1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright (c) 2009, Microsoft Corporation.
6 * Haiyang Zhang <haiyangz@microsoft.com>
7 * Hank Janssen <hjanssen@microsoft.com>
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/kernel.h>
13 #include <linux/slab.h>
14 #include <linux/vmalloc.h>
15 #include <linux/hyperv.h>
16 #include <linux/version.h>
17 #include <linux/random.h>
18 #include <linux/clockchips.h>
19 #include <linux/interrupt.h>
20 #include <clocksource/hyperv_timer.h>
21 #include <asm/mshyperv.h>
22 #include "hyperv_vmbus.h"
24 /* The one and only */
25 struct hv_context hv_context;
28 * hv_init - Main initialization routine.
30 * This routine must be called before any other routines in here are called
34 hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context);
35 if (!hv_context.cpu_context)
41 * Functions for allocating and freeing memory with size and
42 * alignment HV_HYP_PAGE_SIZE. These functions are needed because
43 * the guest page size may not be the same as the Hyper-V page
44 * size. We depend upon kmalloc() aligning power-of-two size
45 * allocations to the allocation size boundary, so that the
46 * allocated memory appears to Hyper-V as a page of the size
50 void *hv_alloc_hyperv_page(void)
52 BUILD_BUG_ON(PAGE_SIZE < HV_HYP_PAGE_SIZE);
54 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
55 return (void *)__get_free_page(GFP_KERNEL);
57 return kmalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
60 void *hv_alloc_hyperv_zeroed_page(void)
62 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
63 return (void *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
65 return kzalloc(HV_HYP_PAGE_SIZE, GFP_KERNEL);
68 void hv_free_hyperv_page(unsigned long addr)
70 if (PAGE_SIZE == HV_HYP_PAGE_SIZE)
77 * hv_post_message - Post a message using the hypervisor message IPC.
79 * This involves a hypercall.
81 int hv_post_message(union hv_connection_id connection_id,
82 enum hv_message_type message_type,
83 void *payload, size_t payload_size)
85 struct hv_input_post_message *aligned_msg;
86 struct hv_per_cpu_context *hv_cpu;
89 if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT)
92 hv_cpu = get_cpu_ptr(hv_context.cpu_context);
93 aligned_msg = hv_cpu->post_msg_page;
94 aligned_msg->connectionid = connection_id;
95 aligned_msg->reserved = 0;
96 aligned_msg->message_type = message_type;
97 aligned_msg->payload_size = payload_size;
98 memcpy((void *)aligned_msg->payload, payload, payload_size);
100 status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL);
102 /* Preemption must remain disabled until after the hypercall
103 * so some other thread can't get scheduled onto this cpu and
104 * corrupt the per-cpu post_msg_page
108 return status & 0xFFFF;
111 int hv_synic_alloc(void)
114 struct hv_per_cpu_context *hv_cpu;
117 * First, zero all per-cpu memory areas so hv_synic_free() can
118 * detect what memory has been allocated and cleanup properly
119 * after any failures.
121 for_each_present_cpu(cpu) {
122 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
123 memset(hv_cpu, 0, sizeof(*hv_cpu));
126 hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask),
128 if (hv_context.hv_numa_map == NULL) {
129 pr_err("Unable to allocate NUMA map\n");
133 for_each_present_cpu(cpu) {
134 hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu);
136 tasklet_init(&hv_cpu->msg_dpc,
137 vmbus_on_msg_dpc, (unsigned long) hv_cpu);
139 hv_cpu->synic_message_page =
140 (void *)get_zeroed_page(GFP_ATOMIC);
141 if (hv_cpu->synic_message_page == NULL) {
142 pr_err("Unable to allocate SYNIC message page\n");
146 hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC);
147 if (hv_cpu->synic_event_page == NULL) {
148 pr_err("Unable to allocate SYNIC event page\n");
152 hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC);
153 if (hv_cpu->post_msg_page == NULL) {
154 pr_err("Unable to allocate post msg page\n");
162 * Any memory allocations that succeeded will be freed when
163 * the caller cleans up by calling hv_synic_free()
169 void hv_synic_free(void)
173 for_each_present_cpu(cpu) {
174 struct hv_per_cpu_context *hv_cpu
175 = per_cpu_ptr(hv_context.cpu_context, cpu);
177 free_page((unsigned long)hv_cpu->synic_event_page);
178 free_page((unsigned long)hv_cpu->synic_message_page);
179 free_page((unsigned long)hv_cpu->post_msg_page);
182 kfree(hv_context.hv_numa_map);
186 * hv_synic_init - Initialize the Synthetic Interrupt Controller.
188 * If it is already initialized by another entity (ie x2v shim), we need to
189 * retrieve the initialized message and event pages. Otherwise, we create and
190 * initialize the message and event pages.
192 void hv_synic_enable_regs(unsigned int cpu)
194 struct hv_per_cpu_context *hv_cpu
195 = per_cpu_ptr(hv_context.cpu_context, cpu);
196 union hv_synic_simp simp;
197 union hv_synic_siefp siefp;
198 union hv_synic_sint shared_sint;
199 union hv_synic_scontrol sctrl;
201 /* Setup the Synic's message page */
202 simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
203 simp.simp_enabled = 1;
204 simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page)
205 >> HV_HYP_PAGE_SHIFT;
207 hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
209 /* Setup the Synic's event page */
210 siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
211 siefp.siefp_enabled = 1;
212 siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page)
213 >> HV_HYP_PAGE_SHIFT;
215 hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
217 /* Setup the shared SINT. */
219 enable_percpu_irq(vmbus_irq, 0);
220 shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
223 shared_sint.vector = vmbus_interrupt;
224 shared_sint.masked = false;
227 * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64),
228 * it doesn't provide a recommendation flag and AEOI must be disabled.
230 #ifdef HV_DEPRECATING_AEOI_RECOMMENDED
231 shared_sint.auto_eoi =
232 !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED);
234 shared_sint.auto_eoi = 0;
236 hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
237 shared_sint.as_uint64);
239 /* Enable the global synic bit */
240 sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
243 hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
246 int hv_synic_init(unsigned int cpu)
248 hv_synic_enable_regs(cpu);
250 hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);
256 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
258 void hv_synic_disable_regs(unsigned int cpu)
260 union hv_synic_sint shared_sint;
261 union hv_synic_simp simp;
262 union hv_synic_siefp siefp;
263 union hv_synic_scontrol sctrl;
265 shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 +
268 shared_sint.masked = 1;
270 /* Need to correctly cleanup in the case of SMP!!! */
271 /* Disable the interrupt */
272 hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT,
273 shared_sint.as_uint64);
275 simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP);
276 simp.simp_enabled = 0;
277 simp.base_simp_gpa = 0;
279 hv_set_register(HV_REGISTER_SIMP, simp.as_uint64);
281 siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP);
282 siefp.siefp_enabled = 0;
283 siefp.base_siefp_gpa = 0;
285 hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64);
287 /* Disable the global synic bit */
288 sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL);
290 hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64);
293 disable_percpu_irq(vmbus_irq);
297 int hv_synic_cleanup(unsigned int cpu)
299 struct vmbus_channel *channel, *sc;
300 bool channel_found = false;
303 * Hyper-V does not provide a way to change the connect CPU once
304 * it is set; we must prevent the connect CPU from going offline
305 * while the VM is running normally. But in the panic or kexec()
306 * path where the vmbus is already disconnected, the CPU must be
307 * allowed to shut down.
309 if (cpu == VMBUS_CONNECT_CPU &&
310 vmbus_connection.conn_state == CONNECTED)
314 * Search for channels which are bound to the CPU we're about to
315 * cleanup. In case we find one and vmbus is still connected, we
316 * fail; this will effectively prevent CPU offlining.
318 * TODO: Re-bind the channels to different CPUs.
320 mutex_lock(&vmbus_connection.channel_mutex);
321 list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) {
322 if (channel->target_cpu == cpu) {
323 channel_found = true;
326 list_for_each_entry(sc, &channel->sc_list, sc_list) {
327 if (sc->target_cpu == cpu) {
328 channel_found = true;
335 mutex_unlock(&vmbus_connection.channel_mutex);
337 if (channel_found && vmbus_connection.conn_state == CONNECTED)
340 hv_stimer_legacy_cleanup(cpu);
342 hv_synic_disable_regs(cpu);