drivers/hv/hv.c

   1 /*
   2  * Copyright (c) 2009, Microsoft Corporation.
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms and conditions of the GNU General Public License,
   6  * version 2, as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  11  * more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along with
  14  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  15  * Place - Suite 330, Boston, MA 02111-1307 USA.
  16  *
  17  * Authors:
  18  *   Haiyang Zhang <haiyangz@microsoft.com>
  19  *   Hank Janssen  <hjanssen@microsoft.com>
  20  *
  21  */
  22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/kernel.h>
  25 #include <linux/mm.h>
  26 #include <linux/slab.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/hyperv.h>
  29 #include <linux/version.h>
  30 #include <linux/interrupt.h>
  31 #include <asm/hyperv.h>
  32 #include "hyperv_vmbus.h"
  33
  34 /* The one and only */
  35 struct hv_context hv_context = {
  36         .synic_initialized      = false,
  37         .hypercall_page         = NULL,
  38 };
  39
  40 /*
  41  * query_hypervisor_info - Get version info of the windows hypervisor
  42  */
  43 static int query_hypervisor_info(void)
  44 {
  45         unsigned int eax;
  46         unsigned int ebx;
  47         unsigned int ecx;
  48         unsigned int edx;
  49         unsigned int max_leaf;
  50         unsigned int op;
  51
  52         /*
  53         * Its assumed that this is called after confirming that Viridian
  54         * is present. Query id and revision.
  55         */
  56         eax = 0;
  57         ebx = 0;
  58         ecx = 0;
  59         edx = 0;
  60         op = HVCPUID_VENDOR_MAXFUNCTION;
  61         cpuid(op, &eax, &ebx, &ecx, &edx);
  62
  63         max_leaf = eax;
  64
  65         if (max_leaf >= HVCPUID_VERSION) {
  66                 eax = 0;
  67                 ebx = 0;
  68                 ecx = 0;
  69                 edx = 0;
  70                 op = HVCPUID_VERSION;
  71                 cpuid(op, &eax, &ebx, &ecx, &edx);
  72                 pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
  73                             eax,
  74                             ebx >> 16,
  75                             ebx & 0xFFFF,
  76                             ecx,
  77                             edx >> 24,
  78                             edx & 0xFFFFFF);
  79         }
  80         return max_leaf;
  81 }
  82
  83 /*
  84  * do_hypercall- Invoke the specified hypercall
  85  */
  86 static u64 do_hypercall(u64 control, void *input, void *output)
  87 {
  88 #ifdef CONFIG_X86_64
  89         u64 hv_status = 0;
  90         u64 input_address = (input) ? virt_to_phys(input) : 0;
  91         u64 output_address = (output) ? virt_to_phys(output) : 0;
  92         void *hypercall_page = hv_context.hypercall_page;
  93
  94         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
  95         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
  96                              "c" (control), "d" (input_address),
  97                              "m" (hypercall_page));
  98
  99         return hv_status;
 100
 101 #else
 102
 103         u32 control_hi = control >> 32;
 104         u32 control_lo = control & 0xFFFFFFFF;
 105         u32 hv_status_hi = 1;
 106         u32 hv_status_lo = 1;
 107         u64 input_address = (input) ? virt_to_phys(input) : 0;
 108         u32 input_address_hi = input_address >> 32;
 109         u32 input_address_lo = input_address & 0xFFFFFFFF;
 110         u64 output_address = (output) ? virt_to_phys(output) : 0;
 111         u32 output_address_hi = output_address >> 32;
 112         u32 output_address_lo = output_address & 0xFFFFFFFF;
 113         void *hypercall_page = hv_context.hypercall_page;
 114
 115         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
 116                               "=a"(hv_status_lo) : "d" (control_hi),
 117                               "a" (control_lo), "b" (input_address_hi),
 118                               "c" (input_address_lo), "D"(output_address_hi),
 119                               "S"(output_address_lo), "m" (hypercall_page));
 120
 121         return hv_status_lo | ((u64)hv_status_hi << 32);
 122 #endif /* !x86_64 */
 123 }
 124
 125 /*
 126  * hv_init - Main initialization routine.
 127  *
 128  * This routine must be called before any other routines in here are called
 129  */
 130 int hv_init(void)
 131 {
 132         int max_leaf;
 133         union hv_x64_msr_hypercall_contents hypercall_msr;
 134         void *virtaddr = NULL;
 135
 136         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
 137         memset(hv_context.synic_message_page, 0,
 138                sizeof(void *) * NR_CPUS);
 139         memset(hv_context.vp_index, 0,
 140                sizeof(int) * NR_CPUS);
 141         memset(hv_context.event_dpc, 0,
 142                sizeof(void *) * NR_CPUS);
 143
 144         max_leaf = query_hypervisor_info();
 145
 146         /*
 147          * Write our OS ID.
 148          */
 149         hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 150         wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 151
 152         /* See if the hypercall page is already set */
 153         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 154
 155         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 156
 157         if (!virtaddr)
 158                 goto cleanup;
 159
 160         hypercall_msr.enable = 1;
 161
 162         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 163         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 164
 165         /* Confirm that hypercall page did get setup. */
 166         hypercall_msr.as_uint64 = 0;
 167         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 168
 169         if (!hypercall_msr.enable)
 170                 goto cleanup;
 171
 172         hv_context.hypercall_page = virtaddr;
 173
 174         return 0;
 175
 176 cleanup:
 177         if (virtaddr) {
 178                 if (hypercall_msr.enable) {
 179                         hypercall_msr.as_uint64 = 0;
 180                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 181                 }
 182
 183                 vfree(virtaddr);
 184         }
 185
 186         return -ENOTSUPP;
 187 }
 188
 189 /*
 190  * hv_cleanup - Cleanup routine.
 191  *
 192  * This routine is called normally during driver unloading or exiting.
 193  */
 194 void hv_cleanup(void)
 195 {
 196         union hv_x64_msr_hypercall_contents hypercall_msr;
 197
 198         /* Reset our OS id */
 199         wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 200
 201         if (hv_context.hypercall_page) {
 202                 hypercall_msr.as_uint64 = 0;
 203                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 204                 vfree(hv_context.hypercall_page);
 205                 hv_context.hypercall_page = NULL;
 206         }
 207 }
 208
 209 /*
 210  * hv_post_message - Post a message using the hypervisor message IPC.
 211  *
 212  * This involves a hypercall.
 213  */
 214 int hv_post_message(union hv_connection_id connection_id,
 215                   enum hv_message_type message_type,
 216                   void *payload, size_t payload_size)
 217 {
 218         struct aligned_input {
 219                 u64 alignment8;
 220                 struct hv_input_post_message msg;
 221         };
 222
 223         struct hv_input_post_message *aligned_msg;
 224         u16 status;
 225         unsigned long addr;
 226
 227         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 228                 return -EMSGSIZE;
 229
 230         addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 231         if (!addr)
 232                 return -ENOMEM;
 233
 234         aligned_msg = (struct hv_input_post_message *)
 235                         (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 236
 237         aligned_msg->connectionid = connection_id;
 238         aligned_msg->message_type = message_type;
 239         aligned_msg->payload_size = payload_size;
 240         memcpy((void *)aligned_msg->payload, payload, payload_size);
 241
 242         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 243                 & 0xFFFF;
 244
 245         kfree((void *)addr);
 246
 247         return status;
 248 }
 249
 250
 251 /*
 252  * hv_signal_event -
 253  * Signal an event on the specified connection using the hypervisor event IPC.
 254  *
 255  * This involves a hypercall.
 256  */
 257 u16 hv_signal_event(void *con_id)
 258 {
 259         u16 status;
 260
 261         status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
 262
 263         return status;
 264 }
 265
 266 /*
 267  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 268  *
 269  * If it is already initialized by another entity (ie x2v shim), we need to
 270  * retrieve the initialized message and event pages.  Otherwise, we create and
 271  * initialize the message and event pages.
 272  */
 273 void hv_synic_init(void *irqarg)
 274 {
 275         u64 version;
 276         union hv_synic_simp simp;
 277         union hv_synic_siefp siefp;
 278         union hv_synic_sint shared_sint;
 279         union hv_synic_scontrol sctrl;
 280         u64 vp_index;
 281
 282         u32 irq_vector = *((u32 *)(irqarg));
 283         int cpu = smp_processor_id();
 284
 285         if (!hv_context.hypercall_page)
 286                 return;
 287
 288         /* Check the version */
 289         rdmsrl(HV_X64_MSR_SVERSION, version);
 290
 291         hv_context.event_dpc[cpu] = (struct tasklet_struct *)
 292                                         kmalloc(sizeof(struct tasklet_struct),
 293                                                 GFP_ATOMIC);
 294         if (hv_context.event_dpc[cpu] == NULL) {
 295                 pr_err("Unable to allocate event dpc\n");
 296                 goto cleanup;
 297         }
 298         tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);
 299
 300         hv_context.synic_message_page[cpu] =
 301                 (void *)get_zeroed_page(GFP_ATOMIC);
 302
 303         if (hv_context.synic_message_page[cpu] == NULL) {
 304                 pr_err("Unable to allocate SYNIC message page\n");
 305                 goto cleanup;
 306         }
 307
 308         hv_context.synic_event_page[cpu] =
 309                 (void *)get_zeroed_page(GFP_ATOMIC);
 310
 311         if (hv_context.synic_event_page[cpu] == NULL) {
 312                 pr_err("Unable to allocate SYNIC event page\n");
 313                 goto cleanup;
 314         }
 315
 316         /* Setup the Synic's message page */
 317         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 318         simp.simp_enabled = 1;
 319         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 320                 >> PAGE_SHIFT;
 321
 322         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 323
 324         /* Setup the Synic's event page */
 325         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 326         siefp.siefp_enabled = 1;
 327         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 328                 >> PAGE_SHIFT;
 329
 330         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 331
 332         /* Setup the shared SINT. */
 333         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 334
 335         shared_sint.as_uint64 = 0;
 336         shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 337         shared_sint.masked = false;
 338         shared_sint.auto_eoi = false;
 339
 340         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 341
 342         /* Enable the global synic bit */
 343         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 344         sctrl.enable = 1;
 345
 346         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 347
 348         hv_context.synic_initialized = true;
 349
 350         /*
 351          * Setup the mapping between Hyper-V's notion
 352          * of cpuid and Linux' notion of cpuid.
 353          * This array will be indexed using Linux cpuid.
 354          */
 355         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 356         hv_context.vp_index[cpu] = (u32)vp_index;
 357         return;
 358
 359 cleanup:
 360         if (hv_context.synic_event_page[cpu])
 361                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 362
 363         if (hv_context.synic_message_page[cpu])
 364                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 365         return;
 366 }
 367
 368 /*
 369  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 370  */
 371 void hv_synic_cleanup(void *arg)
 372 {
 373         union hv_synic_sint shared_sint;
 374         union hv_synic_simp simp;
 375         union hv_synic_siefp siefp;
 376         int cpu = smp_processor_id();
 377
 378         if (!hv_context.synic_initialized)
 379                 return;
 380
 381         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 382
 383         shared_sint.masked = 1;
 384
 385         /* Need to correctly cleanup in the case of SMP!!! */
 386         /* Disable the interrupt */
 387         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 388
 389         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 390         simp.simp_enabled = 0;
 391         simp.base_simp_gpa = 0;
 392
 393         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 394
 395         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 396         siefp.siefp_enabled = 0;
 397         siefp.base_siefp_gpa = 0;
 398
 399         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 400
 401         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 402         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 403 }