1aa04b4ccSPaul Mackerras /* 2aa04b4ccSPaul Mackerras * Copyright 2011 Paul Mackerras, IBM Corp. <paulus@au1.ibm.com> 3aa04b4ccSPaul Mackerras * 4aa04b4ccSPaul Mackerras * This program is free software; you can redistribute it and/or modify 5aa04b4ccSPaul Mackerras * it under the terms of the GNU General Public License, version 2, as 6aa04b4ccSPaul Mackerras * published by the Free Software Foundation. 7aa04b4ccSPaul Mackerras */ 8aa04b4ccSPaul Mackerras 9aa04b4ccSPaul Mackerras #include <linux/kvm_host.h> 10aa04b4ccSPaul Mackerras #include <linux/preempt.h> 1166b15db6SPaul Gortmaker #include <linux/export.h> 12aa04b4ccSPaul Mackerras #include <linux/sched.h> 13aa04b4ccSPaul Mackerras #include <linux/spinlock.h> 14aa04b4ccSPaul Mackerras #include <linux/bootmem.h> 15aa04b4ccSPaul Mackerras #include <linux/init.h> 16fa61a4e3SAneesh Kumar K.V #include <linux/memblock.h> 17fa61a4e3SAneesh Kumar K.V #include <linux/sizes.h> 18aa04b4ccSPaul Mackerras 19aa04b4ccSPaul Mackerras #include <asm/cputable.h> 20aa04b4ccSPaul Mackerras #include <asm/kvm_ppc.h> 21aa04b4ccSPaul Mackerras #include <asm/kvm_book3s.h> 22aa04b4ccSPaul Mackerras 23fa61a4e3SAneesh Kumar K.V #include "book3s_hv_cma.h" 24fa61a4e3SAneesh Kumar K.V /* 25fa61a4e3SAneesh Kumar K.V * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206) 26fa61a4e3SAneesh Kumar K.V * should be power of 2. 27fa61a4e3SAneesh Kumar K.V */ 28fa61a4e3SAneesh Kumar K.V #define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */ 29fa61a4e3SAneesh Kumar K.V /* 30fa61a4e3SAneesh Kumar K.V * By default we reserve 5% of memory for hash pagetable allocation. 31fa61a4e3SAneesh Kumar K.V */ 32fa61a4e3SAneesh Kumar K.V static unsigned long kvm_cma_resv_ratio = 5; 33aa04b4ccSPaul Mackerras /* 346c45b810SAneesh Kumar K.V * We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area. 35aa04b4ccSPaul Mackerras * Each RMA has to be physically contiguous and of a size that the 36aa04b4ccSPaul Mackerras * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB, 37aa04b4ccSPaul Mackerras * and other larger sizes. Since we are unlikely to be allocate that 38aa04b4ccSPaul Mackerras * much physically contiguous memory after the system is up and running, 396c45b810SAneesh Kumar K.V * we preallocate a set of RMAs in early boot using CMA. 406c45b810SAneesh Kumar K.V * should be power of 2. 41aa04b4ccSPaul Mackerras */ 426c45b810SAneesh Kumar K.V unsigned long kvm_rma_pages = (1 << 27) >> PAGE_SHIFT; /* 128MB */ 436c45b810SAneesh Kumar K.V EXPORT_SYMBOL_GPL(kvm_rma_pages); 44aa04b4ccSPaul Mackerras 45aa04b4ccSPaul Mackerras /* Work out RMLS (real mode limit selector) field value for a given RMA size. 469e368f29SPaul Mackerras Assumes POWER7 or PPC970. */ 47aa04b4ccSPaul Mackerras static inline int lpcr_rmls(unsigned long rma_size) 48aa04b4ccSPaul Mackerras { 49aa04b4ccSPaul Mackerras switch (rma_size) { 50aa04b4ccSPaul Mackerras case 32ul << 20: /* 32 MB */ 519e368f29SPaul Mackerras if (cpu_has_feature(CPU_FTR_ARCH_206)) 529e368f29SPaul Mackerras return 8; /* only supported on POWER7 */ 539e368f29SPaul Mackerras return -1; 54aa04b4ccSPaul Mackerras case 64ul << 20: /* 64 MB */ 55aa04b4ccSPaul Mackerras return 3; 56aa04b4ccSPaul Mackerras case 128ul << 20: /* 128 MB */ 57aa04b4ccSPaul Mackerras return 7; 58aa04b4ccSPaul Mackerras case 256ul << 20: /* 256 MB */ 59aa04b4ccSPaul Mackerras return 4; 60aa04b4ccSPaul Mackerras case 1ul << 30: /* 1 GB */ 61aa04b4ccSPaul Mackerras return 2; 62aa04b4ccSPaul Mackerras case 16ul << 30: /* 16 GB */ 63aa04b4ccSPaul Mackerras return 1; 64aa04b4ccSPaul Mackerras case 256ul << 30: /* 256 GB */ 65aa04b4ccSPaul Mackerras return 0; 66aa04b4ccSPaul Mackerras default: 67aa04b4ccSPaul Mackerras return -1; 68aa04b4ccSPaul Mackerras } 69aa04b4ccSPaul Mackerras } 70aa04b4ccSPaul Mackerras 71b4e70611SAlexander Graf static int __init early_parse_rma_size(char *p) 72b4e70611SAlexander Graf { 736c45b810SAneesh Kumar K.V unsigned long kvm_rma_size; 746c45b810SAneesh Kumar K.V 756c45b810SAneesh Kumar K.V pr_debug("%s(%s)\n", __func__, p); 76b4e70611SAlexander Graf if (!p) 776c45b810SAneesh Kumar K.V return -EINVAL; 78b4e70611SAlexander Graf kvm_rma_size = memparse(p, &p); 796c45b810SAneesh Kumar K.V /* 806c45b810SAneesh Kumar K.V * Check that the requested size is one supported in hardware 816c45b810SAneesh Kumar K.V */ 826c45b810SAneesh Kumar K.V if (lpcr_rmls(kvm_rma_size) < 0) { 836c45b810SAneesh Kumar K.V pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size); 846c45b810SAneesh Kumar K.V return -EINVAL; 856c45b810SAneesh Kumar K.V } 866c45b810SAneesh Kumar K.V kvm_rma_pages = kvm_rma_size >> PAGE_SHIFT; 87b4e70611SAlexander Graf return 0; 88b4e70611SAlexander Graf } 89b4e70611SAlexander Graf early_param("kvm_rma_size", early_parse_rma_size); 90b4e70611SAlexander Graf 916c45b810SAneesh Kumar K.V struct kvm_rma_info *kvm_alloc_rma() 92b4e70611SAlexander Graf { 936c45b810SAneesh Kumar K.V struct page *page; 946c45b810SAneesh Kumar K.V struct kvm_rma_info *ri; 95b4e70611SAlexander Graf 966c45b810SAneesh Kumar K.V ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); 976c45b810SAneesh Kumar K.V if (!ri) 986c45b810SAneesh Kumar K.V return NULL; 996c45b810SAneesh Kumar K.V page = kvm_alloc_cma(kvm_rma_pages, kvm_rma_pages); 1006c45b810SAneesh Kumar K.V if (!page) 1016c45b810SAneesh Kumar K.V goto err_out; 1026c45b810SAneesh Kumar K.V atomic_set(&ri->use_count, 1); 1036c45b810SAneesh Kumar K.V ri->base_pfn = page_to_pfn(page); 1046c45b810SAneesh Kumar K.V return ri; 1056c45b810SAneesh Kumar K.V err_out: 1066c45b810SAneesh Kumar K.V kfree(ri); 1076c45b810SAneesh Kumar K.V return NULL; 108b4e70611SAlexander Graf } 109b4e70611SAlexander Graf EXPORT_SYMBOL_GPL(kvm_alloc_rma); 110b4e70611SAlexander Graf 1116c45b810SAneesh Kumar K.V void kvm_release_rma(struct kvm_rma_info *ri) 112b4e70611SAlexander Graf { 1136c45b810SAneesh Kumar K.V if (atomic_dec_and_test(&ri->use_count)) { 1146c45b810SAneesh Kumar K.V kvm_release_cma(pfn_to_page(ri->base_pfn), kvm_rma_pages); 1156c45b810SAneesh Kumar K.V kfree(ri); 1166c45b810SAneesh Kumar K.V } 117b4e70611SAlexander Graf } 118b4e70611SAlexander Graf EXPORT_SYMBOL_GPL(kvm_release_rma); 119b4e70611SAlexander Graf 120fa61a4e3SAneesh Kumar K.V static int __init early_parse_kvm_cma_resv(char *p) 121d2a1b483SAlexander Graf { 122fa61a4e3SAneesh Kumar K.V pr_debug("%s(%s)\n", __func__, p); 123d2a1b483SAlexander Graf if (!p) 124fa61a4e3SAneesh Kumar K.V return -EINVAL; 125fa61a4e3SAneesh Kumar K.V return kstrtoul(p, 0, &kvm_cma_resv_ratio); 126d2a1b483SAlexander Graf } 127fa61a4e3SAneesh Kumar K.V early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv); 128d2a1b483SAlexander Graf 129fa61a4e3SAneesh Kumar K.V struct page *kvm_alloc_hpt(unsigned long nr_pages) 130d2a1b483SAlexander Graf { 131fa61a4e3SAneesh Kumar K.V unsigned long align_pages = HPT_ALIGN_PAGES; 132fa61a4e3SAneesh Kumar K.V 133fa61a4e3SAneesh Kumar K.V /* Old CPUs require HPT aligned on a multiple of its size */ 134fa61a4e3SAneesh Kumar K.V if (!cpu_has_feature(CPU_FTR_ARCH_206)) 135fa61a4e3SAneesh Kumar K.V align_pages = nr_pages; 136fa61a4e3SAneesh Kumar K.V return kvm_alloc_cma(nr_pages, align_pages); 137d2a1b483SAlexander Graf } 138d2a1b483SAlexander Graf EXPORT_SYMBOL_GPL(kvm_alloc_hpt); 139d2a1b483SAlexander Graf 140fa61a4e3SAneesh Kumar K.V void kvm_release_hpt(struct page *page, unsigned long nr_pages) 141d2a1b483SAlexander Graf { 142fa61a4e3SAneesh Kumar K.V kvm_release_cma(page, nr_pages); 143d2a1b483SAlexander Graf } 144d2a1b483SAlexander Graf EXPORT_SYMBOL_GPL(kvm_release_hpt); 145d2a1b483SAlexander Graf 146fa61a4e3SAneesh Kumar K.V /** 147fa61a4e3SAneesh Kumar K.V * kvm_cma_reserve() - reserve area for kvm hash pagetable 148fa61a4e3SAneesh Kumar K.V * 149fa61a4e3SAneesh Kumar K.V * This function reserves memory from early allocator. It should be 150fa61a4e3SAneesh Kumar K.V * called by arch specific code once the early allocator (memblock or bootmem) 151fa61a4e3SAneesh Kumar K.V * has been activated and all other subsystems have already allocated/reserved 152fa61a4e3SAneesh Kumar K.V * memory. 153fa61a4e3SAneesh Kumar K.V */ 154fa61a4e3SAneesh Kumar K.V void __init kvm_cma_reserve(void) 155fa61a4e3SAneesh Kumar K.V { 156fa61a4e3SAneesh Kumar K.V unsigned long align_size; 157fa61a4e3SAneesh Kumar K.V struct memblock_region *reg; 158fa61a4e3SAneesh Kumar K.V phys_addr_t selected_size = 0; 159fa61a4e3SAneesh Kumar K.V /* 160fa61a4e3SAneesh Kumar K.V * We cannot use memblock_phys_mem_size() here, because 161fa61a4e3SAneesh Kumar K.V * memblock_analyze() has not been called yet. 162fa61a4e3SAneesh Kumar K.V */ 163fa61a4e3SAneesh Kumar K.V for_each_memblock(memory, reg) 164fa61a4e3SAneesh Kumar K.V selected_size += memblock_region_memory_end_pfn(reg) - 165fa61a4e3SAneesh Kumar K.V memblock_region_memory_base_pfn(reg); 166fa61a4e3SAneesh Kumar K.V 167fa61a4e3SAneesh Kumar K.V selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT; 168fa61a4e3SAneesh Kumar K.V if (selected_size) { 169fa61a4e3SAneesh Kumar K.V pr_debug("%s: reserving %ld MiB for global area\n", __func__, 170fa61a4e3SAneesh Kumar K.V (unsigned long)selected_size / SZ_1M); 171fa61a4e3SAneesh Kumar K.V /* 172fa61a4e3SAneesh Kumar K.V * Old CPUs require HPT aligned on a multiple of its size. So for them 173fa61a4e3SAneesh Kumar K.V * make the alignment as max size we could request. 174fa61a4e3SAneesh Kumar K.V */ 175fa61a4e3SAneesh Kumar K.V if (!cpu_has_feature(CPU_FTR_ARCH_206)) 176fa61a4e3SAneesh Kumar K.V align_size = __rounddown_pow_of_two(selected_size); 177fa61a4e3SAneesh Kumar K.V else 178fa61a4e3SAneesh Kumar K.V align_size = HPT_ALIGN_PAGES << PAGE_SHIFT; 1796c45b810SAneesh Kumar K.V 1806c45b810SAneesh Kumar K.V align_size = max(kvm_rma_pages << PAGE_SHIFT, align_size); 181fa61a4e3SAneesh Kumar K.V kvm_cma_declare_contiguous(selected_size, align_size); 182fa61a4e3SAneesh Kumar K.V } 183fa61a4e3SAneesh Kumar K.V } 184