cregit-Linux how code gets into the kernel

Release 4.7 virt/kvm/coalesced_mmio.c

Directory: virt/kvm
/*
 * 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 <kvm/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);
}


Contributors
PersonTokensPropCommitsCommitProp
gregory haskinsgregory haskins25100.00%1100.00%


Total25100.00%1100.00%






static int coalesced_mmio_in_range(struct kvm_coalesced_mmio_dev *dev,
				   gpa_t addr, int len)
{
	/* is it in a batchable area ?
         * (addr,len) is fully included in
         * (zone->addr, zone->size)
         */
	if (len < 0)
		return 0;
	if (addr + len < addr)
		return 0;
	if (addr < dev->zone.addr)
		return 0;
	if (addr + len > dev->zone.addr + dev->zone.size)
		return 0;
	return 1;
}


Contributors
PersonTokensPropCommitsCommitProp
dan carpenterdan carpenter3648.00%125.00%


laurent vivierlaurent vivier2837.33%125.00%


sasha levinsasha levin912.00%125.00%


michael s. tsirkinmichael s. tsirkin22.67%125.00%


Total75100.00%4100.00%






static int coalesced_mmio_has_room(struct kvm_coalesced_mmio_dev *dev)
{
	struct kvm_coalesced_mmio_ring *ring;
	unsigned avail;

	/* 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 == 0) {
		/* full */
		return 0;
	}

	return 1;
}


Contributors
PersonTokensPropCommitsCommitProp
sasha levinsasha levin60100.00%1100.00%


Total60100.00%1100.00%






static int coalesced_mmio_write(struct kvm_vcpu *vcpu,
				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->kvm->ring_lock);

	if (!coalesced_mmio_has_room(dev)) {
		spin_unlock(&dev->kvm->ring_lock);
		return -EOPNOTSUPP;
	}

	/* 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->kvm->ring_lock);
	return 0;
}


Contributors
PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier10158.38%114.29%


sasha levinsasha levin3017.34%228.57%


michael s. tsirkinmichael s. tsirkin2011.56%114.29%


marcelo tosattimarcelo tosatti148.09%114.29%


nikolay nikolaevnikolay nikolaev52.89%114.29%


gregory haskinsgregory haskins31.73%114.29%


Total173100.00%7100.00%






static void coalesced_mmio_destructor(struct kvm_io_device *this)
{
	struct kvm_coalesced_mmio_dev *dev = to_mmio(this);

	list_del(&dev->list);

	kfree(dev);
}


Contributors
PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier1544.12%125.00%


gregory haskinsgregory haskins1132.35%250.00%


sasha levinsasha levin823.53%125.00%


Total34100.00%4100.00%




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 page *page;
	int ret;

	ret = -ENOMEM;
	page = alloc_page(GFP_KERNEL | __GFP_ZERO);
	if (!page)
		goto out_err;

	ret = 0;
	kvm->coalesced_mmio_ring = page_address(page);

	/*
         * We're using this spinlock to sync access to the coalesced ring.
         * The list doesn't need it's own lock since device registration and
         * unregistration should only happen when kvm->slots_lock is held.
         */
	spin_lock_init(&kvm->ring_lock);
	INIT_LIST_HEAD(&kvm->coalesced_zones);

out_err:
	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
avi kivityavi kivity3952.00%116.67%


laurent vivierlaurent vivier1621.33%116.67%


sasha levinsasha levin810.67%116.67%


marcelo tosattimarcelo tosatti79.33%233.33%


gregory haskinsgregory haskins56.67%116.67%


Total75100.00%6100.00%






void kvm_coalesced_mmio_free(struct kvm *kvm)
{
	if (kvm->coalesced_mmio_ring)
		free_page((unsigned long)kvm->coalesced_mmio_ring);
}


Contributors
PersonTokensPropCommitsCommitProp
avi kivityavi kivity27100.00%1100.00%


Total27100.00%1100.00%






int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
					 struct kvm_coalesced_mmio_zone *zone)
{
	int ret;
	struct kvm_coalesced_mmio_dev *dev;

	dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
	if (!dev)
		return -ENOMEM;

	kvm_iodevice_init(&dev->dev, &coalesced_mmio_ops);
	dev->kvm = kvm;
	dev->zone = *zone;

	mutex_lock(&kvm->slots_lock);
	ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS, zone->addr,
				      zone->size, &dev->dev);
	if (ret < 0)
		goto out_free_dev;
	list_add_tail(&dev->list, &kvm->coalesced_zones);
	mutex_unlock(&kvm->slots_lock);

	return 0;

out_free_dev:
	mutex_unlock(&kvm->slots_lock);
	kfree(dev);

	return ret;
}


Contributors
PersonTokensPropCommitsCommitProp
sasha levinsasha levin8959.33%233.33%


laurent vivierlaurent vivier5335.33%116.67%


michael s. tsirkinmichael s. tsirkin32.00%116.67%


marcelo tosattimarcelo tosatti32.00%116.67%


dan carpenterdan carpenter21.33%116.67%


Total150100.00%6100.00%






int kvm_vm_ioctl_unregister_coalesced_mmio(struct kvm *kvm,
					   struct kvm_coalesced_mmio_zone *zone)
{
	struct kvm_coalesced_mmio_dev *dev, *tmp;

	mutex_lock(&kvm->slots_lock);

	list_for_each_entry_safe(dev, tmp, &kvm->coalesced_zones, list)
		if (coalesced_mmio_in_range(dev, zone->addr, zone->size)) {
			kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS, &dev->dev);
			kvm_iodevice_destructor(&dev->dev);
		}

	mutex_unlock(&kvm->slots_lock);

	return 0;
}

Contributors
PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier5460.67%125.00%


sasha levinsasha levin3134.83%125.00%


marcelo tosattimarcelo tosatti22.25%125.00%


michael s. tsirkinmichael s. tsirkin22.25%125.00%


Total89100.00%4100.00%




Overall Contributors
PersonTokensPropCommitsCommitProp
laurent vivierlaurent vivier27837.47%15.26%


sasha levinsasha levin23531.67%315.79%


avi kivityavi kivity679.03%210.53%


gregory haskinsgregory haskins628.36%315.79%


dan carpenterdan carpenter385.12%210.53%


michael s. tsirkinmichael s. tsirkin273.64%210.53%


marcelo tosattimarcelo tosatti263.50%315.79%


nikolay nikolaevnikolay nikolaev50.67%15.26%


tejun heotejun heo30.40%15.26%


andre przywaraandre przywara10.13%15.26%


Total742100.00%19100.00%

  
Directory: virt/kvm



Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}