diff options
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 715 |
1 files changed, 466 insertions, 249 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c index 632d25674e7f..c100f04b3581 100644 --- a/drivers/hv/hv.c +++ b/drivers/hv/hv.c @@ -1,54 +1,32 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2009, Microsoft Corporation. * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 59 Temple - * Place - Suite 330, Boston, MA 02111-1307 USA. - * * Authors: * Haiyang Zhang <haiyangz@microsoft.com> * Hank Janssen <hjanssen@microsoft.com> - * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/io.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/slab.h> #include <linux/vmalloc.h> #include <linux/hyperv.h> -#include <linux/version.h> #include <linux/random.h> #include <linux/clockchips.h> +#include <linux/delay.h> +#include <linux/interrupt.h> +#include <linux/export.h> +#include <clocksource/hyperv_timer.h> #include <asm/mshyperv.h> +#include <linux/set_memory.h> #include "hyperv_vmbus.h" /* The one and only */ struct hv_context hv_context; - -/* - * If false, we're using the old mechanism for stimer0 interrupts - * where it sends a VMbus message when it expires. The old - * mechanism is used when running on older versions of Hyper-V - * that don't support Direct Mode. While Hyper-V provides - * four stimer's per CPU, Linux uses only stimer0. - */ -static bool direct_mode_enabled; -static int stimer0_irq; -static int stimer0_vector; - -#define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */ -#define HV_MAX_MAX_DELTA_TICKS 0xffffffff -#define HV_MIN_DELTA_TICKS 1 +EXPORT_SYMBOL_FOR_MODULES(hv_context, "mshv_vtl"); /* * hv_init - Main initialization routine. @@ -60,9 +38,6 @@ int hv_init(void) hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context); if (!hv_context.cpu_context) return -ENOMEM; - - direct_mode_enabled = ms_hyperv.misc_features & - HV_STIMER_DIRECT_MODE_AVAILABLE; return 0; } @@ -72,122 +47,131 @@ int hv_init(void) * This involves a hypercall. */ int hv_post_message(union hv_connection_id connection_id, - enum hv_message_type message_type, - void *payload, size_t payload_size) + enum hv_message_type message_type, + void *payload, size_t payload_size) { struct hv_input_post_message *aligned_msg; - struct hv_per_cpu_context *hv_cpu; + unsigned long flags; u64 status; if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) return -EMSGSIZE; - hv_cpu = get_cpu_ptr(hv_context.cpu_context); - aligned_msg = hv_cpu->post_msg_page; + local_irq_save(flags); + + /* + * A TDX VM with the paravisor must use the decrypted post_msg_page: see + * the comment in struct hv_per_cpu_context. A SNP VM with the paravisor + * can use the encrypted hyperv_pcpu_input_arg because it copies the + * input into the GHCB page, which has been decrypted by the paravisor. + */ + if (hv_isolation_type_tdx() && ms_hyperv.paravisor_present) + aligned_msg = this_cpu_ptr(hv_context.cpu_context)->post_msg_page; + else + aligned_msg = *this_cpu_ptr(hyperv_pcpu_input_arg); + aligned_msg->connectionid = connection_id; aligned_msg->reserved = 0; aligned_msg->message_type = message_type; aligned_msg->payload_size = payload_size; memcpy((void *)aligned_msg->payload, payload, payload_size); - status = hv_do_hypercall(HVCALL_POST_MESSAGE, aligned_msg, NULL); - - /* Preemption must remain disabled until after the hypercall - * so some other thread can't get scheduled onto this cpu and - * corrupt the per-cpu post_msg_page - */ - put_cpu_ptr(hv_cpu); - - return status & 0xFFFF; -} + if (ms_hyperv.paravisor_present && !vmbus_is_confidential()) { + /* + * If the VMBus isn't confidential, use the CoCo-specific + * mechanism to communicate with the hypervisor. + */ + if (hv_isolation_type_tdx()) + status = hv_tdx_hypercall(HVCALL_POST_MESSAGE, + virt_to_phys(aligned_msg), 0); + else if (hv_isolation_type_snp()) + status = hv_ghcb_hypercall(HVCALL_POST_MESSAGE, + aligned_msg, NULL, + sizeof(*aligned_msg)); + else + status = HV_STATUS_INVALID_PARAMETER; + } else { + u64 control = HVCALL_POST_MESSAGE; -/* - * ISR for when stimer0 is operating in Direct Mode. Direct Mode - * does not use VMbus or any VMbus messages, so process here and not - * in the VMbus driver code. - */ + control |= hv_nested ? HV_HYPERCALL_NESTED : 0; + /* + * If there is no paravisor, this will go to the hypervisor. + * In the Confidential VMBus case, there is the paravisor + * to which this will trap. + */ + status = hv_do_hypercall(control, aligned_msg, NULL); + } -static void hv_stimer0_isr(void) -{ - struct hv_per_cpu_context *hv_cpu; + local_irq_restore(flags); - hv_cpu = this_cpu_ptr(hv_context.cpu_context); - hv_cpu->clk_evt->event_handler(hv_cpu->clk_evt); - add_interrupt_randomness(stimer0_vector, 0); + return hv_result(status); } +EXPORT_SYMBOL_FOR_MODULES(hv_post_message, "mshv_vtl"); -static int hv_ce_set_next_event(unsigned long delta, - struct clock_event_device *evt) +static int hv_alloc_page(void **page, bool decrypt, const char *note) { - u64 current_tick; - - WARN_ON(!clockevent_state_oneshot(evt)); + int ret = 0; - current_tick = hyperv_cs->read(NULL); - current_tick += delta; - hv_init_timer(0, current_tick); - return 0; -} + /* + * After the page changes its encryption status, its contents might + * appear scrambled on some hardware. Thus `get_zeroed_page` would + * zero the page out in vain, so do that explicitly exactly once. + * + * By default, the page is allocated encrypted in a CoCo VM. + */ + *page = (void *)__get_free_page(GFP_KERNEL); + if (!*page) + return -ENOMEM; -static int hv_ce_shutdown(struct clock_event_device *evt) -{ - hv_init_timer(0, 0); - hv_init_timer_config(0, 0); - if (direct_mode_enabled) - hv_disable_stimer0_percpu_irq(stimer0_irq); + if (decrypt) + ret = set_memory_decrypted((unsigned long)*page, 1); + if (ret) + goto failed; + memset(*page, 0, PAGE_SIZE); return 0; + +failed: + /* + * Report the failure but don't put the page back on the free list as + * its encryption status is unknown. + */ + pr_err("allocation failed for %s page, error %d, decrypted %d\n", + note, ret, decrypt); + *page = NULL; + return ret; } -static int hv_ce_set_oneshot(struct clock_event_device *evt) +static int hv_free_page(void **page, bool encrypt, const char *note) { - union hv_stimer_config timer_cfg; + int ret = 0; - timer_cfg.as_uint64 = 0; - timer_cfg.enable = 1; - timer_cfg.auto_enable = 1; - if (direct_mode_enabled) { - /* - * When it expires, the timer will directly interrupt - * on the specified hardware vector/IRQ. - */ - timer_cfg.direct_mode = 1; - timer_cfg.apic_vector = stimer0_vector; - hv_enable_stimer0_percpu_irq(stimer0_irq); - } else { - /* - * When it expires, the timer will generate a VMbus message, - * to be handled by the normal VMbus interrupt handler. - */ - timer_cfg.direct_mode = 0; - timer_cfg.sintx = VMBUS_MESSAGE_SINT; - } - hv_init_timer_config(0, timer_cfg.as_uint64); - return 0; -} + if (!*page) + return 0; + + if (encrypt) + ret = set_memory_encrypted((unsigned long)*page, 1); -static void hv_init_clockevent_device(struct clock_event_device *dev, int cpu) -{ - dev->name = "Hyper-V clockevent"; - dev->features = CLOCK_EVT_FEAT_ONESHOT; - dev->cpumask = cpumask_of(cpu); - dev->rating = 1000; /* - * Avoid settint dev->owner = THIS_MODULE deliberately as doing so will - * result in clockevents_config_and_register() taking additional - * references to the hv_vmbus module making it impossible to unload. + * In the case of the failure, the page is leaked. Something is wrong, + * prefer to lose the page with the unknown encryption status and stay afloat. */ + if (ret) + pr_err("deallocation failed for %s page, error %d, encrypt %d\n", + note, ret, encrypt); + else + free_page((unsigned long)*page); - dev->set_state_shutdown = hv_ce_shutdown; - dev->set_state_oneshot = hv_ce_set_oneshot; - dev->set_next_event = hv_ce_set_next_event; -} + *page = NULL; + return ret; +} int hv_synic_alloc(void) { - int cpu; + int cpu, ret = -ENOMEM; struct hv_per_cpu_context *hv_cpu; + const bool decrypt = !vmbus_is_confidential(); /* * First, zero all per-cpu memory areas so hv_synic_free() can @@ -201,7 +185,7 @@ int hv_synic_alloc(void) hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask), GFP_KERNEL); - if (hv_context.hv_numa_map == NULL) { + if (!hv_context.hv_numa_map) { pr_err("Unable to allocate NUMA map\n"); goto err; } @@ -210,150 +194,382 @@ int hv_synic_alloc(void) hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); tasklet_init(&hv_cpu->msg_dpc, - vmbus_on_msg_dpc, (unsigned long) hv_cpu); - - hv_cpu->clk_evt = kzalloc(sizeof(struct clock_event_device), - GFP_KERNEL); - if (hv_cpu->clk_evt == NULL) { - pr_err("Unable to allocate clock event device\n"); - goto err; - } - hv_init_clockevent_device(hv_cpu->clk_evt, cpu); + vmbus_on_msg_dpc, (unsigned long)hv_cpu); - hv_cpu->synic_message_page = - (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->synic_message_page == NULL) { - pr_err("Unable to allocate SYNIC message page\n"); - goto err; + if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { + ret = hv_alloc_page(&hv_cpu->post_msg_page, + decrypt, "post msg"); + if (ret) + goto err; } - hv_cpu->synic_event_page = (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->synic_event_page == NULL) { - pr_err("Unable to allocate SYNIC event page\n"); - goto err; + /* + * If these SynIC pages are not allocated, SIEF and SIM pages + * are configured using what the root partition or the paravisor + * provides upon reading the SIEFP and SIMP registers. + */ + if (!ms_hyperv.paravisor_present && !hv_root_partition()) { + ret = hv_alloc_page(&hv_cpu->hyp_synic_message_page, + decrypt, "hypervisor SynIC msg"); + if (ret) + goto err; + ret = hv_alloc_page(&hv_cpu->hyp_synic_event_page, + decrypt, "hypervisor SynIC event"); + if (ret) + goto err; } - hv_cpu->post_msg_page = (void *)get_zeroed_page(GFP_ATOMIC); - if (hv_cpu->post_msg_page == NULL) { - pr_err("Unable to allocate post msg page\n"); - goto err; + if (vmbus_is_confidential()) { + ret = hv_alloc_page(&hv_cpu->para_synic_message_page, + false, "paravisor SynIC msg"); + if (ret) + goto err; + ret = hv_alloc_page(&hv_cpu->para_synic_event_page, + false, "paravisor SynIC event"); + if (ret) + goto err; } - - INIT_LIST_HEAD(&hv_cpu->chan_list); } - if (direct_mode_enabled && - hv_setup_stimer0_irq(&stimer0_irq, &stimer0_vector, - hv_stimer0_isr)) - goto err; - return 0; + err: /* * Any memory allocations that succeeded will be freed when * the caller cleans up by calling hv_synic_free() */ - return -ENOMEM; + return ret; } - void hv_synic_free(void) { int cpu; + const bool encrypt = !vmbus_is_confidential(); for_each_present_cpu(cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); - - kfree(hv_cpu->clk_evt); - free_page((unsigned long)hv_cpu->synic_event_page); - free_page((unsigned long)hv_cpu->synic_message_page); - free_page((unsigned long)hv_cpu->post_msg_page); + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); + + if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) + hv_free_page(&hv_cpu->post_msg_page, + encrypt, "post msg"); + if (!ms_hyperv.paravisor_present && !hv_root_partition()) { + hv_free_page(&hv_cpu->hyp_synic_event_page, + encrypt, "hypervisor SynIC event"); + hv_free_page(&hv_cpu->hyp_synic_message_page, + encrypt, "hypervisor SynIC msg"); + } + if (vmbus_is_confidential()) { + hv_free_page(&hv_cpu->para_synic_event_page, + false, "paravisor SynIC event"); + hv_free_page(&hv_cpu->para_synic_message_page, + false, "paravisor SynIC msg"); + } } kfree(hv_context.hv_numa_map); } /* - * hv_synic_init - Initialize the Synthetic Interrupt Controller. - * - * If it is already initialized by another entity (ie x2v shim), we need to - * retrieve the initialized message and event pages. Otherwise, we create and - * initialize the message and event pages. + * hv_hyp_synic_enable_regs - Initialize the Synthetic Interrupt Controller + * with the hypervisor. */ -int hv_synic_init(unsigned int cpu) +void hv_hyp_synic_enable_regs(unsigned int cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); union hv_synic_simp simp; union hv_synic_siefp siefp; union hv_synic_sint shared_sint; - union hv_synic_scontrol sctrl; - /* Setup the Synic's message page */ - hv_get_simp(simp.as_uint64); + /* Setup the Synic's message page with the hypervisor. */ + simp.as_uint64 = hv_get_msr(HV_MSR_SIMP); simp.simp_enabled = 1; - simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page) - >> PAGE_SHIFT; - hv_set_simp(simp.as_uint64); + if (ms_hyperv.paravisor_present || hv_root_partition()) { + /* Mask out vTOM bit. ioremap_cache() maps decrypted */ + u64 base = (simp.base_simp_gpa << HV_HYP_PAGE_SHIFT) & + ~ms_hyperv.shared_gpa_boundary; + hv_cpu->hyp_synic_message_page = + (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + if (!hv_cpu->hyp_synic_message_page) + pr_err("Fail to map synic message page.\n"); + } else { + simp.base_simp_gpa = virt_to_phys(hv_cpu->hyp_synic_message_page) + >> HV_HYP_PAGE_SHIFT; + } - /* Setup the Synic's event page */ - hv_get_siefp(siefp.as_uint64); + hv_set_msr(HV_MSR_SIMP, simp.as_uint64); + + /* Setup the Synic's event page with the hypervisor. */ + siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP); siefp.siefp_enabled = 1; - siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page) - >> PAGE_SHIFT; - hv_set_siefp(siefp.as_uint64); + if (ms_hyperv.paravisor_present || hv_root_partition()) { + /* Mask out vTOM bit. ioremap_cache() maps decrypted */ + u64 base = (siefp.base_siefp_gpa << HV_HYP_PAGE_SHIFT) & + ~ms_hyperv.shared_gpa_boundary; + hv_cpu->hyp_synic_event_page = + (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + if (!hv_cpu->hyp_synic_event_page) + pr_err("Fail to map synic event page.\n"); + } else { + siefp.base_siefp_gpa = virt_to_phys(hv_cpu->hyp_synic_event_page) + >> HV_HYP_PAGE_SHIFT; + } + + hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64); + hv_enable_coco_interrupt(cpu, vmbus_interrupt, true); /* Setup the shared SINT. */ - hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64); + if (vmbus_irq != -1) + enable_percpu_irq(vmbus_irq, 0); + shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT); - shared_sint.vector = HYPERVISOR_CALLBACK_VECTOR; + shared_sint.vector = vmbus_interrupt; shared_sint.masked = false; - if (ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED) - shared_sint.auto_eoi = false; - else - shared_sint.auto_eoi = true; + shared_sint.auto_eoi = hv_recommend_using_aeoi(); + hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64); +} - hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64); +static void hv_hyp_synic_enable_interrupts(void) +{ + union hv_synic_scontrol sctrl; + + /* Enable the global synic bit */ + sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL); + sctrl.enable = 1; + + hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64); +} + +static void hv_para_synic_enable_regs(unsigned int cpu) +{ + union hv_synic_simp simp; + union hv_synic_siefp siefp; + struct hv_per_cpu_context *hv_cpu + = per_cpu_ptr(hv_context.cpu_context, cpu); + + /* Setup the Synic's message page with the paravisor. */ + simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP); + simp.simp_enabled = 1; + simp.base_simp_gpa = virt_to_phys(hv_cpu->para_synic_message_page) + >> HV_HYP_PAGE_SHIFT; + hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64); + + /* Setup the Synic's event page with the paravisor. */ + siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP); + siefp.siefp_enabled = 1; + siefp.base_siefp_gpa = virt_to_phys(hv_cpu->para_synic_event_page) + >> HV_HYP_PAGE_SHIFT; + hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64); +} + +static void hv_para_synic_enable_interrupts(void) +{ + union hv_synic_scontrol sctrl; /* Enable the global synic bit */ - hv_get_synic_state(sctrl.as_uint64); + sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL); sctrl.enable = 1; + hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64); +} - hv_set_synic_state(sctrl.as_uint64); +int hv_synic_init(unsigned int cpu) +{ + if (vmbus_is_confidential()) + hv_para_synic_enable_regs(cpu); /* - * Register the per-cpu clockevent source. + * The SINT is set in hv_hyp_synic_enable_regs() by calling + * hv_set_msr(). hv_set_msr() in turn has special case code for the + * SINT MSRs that write to the hypervisor version of the MSR *and* + * the paravisor version of the MSR (but *without* the proxy bit when + * VMBus is confidential). + * + * Then enable interrupts via the paravisor if VMBus is confidential, + * and otherwise via the hypervisor. */ - if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) - clockevents_config_and_register(hv_cpu->clk_evt, - HV_TIMER_FREQUENCY, - HV_MIN_DELTA_TICKS, - HV_MAX_MAX_DELTA_TICKS); + + hv_hyp_synic_enable_regs(cpu); + if (vmbus_is_confidential()) + hv_para_synic_enable_interrupts(); + else + hv_hyp_synic_enable_interrupts(); + + hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT); + return 0; } +void hv_hyp_synic_disable_regs(unsigned int cpu) +{ + struct hv_per_cpu_context *hv_cpu = + per_cpu_ptr(hv_context.cpu_context, cpu); + union hv_synic_sint shared_sint; + union hv_synic_simp simp; + union hv_synic_siefp siefp; + + shared_sint.as_uint64 = hv_get_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT); + + shared_sint.masked = 1; + + /* Need to correctly cleanup in the case of SMP!!! */ + /* Disable the interrupt */ + hv_set_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64); + hv_enable_coco_interrupt(cpu, vmbus_interrupt, false); + + simp.as_uint64 = hv_get_msr(HV_MSR_SIMP); + /* + * In Isolation VM, simp and sief pages are allocated by + * paravisor. These pages also will be used by kdump + * kernel. So just reset enable bit here and keep page + * addresses. + */ + simp.simp_enabled = 0; + if (ms_hyperv.paravisor_present || hv_root_partition()) { + if (hv_cpu->hyp_synic_message_page) { + iounmap(hv_cpu->hyp_synic_message_page); + hv_cpu->hyp_synic_message_page = NULL; + } + } else { + simp.base_simp_gpa = 0; + } + + hv_set_msr(HV_MSR_SIMP, simp.as_uint64); + + siefp.as_uint64 = hv_get_msr(HV_MSR_SIEFP); + siefp.siefp_enabled = 0; + + if (ms_hyperv.paravisor_present || hv_root_partition()) { + if (hv_cpu->hyp_synic_event_page) { + iounmap(hv_cpu->hyp_synic_event_page); + hv_cpu->hyp_synic_event_page = NULL; + } + } else { + siefp.base_siefp_gpa = 0; + } + + hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64); +} + +static void hv_hyp_synic_disable_interrupts(void) +{ + union hv_synic_scontrol sctrl; + + /* Disable the global synic bit */ + sctrl.as_uint64 = hv_get_msr(HV_MSR_SCONTROL); + sctrl.enable = 0; + hv_set_msr(HV_MSR_SCONTROL, sctrl.as_uint64); +} + +static void hv_para_synic_disable_regs(unsigned int cpu) +{ + union hv_synic_simp simp; + union hv_synic_siefp siefp; + + /* Disable SynIC's message page in the paravisor. */ + simp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIMP); + simp.simp_enabled = 0; + hv_para_set_synic_register(HV_MSR_SIMP, simp.as_uint64); + + /* Disable SynIC's event page in the paravisor. */ + siefp.as_uint64 = hv_para_get_synic_register(HV_MSR_SIEFP); + siefp.siefp_enabled = 0; + hv_para_set_synic_register(HV_MSR_SIEFP, siefp.as_uint64); +} + +static void hv_para_synic_disable_interrupts(void) +{ + union hv_synic_scontrol sctrl; + + /* Disable the global synic bit */ + sctrl.as_uint64 = hv_para_get_synic_register(HV_MSR_SCONTROL); + sctrl.enable = 0; + hv_para_set_synic_register(HV_MSR_SCONTROL, sctrl.as_uint64); +} + +#define HV_MAX_TRIES 3 /* - * hv_synic_clockevents_cleanup - Cleanup clockevent devices + * Scan the event flags page of 'this' CPU looking for any bit that is set. If we find one + * bit set, then wait for a few milliseconds. Repeat these steps for a maximum of 3 times. + * Return 'true', if there is still any set bit after this operation; 'false', otherwise. + * + * If a bit is set, that means there is a pending channel interrupt. The expectation is + * that the normal interrupt handling mechanism will find and process the channel interrupt + * "very soon", and in the process clear the bit. */ -void hv_synic_clockevents_cleanup(void) +static bool __hv_synic_event_pending(union hv_synic_event_flags *event, int sint) { + unsigned long *recv_int_page; + bool pending; + u32 relid; + int tries = 0; + + if (!event) + return false; + + event += sint; + recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */ +retry: + pending = false; + for_each_set_bit(relid, recv_int_page, HV_EVENT_FLAGS_COUNT) { + /* Special case - VMBus channel protocol messages */ + if (relid == 0) + continue; + pending = true; + break; + } + if (pending && tries++ < HV_MAX_TRIES) { + usleep_range(10000, 20000); + goto retry; + } + return pending; +} + +static bool hv_synic_event_pending(void) +{ + struct hv_per_cpu_context *hv_cpu = this_cpu_ptr(hv_context.cpu_context); + union hv_synic_event_flags *hyp_synic_event_page = hv_cpu->hyp_synic_event_page; + union hv_synic_event_flags *para_synic_event_page = hv_cpu->para_synic_event_page; + + return + __hv_synic_event_pending(hyp_synic_event_page, VMBUS_MESSAGE_SINT) || + __hv_synic_event_pending(para_synic_event_page, VMBUS_MESSAGE_SINT); +} + +static int hv_pick_new_cpu(struct vmbus_channel *channel) +{ + int ret = -EBUSY; + int start; int cpu; - if (!(ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE)) - return; + lockdep_assert_cpus_held(); + lockdep_assert_held(&vmbus_connection.channel_mutex); - if (direct_mode_enabled) - hv_remove_stimer0_irq(stimer0_irq); + /* + * We can't assume that the relevant interrupts will be sent before + * the cpu is offlined on older versions of hyperv. + */ + if (vmbus_proto_version < VERSION_WIN10_V5_3) + return -EBUSY; - for_each_present_cpu(cpu) { - struct hv_per_cpu_context *hv_cpu - = per_cpu_ptr(hv_context.cpu_context, cpu); + start = get_random_u32_below(nr_cpu_ids); - clockevents_unbind_device(hv_cpu->clk_evt, cpu); + for_each_cpu_wrap(cpu, cpu_online_mask, start) { + if (channel->target_cpu == cpu || + channel->target_cpu == VMBUS_CONNECT_CPU) + continue; + + ret = vmbus_channel_set_cpu(channel, cpu); + if (!ret) + break; } + + if (ret) + ret = vmbus_channel_set_cpu(channel, VMBUS_CONNECT_CPU); + + return ret; } /* @@ -361,79 +577,80 @@ void hv_synic_clockevents_cleanup(void) */ int hv_synic_cleanup(unsigned int cpu) { - union hv_synic_sint shared_sint; - union hv_synic_simp simp; - union hv_synic_siefp siefp; - union hv_synic_scontrol sctrl; struct vmbus_channel *channel, *sc; - bool channel_found = false; - unsigned long flags; + int ret = 0; + + if (vmbus_connection.conn_state != CONNECTED) + goto always_cleanup; - hv_get_synic_state(sctrl.as_uint64); - if (sctrl.enable != 1) - return -EFAULT; + /* + * Hyper-V does not provide a way to change the connect CPU once + * it is set; we must prevent the connect CPU from going offline + * while the VM is running normally. But in the panic or kexec() + * path where the vmbus is already disconnected, the CPU must be + * allowed to shut down. + */ + if (cpu == VMBUS_CONNECT_CPU) + return -EBUSY; /* * Search for channels which are bound to the CPU we're about to - * cleanup. In case we find one and vmbus is still connected we need to - * fail, this will effectively prevent CPU offlining. There is no way - * we can re-bind channels to different CPUs for now. + * cleanup. */ mutex_lock(&vmbus_connection.channel_mutex); list_for_each_entry(channel, &vmbus_connection.chn_list, listentry) { if (channel->target_cpu == cpu) { - channel_found = true; - break; + ret = hv_pick_new_cpu(channel); + if (ret) { + mutex_unlock(&vmbus_connection.channel_mutex); + return ret; + } } - spin_lock_irqsave(&channel->lock, flags); list_for_each_entry(sc, &channel->sc_list, sc_list) { if (sc->target_cpu == cpu) { - channel_found = true; - break; + ret = hv_pick_new_cpu(sc); + if (ret) { + mutex_unlock(&vmbus_connection.channel_mutex); + return ret; + } } } - spin_unlock_irqrestore(&channel->lock, flags); - if (channel_found) - break; } mutex_unlock(&vmbus_connection.channel_mutex); - if (channel_found && vmbus_connection.conn_state == CONNECTED) + /* + * Scan the event flags page looking for bits that are set and waiting + * with a timeout for vmbus_chan_sched() to process such bits. If bits + * are still set after this operation and VMBus is connected, fail the + * CPU offlining operation. + */ + if (vmbus_proto_version >= VERSION_WIN10_V4_1 && hv_synic_event_pending()) return -EBUSY; - /* Turn off clockevent device */ - if (ms_hyperv.features & HV_MSR_SYNTIMER_AVAILABLE) { - struct hv_per_cpu_context *hv_cpu - = this_cpu_ptr(hv_context.cpu_context); - - clockevents_unbind_device(hv_cpu->clk_evt, cpu); - hv_ce_shutdown(hv_cpu->clk_evt); - put_cpu_ptr(hv_cpu); - } - - hv_get_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64); - - shared_sint.masked = 1; - - /* Need to correctly cleanup in the case of SMP!!! */ - /* Disable the interrupt */ - hv_set_synint_state(VMBUS_MESSAGE_SINT, shared_sint.as_uint64); - - hv_get_simp(simp.as_uint64); - simp.simp_enabled = 0; - simp.base_simp_gpa = 0; - - hv_set_simp(simp.as_uint64); +always_cleanup: + hv_stimer_legacy_cleanup(cpu); - hv_get_siefp(siefp.as_uint64); - siefp.siefp_enabled = 0; - siefp.base_siefp_gpa = 0; - - hv_set_siefp(siefp.as_uint64); + /* + * First, disable the event and message pages + * used for communicating with the host, and then + * disable the host interrupts if VMBus is not + * confidential. + */ + hv_hyp_synic_disable_regs(cpu); + if (!vmbus_is_confidential()) + hv_hyp_synic_disable_interrupts(); - /* Disable the global synic bit */ - sctrl.enable = 0; - hv_set_synic_state(sctrl.as_uint64); + /* + * Perform the same steps for the Confidential VMBus. + * The sequencing provides the guarantee that no data + * may be posted for processing before disabling interrupts. + */ + if (vmbus_is_confidential()) { + hv_para_synic_disable_regs(cpu); + hv_para_synic_disable_interrupts(); + } + if (vmbus_irq != -1) + disable_percpu_irq(vmbus_irq); - return 0; + return ret; } |