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-rw-r--r--drivers/hv/hv.c506
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;
+}