diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_builtin.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_builtin.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_builtin.c b/arch/powerpc/kvm/book3s_hv_builtin.c new file mode 100644 index 0000000..286f13d --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_builtin.c @@ -0,0 +1,156 @@ +/* + * 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. + */ + +#include <linux/kvm_host.h> +#include <linux/preempt.h> +#include <linux/export.h> +#include <linux/sched.h> +#include <linux/spinlock.h> +#include <linux/bootmem.h> +#include <linux/init.h> + +#include <asm/cputable.h> +#include <asm/kvm_ppc.h> +#include <asm/kvm_book3s.h> + +/* + * This maintains a list of RMAs (real mode areas) for KVM guests to use. + * Each RMA has to be physically contiguous and of a size that the + * hardware supports. PPC970 and POWER7 support 64MB, 128MB and 256MB, + * and other larger sizes. Since we are unlikely to be allocate that + * much physically contiguous memory after the system is up and running, + * we preallocate a set of RMAs in early boot for KVM to use. + */ +static unsigned long kvm_rma_size = 64 << 20; /* 64MB */ +static unsigned long kvm_rma_count; + +static int __init early_parse_rma_size(char *p) +{ + if (!p) + return 1; + + kvm_rma_size = memparse(p, &p); + + return 0; +} +early_param("kvm_rma_size", early_parse_rma_size); + +static int __init early_parse_rma_count(char *p) +{ + if (!p) + return 1; + + kvm_rma_count = simple_strtoul(p, NULL, 0); + + return 0; +} +early_param("kvm_rma_count", early_parse_rma_count); + +static struct kvmppc_rma_info *rma_info; +static LIST_HEAD(free_rmas); +static DEFINE_SPINLOCK(rma_lock); + +/* Work out RMLS (real mode limit selector) field value for a given RMA size. + Assumes POWER7 or PPC970. */ +static inline int lpcr_rmls(unsigned long rma_size) +{ + switch (rma_size) { + case 32ul << 20: /* 32 MB */ + if (cpu_has_feature(CPU_FTR_ARCH_206)) + return 8; /* only supported on POWER7 */ + return -1; + case 64ul << 20: /* 64 MB */ + return 3; + case 128ul << 20: /* 128 MB */ + return 7; + case 256ul << 20: /* 256 MB */ + return 4; + case 1ul << 30: /* 1 GB */ + return 2; + case 16ul << 30: /* 16 GB */ + return 1; + case 256ul << 30: /* 256 GB */ + return 0; + default: + return -1; + } +} + +/* + * Called at boot time while the bootmem allocator is active, + * to allocate contiguous physical memory for the real memory + * areas for guests. + */ +void kvm_rma_init(void) +{ + unsigned long i; + unsigned long j, npages; + void *rma; + struct page *pg; + + /* Only do this on PPC970 in HV mode */ + if (!cpu_has_feature(CPU_FTR_HVMODE) || + !cpu_has_feature(CPU_FTR_ARCH_201)) + return; + + if (!kvm_rma_size || !kvm_rma_count) + return; + + /* Check that the requested size is one supported in hardware */ + if (lpcr_rmls(kvm_rma_size) < 0) { + pr_err("RMA size of 0x%lx not supported\n", kvm_rma_size); + return; + } + + npages = kvm_rma_size >> PAGE_SHIFT; + rma_info = alloc_bootmem(kvm_rma_count * sizeof(struct kvmppc_rma_info)); + for (i = 0; i < kvm_rma_count; ++i) { + rma = alloc_bootmem_align(kvm_rma_size, kvm_rma_size); + pr_info("Allocated KVM RMA at %p (%ld MB)\n", rma, + kvm_rma_size >> 20); + rma_info[i].base_virt = rma; + rma_info[i].base_pfn = __pa(rma) >> PAGE_SHIFT; + rma_info[i].npages = npages; + list_add_tail(&rma_info[i].list, &free_rmas); + atomic_set(&rma_info[i].use_count, 0); + + pg = pfn_to_page(rma_info[i].base_pfn); + for (j = 0; j < npages; ++j) { + atomic_inc(&pg->_count); + ++pg; + } + } +} + +struct kvmppc_rma_info *kvm_alloc_rma(void) +{ + struct kvmppc_rma_info *ri; + + ri = NULL; + spin_lock(&rma_lock); + if (!list_empty(&free_rmas)) { + ri = list_first_entry(&free_rmas, struct kvmppc_rma_info, list); + list_del(&ri->list); + atomic_inc(&ri->use_count); + } + spin_unlock(&rma_lock); + return ri; +} +EXPORT_SYMBOL_GPL(kvm_alloc_rma); + +void kvm_release_rma(struct kvmppc_rma_info *ri) +{ + if (atomic_dec_and_test(&ri->use_count)) { + spin_lock(&rma_lock); + list_add_tail(&ri->list, &free_rmas); + spin_unlock(&rma_lock); + + } +} +EXPORT_SYMBOL_GPL(kvm_release_rma); + |