printf: Remove unused 'bprintf'

[drm/drm-misc.git] / drivers / hv / hv.c

// 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) {
                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) {
                                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) {
                                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) {
                                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_msr(HV_MSR_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_msr(HV_MSR_SIMP, simp.as_uint64);

        /* Setup the Synic's event page */
        siefp.as_uint64 = hv_get_msr(HV_MSR_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_msr(HV_MSR_SIEFP, siefp.as_uint64);

        /* Setup the shared SINT. */
        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 = 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_msr(HV_MSR_SINT0 + VMBUS_MESSAGE_SINT, shared_sint.as_uint64);

        /* 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);
}

int hv_synic_init(unsigned int cpu)
{
        hv_synic_enable_regs(cpu);

        hv_stimer_legacy_init(cpu, VMBUS_MESSAGE_SINT);

        return 0;
}

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_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);

        simp.as_uint64 = hv_get_msr(HV_MSR_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_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) {
                iounmap(hv_cpu->synic_event_page);
                hv_cpu->synic_event_page = NULL;
        } else {
                siefp.base_siefp_gpa = 0;
        }

        hv_set_msr(HV_MSR_SIEFP, siefp.as_uint64);

        /* 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);

        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;
}

/*
 * hv_synic_cleanup - Cleanup routine for hv_synic_init().
 */
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;
}