drivers/staging/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 "hv_api.h"
  29 #include "logging.h"
  30 #include "vmbus_private.h"
  31
  32 /* The one and only */
  33 struct hv_context hv_context = {
  34         .synic_initialized      = false,
  35         .hypercall_page         = NULL,
  36         .signal_event_param     = NULL,
  37         .signal_event_buffer    = NULL,
  38 };
  39
  40 /*
  41  * query_hypervisor_presence
  42  * - Query the cpuid for presence of windows hypervisor
  43  */
  44 static int query_hypervisor_presence(void)
  45 {
  46         unsigned int eax;
  47         unsigned int ebx;
  48         unsigned int ecx;
  49         unsigned int edx;
  50         unsigned int op;
  51
  52         eax = 0;
  53         ebx = 0;
  54         ecx = 0;
  55         edx = 0;
  56         op = HVCPUID_VERSION_FEATURES;
  57         cpuid(op, &eax, &ebx, &ecx, &edx);
  58
  59         return ecx & HV_PRESENT_BIT;
  60 }
  61
  62 /*
  63  * query_hypervisor_info - Get version info of the windows hypervisor
  64  */
  65 static int query_hypervisor_info(void)
  66 {
  67         unsigned int eax;
  68         unsigned int ebx;
  69         unsigned int ecx;
  70         unsigned int edx;
  71         unsigned int max_leaf;
  72         unsigned int op;
  73
  74         /*
  75         * Its assumed that this is called after confirming that Viridian
  76         * is present. Query id and revision.
  77         */
  78         eax = 0;
  79         ebx = 0;
  80         ecx = 0;
  81         edx = 0;
  82         op = HVCPUID_VENDOR_MAXFUNCTION;
  83         cpuid(op, &eax, &ebx, &ecx, &edx);
  84
  85 /*      DPRINT_INFO(VMBUS, "Vendor ID: %c%c%c%c%c%c%c%c%c%c%c%c",
  86                     (ebx & 0xFF),
  87                     ((ebx >> 8) & 0xFF),
  88                     ((ebx >> 16) & 0xFF),
  89                     ((ebx >> 24) & 0xFF),
  90                     (ecx & 0xFF),
  91                     ((ecx >> 8) & 0xFF),
  92                     ((ecx >> 16) & 0xFF),
  93                     ((ecx >> 24) & 0xFF),
  94                     (edx & 0xFF),
  95                     ((edx >> 8) & 0xFF),
  96                     ((edx >> 16) & 0xFF),
  97                     ((edx >> 24) & 0xFF));
  98 */
  99         max_leaf = eax;
 100 /*      eax = 0;
 101         ebx = 0;
 102         ecx = 0;
 103         edx = 0;
 104         op = HVCPUID_INTERFACE;
 105         cpuid(op, &eax, &ebx, &ecx, &edx);
 106
 107         DPRINT_INFO(VMBUS, "Interface ID: %c%c%c%c",
 108                     (eax & 0xFF),
 109                     ((eax >> 8) & 0xFF),
 110                     ((eax >> 16) & 0xFF),
 111                     ((eax >> 24) & 0xFF));
 112 */
 113
 114         if (max_leaf >= HVCPUID_VERSION) {
 115                 eax = 0;
 116                 ebx = 0;
 117                 ecx = 0;
 118                 edx = 0;
 119                 op = HVCPUID_VERSION;
 120                 cpuid(op, &eax, &ebx, &ecx, &edx);
 121                 pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
 122                             eax,
 123                             ebx >> 16,
 124                             ebx & 0xFFFF,
 125                             ecx,
 126                             edx >> 24,
 127                             edx & 0xFFFFFF);
 128         }
 129         return max_leaf;
 130 }
 131
 132 /*
 133  * do_hypercall- Invoke the specified hypercall
 134  */
 135 static u64 do_hypercall(u64 control, void *input, void *output)
 136 {
 137 #ifdef CONFIG_X86_64
 138         u64 hv_status = 0;
 139         u64 input_address = (input) ? virt_to_phys(input) : 0;
 140         u64 output_address = (output) ? virt_to_phys(output) : 0;
 141         volatile void *hypercall_page = hv_context.hypercall_page;
 142
 143         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
 144         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
 145                              "c" (control), "d" (input_address),
 146                              "m" (hypercall_page));
 147
 148         return hv_status;
 149
 150 #else
 151
 152         u32 control_hi = control >> 32;
 153         u32 control_lo = control & 0xFFFFFFFF;
 154         u32 hv_status_hi = 1;
 155         u32 hv_status_lo = 1;
 156         u64 input_address = (input) ? virt_to_phys(input) : 0;
 157         u32 input_address_hi = input_address >> 32;
 158         u32 input_address_lo = input_address & 0xFFFFFFFF;
 159         u64 output_address = (output) ? virt_to_phys(output) : 0;
 160         u32 output_address_hi = output_address >> 32;
 161         u32 output_address_lo = output_address & 0xFFFFFFFF;
 162         volatile void *hypercall_page = hv_context.hypercall_page;
 163
 164         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
 165                               "=a"(hv_status_lo) : "d" (control_hi),
 166                               "a" (control_lo), "b" (input_address_hi),
 167                               "c" (input_address_lo), "D"(output_address_hi),
 168                               "S"(output_address_lo), "m" (hypercall_page));
 169
 170         return hv_status_lo | ((u64)hv_status_hi << 32);
 171 #endif /* !x86_64 */
 172 }
 173
 174 /*
 175  * hv_init - Main initialization routine.
 176  *
 177  * This routine must be called before any other routines in here are called
 178  */
 179 int hv_init(void)
 180 {
 181         int ret = 0;
 182         int max_leaf;
 183         union hv_x64_msr_hypercall_contents hypercall_msr;
 184         void *virtaddr = NULL;
 185
 186         memset(hv_context.synic_event_page, 0, sizeof(void *) * MAX_NUM_CPUS);
 187         memset(hv_context.synic_message_page, 0,
 188                sizeof(void *) * MAX_NUM_CPUS);
 189
 190         if (!query_hypervisor_presence())
 191                 goto Cleanup;
 192
 193         max_leaf = query_hypervisor_info();
 194         /* HvQueryHypervisorFeatures(maxLeaf); */
 195
 196         /*
 197          * We only support running on top of Hyper-V
 198          */
 199         rdmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 200
 201         if (hv_context.guestid != 0)
 202                 goto Cleanup;
 203
 204         /* Write our OS info */
 205         wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
 206         hv_context.guestid = HV_LINUX_GUEST_ID;
 207
 208         /* See if the hypercall page is already set */
 209         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 210
 211         /*
 212         * Allocate the hypercall page memory
 213         * virtaddr = osd_page_alloc(1);
 214         */
 215         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 216
 217         if (!virtaddr)
 218                 goto Cleanup;
 219
 220         hypercall_msr.enable = 1;
 221
 222         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 223         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 224
 225         /* Confirm that hypercall page did get setup. */
 226         hypercall_msr.as_uint64 = 0;
 227         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 228
 229         if (!hypercall_msr.enable)
 230                 goto Cleanup;
 231
 232         hv_context.hypercall_page = virtaddr;
 233
 234         /* Setup the global signal event param for the signal event hypercall */
 235         hv_context.signal_event_buffer =
 236                         kmalloc(sizeof(struct hv_input_signal_event_buffer),
 237                                 GFP_KERNEL);
 238         if (!hv_context.signal_event_buffer)
 239                 goto Cleanup;
 240
 241         hv_context.signal_event_param =
 242                 (struct hv_input_signal_event *)
 243                         (ALIGN((unsigned long)
 244                                   hv_context.signal_event_buffer,
 245                                   HV_HYPERCALL_PARAM_ALIGN));
 246         hv_context.signal_event_param->connectionid.asu32 = 0;
 247         hv_context.signal_event_param->connectionid.u.id =
 248                                                 VMBUS_EVENT_CONNECTION_ID;
 249         hv_context.signal_event_param->flag_number = 0;
 250         hv_context.signal_event_param->rsvdz = 0;
 251
 252         return ret;
 253
 254 Cleanup:
 255         if (virtaddr) {
 256                 if (hypercall_msr.enable) {
 257                         hypercall_msr.as_uint64 = 0;
 258                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 259                 }
 260
 261                 vfree(virtaddr);
 262         }
 263         ret = -1;
 264         return ret;
 265 }
 266
 267 /*
 268  * hv_cleanup - Cleanup routine.
 269  *
 270  * This routine is called normally during driver unloading or exiting.
 271  */
 272 void hv_cleanup(void)
 273 {
 274         union hv_x64_msr_hypercall_contents hypercall_msr;
 275
 276         kfree(hv_context.signal_event_buffer);
 277         hv_context.signal_event_buffer = NULL;
 278         hv_context.signal_event_param = NULL;
 279
 280         if (hv_context.hypercall_page) {
 281                 hypercall_msr.as_uint64 = 0;
 282                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 283                 vfree(hv_context.hypercall_page);
 284                 hv_context.hypercall_page = NULL;
 285         }
 286 }
 287
 288 /*
 289  * hv_post_message - Post a message using the hypervisor message IPC.
 290  *
 291  * This involves a hypercall.
 292  */
 293 u16 hv_post_message(union hv_connection_id connection_id,
 294                   enum hv_message_type message_type,
 295                   void *payload, size_t payload_size)
 296 {
 297         struct aligned_input {
 298                 u64 alignment8;
 299                 struct hv_input_post_message msg;
 300         };
 301
 302         struct hv_input_post_message *aligned_msg;
 303         u16 status;
 304         unsigned long addr;
 305
 306         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 307                 return -1;
 308
 309         addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 310         if (!addr)
 311                 return -1;
 312
 313         aligned_msg = (struct hv_input_post_message *)
 314                         (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 315
 316         aligned_msg->connectionid = connection_id;
 317         aligned_msg->message_type = message_type;
 318         aligned_msg->payload_size = payload_size;
 319         memcpy((void *)aligned_msg->payload, payload, payload_size);
 320
 321         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 322                 & 0xFFFF;
 323
 324         kfree((void *)addr);
 325
 326         return status;
 327 }
 328
 329
 330 /*
 331  * hv_signal_event -
 332  * Signal an event on the specified connection using the hypervisor event IPC.
 333  *
 334  * This involves a hypercall.
 335  */
 336 u16 hv_signal_event(void)
 337 {
 338         u16 status;
 339
 340         status = do_hypercall(HVCALL_SIGNAL_EVENT,
 341                                hv_context.signal_event_param,
 342                                NULL) & 0xFFFF;
 343         return status;
 344 }
 345
 346 /*
 347  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 348  *
 349  * If it is already initialized by another entity (ie x2v shim), we need to
 350  * retrieve the initialized message and event pages.  Otherwise, we create and
 351  * initialize the message and event pages.
 352  */
 353 void hv_synic_init(void *irqarg)
 354 {
 355         u64 version;
 356         union hv_synic_simp simp;
 357         union hv_synic_siefp siefp;
 358         union hv_synic_sint shared_sint;
 359         union hv_synic_scontrol sctrl;
 360
 361         u32 irq_vector = *((u32 *)(irqarg));
 362         int cpu = smp_processor_id();
 363
 364         if (!hv_context.hypercall_page)
 365                 return;
 366
 367         /* Check the version */
 368         rdmsrl(HV_X64_MSR_SVERSION, version);
 369
 370         hv_context.synic_message_page[cpu] =
 371                 (void *)get_zeroed_page(GFP_ATOMIC);
 372
 373         if (hv_context.synic_message_page[cpu] == NULL) {
 374                 pr_err("Unable to allocate SYNIC message page\n");
 375                 goto Cleanup;
 376         }
 377
 378         hv_context.synic_event_page[cpu] =
 379                 (void *)get_zeroed_page(GFP_ATOMIC);
 380
 381         if (hv_context.synic_event_page[cpu] == NULL) {
 382                 pr_err("Unable to allocate SYNIC event page\n");
 383                 goto Cleanup;
 384         }
 385
 386         /* Setup the Synic's message page */
 387         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 388         simp.simp_enabled = 1;
 389         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 390                 >> PAGE_SHIFT;
 391
 392         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 393
 394         /* Setup the Synic's event page */
 395         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 396         siefp.siefp_enabled = 1;
 397         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 398                 >> PAGE_SHIFT;
 399
 400         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 401
 402         /* Setup the interception SINT. */
 403         /* wrmsrl((HV_X64_MSR_SINT0 + HV_SYNIC_INTERCEPTION_SINT_INDEX), */
 404         /*        interceptionSint.as_uint64); */
 405
 406         /* Setup the shared SINT. */
 407         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 408
 409         shared_sint.as_uint64 = 0;
 410         shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 411         shared_sint.masked = false;
 412         shared_sint.auto_eoi = true;
 413
 414         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 415
 416         /* Enable the global synic bit */
 417         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 418         sctrl.enable = 1;
 419
 420         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 421
 422         hv_context.synic_initialized = true;
 423         return;
 424
 425 Cleanup:
 426         if (hv_context.synic_event_page[cpu])
 427                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 428
 429         if (hv_context.synic_message_page[cpu])
 430                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 431         return;
 432 }
 433
 434 /*
 435  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 436  */
 437 void hv_synic_cleanup(void *arg)
 438 {
 439         union hv_synic_sint shared_sint;
 440         union hv_synic_simp simp;
 441         union hv_synic_siefp siefp;
 442         int cpu = smp_processor_id();
 443
 444         if (!hv_context.synic_initialized)
 445                 return;
 446
 447         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 448
 449         shared_sint.masked = 1;
 450
 451         /* Need to correctly cleanup in the case of SMP!!! */
 452         /* Disable the interrupt */
 453         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 454
 455         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 456         simp.simp_enabled = 0;
 457         simp.base_simp_gpa = 0;
 458
 459         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 460
 461         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 462         siefp.siefp_enabled = 0;
 463         siefp.base_siefp_gpa = 0;
 464
 465         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 466
 467         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 468         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 469 }