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