book3s_hv_builtin.c 3.6 KB
Newer Older
1 2 3 4 5 6 7 8
/*
 * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 */

9
#include <linux/cpu.h>
10 11
#include <linux/kvm_host.h>
#include <linux/preempt.h>
12
#include <linux/export.h>
13 14 15 16
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/bootmem.h>
#include <linux/init.h>
17 18
#include <linux/memblock.h>
#include <linux/sizes.h>
19
#include <linux/cma.h>
20 21 22 23 24

#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>

25 26
#define KVM_CMA_CHUNK_ORDER	18

27 28 29 30 31 32 33 34 35
/*
 * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
 * should be power of 2.
 */
#define HPT_ALIGN_PAGES		((1 << 18) >> PAGE_SHIFT) /* 256k */
/*
 * By default we reserve 5% of memory for hash pagetable allocation.
 */
static unsigned long kvm_cma_resv_ratio = 5;
36

37 38
static struct cma *kvm_cma;

39
static int __init early_parse_kvm_cma_resv(char *p)
A
Alexander Graf 已提交
40
{
41
	pr_debug("%s(%s)\n", __func__, p);
A
Alexander Graf 已提交
42
	if (!p)
43 44
		return -EINVAL;
	return kstrtoul(p, 0, &kvm_cma_resv_ratio);
A
Alexander Graf 已提交
45
}
46
early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
A
Alexander Graf 已提交
47

48
struct page *kvm_alloc_hpt(unsigned long nr_pages)
A
Alexander Graf 已提交
49
{
50
	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
51

52
	return cma_alloc(kvm_cma, nr_pages, order_base_2(HPT_ALIGN_PAGES));
A
Alexander Graf 已提交
53 54 55
}
EXPORT_SYMBOL_GPL(kvm_alloc_hpt);

56
void kvm_release_hpt(struct page *page, unsigned long nr_pages)
A
Alexander Graf 已提交
57
{
58
	cma_release(kvm_cma, page, nr_pages);
A
Alexander Graf 已提交
59 60 61
}
EXPORT_SYMBOL_GPL(kvm_release_hpt);

62 63 64 65 66 67 68 69 70 71 72 73 74
/**
 * kvm_cma_reserve() - reserve area for kvm hash pagetable
 *
 * This function reserves memory from early allocator. It should be
 * called by arch specific code once the early allocator (memblock or bootmem)
 * has been activated and all other subsystems have already allocated/reserved
 * memory.
 */
void __init kvm_cma_reserve(void)
{
	unsigned long align_size;
	struct memblock_region *reg;
	phys_addr_t selected_size = 0;
75 76 77 78 79 80

	/*
	 * We need CMA reservation only when we are in HV mode
	 */
	if (!cpu_has_feature(CPU_FTR_HVMODE))
		return;
81 82 83 84 85 86 87 88 89 90 91 92
	/*
	 * We cannot use memblock_phys_mem_size() here, because
	 * memblock_analyze() has not been called yet.
	 */
	for_each_memblock(memory, reg)
		selected_size += memblock_region_memory_end_pfn(reg) -
				 memblock_region_memory_base_pfn(reg);

	selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
	if (selected_size) {
		pr_debug("%s: reserving %ld MiB for global area\n", __func__,
			 (unsigned long)selected_size / SZ_1M);
93
		align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
94 95
		cma_declare_contiguous(0, selected_size, 0, align_size,
			KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, &kvm_cma);
96 97
	}
}
98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127

/*
 * When running HV mode KVM we need to block certain operations while KVM VMs
 * exist in the system. We use a counter of VMs to track this.
 *
 * One of the operations we need to block is onlining of secondaries, so we
 * protect hv_vm_count with get/put_online_cpus().
 */
static atomic_t hv_vm_count;

void kvm_hv_vm_activated(void)
{
	get_online_cpus();
	atomic_inc(&hv_vm_count);
	put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);

void kvm_hv_vm_deactivated(void)
{
	get_online_cpus();
	atomic_dec(&hv_vm_count);
	put_online_cpus();
}
EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated);

bool kvm_hv_mode_active(void)
{
	return atomic_read(&hv_vm_count) != 0;
}
128 129 130 131 132 133 134 135 136 137 138 139 140

extern int hcall_real_table[], hcall_real_table_end[];

int kvmppc_hcall_impl_hv_realmode(unsigned long cmd)
{
	cmd /= 4;
	if (cmd < hcall_real_table_end - hcall_real_table &&
	    hcall_real_table[cmd])
		return 1;

	return 0;
}
EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);