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