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 unsigned int host_info_eax;
  44 unsigned int host_info_ebx;
  45 unsigned int host_info_ecx;
  46 unsigned int host_info_edx;
  47
  48 static int query_hypervisor_info(void)
  49 {
  50         unsigned int eax;
  51         unsigned int ebx;
  52         unsigned int ecx;
  53         unsigned int edx;
  54         unsigned int max_leaf;
  55         unsigned int op;
  56
  57         /*
  58         * Its assumed that this is called after confirming that Viridian
  59         * is present. Query id and revision.
  60         */
  61         eax = 0;
  62         ebx = 0;
  63         ecx = 0;
  64         edx = 0;
  65         op = HVCPUID_VENDOR_MAXFUNCTION;
  66         cpuid(op, &eax, &ebx, &ecx, &edx);
  67
  68         max_leaf = eax;
  69
  70         if (max_leaf >= HVCPUID_VERSION) {
  71                 eax = 0;
  72                 ebx = 0;
  73                 ecx = 0;
  74                 edx = 0;
  75                 op = HVCPUID_VERSION;
  76                 cpuid(op, &eax, &ebx, &ecx, &edx);
  77                 host_info_eax = eax;
  78                 host_info_ebx = ebx;
  79                 host_info_ecx = ecx;
  80                 host_info_edx = edx;
  81         }
  82         return max_leaf;
  83 }
  84
  85 /*
  86  * do_hypercall- Invoke the specified hypercall
  87  */
  88 static u64 do_hypercall(u64 control, void *input, void *output)
  89 {
  90 #ifdef CONFIG_X86_64
  91         u64 hv_status = 0;
  92         u64 input_address = (input) ? virt_to_phys(input) : 0;
  93         u64 output_address = (output) ? virt_to_phys(output) : 0;
  94         void *hypercall_page = hv_context.hypercall_page;
  95
  96         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
  97         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
  98                              "c" (control), "d" (input_address),
  99                              "m" (hypercall_page));
 100
 101         return hv_status;
 102
 103 #else
 104
 105         u32 control_hi = control >> 32;
 106         u32 control_lo = control & 0xFFFFFFFF;
 107         u32 hv_status_hi = 1;
 108         u32 hv_status_lo = 1;
 109         u64 input_address = (input) ? virt_to_phys(input) : 0;
 110         u32 input_address_hi = input_address >> 32;
 111         u32 input_address_lo = input_address & 0xFFFFFFFF;
 112         u64 output_address = (output) ? virt_to_phys(output) : 0;
 113         u32 output_address_hi = output_address >> 32;
 114         u32 output_address_lo = output_address & 0xFFFFFFFF;
 115         void *hypercall_page = hv_context.hypercall_page;
 116
 117         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
 118                               "=a"(hv_status_lo) : "d" (control_hi),
 119                               "a" (control_lo), "b" (input_address_hi),
 120                               "c" (input_address_lo), "D"(output_address_hi),
 121                               "S"(output_address_lo), "m" (hypercall_page));
 122
 123         return hv_status_lo | ((u64)hv_status_hi << 32);
 124 #endif /* !x86_64 */
 125 }
 126
 127 /*
 128  * hv_init - Main initialization routine.
 129  *
 130  * This routine must be called before any other routines in here are called
 131  */
 132 int hv_init(void)
 133 {
 134         int max_leaf;
 135         union hv_x64_msr_hypercall_contents hypercall_msr;
 136         void *virtaddr = NULL;
 137
 138         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
 139         memset(hv_context.synic_message_page, 0,
 140                sizeof(void *) * NR_CPUS);
 141         memset(hv_context.post_msg_page, 0,
 142                sizeof(void *) * NR_CPUS);
 143         memset(hv_context.vp_index, 0,
 144                sizeof(int) * NR_CPUS);
 145         memset(hv_context.event_dpc, 0,
 146                sizeof(void *) * NR_CPUS);
 147
 148         max_leaf = query_hypervisor_info();
 149
 150         /*
 151          * Write our OS ID.
 152          */
 153         hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 154         wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 155
 156         /* See if the hypercall page is already set */
 157         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 158
 159         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 160
 161         if (!virtaddr)
 162                 goto cleanup;
 163
 164         hypercall_msr.enable = 1;
 165
 166         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 167         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 168
 169         /* Confirm that hypercall page did get setup. */
 170         hypercall_msr.as_uint64 = 0;
 171         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 172
 173         if (!hypercall_msr.enable)
 174                 goto cleanup;
 175
 176         hv_context.hypercall_page = virtaddr;
 177
 178         return 0;
 179
 180 cleanup:
 181         if (virtaddr) {
 182                 if (hypercall_msr.enable) {
 183                         hypercall_msr.as_uint64 = 0;
 184                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 185                 }
 186
 187                 vfree(virtaddr);
 188         }
 189
 190         return -ENOTSUPP;
 191 }
 192
 193 /*
 194  * hv_cleanup - Cleanup routine.
 195  *
 196  * This routine is called normally during driver unloading or exiting.
 197  */
 198 void hv_cleanup(void)
 199 {
 200         union hv_x64_msr_hypercall_contents hypercall_msr;
 201
 202         /* Reset our OS id */
 203         wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 204
 205         if (hv_context.hypercall_page) {
 206                 hypercall_msr.as_uint64 = 0;
 207                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 208                 vfree(hv_context.hypercall_page);
 209                 hv_context.hypercall_page = NULL;
 210         }
 211 }
 212
 213 /*
 214  * hv_post_message - Post a message using the hypervisor message IPC.
 215  *
 216  * This involves a hypercall.
 217  */
 218 int hv_post_message(union hv_connection_id connection_id,
 219                   enum hv_message_type message_type,
 220                   void *payload, size_t payload_size)
 221 {
 222
 223         struct hv_input_post_message *aligned_msg;
 224         u16 status;
 225
 226         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 227                 return -EMSGSIZE;
 228
 229         aligned_msg = (struct hv_input_post_message *)
 230                         hv_context.post_msg_page[get_cpu()];
 231
 232         aligned_msg->connectionid = connection_id;
 233         aligned_msg->reserved = 0;
 234         aligned_msg->message_type = message_type;
 235         aligned_msg->payload_size = payload_size;
 236         memcpy((void *)aligned_msg->payload, payload, payload_size);
 237
 238         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 239                 & 0xFFFF;
 240
 241         put_cpu();
 242         return status;
 243 }
 244
 245
 246 /*
 247  * hv_signal_event -
 248  * Signal an event on the specified connection using the hypervisor event IPC.
 249  *
 250  * This involves a hypercall.
 251  */
 252 u16 hv_signal_event(void *con_id)
 253 {
 254         u16 status;
 255
 256         status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
 257
 258         return status;
 259 }
 260
 261
 262 int hv_synic_alloc(void)
 263 {
 264         size_t size = sizeof(struct tasklet_struct);
 265         int cpu;
 266
 267         for_each_online_cpu(cpu) {
 268                 hv_context.event_dpc[cpu] = kmalloc(size, GFP_ATOMIC);
 269                 if (hv_context.event_dpc[cpu] == NULL) {
 270                         pr_err("Unable to allocate event dpc\n");
 271                         goto err;
 272                 }
 273                 tasklet_init(hv_context.event_dpc[cpu], vmbus_on_event, cpu);
 274
 275                 hv_context.synic_message_page[cpu] =
 276                         (void *)get_zeroed_page(GFP_ATOMIC);
 277
 278                 if (hv_context.synic_message_page[cpu] == NULL) {
 279                         pr_err("Unable to allocate SYNIC message page\n");
 280                         goto err;
 281                 }
 282
 283                 hv_context.synic_event_page[cpu] =
 284                         (void *)get_zeroed_page(GFP_ATOMIC);
 285
 286                 if (hv_context.synic_event_page[cpu] == NULL) {
 287                         pr_err("Unable to allocate SYNIC event page\n");
 288                         goto err;
 289                 }
 290
 291                 hv_context.post_msg_page[cpu] =
 292                         (void *)get_zeroed_page(GFP_ATOMIC);
 293
 294                 if (hv_context.post_msg_page[cpu] == NULL) {
 295                         pr_err("Unable to allocate post msg page\n");
 296                         goto err;
 297                 }
 298         }
 299
 300         return 0;
 301 err:
 302         return -ENOMEM;
 303 }
 304
 305 static void hv_synic_free_cpu(int cpu)
 306 {
 307         kfree(hv_context.event_dpc[cpu]);
 308         if (hv_context.synic_event_page[cpu])
 309                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 310         if (hv_context.synic_message_page[cpu])
 311                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 312         if (hv_context.post_msg_page[cpu])
 313                 free_page((unsigned long)hv_context.post_msg_page[cpu]);
 314 }
 315
 316 void hv_synic_free(void)
 317 {
 318         int cpu;
 319
 320         for_each_online_cpu(cpu)
 321                 hv_synic_free_cpu(cpu);
 322 }
 323
 324 /*
 325  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 326  *
 327  * If it is already initialized by another entity (ie x2v shim), we need to
 328  * retrieve the initialized message and event pages.  Otherwise, we create and
 329  * initialize the message and event pages.
 330  */
 331 void hv_synic_init(void *arg)
 332 {
 333         u64 version;
 334         union hv_synic_simp simp;
 335         union hv_synic_siefp siefp;
 336         union hv_synic_sint shared_sint;
 337         union hv_synic_scontrol sctrl;
 338         u64 vp_index;
 339
 340         int cpu = smp_processor_id();
 341
 342         if (!hv_context.hypercall_page)
 343                 return;
 344
 345         /* Check the version */
 346         rdmsrl(HV_X64_MSR_SVERSION, version);
 347
 348         /* Setup the Synic's message page */
 349         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 350         simp.simp_enabled = 1;
 351         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 352                 >> PAGE_SHIFT;
 353
 354         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 355
 356         /* Setup the Synic's event page */
 357         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 358         siefp.siefp_enabled = 1;
 359         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 360                 >> PAGE_SHIFT;
 361
 362         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 363
 364         /* Setup the shared SINT. */
 365         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 366
 367         shared_sint.as_uint64 = 0;
 368         shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR;
 369         shared_sint.masked = false;
 370         shared_sint.auto_eoi = true;
 371
 372         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 373
 374         /* Enable the global synic bit */
 375         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 376         sctrl.enable = 1;
 377
 378         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 379
 380         hv_context.synic_initialized = true;
 381
 382         /*
 383          * Setup the mapping between Hyper-V's notion
 384          * of cpuid and Linux' notion of cpuid.
 385          * This array will be indexed using Linux cpuid.
 386          */
 387         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 388         hv_context.vp_index[cpu] = (u32)vp_index;
 389
 390         INIT_LIST_HEAD(&hv_context.percpu_list[cpu]);
 391         return;
 392 }
 393
 394 /*
 395  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 396  */
 397 void hv_synic_cleanup(void *arg)
 398 {
 399         union hv_synic_sint shared_sint;
 400         union hv_synic_simp simp;
 401         union hv_synic_siefp siefp;
 402         int cpu = smp_processor_id();
 403
 404         if (!hv_context.synic_initialized)
 405                 return;
 406
 407         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 408
 409         shared_sint.masked = 1;
 410
 411         /* Need to correctly cleanup in the case of SMP!!! */
 412         /* Disable the interrupt */
 413         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 414
 415         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 416         simp.simp_enabled = 0;
 417         simp.base_simp_gpa = 0;
 418
 419         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 420
 421         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 422         siefp.siefp_enabled = 0;
 423         siefp.base_siefp_gpa = 0;
 424
 425         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 426
 427         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 428         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 429 }