linux/drivers/hv/hv.c
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   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 */
  33struct 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 */
  44static 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 */
  65static 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 */
 108static 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 */
 152int 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 *) * NR_CPUS);
 159        memset(hv_context.synic_message_page, 0,
 160               sizeof(void *) * NR_CPUS);
 161
 162        if (!query_hypervisor_presence())
 163                goto cleanup;
 164
 165        max_leaf = query_hypervisor_info();
 166
 167        /* Write our OS info */
 168        wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
 169        hv_context.guestid = HV_LINUX_GUEST_ID;
 170
 171        /* See if the hypercall page is already set */
 172        rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 173
 174        virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 175
 176        if (!virtaddr)
 177                goto cleanup;
 178
 179        hypercall_msr.enable = 1;
 180
 181        hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 182        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 183
 184        /* Confirm that hypercall page did get setup. */
 185        hypercall_msr.as_uint64 = 0;
 186        rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 187
 188        if (!hypercall_msr.enable)
 189                goto cleanup;
 190
 191        hv_context.hypercall_page = virtaddr;
 192
 193        /* Setup the global signal event param for the signal event hypercall */
 194        hv_context.signal_event_buffer =
 195                        kmalloc(sizeof(struct hv_input_signal_event_buffer),
 196                                GFP_KERNEL);
 197        if (!hv_context.signal_event_buffer)
 198                goto cleanup;
 199
 200        hv_context.signal_event_param =
 201                (struct hv_input_signal_event *)
 202                        (ALIGN((unsigned long)
 203                                  hv_context.signal_event_buffer,
 204                                  HV_HYPERCALL_PARAM_ALIGN));
 205        hv_context.signal_event_param->connectionid.asu32 = 0;
 206        hv_context.signal_event_param->connectionid.u.id =
 207                                                VMBUS_EVENT_CONNECTION_ID;
 208        hv_context.signal_event_param->flag_number = 0;
 209        hv_context.signal_event_param->rsvdz = 0;
 210
 211        return 0;
 212
 213cleanup:
 214        if (virtaddr) {
 215                if (hypercall_msr.enable) {
 216                        hypercall_msr.as_uint64 = 0;
 217                        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 218                }
 219
 220                vfree(virtaddr);
 221        }
 222
 223        return -ENOTSUPP;
 224}
 225
 226/*
 227 * hv_cleanup - Cleanup routine.
 228 *
 229 * This routine is called normally during driver unloading or exiting.
 230 */
 231void hv_cleanup(void)
 232{
 233        union hv_x64_msr_hypercall_contents hypercall_msr;
 234
 235        /* Reset our OS id */
 236        wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 237
 238        kfree(hv_context.signal_event_buffer);
 239        hv_context.signal_event_buffer = NULL;
 240        hv_context.signal_event_param = NULL;
 241
 242        if (hv_context.hypercall_page) {
 243                hypercall_msr.as_uint64 = 0;
 244                wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 245                vfree(hv_context.hypercall_page);
 246                hv_context.hypercall_page = NULL;
 247        }
 248}
 249
 250/*
 251 * hv_post_message - Post a message using the hypervisor message IPC.
 252 *
 253 * This involves a hypercall.
 254 */
 255int hv_post_message(union hv_connection_id connection_id,
 256                  enum hv_message_type message_type,
 257                  void *payload, size_t payload_size)
 258{
 259        struct aligned_input {
 260                u64 alignment8;
 261                struct hv_input_post_message msg;
 262        };
 263
 264        struct hv_input_post_message *aligned_msg;
 265        u16 status;
 266        unsigned long addr;
 267
 268        if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 269                return -EMSGSIZE;
 270
 271        addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 272        if (!addr)
 273                return -ENOMEM;
 274
 275        aligned_msg = (struct hv_input_post_message *)
 276                        (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 277
 278        aligned_msg->connectionid = connection_id;
 279        aligned_msg->message_type = message_type;
 280        aligned_msg->payload_size = payload_size;
 281        memcpy((void *)aligned_msg->payload, payload, payload_size);
 282
 283        status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 284                & 0xFFFF;
 285
 286        kfree((void *)addr);
 287
 288        return status;
 289}
 290
 291
 292/*
 293 * hv_signal_event -
 294 * Signal an event on the specified connection using the hypervisor event IPC.
 295 *
 296 * This involves a hypercall.
 297 */
 298u16 hv_signal_event(void)
 299{
 300        u16 status;
 301
 302        status = do_hypercall(HVCALL_SIGNAL_EVENT,
 303                               hv_context.signal_event_param,
 304                               NULL) & 0xFFFF;
 305        return status;
 306}
 307
 308/*
 309 * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 310 *
 311 * If it is already initialized by another entity (ie x2v shim), we need to
 312 * retrieve the initialized message and event pages.  Otherwise, we create and
 313 * initialize the message and event pages.
 314 */
 315void hv_synic_init(void *irqarg)
 316{
 317        u64 version;
 318        union hv_synic_simp simp;
 319        union hv_synic_siefp siefp;
 320        union hv_synic_sint shared_sint;
 321        union hv_synic_scontrol sctrl;
 322
 323        u32 irq_vector = *((u32 *)(irqarg));
 324        int cpu = smp_processor_id();
 325
 326        if (!hv_context.hypercall_page)
 327                return;
 328
 329        /* Check the version */
 330        rdmsrl(HV_X64_MSR_SVERSION, version);
 331
 332        hv_context.synic_message_page[cpu] =
 333                (void *)get_zeroed_page(GFP_ATOMIC);
 334
 335        if (hv_context.synic_message_page[cpu] == NULL) {
 336                pr_err("Unable to allocate SYNIC message page\n");
 337                goto cleanup;
 338        }
 339
 340        hv_context.synic_event_page[cpu] =
 341                (void *)get_zeroed_page(GFP_ATOMIC);
 342
 343        if (hv_context.synic_event_page[cpu] == NULL) {
 344                pr_err("Unable to allocate SYNIC event page\n");
 345                goto cleanup;
 346        }
 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 = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 369        shared_sint.masked = false;
 370        shared_sint.auto_eoi = false;
 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        return;
 382
 383cleanup:
 384        if (hv_context.synic_event_page[cpu])
 385                free_page((unsigned long)hv_context.synic_event_page[cpu]);
 386
 387        if (hv_context.synic_message_page[cpu])
 388                free_page((unsigned long)hv_context.synic_message_page[cpu]);
 389        return;
 390}
 391
 392/*
 393 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 394 */
 395void hv_synic_cleanup(void *arg)
 396{
 397        union hv_synic_sint shared_sint;
 398        union hv_synic_simp simp;
 399        union hv_synic_siefp siefp;
 400        int cpu = smp_processor_id();
 401
 402        if (!hv_context.synic_initialized)
 403                return;
 404
 405        rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 406
 407        shared_sint.masked = 1;
 408
 409        /* Need to correctly cleanup in the case of SMP!!! */
 410        /* Disable the interrupt */
 411        wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 412
 413        rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 414        simp.simp_enabled = 0;
 415        simp.base_simp_gpa = 0;
 416
 417        wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 418
 419        rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 420        siefp.siefp_enabled = 0;
 421        siefp.base_siefp_gpa = 0;
 422
 423        wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 424
 425        free_page((unsigned long)hv_context.synic_message_page[cpu]);
 426        free_page((unsigned long)hv_context.synic_event_page[cpu]);
 427}
 428
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