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 9441c19c8SMichael Ellerman #include <linux/cpu.h> 10aa04b4ccSPaul Mackerras #include <linux/kvm_host.h> 11aa04b4ccSPaul Mackerras #include <linux/preempt.h> 1266b15db6SPaul Gortmaker #include <linux/export.h> 13aa04b4ccSPaul Mackerras #include <linux/sched.h> 14aa04b4ccSPaul Mackerras #include <linux/spinlock.h> 15aa04b4ccSPaul Mackerras #include <linux/bootmem.h> 16aa04b4ccSPaul Mackerras #include <linux/init.h> 17fa61a4e3SAneesh Kumar K.V #include <linux/memblock.h> 18fa61a4e3SAneesh Kumar K.V #include <linux/sizes.h> 19fc95ca72SJoonsoo Kim #include <linux/cma.h> 20aa04b4ccSPaul Mackerras 21aa04b4ccSPaul Mackerras #include <asm/cputable.h> 22aa04b4ccSPaul Mackerras #include <asm/kvm_ppc.h> 23aa04b4ccSPaul Mackerras #include <asm/kvm_book3s.h> 24aa04b4ccSPaul Mackerras 25fc95ca72SJoonsoo Kim #define KVM_CMA_CHUNK_ORDER 18 26fc95ca72SJoonsoo Kim 27fa61a4e3SAneesh Kumar K.V /* 28fa61a4e3SAneesh Kumar K.V * Hash page table alignment on newer cpus(CPU_FTR_ARCH_206) 29fa61a4e3SAneesh Kumar K.V * should be power of 2. 30fa61a4e3SAneesh Kumar K.V */ 31fa61a4e3SAneesh Kumar K.V #define HPT_ALIGN_PAGES ((1 << 18) >> PAGE_SHIFT) /* 256k */ 32fa61a4e3SAneesh Kumar K.V /* 33fa61a4e3SAneesh Kumar K.V * By default we reserve 5% of memory for hash pagetable allocation. 34fa61a4e3SAneesh Kumar K.V */ 35fa61a4e3SAneesh Kumar K.V static unsigned long kvm_cma_resv_ratio = 5; 36aa04b4ccSPaul Mackerras /* 376c45b810SAneesh Kumar K.V * We allocate RMAs (real mode areas) for KVM guests from the KVM CMA area. 38aa04b4ccSPaul Mackerras * Each RMA has to be physically contiguous and of a size that the 39aa04b4ccSPaul Mackerras * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB, 40aa04b4ccSPaul Mackerras * and other larger sizes. Since we are unlikely to be allocate that 41aa04b4ccSPaul Mackerras * much physically contiguous memory after the system is up and running, 426c45b810SAneesh Kumar K.V * we preallocate a set of RMAs in early boot using CMA. 436c45b810SAneesh Kumar K.V * should be power of 2. 44aa04b4ccSPaul Mackerras */ 456c45b810SAneesh Kumar K.V unsigned long kvm_rma_pages = (1 << 27) >> PAGE_SHIFT; /* 128MB */ 466c45b810SAneesh Kumar K.V EXPORT_SYMBOL_GPL(kvm_rma_pages); 47aa04b4ccSPaul Mackerras 48fc95ca72SJoonsoo Kim static struct cma *kvm_cma; 49fc95ca72SJoonsoo Kim 50aa04b4ccSPaul Mackerras /* Work out RMLS (real mode limit selector) field value for a given RMA size. 519e368f29SPaul Mackerras Assumes POWER7 or PPC970. */ 52aa04b4ccSPaul Mackerras static inline int lpcr_rmls(unsigned long rma_size) 53aa04b4ccSPaul Mackerras { 54aa04b4ccSPaul Mackerras switch (rma_size) { 55aa04b4ccSPaul Mackerras case 32ul << 20: /* 32 MB */ 569e368f29SPaul Mackerras if (cpu_has_feature(CPU_FTR_ARCH_206)) 579e368f29SPaul Mackerras return 8; /* only supported on POWER7 */ 589e368f29SPaul Mackerras return -1; 59aa04b4ccSPaul Mackerras case 64ul << 20: /* 64 MB */ 60aa04b4ccSPaul Mackerras return 3; 61aa04b4ccSPaul Mackerras case 128ul << 20: /* 128 MB */ 62aa04b4ccSPaul Mackerras return 7; 63aa04b4ccSPaul Mackerras case 256ul << 20: /* 256 MB */ 64aa04b4ccSPaul Mackerras return 4; 65aa04b4ccSPaul Mackerras case 1ul << 30: /* 1 GB */ 66aa04b4ccSPaul Mackerras return 2; 67aa04b4ccSPaul Mackerras case 16ul << 30: /* 16 GB */ 68aa04b4ccSPaul Mackerras return 1; 69aa04b4ccSPaul Mackerras case 256ul << 30: /* 256 GB */ 70aa04b4ccSPaul Mackerras return 0; 71aa04b4ccSPaul Mackerras default: 72aa04b4ccSPaul Mackerras return -1; 73aa04b4ccSPaul Mackerras } 74aa04b4ccSPaul Mackerras } 75aa04b4ccSPaul Mackerras 76b4e70611SAlexander Graf static int __init early_parse_rma_size(char *p) 77b4e70611SAlexander Graf { 786c45b810SAneesh Kumar K.V unsigned long kvm_rma_size; 796c45b810SAneesh Kumar K.V 806c45b810SAneesh Kumar K.V pr_debug("%s(%s)\n", __func__, p); 81b4e70611SAlexander Graf if (!p) 826c45b810SAneesh Kumar K.V return -EINVAL; 83b4e70611SAlexander Graf kvm_rma_size = memparse(p, &p); 846c45b810SAneesh Kumar K.V /* 856c45b810SAneesh Kumar K.V * Check that the requested size is one supported in hardware 866c45b810SAneesh Kumar K.V */ 876c45b810SAneesh Kumar K.V if (lpcr_rmls(kvm_rma_size) < 0) { 886c45b810SAneesh Kumar K.V pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size); 896c45b810SAneesh Kumar K.V return -EINVAL; 906c45b810SAneesh Kumar K.V } 916c45b810SAneesh Kumar K.V kvm_rma_pages = kvm_rma_size >> PAGE_SHIFT; 92b4e70611SAlexander Graf return 0; 93b4e70611SAlexander Graf } 94b4e70611SAlexander Graf early_param("kvm_rma_size", early_parse_rma_size); 95b4e70611SAlexander Graf 966c45b810SAneesh Kumar K.V struct kvm_rma_info *kvm_alloc_rma() 97b4e70611SAlexander Graf { 986c45b810SAneesh Kumar K.V struct page *page; 996c45b810SAneesh Kumar K.V struct kvm_rma_info *ri; 100b4e70611SAlexander Graf 1016c45b810SAneesh Kumar K.V ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL); 1026c45b810SAneesh Kumar K.V if (!ri) 1036c45b810SAneesh Kumar K.V return NULL; 104c04fa583SAlexey Kardashevskiy page = cma_alloc(kvm_cma, kvm_rma_pages, order_base_2(kvm_rma_pages)); 1056c45b810SAneesh Kumar K.V if (!page) 1066c45b810SAneesh Kumar K.V goto err_out; 1076c45b810SAneesh Kumar K.V atomic_set(&ri->use_count, 1); 1086c45b810SAneesh Kumar K.V ri->base_pfn = page_to_pfn(page); 1096c45b810SAneesh Kumar K.V return ri; 1106c45b810SAneesh Kumar K.V err_out: 1116c45b810SAneesh Kumar K.V kfree(ri); 1126c45b810SAneesh Kumar K.V return NULL; 113b4e70611SAlexander Graf } 114b4e70611SAlexander Graf EXPORT_SYMBOL_GPL(kvm_alloc_rma); 115b4e70611SAlexander Graf 1166c45b810SAneesh Kumar K.V void kvm_release_rma(struct kvm_rma_info *ri) 117b4e70611SAlexander Graf { 1186c45b810SAneesh Kumar K.V if (atomic_dec_and_test(&ri->use_count)) { 119fc95ca72SJoonsoo Kim cma_release(kvm_cma, pfn_to_page(ri->base_pfn), kvm_rma_pages); 1206c45b810SAneesh Kumar K.V kfree(ri); 1216c45b810SAneesh Kumar K.V } 122b4e70611SAlexander Graf } 123b4e70611SAlexander Graf EXPORT_SYMBOL_GPL(kvm_release_rma); 124b4e70611SAlexander Graf 125fa61a4e3SAneesh Kumar K.V static int __init early_parse_kvm_cma_resv(char *p) 126d2a1b483SAlexander Graf { 127fa61a4e3SAneesh Kumar K.V pr_debug("%s(%s)\n", __func__, p); 128d2a1b483SAlexander Graf if (!p) 129fa61a4e3SAneesh Kumar K.V return -EINVAL; 130fa61a4e3SAneesh Kumar K.V return kstrtoul(p, 0, &kvm_cma_resv_ratio); 131d2a1b483SAlexander Graf } 132fa61a4e3SAneesh Kumar K.V early_param("kvm_cma_resv_ratio", early_parse_kvm_cma_resv); 133d2a1b483SAlexander Graf 134fa61a4e3SAneesh Kumar K.V struct page *kvm_alloc_hpt(unsigned long nr_pages) 135d2a1b483SAlexander Graf { 136fa61a4e3SAneesh Kumar K.V unsigned long align_pages = HPT_ALIGN_PAGES; 137fa61a4e3SAneesh Kumar K.V 138c04fa583SAlexey Kardashevskiy VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT); 139fc95ca72SJoonsoo Kim 140fa61a4e3SAneesh Kumar K.V /* Old CPUs require HPT aligned on a multiple of its size */ 141fa61a4e3SAneesh Kumar K.V if (!cpu_has_feature(CPU_FTR_ARCH_206)) 142fa61a4e3SAneesh Kumar K.V align_pages = nr_pages; 143c04fa583SAlexey Kardashevskiy return cma_alloc(kvm_cma, nr_pages, order_base_2(align_pages)); 144d2a1b483SAlexander Graf } 145d2a1b483SAlexander Graf EXPORT_SYMBOL_GPL(kvm_alloc_hpt); 146d2a1b483SAlexander Graf 147fa61a4e3SAneesh Kumar K.V void kvm_release_hpt(struct page *page, unsigned long nr_pages) 148d2a1b483SAlexander Graf { 149fc95ca72SJoonsoo Kim cma_release(kvm_cma, page, nr_pages); 150d2a1b483SAlexander Graf } 151d2a1b483SAlexander Graf EXPORT_SYMBOL_GPL(kvm_release_hpt); 152d2a1b483SAlexander Graf 153fa61a4e3SAneesh Kumar K.V /** 154fa61a4e3SAneesh Kumar K.V * kvm_cma_reserve() - reserve area for kvm hash pagetable 155fa61a4e3SAneesh Kumar K.V * 156fa61a4e3SAneesh Kumar K.V * This function reserves memory from early allocator. It should be 157fa61a4e3SAneesh Kumar K.V * called by arch specific code once the early allocator (memblock or bootmem) 158fa61a4e3SAneesh Kumar K.V * has been activated and all other subsystems have already allocated/reserved 159fa61a4e3SAneesh Kumar K.V * memory. 160fa61a4e3SAneesh Kumar K.V */ 161fa61a4e3SAneesh Kumar K.V void __init kvm_cma_reserve(void) 162fa61a4e3SAneesh Kumar K.V { 163fa61a4e3SAneesh Kumar K.V unsigned long align_size; 164fa61a4e3SAneesh Kumar K.V struct memblock_region *reg; 165fa61a4e3SAneesh Kumar K.V phys_addr_t selected_size = 0; 166fa61a4e3SAneesh Kumar K.V /* 167fa61a4e3SAneesh Kumar K.V * We cannot use memblock_phys_mem_size() here, because 168fa61a4e3SAneesh Kumar K.V * memblock_analyze() has not been called yet. 169fa61a4e3SAneesh Kumar K.V */ 170fa61a4e3SAneesh Kumar K.V for_each_memblock(memory, reg) 171fa61a4e3SAneesh Kumar K.V selected_size += memblock_region_memory_end_pfn(reg) - 172fa61a4e3SAneesh Kumar K.V memblock_region_memory_base_pfn(reg); 173fa61a4e3SAneesh Kumar K.V 174fa61a4e3SAneesh Kumar K.V selected_size = (selected_size * kvm_cma_resv_ratio / 100) << PAGE_SHIFT; 175fa61a4e3SAneesh Kumar K.V if (selected_size) { 176fa61a4e3SAneesh Kumar K.V pr_debug("%s: reserving %ld MiB for global area\n", __func__, 177fa61a4e3SAneesh Kumar K.V (unsigned long)selected_size / SZ_1M); 178fa61a4e3SAneesh Kumar K.V /* 179fa61a4e3SAneesh Kumar K.V * Old CPUs require HPT aligned on a multiple of its size. So for them 180fa61a4e3SAneesh Kumar K.V * make the alignment as max size we could request. 181fa61a4e3SAneesh Kumar K.V */ 182fa61a4e3SAneesh Kumar K.V if (!cpu_has_feature(CPU_FTR_ARCH_206)) 183fa61a4e3SAneesh Kumar K.V align_size = __rounddown_pow_of_two(selected_size); 184fa61a4e3SAneesh Kumar K.V else 185fa61a4e3SAneesh Kumar K.V align_size = HPT_ALIGN_PAGES << PAGE_SHIFT; 1866c45b810SAneesh Kumar K.V 1876c45b810SAneesh Kumar K.V align_size = max(kvm_rma_pages << PAGE_SHIFT, align_size); 188c1f733aaSJoonsoo Kim cma_declare_contiguous(0, selected_size, 0, align_size, 189c1f733aaSJoonsoo Kim KVM_CMA_CHUNK_ORDER - PAGE_SHIFT, false, &kvm_cma); 190fa61a4e3SAneesh Kumar K.V } 191fa61a4e3SAneesh Kumar K.V } 192441c19c8SMichael Ellerman 193441c19c8SMichael Ellerman /* 194441c19c8SMichael Ellerman * When running HV mode KVM we need to block certain operations while KVM VMs 195441c19c8SMichael Ellerman * exist in the system. We use a counter of VMs to track this. 196441c19c8SMichael Ellerman * 197441c19c8SMichael Ellerman * One of the operations we need to block is onlining of secondaries, so we 198441c19c8SMichael Ellerman * protect hv_vm_count with get/put_online_cpus(). 199441c19c8SMichael Ellerman */ 200441c19c8SMichael Ellerman static atomic_t hv_vm_count; 201441c19c8SMichael Ellerman 202441c19c8SMichael Ellerman void kvm_hv_vm_activated(void) 203441c19c8SMichael Ellerman { 204441c19c8SMichael Ellerman get_online_cpus(); 205441c19c8SMichael Ellerman atomic_inc(&hv_vm_count); 206441c19c8SMichael Ellerman put_online_cpus(); 207441c19c8SMichael Ellerman } 208441c19c8SMichael Ellerman EXPORT_SYMBOL_GPL(kvm_hv_vm_activated); 209441c19c8SMichael Ellerman 210441c19c8SMichael Ellerman void kvm_hv_vm_deactivated(void) 211441c19c8SMichael Ellerman { 212441c19c8SMichael Ellerman get_online_cpus(); 213441c19c8SMichael Ellerman atomic_dec(&hv_vm_count); 214441c19c8SMichael Ellerman put_online_cpus(); 215441c19c8SMichael Ellerman } 216441c19c8SMichael Ellerman EXPORT_SYMBOL_GPL(kvm_hv_vm_deactivated); 217441c19c8SMichael Ellerman 218441c19c8SMichael Ellerman bool kvm_hv_mode_active(void) 219441c19c8SMichael Ellerman { 220441c19c8SMichael Ellerman return atomic_read(&hv_vm_count) != 0; 221441c19c8SMichael Ellerman } 222ae2113a4SPaul Mackerras 223ae2113a4SPaul Mackerras extern int hcall_real_table[], hcall_real_table_end[]; 224ae2113a4SPaul Mackerras 225ae2113a4SPaul Mackerras int kvmppc_hcall_impl_hv_realmode(unsigned long cmd) 226ae2113a4SPaul Mackerras { 227ae2113a4SPaul Mackerras cmd /= 4; 228ae2113a4SPaul Mackerras if (cmd < hcall_real_table_end - hcall_real_table && 229ae2113a4SPaul Mackerras hcall_real_table[cmd]) 230ae2113a4SPaul Mackerras return 1; 231ae2113a4SPaul Mackerras 232ae2113a4SPaul Mackerras return 0; 233ae2113a4SPaul Mackerras } 234ae2113a4SPaul Mackerras EXPORT_SYMBOL_GPL(kvmppc_hcall_impl_hv_realmode); 235