alistair23-linux/arch/powerpc/kvm/book3s_xive_native.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2017-2019, IBM Corporation.
 */

#define pr_fmt(fmt) "xive-kvm: " fmt

#include <linux/kernel.h>
#include <linux/kvm_host.h>
#include <linux/err.h>
#include <linux/gfp.h>
#include <linux/spinlock.h>
#include <linux/delay.h>
#include <asm/uaccess.h>
#include <asm/kvm_book3s.h>
#include <asm/kvm_ppc.h>
#include <asm/hvcall.h>
#include <asm/xive.h>
#include <asm/xive-regs.h>
#include <asm/debug.h>
#include <asm/debugfs.h>
#include <asm/opal.h>

#include <linux/debugfs.h>
#include <linux/seq_file.h>

#include "book3s_xive.h"

static int kvmppc_xive_native_set_attr(struct kvm_device *dev,
				       struct kvm_device_attr *attr)
{
	switch (attr->group) {
	case KVM_DEV_XIVE_GRP_CTRL:
		break;
	}
	return -ENXIO;
}

static int kvmppc_xive_native_get_attr(struct kvm_device *dev,
				       struct kvm_device_attr *attr)
{
	return -ENXIO;
}

static int kvmppc_xive_native_has_attr(struct kvm_device *dev,
				       struct kvm_device_attr *attr)
{
	switch (attr->group) {
	case KVM_DEV_XIVE_GRP_CTRL:
		break;
	}
	return -ENXIO;
}

static void kvmppc_xive_native_free(struct kvm_device *dev)
{
	struct kvmppc_xive *xive = dev->private;
	struct kvm *kvm = xive->kvm;

	debugfs_remove(xive->dentry);

	pr_devel("Destroying xive native device\n");

	if (kvm)
		kvm->arch.xive = NULL;

	if (xive->vp_base != XIVE_INVALID_VP)
		xive_native_free_vp_block(xive->vp_base);

	kfree(xive);
	kfree(dev);
}

static int kvmppc_xive_native_create(struct kvm_device *dev, u32 type)
{
	struct kvmppc_xive *xive;
	struct kvm *kvm = dev->kvm;
	int ret = 0;

	pr_devel("Creating xive native device\n");

	if (kvm->arch.xive)
		return -EEXIST;

	xive = kzalloc(sizeof(*xive), GFP_KERNEL);
	if (!xive)
		return -ENOMEM;

	dev->private = xive;
	xive->dev = dev;
	xive->kvm = kvm;
	kvm->arch.xive = xive;

	/*
	 * Allocate a bunch of VPs. KVM_MAX_VCPUS is a large value for
	 * a default. Getting the max number of CPUs the VM was
	 * configured with would improve our usage of the XIVE VP space.
	 */
	xive->vp_base = xive_native_alloc_vp_block(KVM_MAX_VCPUS);
	pr_devel("VP_Base=%x\n", xive->vp_base);

	if (xive->vp_base == XIVE_INVALID_VP)
		ret = -ENXIO;

	xive->single_escalation = xive_native_has_single_escalation();

	if (ret)
		kfree(xive);

	return ret;
}

static int xive_native_debug_show(struct seq_file *m, void *private)
{
	struct kvmppc_xive *xive = m->private;
	struct kvm *kvm = xive->kvm;

	if (!kvm)
		return 0;

	return 0;
}

static int xive_native_debug_open(struct inode *inode, struct file *file)
{
	return single_open(file, xive_native_debug_show, inode->i_private);
}

static const struct file_operations xive_native_debug_fops = {
	.open = xive_native_debug_open,
	.read = seq_read,
	.llseek = seq_lseek,
	.release = single_release,
};

static void xive_native_debugfs_init(struct kvmppc_xive *xive)
{
	char *name;

	name = kasprintf(GFP_KERNEL, "kvm-xive-%p", xive);
	if (!name) {
		pr_err("%s: no memory for name\n", __func__);
		return;
	}

	xive->dentry = debugfs_create_file(name, 0444, powerpc_debugfs_root,
					   xive, &xive_native_debug_fops);

	pr_debug("%s: created %s\n", __func__, name);
	kfree(name);
}

static void kvmppc_xive_native_init(struct kvm_device *dev)
{
	struct kvmppc_xive *xive = (struct kvmppc_xive *)dev->private;

	/* Register some debug interfaces */
	xive_native_debugfs_init(xive);
}

struct kvm_device_ops kvm_xive_native_ops = {
	.name = "kvm-xive-native",
	.create = kvmppc_xive_native_create,
	.init = kvmppc_xive_native_init,
	.destroy = kvmppc_xive_native_free,
	.set_attr = kvmppc_xive_native_set_attr,
	.get_attr = kvmppc_xive_native_get_attr,
	.has_attr = kvmppc_xive_native_has_attr,
};

void kvmppc_xive_native_init_module(void)
{
	;
}

void kvmppc_xive_native_exit_module(void)
{
	;
}