235 lines
6.2 KiB
C
235 lines
6.2 KiB
C
/*
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* Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License, version 2, as
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* published by the Free Software Foundation.
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*/
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#include <linux/cpu.h>
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#include <linux/kvm_host.h>
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#include <linux/preempt.h>
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#include <linux/export.h>
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#include <linux/sched.h>
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#include <linux/spinlock.h>
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#include <linux/bootmem.h>
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#include <linux/init.h>
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#include <linux/memblock.h>
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#include <linux/sizes.h>
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#include <linux/cma.h>
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#include <asm/cputable.h>
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#include <asm/kvm_ppc.h>
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#include <asm/kvm_book3s.h>
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#define KVM_CMA_CHUNK_ORDER 18
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/*
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* Hash page table alignment on newer cpus(CPU_FTR_ARCH_206)
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* should be power of 2.
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*/
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#define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */
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/*
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* By default we reserve 5% of memory for hash pagetable allocation.
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*/
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static unsigned long kvm_cma_resv_ratio = 5;
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/*
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* We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area.
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* Each RMA has to be physically contiguous and of a size that the
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* hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB,
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* and other larger sizes. Since we are unlikely to be allocate that
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* much physically contiguous memory after the system is up and running,
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* we preallocate a set of RMAs in early boot using CMA.
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* should be power of 2.
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*/
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unsigned long kvm_rma_pages = (1 << 27) >> PAGE_SHIFT; /* 128MB */
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EXPORT_SYMBOL_GPL(kvm_rma_pages);
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static struct cma *kvm_cma;
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/* Work out RMLS (real mode limit selector) field value for a given RMA size.
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Assumes POWER7 or PPC970. */
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static inline int lpcr_rmls(unsigned long rma_size)
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{
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switch (rma_size) {
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case 32ul << 20: /* 32 MB */
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if (cpu_has_feature(CPU_FTR_ARCH_206))
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return 8; /* only supported on POWER7 */
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return -1;
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case 64ul << 20: /* 64 MB */
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return 3;
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case 128ul << 20: /* 128 MB */
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return 7;
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case 256ul << 20: /* 256 MB */
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return 4;
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case 1ul << 30: /* 1 GB */
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return 2;
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case 16ul << 30: /* 16 GB */
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return 1;
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case 256ul << 30: /* 256 GB */
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return 0;
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default:
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return -1;
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}
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}
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static int __init early_parse_rma_size(char *p)
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{
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unsigned long kvm_rma_size;
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pr_debug("%s(%s)\n", __func__, p);
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if (!p)
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return -EINVAL;
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kvm_rma_size = memparse(p, &p);
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/*
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* Check that the requested size is one supported in hardware
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*/
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if (lpcr_rmls(kvm_rma_size) < 0) {
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pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size);
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return -EINVAL;
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}
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kvm_rma_pages = kvm_rma_size >> PAGE_SHIFT;
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return 0;
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}
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early_param("kvm_rma_size", early_parse_rma_size);
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struct kvm_rma_info *kvm_alloc_rma()
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{
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struct page *page;
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struct kvm_rma_info *ri;
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ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL);
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if (!ri)
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return NULL;
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page = cma_alloc(kvm_cma, kvm_rma_pages, order_base_2(kvm_rma_pages));
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if (!page)
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goto err_out;
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atomic_set(&ri->use_count, 1);
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ri->base_pfn = page_to_pfn(page);
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return ri;
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err_out:
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kfree(ri);
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return NULL;
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}
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EXPORT_SYMBOL_GPL(kvm_alloc_rma);
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void kvm_release_rma(struct kvm_rma_info *ri)
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{
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if (atomic_dec_and_test(&ri->use_count)) {
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cma_release(kvm_cma, pfn_to_page(ri->base_pfn), kvm_rma_pages);
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kfree(ri);
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}
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}
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EXPORT_SYMBOL_GPL(kvm_release_rma);
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static int __init early_parse_kvm_cma_resv(char *p)
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{
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pr_debug("%s(%s)\n", __func__, p);
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if (!p)
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return -EINVAL;
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return kstrtoul(p, 0, &kvm_cma_resv_ratio);
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}
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early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv);
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struct page *kvm_alloc_hpt(unsigned long nr_pages)
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{
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unsigned long align_pages = HPT_ALIGN_PAGES;
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VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
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/* Old CPUs require HPT aligned on a multiple of its size */
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if (!cpu_has_feature(CPU_FTR_ARCH_206))
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align_pages = nr_pages;
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return cma_alloc(kvm_cma, nr_pages, order_base_2(align_pages));
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}
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EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
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void kvm_release_hpt(struct page *page, unsigned long nr_pages)
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{
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cma_release(kvm_cma, page, nr_pages);
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}
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EXPORT_SYMBOL_GPL(kvm_release_hpt);
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/**
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* kvm_cma_reserve() - reserve area for kvm hash pagetable
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*
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* This function reserves memory from early allocator. It should be
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* called by arch specific code once the early allocator (memblock or bootmem)
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* has been activated and all other subsystems have already allocated/reserved
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* memory.
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*/
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void __init kvm_cma_reserve(void)
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{
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unsigned long align_size;
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struct memblock_region *reg;
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phys_addr_t selected_size = 0;
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/*
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* We cannot use memblock_phys_mem_size() here, because
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* memblock_analyze() has not been called yet.
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*/
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for_each_memblock(memory, reg)
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selected_size += memblock_region_memory_end_pfn(reg) -
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memblock_region_memory_base_pfn(reg);
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selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT;
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if (selected_size) {
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pr_debug("%s: reserving %ld MiB for global area\n", __func__,
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(unsigned long)selected_size / SZ_1M);
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/*
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* Old CPUs require HPT aligned on a multiple of its size. So for them
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* make the alignment as max size we could request.
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*/
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if (!cpu_has_feature(CPU_FTR_ARCH_206))
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align_size = __rounddown_pow_of_two(selected_size);
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else
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align_size = HPT_ALIGN_PAGES << PAGE_SHIFT;
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align_size = max(kvm_rma_pages << PAGE_SHIFT, align_size);
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cma_declare_contiguous(0, selected_size, 0, align_size,
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KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, &kvm_cma);
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}
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}
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/*
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* When running HV mode KVM we need to block certain operations while KVM VMs
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* exist in the system. We use a counter of VMs to track this.
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*
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* One of the operations we need to block is onlining of secondaries, so we
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* protect hv_vm_count with get/put_online_cpus().
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*/
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static atomic_t hv_vm_count;
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void kvm_hv_vm_activated(void)
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{
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get_online_cpus();
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atomic_inc(&hv_vm_count);
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put_online_cpus();
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}
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EXPORT_SYMBOL_GPL(kvm_hv_vm_activated);
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void kvm_hv_vm_deactivated(void)
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{
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get_online_cpus();
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atomic_dec(&hv_vm_count);
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put_online_cpus();
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}
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EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated);
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bool kvm_hv_mode_active(void)
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{
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return atomic_read(&hv_vm_count) != 0;
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}
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extern int hcall_real_table[], hcall_real_table_end[];
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int kvmppc_hcall_impl_hv_realmode(unsigned long cmd)
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{
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cmd /= 4;
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if (cmd < hcall_real_table_end - hcall_real_table &&
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hcall_real_table[cmd])
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return 1;
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return 0;
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}
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EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode);
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