diff options
Diffstat (limited to 'drivers/hv/hv.c')
| -rw-r--r-- | drivers/hv/hv.c | 506 |
1 files changed, 506 insertions, 0 deletions
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c new file mode 100644 index 0000000000..51e5018ac9 --- /dev/null +++ b/drivers/hv/hv.c @@ -0,0 +1,506 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2009, Microsoft Corporation. + * + * 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/random.h> +#include <linux/clockchips.h> +#include <linux/delay.h> +#include <linux/interrupt.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; + +/* + * hv_init - Main initialization routine. + * + * This routine must be called before any other routines in here are called + */ +int hv_init(void) +{ + hv_context.cpu_context = alloc_percpu(struct hv_per_cpu_context); + if (!hv_context.cpu_context) + return -ENOMEM; + return 0; +} + +/* + * hv_post_message - Post a message using the hypervisor message IPC. + * + * 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) +{ + struct hv_input_post_message *aligned_msg; + unsigned long flags; + u64 status; + + if (payload_size > HV_MESSAGE_PAYLOAD_BYTE_COUNT) + return -EMSGSIZE; + + 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); + + if (ms_hyperv.paravisor_present) { + 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 { + status = hv_do_hypercall(HVCALL_POST_MESSAGE, + aligned_msg, NULL); + } + + local_irq_restore(flags); + + return hv_result(status); +} + +int hv_synic_alloc(void) +{ + int cpu, ret = -ENOMEM; + struct hv_per_cpu_context *hv_cpu; + + /* + * First, zero all per-cpu memory areas so hv_synic_free() can + * detect what memory has been allocated and cleanup properly + * after any failures. + */ + for_each_present_cpu(cpu) { + hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); + memset(hv_cpu, 0, sizeof(*hv_cpu)); + } + + hv_context.hv_numa_map = kcalloc(nr_node_ids, sizeof(struct cpumask), + GFP_KERNEL); + if (hv_context.hv_numa_map == NULL) { + pr_err("Unable to allocate NUMA map\n"); + goto err; + } + + for_each_present_cpu(cpu) { + hv_cpu = per_cpu_ptr(hv_context.cpu_context, cpu); + + tasklet_init(&hv_cpu->msg_dpc, + vmbus_on_msg_dpc, (unsigned long) hv_cpu); + + if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { + 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; + } + + ret = set_memory_decrypted((unsigned long)hv_cpu->post_msg_page, 1); + if (ret) { + pr_err("Failed to decrypt post msg page: %d\n", ret); + /* Just leak the page, as it's unsafe to free the page. */ + hv_cpu->post_msg_page = NULL; + goto err; + } + + memset(hv_cpu->post_msg_page, 0, PAGE_SIZE); + } + + /* + * Synic message and event pages are allocated by paravisor. + * Skip these pages allocation here. + */ + if (!ms_hyperv.paravisor_present && !hv_root_partition) { + 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; + } + + 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"); + + free_page((unsigned long)hv_cpu->synic_message_page); + hv_cpu->synic_message_page = NULL; + goto err; + } + } + + if (!ms_hyperv.paravisor_present && + (hv_isolation_type_snp() || hv_isolation_type_tdx())) { + ret = set_memory_decrypted((unsigned long) + hv_cpu->synic_message_page, 1); + if (ret) { + pr_err("Failed to decrypt SYNIC msg page: %d\n", ret); + hv_cpu->synic_message_page = NULL; + + /* + * Free the event page here so that hv_synic_free() + * won't later try to re-encrypt it. + */ + free_page((unsigned long)hv_cpu->synic_event_page); + hv_cpu->synic_event_page = NULL; + goto err; + } + + ret = set_memory_decrypted((unsigned long) + hv_cpu->synic_event_page, 1); + if (ret) { + pr_err("Failed to decrypt SYNIC event page: %d\n", ret); + hv_cpu->synic_event_page = NULL; + goto err; + } + + memset(hv_cpu->synic_message_page, 0, PAGE_SIZE); + memset(hv_cpu->synic_event_page, 0, PAGE_SIZE); + } + } + + return 0; + +err: + /* + * Any memory allocations that succeeded will be freed when + * the caller cleans up by calling hv_synic_free() + */ + return ret; +} + + +void hv_synic_free(void) +{ + int cpu, ret; + + for_each_present_cpu(cpu) { + struct hv_per_cpu_context *hv_cpu + = per_cpu_ptr(hv_context.cpu_context, cpu); + + /* It's better to leak the page if the encryption fails. */ + if (ms_hyperv.paravisor_present && hv_isolation_type_tdx()) { + if (hv_cpu->post_msg_page) { + ret = set_memory_encrypted((unsigned long) + hv_cpu->post_msg_page, 1); + if (ret) { + pr_err("Failed to encrypt post msg page: %d\n", ret); + hv_cpu->post_msg_page = NULL; + } + } + } + + if (!ms_hyperv.paravisor_present && + (hv_isolation_type_snp() || hv_isolation_type_tdx())) { + if (hv_cpu->synic_message_page) { + ret = set_memory_encrypted((unsigned long) + hv_cpu->synic_message_page, 1); + if (ret) { + pr_err("Failed to encrypt SYNIC msg page: %d\n", ret); + hv_cpu->synic_message_page = NULL; + } + } + + if (hv_cpu->synic_event_page) { + ret = set_memory_encrypted((unsigned long) + hv_cpu->synic_event_page, 1); + if (ret) { + pr_err("Failed to encrypt SYNIC event page: %d\n", ret); + hv_cpu->synic_event_page = NULL; + } + } + } + + free_page((unsigned long)hv_cpu->post_msg_page); + free_page((unsigned long)hv_cpu->synic_event_page); + free_page((unsigned long)hv_cpu->synic_message_page); + } + + 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. + */ +void hv_synic_enable_regs(unsigned int 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 */ + simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP); + simp.simp_enabled = 1; + + 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->synic_message_page + = (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + if (!hv_cpu->synic_message_page) + pr_err("Fail to map synic message page.\n"); + } else { + simp.base_simp_gpa = virt_to_phys(hv_cpu->synic_message_page) + >> HV_HYP_PAGE_SHIFT; + } + + hv_set_register(HV_REGISTER_SIMP, simp.as_uint64); + + /* Setup the Synic's event page */ + siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP); + siefp.siefp_enabled = 1; + + 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->synic_event_page + = (void *)ioremap_cache(base, HV_HYP_PAGE_SIZE); + if (!hv_cpu->synic_event_page) + pr_err("Fail to map synic event page.\n"); + } else { + siefp.base_siefp_gpa = virt_to_phys(hv_cpu->synic_event_page) + >> HV_HYP_PAGE_SHIFT; + } + + hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64); + + /* Setup the shared SINT. */ + if (vmbus_irq != -1) + enable_percpu_irq(vmbus_irq, 0); + shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 + + VMBUS_MESSAGE_SINT); + + shared_sint.vector = vmbus_interrupt; + shared_sint.masked = false; + + /* + * On architectures where Hyper-V doesn't support AEOI (e.g., ARM64), + * it doesn't provide a recommendation flag and AEOI must be disabled. + */ +#ifdef HV_DEPRECATING_AEOI_RECOMMENDED + shared_sint.auto_eoi = + !(ms_hyperv.hints & HV_DEPRECATING_AEOI_RECOMMENDED); +#else + shared_sint.auto_eoi = 0; +#endif + hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT, + shared_sint.as_uint64); + + /* Enable the global synic bit */ + sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL); + sctrl.enable = 1; + + hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64); +} + +int hv_synic_init(unsigned int cpu) +{ + hv_synic_enable_regs(cpu); + + hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT); + + return 0; +} + +/* + * hv_synic_cleanup - Cleanup routine for hv_synic_init(). + */ +void hv_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; + union hv_synic_scontrol sctrl; + + shared_sint.as_uint64 = hv_get_register(HV_REGISTER_SINT0 + + VMBUS_MESSAGE_SINT); + + shared_sint.masked = 1; + + /* Need to correctly cleanup in the case of SMP!!! */ + /* Disable the interrupt */ + hv_set_register(HV_REGISTER_SINT0 + VMBUS_MESSAGE_SINT, + shared_sint.as_uint64); + + simp.as_uint64 = hv_get_register(HV_REGISTER_SIMP); + /* + * In Isolation VM, sim 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) { + iounmap(hv_cpu->synic_message_page); + hv_cpu->synic_message_page = NULL; + } else { + simp.base_simp_gpa = 0; + } + + hv_set_register(HV_REGISTER_SIMP, simp.as_uint64); + + siefp.as_uint64 = hv_get_register(HV_REGISTER_SIEFP); + siefp.siefp_enabled = 0; + + if (ms_hyperv.paravisor_present || hv_root_partition) { + iounmap(hv_cpu->synic_event_page); + hv_cpu->synic_event_page = NULL; + } else { + siefp.base_siefp_gpa = 0; + } + + hv_set_register(HV_REGISTER_SIEFP, siefp.as_uint64); + + /* Disable the global synic bit */ + sctrl.as_uint64 = hv_get_register(HV_REGISTER_SCONTROL); + sctrl.enable = 0; + hv_set_register(HV_REGISTER_SCONTROL, sctrl.as_uint64); + + if (vmbus_irq != -1) + disable_percpu_irq(vmbus_irq); +} + +#define HV_MAX_TRIES 3 +/* + * 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. + */ +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 *event = + (union hv_synic_event_flags *)hv_cpu->synic_event_page + VMBUS_MESSAGE_SINT; + unsigned long *recv_int_page = event->flags; /* assumes VMBus version >= VERSION_WIN8 */ + bool pending; + u32 relid; + int tries = 0; + +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; +} + +int hv_synic_cleanup(unsigned int cpu) +{ + struct vmbus_channel *channel, *sc; + bool channel_found = false; + + if (vmbus_connection.conn_state != CONNECTED) + goto always_cleanup; + + /* + * 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 + * fail; this will effectively prevent CPU offlining. + * + * TODO: Re-bind the channels to different CPUs. + */ + 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; + } + list_for_each_entry(sc, &channel->sc_list, sc_list) { + if (sc->target_cpu == cpu) { + channel_found = true; + break; + } + } + if (channel_found) + break; + } + mutex_unlock(&vmbus_connection.channel_mutex); + + if (channel_found) + return -EBUSY; + + /* + * channel_found == false means that any channels that were previously + * assigned to the CPU have been reassigned elsewhere with a call of + * vmbus_send_modifychannel(). 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; + +always_cleanup: + hv_stimer_legacy_cleanup(cpu); + + hv_synic_disable_regs(cpu); + + return 0; +} |