_coalesced_mmio_zone *zone;
+ int next;
+ int i;
+
+ if (!is_write)
+ return 0;
+
+ /* kvm->lock is taken by the caller and must be not released before
+ * dev.read/write
+ */
+
+ /* 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
+ */
+
+ next = (dev->kvm->coalesced_mmio_ring->last + 1) %
+ KVM_COALESCED_MMIO_MAX;
+ if (next == dev->kvm->coalesced_mmio_ring->first) {
+ /* 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 void coalesced_mmio_write(struct kvm_io_device *this,
+ gpa_t addr, int len, const void *val)
+{
+ struct kvm_coalesced_mmio_dev *dev =
+ (struct kvm_coalesced_mmio_dev*)this->private;
+ struct kvm_coalesced_mmio_ring *ring = dev->kvm->coalesced_mmio_ring;
+
+ /* kvm->lock must be taken by caller before call to in_range()*/
+
+ /* 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;
+}
+
+static void coalesced_mmio_destructor(struct kvm_io_device *this)
+{
+ kfree(this);
+}
+
+int kvm_coalesced_mmio_init(struct kvm *kvm)
+{
+ struct kvm_coalesced_mmio_dev *dev;
+
+ dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;
+ dev->dev.write = coalesced_mmio_write;
+ dev->dev.in_range = coalesced_mmio_in_range;
+ dev->dev.destructor = coalesced_mmio_destructor;
+ dev->dev.private = dev;
+ dev->kvm = kvm;
+ kvm->coalesced_mmio_dev = dev;
+ kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev);
+
+ return 0;
+}
+
+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 -EINVAL;
+
+ mutex_lock(&kvm->lock);
+ if (dev->nb_zones >= KVM_COALESCED_MMIO_ZONE_MAX) {
+ mutex_unlock(&kvm->lock);
+ return -ENOBUFS;
+ }
+
+ dev->zone[dev->nb_zones] = *zone;
+ dev->nb_zones++;
+
+ mutex_unlock(&kvm->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 -EINVAL;
+
+ mutex_lock(&kvm->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->lock);
+
+ return 0;
+}
diff --git a/virt/kvm/coalesced_mmio.h b/virt/kvm/coalesced_mmio.h
new file mode 100644
index 00000000000..5ac0ec62846
--- /dev/null
+++ b/virt/kvm/coalesced_mmio.h
@@ -0,0 +1,23 @@
+/*
+ * KVM coalesced MMIO
+ *
+ * Copyright (c) 2008 Bull S.A.S.
+ *
+ * Author: Laurent Vivier <Laurent.Vivier@bull.net>
+ *
+ */
+
+#define KVM_COALESCED_MMIO_ZONE_MAX 100
+
+struct kvm_coalesced_mmio_dev {
+ struct kvm_io_device dev;
+ struct kvm *kvm;
+ int nb_zones;
+ struct kvm_coalesced_mmio_zone zone[KVM_COALESCED_MMIO_ZONE_MAX];
+};
+
+int kvm_coalesced_mmio_init(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);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9330fad2b91..7d10dfa0d38 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -47,6 +47,10 @@
#include <asm/uaccess.h>
#include <asm/pgtable.h>
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+#include "coalesced_mmio.h"
+#endif
+
MODULE_AUTHOR("Qumranet");
MODULE_LICENSE("GPL");
@@ -185,10 +189,23 @@ EXPORT_SYMBOL_GPL(kvm_vcpu_uninit);
static struct kvm *kvm_create_vm(void)
{
struct kvm *kvm = kvm_arch_create_vm();
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ struct page *page;
+#endif
if (IS_ERR(kvm))
goto out;
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page) {
+ kfree(kvm);
+ return ERR_PTR(-ENOMEM);
+ }
+ kvm->coalesced_mmio_ring =
+ (struct kvm_coalesced_mmio_ring *)page_address(page);
+#endif
+
kvm->mm = current->mm;
atomic_inc(&kvm->mm->mm_count);
spin_lock_init(&kvm->mmu_lock);
@@ -200,6 +217,9 @@ static struct kvm *kvm_create_vm(void)
spin_lock(&kvm_lock);
list_add(&kvm->vm_list, &vm_list);
spin_unlock(&kvm_lock);
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ kvm_coalesced_mmio_init(kvm);
+#endif
out:
return kvm;
}
@@ -242,6 +262,10 @@ static void kvm_destroy_vm(struct kvm *kvm)
spin_unlock(&kvm_lock);
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_arch_destroy_vm(kvm);
mmdrop(mm);
}
@@ -826,6 +850,10 @@ static int kvm_vcpu_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
else if (vmf->pgoff == KVM_PIO_PAGE_OFFSET)
page = virt_to_page(vcpu->arch.pio_data);
#endif
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ else if (vmf->pgoff == KVM_COALESCED_MMIO_PAGE_OFFSET)
+ page = virt_to_page(vcpu->kvm->coalesced_mmio_ring);
+#endif
else
return VM_FAULT_SIGBUS;
get_page(page);
@@ -1148,6 +1176,32 @@ static long kvm_vm_ioctl(struct file *filp,
goto out;
break;
}
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ case KVM_REGISTER_COALESCED_MMIO: {
+ struct kvm_coalesced_mmio_zone zone;
+ r = -EFAULT;
+ if (copy_from_user(&zone, argp, sizeof zone))
+ goto out;
+ r = -ENXIO;
+ r = kvm_vm_ioctl_register_coalesced_mmio(kvm, &zone);
+ if (r)
+ goto out;
+ r = 0;
+ break;
+ }
+ case KVM_UNREGISTER_COALESCED_MMIO: {
+ struct kvm_coalesced_mmio_zone zone;
+ r = -EFAULT;
+ if (copy_from_user(&zone, argp, sizeof zone))
+ goto out;
+ r = -ENXIO;
+ r = kvm_vm_ioctl_unregister_coalesced_mmio(kvm, &zone);
+ if (r)
+ goto out;
+ r = 0;
+ break;
+ }
+#endif
default:
r = kvm_arch_vm_ioctl(filp, ioctl, arg);
}
@@ -1232,6 +1286,9 @@ static long kvm_dev_ioctl(struct file *filp,
#ifdef CONFIG_X86
r += PAGE_SIZE; /* pio data page */
#endif
+#ifdef KVM_COALESCED_MMIO_PAGE_OFFSET
+ r += PAGE_SIZE; /* coalesced mmio ring page */
+#endif
break;
case KVM_TRACE_ENABLE:
case KVM_TRACE_PAUSE:
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-28 20:34:01 +0000