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 <linux/version.h>
  30#include <asm/hyperv.h>
  31#include "hyperv_vmbus.h"
  32
  33/* The one and only */
  34struct 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 */
  44static 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 */
  87static 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 */
 131int 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
 141        max_leaf = query_hypervisor_info();
 142
 143        /*
 144         * Write our OS ID.
 145         */
 146        hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
 147        wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 148
 149        /* See if the hypercall page is already set */
 150        rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 151
 152        virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 153
 154        if (!virtaddr)
 155                goto cleanup;
 156
 157        hypercall_msr.enable = 1;
 158
 159        hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 160        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 161
 162        /* Confirm that hypercall page did get setup. */
 163        hypercall_msr.as_uint64 = 0;
 164        rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 165
 166        if (!hypercall_msr.enable)
 167                goto cleanup;
 168
 169        hv_context.hypercall_page = virtaddr;
 170
 171        /* Setup the global signal event param for the signal event hypercall */
 172        hv_context.signal_event_buffer =
 173                        kmalloc(sizeof(struct hv_input_signal_event_buffer),
 174                                GFP_KERNEL);
 175        if (!hv_context.signal_event_buffer)
 176                goto cleanup;
 177
 178        hv_context.signal_event_param =
 179                (struct hv_input_signal_event *)
 180                        (ALIGN((unsigned long)
 181                                  hv_context.signal_event_buffer,
 182                                  HV_HYPERCALL_PARAM_ALIGN));
 183        hv_context.signal_event_param->connectionid.asu32 = 0;
 184        hv_context.signal_event_param->connectionid.u.id =
 185                                                VMBUS_EVENT_CONNECTION_ID;
 186        hv_context.signal_event_param->flag_number = 0;
 187        hv_context.signal_event_param->rsvdz = 0;
 188
 189        return 0;
 190
 191cleanup:
 192        if (virtaddr) {
 193                if (hypercall_msr.enable) {
 194                        hypercall_msr.as_uint64 = 0;
 195                        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 196                }
 197
 198                vfree(virtaddr);
 199        }
 200
 201        return -ENOTSUPP;
 202}
 203
 204/*
 205 * hv_cleanup - Cleanup routine.
 206 *
 207 * This routine is called normally during driver unloading or exiting.
 208 */
 209void hv_cleanup(void)
 210{
 211        union hv_x64_msr_hypercall_contents hypercall_msr;
 212
 213        /* Reset our OS id */
 214        wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 215
 216        kfree(hv_context.signal_event_buffer);
 217        hv_context.signal_event_buffer = NULL;
 218        hv_context.signal_event_param = NULL;
 219
 220        if (hv_context.hypercall_page) {
 221                hypercall_msr.as_uint64 = 0;
 222                wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 223                vfree(hv_context.hypercall_page);
 224                hv_context.hypercall_page = NULL;
 225        }
 226}
 227
 228/*
 229 * hv_post_message - Post a message using the hypervisor message IPC.
 230 *
 231 * This involves a hypercall.
 232 */
 233int hv_post_message(union hv_connection_id connection_id,
 234                  enum hv_message_type message_type,
 235                  void *payload, size_t payload_size)
 236{
 237        struct aligned_input {
 238                u64 alignment8;
 239                struct hv_input_post_message msg;
 240        };
 241
 242        struct hv_input_post_message *aligned_msg;
 243        u16 status;
 244        unsigned long addr;
 245
 246        if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 247                return -EMSGSIZE;
 248
 249        addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 250        if (!addr)
 251                return -ENOMEM;
 252
 253        aligned_msg = (struct hv_input_post_message *)
 254                        (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 255
 256        aligned_msg->connectionid = connection_id;
 257        aligned_msg->message_type = message_type;
 258        aligned_msg->payload_size = payload_size;
 259        memcpy((void *)aligned_msg->payload, payload, payload_size);
 260
 261        status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 262                & 0xFFFF;
 263
 264        kfree((void *)addr);
 265
 266        return status;
 267}
 268
 269
 270/*
 271 * hv_signal_event -
 272 * Signal an event on the specified connection using the hypervisor event IPC.
 273 *
 274 * This involves a hypercall.
 275 */
 276u16 hv_signal_event(void)
 277{
 278        u16 status;
 279
 280        status = do_hypercall(HVCALL_SIGNAL_EVENT,
 281                               hv_context.signal_event_param,
 282                               NULL) & 0xFFFF;
 283        return status;
 284}
 285
 286/*
 287 * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 288 *
 289 * If it is already initialized by another entity (ie x2v shim), we need to
 290 * retrieve the initialized message and event pages.  Otherwise, we create and
 291 * initialize the message and event pages.
 292 */
 293void hv_synic_init(void *irqarg)
 294{
 295        u64 version;
 296        union hv_synic_simp simp;
 297        union hv_synic_siefp siefp;
 298        union hv_synic_sint shared_sint;
 299        union hv_synic_scontrol sctrl;
 300
 301        u32 irq_vector = *((u32 *)(irqarg));
 302        int cpu = smp_processor_id();
 303
 304        if (!hv_context.hypercall_page)
 305                return;
 306
 307        /* Check the version */
 308        rdmsrl(HV_X64_MSR_SVERSION, version);
 309
 310        hv_context.synic_message_page[cpu] =
 311                (void *)get_zeroed_page(GFP_ATOMIC);
 312
 313        if (hv_context.synic_message_page[cpu] == NULL) {
 314                pr_err("Unable to allocate SYNIC message page\n");
 315                goto cleanup;
 316        }
 317
 318        hv_context.synic_event_page[cpu] =
 319                (void *)get_zeroed_page(GFP_ATOMIC);
 320
 321        if (hv_context.synic_event_page[cpu] == NULL) {
 322                pr_err("Unable to allocate SYNIC event page\n");
 323                goto cleanup;
 324        }
 325
 326        /* Setup the Synic's message page */
 327        rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 328        simp.simp_enabled = 1;
 329        simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 330                >> PAGE_SHIFT;
 331
 332        wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 333
 334        /* Setup the Synic's event page */
 335        rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 336        siefp.siefp_enabled = 1;
 337        siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 338                >> PAGE_SHIFT;
 339
 340        wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 341
 342        /* Setup the shared SINT. */
 343        rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 344
 345        shared_sint.as_uint64 = 0;
 346        shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 347        shared_sint.masked = false;
 348        shared_sint.auto_eoi = false;
 349
 350        wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 351
 352        /* Enable the global synic bit */
 353        rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 354        sctrl.enable = 1;
 355
 356        wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 357
 358        hv_context.synic_initialized = true;
 359        return;
 360
 361cleanup:
 362        if (hv_context.synic_event_page[cpu])
 363                free_page((unsigned long)hv_context.synic_event_page[cpu]);
 364
 365        if (hv_context.synic_message_page[cpu])
 366                free_page((unsigned long)hv_context.synic_message_page[cpu]);
 367        return;
 368}
 369
 370/*
 371 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 372 */
 373void hv_synic_cleanup(void *arg)
 374{
 375        union hv_synic_sint shared_sint;
 376        union hv_synic_simp simp;
 377        union hv_synic_siefp siefp;
 378        int cpu = smp_processor_id();
 379
 380        if (!hv_context.synic_initialized)
 381                return;
 382
 383        rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 384
 385        shared_sint.masked = 1;
 386
 387        /* Need to correctly cleanup in the case of SMP!!! */
 388        /* Disable the interrupt */
 389        wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 390
 391        rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 392        simp.simp_enabled = 0;
 393        simp.base_simp_gpa = 0;
 394
 395        wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 396
 397        rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 398        siefp.siefp_enabled = 0;
 399        siefp.base_siefp_gpa = 0;
 400
 401        wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 402
 403        free_page((unsigned long)hv_context.synic_message_page[cpu]);
 404        free_page((unsigned long)hv_context.synic_event_page[cpu]);
 405}
 406
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