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 };
  38
  39 /*
  40  * query_hypervisor_info - Get version info of the windows hypervisor
  41  */
  42 static int query_hypervisor_info(void)
  43 {
  44         unsigned int eax;
  45         unsigned int ebx;
  46         unsigned int ecx;
  47         unsigned int edx;
  48         unsigned int max_leaf;
  49         unsigned int op;
  50
  51         /*
  52         * Its assumed that this is called after confirming that Viridian
  53         * is present. Query id and revision.
  54         */
  55         eax = 0;
  56         ebx = 0;
  57         ecx = 0;
  58         edx = 0;
  59         op = HVCPUID_VENDOR_MAXFUNCTION;
  60         cpuid(op, &eax, &ebx, &ecx, &edx);
  61
  62         max_leaf = eax;
  63
  64         if (max_leaf >= HVCPUID_VERSION) {
  65                 eax = 0;
  66                 ebx = 0;
  67                 ecx = 0;
  68                 edx = 0;
  69                 op = HVCPUID_VERSION;
  70                 cpuid(op, &eax, &ebx, &ecx, &edx);
  71                 pr_info("Hyper-V Host OS Build:%d-%d.%d-%d-%d.%d\n",
  72                             eax,
  73                             ebx >> 16,
  74                             ebx & 0xFFFF,
  75                             ecx,
  76                             edx >> 24,
  77                             edx & 0xFFFFFF);
  78         }
  79         return max_leaf;
  80 }
  81
  82 /*
  83  * do_hypercall- Invoke the specified hypercall
  84  */
  85 static u64 do_hypercall(u64 control, void *input, void *output)
  86 {
  87 #ifdef CONFIG_X86_64
  88         u64 hv_status = 0;
  89         u64 input_address = (input) ? virt_to_phys(input) : 0;
  90         u64 output_address = (output) ? virt_to_phys(output) : 0;
  91         void *hypercall_page = hv_context.hypercall_page;
  92
  93         __asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
  94         __asm__ __volatile__("call *%3" : "=a" (hv_status) :
  95                              "c" (control), "d" (input_address),
  96                              "m" (hypercall_page));
  97
  98         return hv_status;
  99
 100 #else
 101
 102         u32 control_hi = control >> 32;
 103         u32 control_lo = control & 0xFFFFFFFF;
 104         u32 hv_status_hi = 1;
 105         u32 hv_status_lo = 1;
 106         u64 input_address = (input) ? virt_to_phys(input) : 0;
 107         u32 input_address_hi = input_address >> 32;
 108         u32 input_address_lo = input_address & 0xFFFFFFFF;
 109         u64 output_address = (output) ? virt_to_phys(output) : 0;
 110         u32 output_address_hi = output_address >> 32;
 111         u32 output_address_lo = output_address & 0xFFFFFFFF;
 112         void *hypercall_page = hv_context.hypercall_page;
 113
 114         __asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
 115                               "=a"(hv_status_lo) : "d" (control_hi),
 116                               "a" (control_lo), "b" (input_address_hi),
 117                               "c" (input_address_lo), "D"(output_address_hi),
 118                               "S"(output_address_lo), "m" (hypercall_page));
 119
 120         return hv_status_lo | ((u64)hv_status_hi << 32);
 121 #endif /* !x86_64 */
 122 }
 123
 124 /*
 125  * hv_init - Main initialization routine.
 126  *
 127  * This routine must be called before any other routines in here are called
 128  */
 129 int hv_init(void)
 130 {
 131         int max_leaf;
 132         union hv_x64_msr_hypercall_contents hypercall_msr;
 133         void *virtaddr = NULL;
 134
 135         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
 136         memset(hv_context.synic_message_page, 0,
 137                sizeof(void *) * NR_CPUS);
 138         memset(hv_context.vp_index, 0,
 139                sizeof(int) * 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         return 0;
 172
 173 cleanup:
 174         if (virtaddr) {
 175                 if (hypercall_msr.enable) {
 176                         hypercall_msr.as_uint64 = 0;
 177                         wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 178                 }
 179
 180                 vfree(virtaddr);
 181         }
 182
 183         return -ENOTSUPP;
 184 }
 185
 186 /*
 187  * hv_cleanup - Cleanup routine.
 188  *
 189  * This routine is called normally during driver unloading or exiting.
 190  */
 191 void hv_cleanup(void)
 192 {
 193         union hv_x64_msr_hypercall_contents hypercall_msr;
 194
 195         /* Reset our OS id */
 196         wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 197
 198         if (hv_context.hypercall_page) {
 199                 hypercall_msr.as_uint64 = 0;
 200                 wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 201                 vfree(hv_context.hypercall_page);
 202                 hv_context.hypercall_page = NULL;
 203         }
 204 }
 205
 206 /*
 207  * hv_post_message - Post a message using the hypervisor message IPC.
 208  *
 209  * This involves a hypercall.
 210  */
 211 int hv_post_message(union hv_connection_id connection_id,
 212                   enum hv_message_type message_type,
 213                   void *payload, size_t payload_size)
 214 {
 215         struct aligned_input {
 216                 u64 alignment8;
 217                 struct hv_input_post_message msg;
 218         };
 219
 220         struct hv_input_post_message *aligned_msg;
 221         u16 status;
 222         unsigned long addr;
 223
 224         if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
 225                 return -EMSGSIZE;
 226
 227         addr = (unsigned long)kmalloc(sizeof(struct aligned_input), GFP_ATOMIC);
 228         if (!addr)
 229                 return -ENOMEM;
 230
 231         aligned_msg = (struct hv_input_post_message *)
 232                         (ALIGN(addr, HV_HYPERCALL_PARAM_ALIGN));
 233
 234         aligned_msg->connectionid = connection_id;
 235         aligned_msg->message_type = message_type;
 236         aligned_msg->payload_size = payload_size;
 237         memcpy((void *)aligned_msg->payload, payload, payload_size);
 238
 239         status = do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL)
 240                 & 0xFFFF;
 241
 242         kfree((void *)addr);
 243
 244         return status;
 245 }
 246
 247
 248 /*
 249  * hv_signal_event -
 250  * Signal an event on the specified connection using the hypervisor event IPC.
 251  *
 252  * This involves a hypercall.
 253  */
 254 u16 hv_signal_event(void *con_id)
 255 {
 256         u16 status;
 257
 258         status = (do_hypercall(HVCALL_SIGNAL_EVENT, con_id, NULL) & 0xFFFF);
 259
 260         return status;
 261 }
 262
 263 /*
 264  * hv_synic_init - Initialize the Synthethic Interrupt Controller.
 265  *
 266  * If it is already initialized by another entity (ie x2v shim), we need to
 267  * retrieve the initialized message and event pages.  Otherwise, we create and
 268  * initialize the message and event pages.
 269  */
 270 void hv_synic_init(void *irqarg)
 271 {
 272         u64 version;
 273         union hv_synic_simp simp;
 274         union hv_synic_siefp siefp;
 275         union hv_synic_sint shared_sint;
 276         union hv_synic_scontrol sctrl;
 277         u64 vp_index;
 278
 279         u32 irq_vector = *((u32 *)(irqarg));
 280         int cpu = smp_processor_id();
 281
 282         if (!hv_context.hypercall_page)
 283                 return;
 284
 285         /* Check the version */
 286         rdmsrl(HV_X64_MSR_SVERSION, version);
 287
 288         hv_context.synic_message_page[cpu] =
 289                 (void *)get_zeroed_page(GFP_ATOMIC);
 290
 291         if (hv_context.synic_message_page[cpu] == NULL) {
 292                 pr_err("Unable to allocate SYNIC message page\n");
 293                 goto cleanup;
 294         }
 295
 296         hv_context.synic_event_page[cpu] =
 297                 (void *)get_zeroed_page(GFP_ATOMIC);
 298
 299         if (hv_context.synic_event_page[cpu] == NULL) {
 300                 pr_err("Unable to allocate SYNIC event page\n");
 301                 goto cleanup;
 302         }
 303
 304         /* Setup the Synic's message page */
 305         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 306         simp.simp_enabled = 1;
 307         simp.base_simp_gpa = virt_to_phys(hv_context.synic_message_page[cpu])
 308                 >> PAGE_SHIFT;
 309
 310         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 311
 312         /* Setup the Synic's event page */
 313         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 314         siefp.siefp_enabled = 1;
 315         siefp.base_siefp_gpa = virt_to_phys(hv_context.synic_event_page[cpu])
 316                 >> PAGE_SHIFT;
 317
 318         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 319
 320         /* Setup the shared SINT. */
 321         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 322
 323         shared_sint.as_uint64 = 0;
 324         shared_sint.vector = irq_vector; /* HV_SHARED_SINT_IDT_VECTOR + 0x20; */
 325         shared_sint.masked = false;
 326         shared_sint.auto_eoi = false;
 327
 328         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 329
 330         /* Enable the global synic bit */
 331         rdmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 332         sctrl.enable = 1;
 333
 334         wrmsrl(HV_X64_MSR_SCONTROL, sctrl.as_uint64);
 335
 336         hv_context.synic_initialized = true;
 337
 338         /*
 339          * Setup the mapping between Hyper-V's notion
 340          * of cpuid and Linux' notion of cpuid.
 341          * This array will be indexed using Linux cpuid.
 342          */
 343         rdmsrl(HV_X64_MSR_VP_INDEX, vp_index);
 344         hv_context.vp_index[cpu] = (u32)vp_index;
 345         return;
 346
 347 cleanup:
 348         if (hv_context.synic_event_page[cpu])
 349                 free_page((unsigned long)hv_context.synic_event_page[cpu]);
 350
 351         if (hv_context.synic_message_page[cpu])
 352                 free_page((unsigned long)hv_context.synic_message_page[cpu]);
 353         return;
 354 }
 355
 356 /*
 357  * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 358  */
 359 void hv_synic_cleanup(void *arg)
 360 {
 361         union hv_synic_sint shared_sint;
 362         union hv_synic_simp simp;
 363         union hv_synic_siefp siefp;
 364         int cpu = smp_processor_id();
 365
 366         if (!hv_context.synic_initialized)
 367                 return;
 368
 369         rdmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 370
 371         shared_sint.masked = 1;
 372
 373         /* Need to correctly cleanup in the case of SMP!!! */
 374         /* Disable the interrupt */
 375         wrmsrl(HV_X64_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);
 376
 377         rdmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 378         simp.simp_enabled = 0;
 379         simp.base_simp_gpa = 0;
 380
 381         wrmsrl(HV_X64_MSR_SIMP, simp.as_uint64);
 382
 383         rdmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 384         siefp.siefp_enabled = 0;
 385         siefp.base_siefp_gpa = 0;
 386
 387         wrmsrl(HV_X64_MSR_SIEFP, siefp.as_uint64);
 388
 389         free_page((unsigned long)hv_context.synic_message_page[cpu]);
 390         free_page((unsigned long)hv_context.synic_event_page[cpu]);
 391 }