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_info - Get version info of the windows hypervisor
  43  */
  44 static 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  */
  87 static 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  */
 131 int 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
 191 cleanup:
 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  */
 209 void 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  */
 233 int 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  */
 276 u16 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  */
 293 void 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
 361 cleanup:
 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  */
 373 void 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 }