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 <asm/hyperv.h>
  31 #include "hyperv_vmbus.h"
  32
  33 /* The one and only */
  34 struct hv_context hv_context = {
  35         .synic_initialized      = false,
  36         .hypercall_page         = NULL,
  37         .signal_event_param     = NULL,
  38         .signal_event_buffer    = NULL,
  39 };
  40
  41 /*
  42  * query_hypervisor_info - Get version info of the windows hypervisor
  43  */
  44 static int query_hypervisor_info(void)
  45 {
  46         unsigned int eax;
  47         unsigned int ebx;
  48         unsigned int ecx;
  49         unsigned int edx;
  50         unsigned int max_leaf;
  51         unsigned int op;
  52
  53         /*
  54         * Its assumed that this is called after confirming that Viridian
  55         * is present. Query id and revision.
  56         */
  57         eax = 0;
  58         ebx = 0;
  59         ecx = 0;
  60         edx = 0;
  61         op = HVCPUID_VENDOR_MAXFUNCTION;
  62         cpuid(op, &eax, &ebx, &ecx, &edx);
  63
  64         max_leaf = eax;
  65
  66         if (max_leaf >= HVCPUID_VERSION) {
  67                 eax = 0;
  68                 ebx = 0;
  69                 ecx = 0;
  70                 edx = 0;
  71                 op = HVCPUID_VERSION;
  72                 cpuid(op, &eax, &ebx, &ecx, &edx);
  73                 pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
  74                             eax,
  75                             ebx >> 16,
  76                             ebx & 0xFFFF,
  77                             ecx,
  78                             edx >> 24,
  79                             edx & 0xFFFFFF);
  80         }
  81         return max_leaf;
  82 }
  83
  84 /*
  85  * do_hypercall- Invoke the specified hypercall
  86  */
  87 static u64 do_hypercall(u64 control, void *input, void *output)
  88 {
  89 #ifdef CONFIG_X86_64
  90         u64 hv_status = 0;
  91         u64 input_address = (input) ? virt_to_phys(input) : 0;
  92         u64 output_address = (output) ? virt_to_phys(output) : 0;
  93         void *hypercall_page = hv_context.hypercall_page;
  94
  95         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
  96         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
  97                              "c" (control), "d" (input_address),
  98                              "m" (hypercall_page));
  99
 100         return hv_status;
 101
 102 #else
 103
 104         u32 control_hi = control >> 32;
 105         u32 control_lo = control & 0xFFFFFFFF;
 106         u32 hv_status_hi = 1;
 107         u32 hv_status_lo = 1;
 108         u64 input_address = (input) ? virt_to_phys(input) : 0;
 109         u32 input_address_hi = input_address >> 32;
 110         u32 input_address_lo = input_address & 0xFFFFFFFF;
 111         u64 output_address = (output) ? virt_to_phys(output) : 0;
 112         u32 output_address_hi = output_address >> 32;
 113         u32 output_address_lo = output_address & 0xFFFFFFFF;
 114         void *hypercall_page = hv_context.hypercall_page;
 115
 116         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
 117                               "=a"(hv_status_lo) : "d" (control_hi),
 118                               "a" (control_lo), "b" (input_address_hi),
 119                               "c" (input_address_lo), "D"(output_address_hi),
 120                               "S"(output_address_lo), "m" (hypercall_page));
 121
 122         return hv_status_lo | ((u64)hv_status_hi << 32);
 123 #endif /* !x86_64 */
 124 }
 125
 126 /*
 127  * hv_init - Main initialization routine.
 128  *
 129  * This routine must be called before any other routines in here are called
 130  */
 131 int hv_init(void)
 132 {
 133         int max_leaf;
 134         union hv_x64_msr_hypercall_contents hypercall_msr;
 135         void *virtaddr = NULL;
 136
 137         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
 138         memset(hv_context.synic_message_page, 0,
 139                sizeof(void *) * NR_CPUS);
 140         memset(hv_context.vp_index, 0,
 141                sizeof(int) * NR_CPUS);
 142
 143         max_leaf = query_hypervisor_info();
 144
 145         /*
 146          * Write our OS ID.
 147          */
 148         hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 149         wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 150
 151         /* See if the hypercall page is already set */
 152         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 153
 154         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 155
 156         if (!virtaddr)
 157                 goto cleanup;
 158
 159         hypercall_msr.enable = 1;
 160
 161         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 162         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 163
 164         /* Confirm that hypercall page did get setup. */
 165         hypercall_msr.as_uint64 = 0;
 166         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 167
 168         if (!hypercall_msr.enable)
 169                 goto cleanup;
 170
 171         hv_context.hypercall_page = virtaddr;
 172
 173         /* Setup the global signal event param for the signal event hypercall */
 174         hv_context.signal_event_buffer =
 175                         kmalloc(sizeof(struct hv_input_signal_event_buffer),
 176                                 GFP_KERNEL);
 177         if (!hv_context.signal_event_buffer)
 178                 goto cleanup;
 179
 180         hv_context.signal_event_param =
 181                 (struct hv_input_signal_event *)
 182                         (ALIGN((unsigned long)
 183                                   hv_context.signal_event_buffer,
 184                                   HV_HYPERCALL_PARAM_ALIGN));
 185         hv_context.signal_event_param->connectionid.asu32 = 0;
 186         hv_context.signal_event_param->connectionid.u.id =
 187                                                 VMBUS_EVENT_CONNECTION_ID;
 188         hv_context.signal_event_param->flag_number = 0;
 189         hv_context.signal_event_param->rsvdz = 0;
 190
 191         return 0;
 192
 193 cleanup:
 194         if (virtaddr) {
 195                 if (hypercall_msr.enable) {
 196                         hypercall_msr.as_uint64 = 0;
 197                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 198                 }
 199
 200                 vfree(virtaddr);
 201         }
 202
 203         return -ENOTSUPP;
 204 }
 205
 206 /*
 207  * hv_cleanup - Cleanup routine.
 208  *
 209  * This routine is called normally during driver unloading or exiting.
 210  */
 211 void hv_cleanup(void)
 212 {
 213         union hv_x64_msr_hypercall_contents hypercall_msr;
 214
 215         /* Reset our OS id */
 216         wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 217
 218         kfree(hv_context.signal_event_buffer);
 219         hv_context.signal_event_buffer = NULL;
 220         hv_context.signal_event_param = NULL;
 221
 222         if (hv_context.hypercall_page) {
 223                 hypercall_msr.as_uint64 = 0;
 224                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 225                 vfree(hv_context.hypercall_page);
 226                 hv_context.hypercall_page = NULL;
 227         }
 228 }
 229
 230 /*
 231  * hv_post_message - Post a message using the hypervisor message IPC.
 232  *
 233  * This involves a hypercall.
 234  */
 235 int hv_post_message(union hv_connection_id connection_id,
 236                   enum hv_message_type message_type,
 237                   void *payload, size_t payload_size)
 238 {
 239         struct aligned_input {
 240                 u64 alignment8;
 241                 struct hv_input_post_message msg;
 242         };
 243
 244         struct hv_input_post_message *aligned_msg;
 245         u16 status;
 246         unsigned long addr;
 247
 248         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 249                 return -EMSGSIZE;
 250
 251         addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 252         if (!addr)
 253                 return -ENOMEM;
 254
 255         aligned_msg = (struct hv_input_post_message *)
 256                         (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 257
 258         aligned_msg->connectionid = connection_id;
 259         aligned_msg->message_type = message_type;
 260         aligned_msg->payload_size = payload_size;
 261         memcpy((void *)aligned_msg->payload, payload, payload_size);
 262
 263         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 264                 & 0xFFFF;
 265
 266         kfree((void *)addr);
 267
 268         return status;
 269 }
 270
 271
 272 /*
 273  * hv_signal_event -
 274  * Signal an event on the specified connection using the hypervisor event IPC.
 275  *
 276  * This involves a hypercall.
 277  */
 278 u16 hv_signal_event(void *con_id)
 279 {
 280         u16 status;
 281
 282         status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
 283
 284         return status;
 285 }
 286
 287 /*
 288  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 289  *
 290  * If it is already initialized by another entity (ie x2v shim), we need to
 291  * retrieve the initialized message and event pages.  Otherwise, we create and
 292  * initialize the message and event pages.
 293  */
 294 void hv_synic_init(void *irqarg)
 295 {
 296         u64 version;
 297         union hv_synic_simp simp;
 298         union hv_synic_siefp siefp;
 299         union hv_synic_sint shared_sint;
 300         union hv_synic_scontrol sctrl;
 301         u64 vp_index;
 302
 303         u32 irq_vector = *((u32 *)(irqarg));
 304         int cpu = smp_processor_id();
 305
 306         if (!hv_context.hypercall_page)
 307                 return;
 308
 309         /* Check the version */
 310         rdmsrl(HV_X64_MSR_SVERSION, version);
 311
 312         hv_context.synic_message_page[cpu] =
 313                 (void *)get_zeroed_page(GFP_ATOMIC);
 314
 315         if (hv_context.synic_message_page[cpu] == NULL) {
 316                 pr_err("Unable to allocate SYNIC message page\n");
 317                 goto cleanup;
 318         }
 319
 320         hv_context.synic_event_page[cpu] =
 321                 (void *)get_zeroed_page(GFP_ATOMIC);
 322
 323         if (hv_context.synic_event_page[cpu] == NULL) {
 324                 pr_err("Unable to allocate SYNIC event page\n");
 325                 goto cleanup;
 326         }
 327
 328         /* Setup the Synic's message page */
 329         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 330         simp.simp_enabled = 1;
 331         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 332                 >> PAGE_SHIFT;
 333
 334         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 335
 336         /* Setup the Synic's event page */
 337         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 338         siefp.siefp_enabled = 1;
 339         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 340                 >> PAGE_SHIFT;
 341
 342         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 343
 344         /* Setup the shared SINT. */
 345         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 346
 347         shared_sint.as_uint64 = 0;
 348         shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 349         shared_sint.masked = false;
 350         shared_sint.auto_eoi = false;
 351
 352         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 353
 354         /* Enable the global synic bit */
 355         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 356         sctrl.enable = 1;
 357
 358         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 359
 360         hv_context.synic_initialized = true;
 361
 362         /*
 363          * Setup the mapping between Hyper-V's notion
 364          * of cpuid and Linux' notion of cpuid.
 365          * This array will be indexed using Linux cpuid.
 366          */
 367         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 368         hv_context.vp_index[cpu] = (u32)vp_index;
 369         return;
 370
 371 cleanup:
 372         if (hv_context.synic_event_page[cpu])
 373                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 374
 375         if (hv_context.synic_message_page[cpu])
 376                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 377         return;
 378 }
 379
 380 /*
 381  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 382  */
 383 void hv_synic_cleanup(void *arg)
 384 {
 385         union hv_synic_sint shared_sint;
 386         union hv_synic_simp simp;
 387         union hv_synic_siefp siefp;
 388         int cpu = smp_processor_id();
 389
 390         if (!hv_context.synic_initialized)
 391                 return;
 392
 393         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 394
 395         shared_sint.masked = 1;
 396
 397         /* Need to correctly cleanup in the case of SMP!!! */
 398         /* Disable the interrupt */
 399         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 400
 401         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 402         simp.simp_enabled = 0;
 403         simp.base_simp_gpa = 0;
 404
 405         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 406
 407         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 408         siefp.siefp_enabled = 0;
 409         siefp.base_siefp_gpa = 0;
 410
 411         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 412
 413         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 414         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 415 }