drivers/staging/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
  29 #include "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         volatile 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         volatile 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 ret = 0;
 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 *) * MAX_NUM_CPUS);
 160         memset(hv_context.synic_message_page, 0,
 161                sizeof(void *) * MAX_NUM_CPUS);
 162
 163         if (!query_hypervisor_presence())
 164                 goto cleanup;
 165
 166         max_leaf = query_hypervisor_info();
 167         /* HvQueryHypervisorFeatures(maxLeaf); */
 168
 169         /*
 170          * We only support running on top of Hyper-V
 171          */
 172         rdmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 173
 174         if (hv_context.guestid != 0)
 175                 goto cleanup;
 176
 177         /* Write our OS info */
 178         wrmsrl(HV_X64_MSR_GUEST_OS_ID, HV_LINUX_GUEST_ID);
 179         hv_context.guestid = HV_LINUX_GUEST_ID;
 180
 181         /* See if the hypercall page is already set */
 182         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 183
 184         /*
 185         * Allocate the hypercall page memory
 186         * virtaddr = osd_page_alloc(1);
 187         */
 188         virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
 189
 190         if (!virtaddr)
 191                 goto cleanup;
 192
 193         hypercall_msr.enable = 1;
 194
 195         hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
 196         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 197
 198         /* Confirm that hypercall page did get setup. */
 199         hypercall_msr.as_uint64 = 0;
 200         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 201
 202         if (!hypercall_msr.enable)
 203                 goto cleanup;
 204
 205         hv_context.hypercall_page = virtaddr;
 206
 207         /* Setup the global signal event param for the signal event hypercall */
 208         hv_context.signal_event_buffer =
 209                         kmalloc(sizeof(struct hv_input_signal_event_buffer),
 210                                 GFP_KERNEL);
 211         if (!hv_context.signal_event_buffer)
 212                 goto cleanup;
 213
 214         hv_context.signal_event_param =
 215                 (struct hv_input_signal_event *)
 216                         (ALIGN((unsigned long)
 217                                   hv_context.signal_event_buffer,
 218                                   HV_HYPERCALL_PARAM_ALIGN));
 219         hv_context.signal_event_param->connectionid.asu32 = 0;
 220         hv_context.signal_event_param->connectionid.u.id =
 221                                                 VMBUS_EVENT_CONNECTION_ID;
 222         hv_context.signal_event_param->flag_number = 0;
 223         hv_context.signal_event_param->rsvdz = 0;
 224
 225         return ret;
 226
 227 cleanup:
 228         if (virtaddr) {
 229                 if (hypercall_msr.enable) {
 230                         hypercall_msr.as_uint64 = 0;
 231                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 232                 }
 233
 234                 vfree(virtaddr);
 235         }
 236         ret = -1;
 237         return ret;
 238 }
 239
 240 /*
 241  * hv_cleanup - Cleanup routine.
 242  *
 243  * This routine is called normally during driver unloading or exiting.
 244  */
 245 void hv_cleanup(void)
 246 {
 247         union hv_x64_msr_hypercall_contents hypercall_msr;
 248
 249         kfree(hv_context.signal_event_buffer);
 250         hv_context.signal_event_buffer = NULL;
 251         hv_context.signal_event_param = NULL;
 252
 253         if (hv_context.hypercall_page) {
 254                 hypercall_msr.as_uint64 = 0;
 255                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 256                 vfree(hv_context.hypercall_page);
 257                 hv_context.hypercall_page = NULL;
 258         }
 259 }
 260
 261 /*
 262  * hv_post_message - Post a message using the hypervisor message IPC.
 263  *
 264  * This involves a hypercall.
 265  */
 266 u16 hv_post_message(union hv_connection_id connection_id,
 267                   enum hv_message_type message_type,
 268                   void *payload, size_t payload_size)
 269 {
 270         struct aligned_input {
 271                 u64 alignment8;
 272                 struct hv_input_post_message msg;
 273         };
 274
 275         struct hv_input_post_message *aligned_msg;
 276         u16 status;
 277         unsigned long addr;
 278
 279         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 280                 return -EMSGSIZE;
 281
 282         addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 283         if (!addr)
 284                 return -ENOMEM;
 285
 286         aligned_msg = (struct hv_input_post_message *)
 287                         (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 288
 289         aligned_msg->connectionid = connection_id;
 290         aligned_msg->message_type = message_type;
 291         aligned_msg->payload_size = payload_size;
 292         memcpy((void *)aligned_msg->payload, payload, payload_size);
 293
 294         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 295                 & 0xFFFF;
 296
 297         kfree((void *)addr);
 298
 299         return status;
 300 }
 301
 302
 303 /*
 304  * hv_signal_event -
 305  * Signal an event on the specified connection using the hypervisor event IPC.
 306  *
 307  * This involves a hypercall.
 308  */
 309 u16 hv_signal_event(void)
 310 {
 311         u16 status;
 312
 313         status = do_hypercall(HVCALL_SIGNAL_EVENT,
 314                                hv_context.signal_event_param,
 315                                NULL) & 0xFFFF;
 316         return status;
 317 }
 318
 319 /*
 320  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 321  *
 322  * If it is already initialized by another entity (ie x2v shim), we need to
 323  * retrieve the initialized message and event pages.  Otherwise, we create and
 324  * initialize the message and event pages.
 325  */
 326 void hv_synic_init(void *irqarg)
 327 {
 328         u64 version;
 329         union hv_synic_simp simp;
 330         union hv_synic_siefp siefp;
 331         union hv_synic_sint shared_sint;
 332         union hv_synic_scontrol sctrl;
 333
 334         u32 irq_vector = *((u32 *)(irqarg));
 335         int cpu = smp_processor_id();
 336
 337         if (!hv_context.hypercall_page)
 338                 return;
 339
 340         /* Check the version */
 341         rdmsrl(HV_X64_MSR_SVERSION, version);
 342
 343         hv_context.synic_message_page[cpu] =
 344                 (void *)get_zeroed_page(GFP_ATOMIC);
 345
 346         if (hv_context.synic_message_page[cpu] == NULL) {
 347                 pr_err("Unable to allocate SYNIC message page\n");
 348                 goto cleanup;
 349         }
 350
 351         hv_context.synic_event_page[cpu] =
 352                 (void *)get_zeroed_page(GFP_ATOMIC);
 353
 354         if (hv_context.synic_event_page[cpu] == NULL) {
 355                 pr_err("Unable to allocate SYNIC event page\n");
 356                 goto cleanup;
 357         }
 358
 359         /* Setup the Synic's message page */
 360         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 361         simp.simp_enabled = 1;
 362         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 363                 >> PAGE_SHIFT;
 364
 365         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 366
 367         /* Setup the Synic's event page */
 368         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 369         siefp.siefp_enabled = 1;
 370         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 371                 >> PAGE_SHIFT;
 372
 373         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 374
 375         /* Setup the shared SINT. */
 376         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 377
 378         shared_sint.as_uint64 = 0;
 379         shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 380         shared_sint.masked = false;
 381         shared_sint.auto_eoi = true;
 382
 383         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 384
 385         /* Enable the global synic bit */
 386         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 387         sctrl.enable = 1;
 388
 389         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 390
 391         hv_context.synic_initialized = true;
 392         return;
 393
 394 cleanup:
 395         if (hv_context.synic_event_page[cpu])
 396                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 397
 398         if (hv_context.synic_message_page[cpu])
 399                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 400         return;
 401 }
 402
 403 /*
 404  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 405  */
 406 void hv_synic_cleanup(void *arg)
 407 {
 408         union hv_synic_sint shared_sint;
 409         union hv_synic_simp simp;
 410         union hv_synic_siefp siefp;
 411         int cpu = smp_processor_id();
 412
 413         if (!hv_context.synic_initialized)
 414                 return;
 415
 416         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 417
 418         shared_sint.masked = 1;
 419
 420         /* Need to correctly cleanup in the case of SMP!!! */
 421         /* Disable the interrupt */
 422         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 423
 424         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 425         simp.simp_enabled = 0;
 426         simp.base_simp_gpa = 0;
 427
 428         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 429
 430         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 431         siefp.siefp_enabled = 0;
 432         siefp.base_siefp_gpa = 0;
 433
 434         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 435
 436         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 437         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 438 }