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 *) * 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
 213 cleanup:
 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  */
 231 void 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  */
 255 int 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  */
 298 u16 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  */
 315 void 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
 383 cleanup:
 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  */
 395 void 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 }