arch/arm/xen/enlighten.c

   1 #include <xen/xen.h>
   2 #include <xen/events.h>
   3 #include <xen/grant_table.h>
   4 #include <xen/hvm.h>
   5 #include <xen/interface/xen.h>
   6 #include <xen/interface/memory.h>
   7 #include <xen/interface/hvm/params.h>
   8 #include <xen/features.h>
   9 #include <xen/platform_pci.h>
  10 #include <xen/xenbus.h>
  11 #include <xen/page.h>
  12 #include <xen/xen-ops.h>
  13 #include <asm/xen/hypervisor.h>
  14 #include <asm/xen/hypercall.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/irqreturn.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_irq.h>
  20 #include <linux/of_address.h>
  21
  22 #include <linux/mm.h>
  23
  24 struct start_info _xen_start_info;
  25 struct start_info *xen_start_info = &_xen_start_info;
  26 EXPORT_SYMBOL_GPL(xen_start_info);
  27
  28 enum xen_domain_type xen_domain_type = XEN_NATIVE;
  29 EXPORT_SYMBOL_GPL(xen_domain_type);
  30
  31 struct shared_info xen_dummy_shared_info;
  32 struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info;
  33
  34 DEFINE_PER_CPU(struct vcpu_info *, xen_vcpu);
  35
  36 /* These are unused until we support booting "pre-ballooned" */
  37 unsigned long xen_released_pages;
  38 struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata;
  39
  40 /* TODO: to be removed */
  41 __read_mostly int xen_have_vector_callback;
  42 EXPORT_SYMBOL_GPL(xen_have_vector_callback);
  43
  44 int xen_platform_pci_unplug = XEN_UNPLUG_ALL;
  45 EXPORT_SYMBOL_GPL(xen_platform_pci_unplug);
  46
  47 static __read_mostly int xen_events_irq = -1;
  48
  49 /* map fgmfn of domid to lpfn in the current domain */
  50 static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn,
  51                             unsigned int domid)
  52 {
  53         int rc;
  54         struct xen_add_to_physmap_range xatp = {
  55                 .domid = DOMID_SELF,
  56                 .foreign_domid = domid,
  57                 .size = 1,
  58                 .space = XENMAPSPACE_gmfn_foreign,
  59         };
  60         xen_ulong_t idx = fgmfn;
  61         xen_pfn_t gpfn = lpfn;
  62
  63         set_xen_guest_handle(xatp.idxs, &idx);
  64         set_xen_guest_handle(xatp.gpfns, &gpfn);
  65
  66         rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
  67         if (rc) {
  68                 pr_warn("Failed to map pfn to mfn rc:%d pfn:%lx mfn:%lx\n",
  69                         rc, lpfn, fgmfn);
  70                 return 1;
  71         }
  72         return 0;
  73 }
  74
  75 struct remap_data {
  76         xen_pfn_t fgmfn; /* foreign domain's gmfn */
  77         pgprot_t prot;
  78         domid_t  domid;
  79         struct vm_area_struct *vma;
  80         int index;
  81         struct page **pages;
  82         struct xen_remap_mfn_info *info;
  83 };
  84
  85 static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
  86                         void *data)
  87 {
  88         struct remap_data *info = data;
  89         struct page *page = info->pages[info->index++];
  90         unsigned long pfn = page_to_pfn(page);
  91         pte_t pte = pfn_pte(pfn, info->prot);
  92
  93         if (map_foreign_page(pfn, info->fgmfn, info->domid))
  94                 return -EFAULT;
  95         set_pte_at(info->vma->vm_mm, addr, ptep, pte);
  96
  97         return 0;
  98 }
  99
 100 int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
 101                                unsigned long addr,
 102                                xen_pfn_t mfn, int nr,
 103                                pgprot_t prot, unsigned domid,
 104                                struct page **pages)
 105 {
 106         int err;
 107         struct remap_data data;
 108
 109         /* TBD: Batching, current sole caller only does page at a time */
 110         if (nr > 1)
 111                 return -EINVAL;
 112
 113         data.fgmfn = mfn;
 114         data.prot = prot;
 115         data.domid = domid;
 116         data.vma = vma;
 117         data.index = 0;
 118         data.pages = pages;
 119         err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
 120                                   remap_pte_fn, &data);
 121         return err;
 122 }
 123 EXPORT_SYMBOL_GPL(xen_remap_domain_mfn_range);
 124
 125 int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
 126                                int nr, struct page **pages)
 127 {
 128         int i;
 129
 130         for (i = 0; i < nr; i++) {
 131                 struct xen_remove_from_physmap xrp;
 132                 unsigned long rc, pfn;
 133
 134                 pfn = page_to_pfn(pages[i]);
 135
 136                 xrp.domid = DOMID_SELF;
 137                 xrp.gpfn = pfn;
 138                 rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
 139                 if (rc) {
 140                         pr_warn("Failed to unmap pfn:%lx rc:%ld\n",
 141                                 pfn, rc);
 142                         return rc;
 143                 }
 144         }
 145         return 0;
 146 }
 147 EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);
 148
 149 /*
 150  * see Documentation/devicetree/bindings/arm/xen.txt for the
 151  * documentation of the Xen Device Tree format.
 152  */
 153 #define GRANT_TABLE_PHYSADDR 0
 154 static int __init xen_guest_init(void)
 155 {
 156         struct xen_add_to_physmap xatp;
 157         static struct shared_info *shared_info_page = 0;
 158         struct device_node *node;
 159         int len;
 160         const char *s = NULL;
 161         const char *version = NULL;
 162         const char *xen_prefix = "xen,xen-";
 163         struct resource res;
 164
 165         node = of_find_compatible_node(NULL, NULL, "xen,xen");
 166         if (!node) {
 167                 pr_debug("No Xen support\n");
 168                 return 0;
 169         }
 170         s = of_get_property(node, "compatible", &len);
 171         if (strlen(xen_prefix) + 3  < len &&
 172                         !strncmp(xen_prefix, s, strlen(xen_prefix)))
 173                 version = s + strlen(xen_prefix);
 174         if (version == NULL) {
 175                 pr_debug("Xen version not found\n");
 176                 return 0;
 177         }
 178         if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res))
 179                 return 0;
 180         xen_hvm_resume_frames = res.start >> PAGE_SHIFT;
 181         xen_events_irq = irq_of_parse_and_map(node, 0);
 182         pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n",
 183                         version, xen_events_irq, xen_hvm_resume_frames);
 184         xen_domain_type = XEN_HVM_DOMAIN;
 185
 186         xen_setup_features();
 187         if (xen_feature(XENFEAT_dom0))
 188                 xen_start_info->flags |= SIF_INITDOMAIN|SIF_PRIVILEGED;
 189         else
 190                 xen_start_info->flags &= ~(SIF_INITDOMAIN|SIF_PRIVILEGED);
 191
 192         if (!shared_info_page)
 193                 shared_info_page = (struct shared_info *)
 194                         get_zeroed_page(GFP_KERNEL);
 195         if (!shared_info_page) {
 196                 pr_err("not enough memory\n");
 197                 return -ENOMEM;
 198         }
 199         xatp.domid = DOMID_SELF;
 200         xatp.idx = 0;
 201         xatp.space = XENMAPSPACE_shared_info;
 202         xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT;
 203         if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp))
 204                 BUG();
 205
 206         HYPERVISOR_shared_info = (struct shared_info *)shared_info_page;
 207
 208         /* xen_vcpu is a pointer to the vcpu_info struct in the shared_info
 209          * page, we use it in the event channel upcall and in some pvclock
 210          * related functions. We don't need the vcpu_info placement
 211          * optimizations because we don't use any pv_mmu or pv_irq op on
 212          * HVM.
 213          * The shared info contains exactly 1 CPU (the boot CPU). The guest
 214          * is required to use VCPUOP_register_vcpu_info to place vcpu info
 215          * for secondary CPUs as they are brought up. */
 216         per_cpu(xen_vcpu, 0) = &HYPERVISOR_shared_info->vcpu_info[0];
 217
 218         gnttab_init();
 219         if (!xen_initial_domain())
 220                 xenbus_probe(NULL);
 221
 222         return 0;
 223 }
 224 core_initcall(xen_guest_init);
 225
 226 static irqreturn_t xen_arm_callback(int irq, void *arg)
 227 {
 228         xen_hvm_evtchn_do_upcall();
 229         return IRQ_HANDLED;
 230 }
 231
 232 static int __init xen_init_events(void)
 233 {
 234         if (!xen_domain() || xen_events_irq < 0)
 235                 return -ENODEV;
 236
 237         xen_init_IRQ();
 238
 239         if (request_percpu_irq(xen_events_irq, xen_arm_callback,
 240                         "events", xen_vcpu)) {
 241                 pr_err("Error requesting IRQ %d\n", xen_events_irq);
 242                 return -EINVAL;
 243         }
 244
 245         enable_percpu_irq(xen_events_irq, 0);
 246
 247         return 0;
 248 }
 249 postcore_initcall(xen_init_events);