@@ -45,6 +45,8 @@ enum {
#define MT_HVC_GZVM_ENABLE_CAP GZVM_HCALL_ID(GZVM_FUNC_ENABLE_CAP)
#define MT_HVC_GZVM_INFORM_EXIT GZVM_HCALL_ID(GZVM_FUNC_INFORM_EXIT)
+#define GIC_V3_NR_LRS 16
+
/**
* gzvm_hypcall_wrapper() - the wrapper for hvc calls
* @a0-a7: arguments passed in registers 0 to 7
@@ -68,6 +70,22 @@ static inline u16 get_vcpuid_from_tuple(unsigned int tuple)
return (u16)(tuple & 0xffff);
}
+/**
+ * struct gzvm_vcpu_hwstate: Sync architecture state back to host for handling
+ * @nr_lrs: The available LRs(list registers) in Soc.
+ * @__pad: add an explicit '__u32 __pad;' in the middle to make it clear
+ * what the actual layout is.
+ * @lr: The array of LRs(list registers).
+ *
+ * - Keep the same layout of hypervisor data struct.
+ * - Sync list registers back for acking virtual device interrupt status.
+ */
+struct gzvm_vcpu_hwstate {
+ __le32 nr_lrs;
+ __le32 __pad;
+ __le64 lr[GIC_V3_NR_LRS];
+};
+
static inline unsigned int
assemble_vm_vcpu_tuple(u16 vmid, u16 vcpuid)
{
@@ -7,4 +7,5 @@
GZVM_DIR ?= ../../../drivers/virt/geniezone
gzvm-y := $(GZVM_DIR)/gzvm_main.o $(GZVM_DIR)/gzvm_mmu.o \
- $(GZVM_DIR)/gzvm_vm.o $(GZVM_DIR)/gzvm_vcpu.o
+ $(GZVM_DIR)/gzvm_vm.o $(GZVM_DIR)/gzvm_vcpu.o \
+ $(GZVM_DIR)/gzvm_irqfd.o
new file mode 100644
@@ -0,0 +1,382 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023 MediaTek Inc.
+ */
+
+#include <linux/eventfd.h>
+#include <linux/syscalls.h>
+#include <linux/gzvm_drv.h>
+#include "gzvm_common.h"
+
+struct gzvm_irq_ack_notifier {
+ struct hlist_node link;
+ unsigned int gsi;
+ void (*irq_acked)(struct gzvm_irq_ack_notifier *ian);
+};
+
+/**
+ * struct gzvm_kernel_irqfd: gzvm kernel irqfd descriptor.
+ * @gzvm: Pointer to struct gzvm.
+ * @wait: Wait queue entry.
+ * @gsi: Used for level IRQ fast-path.
+ * @eventfd: Used for setup/shutdown.
+ * @list: struct list_head.
+ * @pt: struct poll_table_struct.
+ * @shutdown: struct work_struct.
+ */
+struct gzvm_kernel_irqfd {
+ struct gzvm *gzvm;
+ wait_queue_entry_t wait;
+
+ int gsi;
+
+ struct eventfd_ctx *eventfd;
+ struct list_head list;
+ poll_table pt;
+ struct work_struct shutdown;
+};
+
+static struct workqueue_struct *irqfd_cleanup_wq;
+
+/**
+ * irqfd_set_irq(): irqfd to inject virtual interrupt.
+ * @gzvm: Pointer to gzvm.
+ * @irq: This is spi interrupt number (starts from 0 instead of 32).
+ * @level: irq triggered level.
+ */
+static void irqfd_set_irq(struct gzvm *gzvm, u32 irq, int level)
+{
+ if (level)
+ gzvm_irqchip_inject_irq(gzvm, 0, irq, level);
+}
+
+/**
+ * irqfd_shutdown() - Race-free decouple logic (ordering is critical).
+ * @work: Pointer to work_struct.
+ */
+static void irqfd_shutdown(struct work_struct *work)
+{
+ struct gzvm_kernel_irqfd *irqfd =
+ container_of(work, struct gzvm_kernel_irqfd, shutdown);
+ struct gzvm *gzvm = irqfd->gzvm;
+ u64 cnt;
+
+ /* Make sure irqfd has been initialized in assign path. */
+ synchronize_srcu(&gzvm->irq_srcu);
+
+ /*
+ * Synchronize with the wait-queue and unhook ourselves to prevent
+ * further events.
+ */
+ eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
+
+ /*
+ * It is now safe to release the object's resources
+ */
+ eventfd_ctx_put(irqfd->eventfd);
+ kfree(irqfd);
+}
+
+/**
+ * irqfd_is_active() - Assumes gzvm->irqfds.lock is held.
+ * @irqfd: Pointer to gzvm_kernel_irqfd.
+ *
+ * Return:
+ * * true - irqfd is active.
+ */
+static bool irqfd_is_active(struct gzvm_kernel_irqfd *irqfd)
+{
+ return list_empty(&irqfd->list) ? false : true;
+}
+
+/**
+ * irqfd_deactivate() - Mark the irqfd as inactive and schedule it for removal.
+ * assumes gzvm->irqfds.lock is held.
+ * @irqfd: Pointer to gzvm_kernel_irqfd.
+ */
+static void irqfd_deactivate(struct gzvm_kernel_irqfd *irqfd)
+{
+ if (!irqfd_is_active(irqfd))
+ return;
+
+ list_del_init(&irqfd->list);
+
+ queue_work(irqfd_cleanup_wq, &irqfd->shutdown);
+}
+
+/**
+ * irqfd_wakeup() - Callback of irqfd wait queue, would be woken by writing to
+ * irqfd to do virtual interrupt injection.
+ * @wait: Pointer to wait_queue_entry_t.
+ * @mode: Unused.
+ * @sync: Unused.
+ * @key: Get flags about Epoll events.
+ *
+ * Return:
+ * * 0 - Success
+ */
+static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync,
+ void *key)
+{
+ struct gzvm_kernel_irqfd *irqfd =
+ container_of(wait, struct gzvm_kernel_irqfd, wait);
+ __poll_t flags = key_to_poll(key);
+ struct gzvm *gzvm = irqfd->gzvm;
+
+ if (flags & EPOLLIN) {
+ u64 cnt;
+
+ eventfd_ctx_do_read(irqfd->eventfd, &cnt);
+ /* gzvm's irq injection is not blocked, don't need workq */
+ irqfd_set_irq(gzvm, irqfd->gsi, 1);
+ }
+
+ if (flags & EPOLLHUP) {
+ /* The eventfd is closing, detach from GZVM */
+ unsigned long iflags;
+
+ spin_lock_irqsave(&gzvm->irqfds.lock, iflags);
+
+ /*
+ * Do more check if someone deactivated the irqfd before
+ * we could acquire the irqfds.lock.
+ */
+ if (irqfd_is_active(irqfd))
+ irqfd_deactivate(irqfd);
+
+ spin_unlock_irqrestore(&gzvm->irqfds.lock, iflags);
+ }
+
+ return 0;
+}
+
+static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh,
+ poll_table *pt)
+{
+ struct gzvm_kernel_irqfd *irqfd =
+ container_of(pt, struct gzvm_kernel_irqfd, pt);
+ add_wait_queue_priority(wqh, &irqfd->wait);
+}
+
+static int gzvm_irqfd_assign(struct gzvm *gzvm, struct gzvm_irqfd *args)
+{
+ struct gzvm_kernel_irqfd *irqfd, *tmp;
+ struct fd f;
+ struct eventfd_ctx *eventfd = NULL;
+ int ret;
+ int idx;
+
+ irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL_ACCOUNT);
+ if (!irqfd)
+ return -ENOMEM;
+
+ irqfd->gzvm = gzvm;
+ irqfd->gsi = args->gsi;
+
+ INIT_LIST_HEAD(&irqfd->list);
+ INIT_WORK(&irqfd->shutdown, irqfd_shutdown);
+
+ f = fdget(args->fd);
+ if (!f.file) {
+ ret = -EBADF;
+ goto out;
+ }
+
+ eventfd = eventfd_ctx_fileget(f.file);
+ if (IS_ERR(eventfd)) {
+ ret = PTR_ERR(eventfd);
+ goto fail;
+ }
+
+ irqfd->eventfd = eventfd;
+
+ /*
+ * Install our own custom wake-up handling so we are notified via
+ * a callback whenever someone signals the underlying eventfd
+ */
+ init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup);
+ init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc);
+
+ spin_lock_irq(&gzvm->irqfds.lock);
+
+ ret = 0;
+ list_for_each_entry(tmp, &gzvm->irqfds.items, list) {
+ if (irqfd->eventfd != tmp->eventfd)
+ continue;
+ /* This fd is used for another irq already. */
+ pr_err("already used: gsi=%d fd=%d\n", args->gsi, args->fd);
+ ret = -EBUSY;
+ spin_unlock_irq(&gzvm->irqfds.lock);
+ goto fail;
+ }
+
+ idx = srcu_read_lock(&gzvm->irq_srcu);
+
+ list_add_tail(&irqfd->list, &gzvm->irqfds.items);
+
+ spin_unlock_irq(&gzvm->irqfds.lock);
+
+ vfs_poll(f.file, &irqfd->pt);
+
+ srcu_read_unlock(&gzvm->irq_srcu, idx);
+
+ /*
+ * do not drop the file until the irqfd is fully initialized, otherwise
+ * we might race against the EPOLLHUP
+ */
+ fdput(f);
+ return 0;
+
+fail:
+ if (eventfd && !IS_ERR(eventfd))
+ eventfd_ctx_put(eventfd);
+
+ fdput(f);
+
+out:
+ kfree(irqfd);
+ return ret;
+}
+
+static void gzvm_notify_acked_gsi(struct gzvm *gzvm, int gsi)
+{
+ struct gzvm_irq_ack_notifier *gian;
+
+ hlist_for_each_entry_srcu(gian, &gzvm->irq_ack_notifier_list,
+ link, srcu_read_lock_held(&gzvm->irq_srcu))
+ if (gian->gsi == gsi)
+ gian->irq_acked(gian);
+}
+
+void gzvm_notify_acked_irq(struct gzvm *gzvm, unsigned int gsi)
+{
+ int idx;
+
+ idx = srcu_read_lock(&gzvm->irq_srcu);
+ gzvm_notify_acked_gsi(gzvm, gsi);
+ srcu_read_unlock(&gzvm->irq_srcu, idx);
+}
+
+/**
+ * gzvm_irqfd_deassign() - Shutdown any irqfd's that match fd+gsi.
+ * @gzvm: Pointer to gzvm.
+ * @args: Pointer to gzvm_irqfd.
+ *
+ * Return:
+ * * 0 - Success.
+ * * Negative value - Failure.
+ */
+static int gzvm_irqfd_deassign(struct gzvm *gzvm, struct gzvm_irqfd *args)
+{
+ struct gzvm_kernel_irqfd *irqfd, *tmp;
+ struct eventfd_ctx *eventfd;
+
+ eventfd = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(eventfd))
+ return PTR_ERR(eventfd);
+
+ spin_lock_irq(&gzvm->irqfds.lock);
+
+ list_for_each_entry_safe(irqfd, tmp, &gzvm->irqfds.items, list) {
+ if (irqfd->eventfd == eventfd && irqfd->gsi == args->gsi)
+ irqfd_deactivate(irqfd);
+ }
+
+ spin_unlock_irq(&gzvm->irqfds.lock);
+ eventfd_ctx_put(eventfd);
+
+ /*
+ * Block until we know all outstanding shutdown jobs have completed
+ * so that we guarantee there will not be any more interrupts on this
+ * gsi once this deassign function returns.
+ */
+ flush_workqueue(irqfd_cleanup_wq);
+
+ return 0;
+}
+
+int gzvm_irqfd(struct gzvm *gzvm, struct gzvm_irqfd *args)
+{
+ for (int i = 0; i < ARRAY_SIZE(args->pad); i++) {
+ if (args->pad[i])
+ return -EINVAL;
+ }
+
+ if (args->flags &
+ ~(GZVM_IRQFD_FLAG_DEASSIGN | GZVM_IRQFD_FLAG_RESAMPLE))
+ return -EINVAL;
+
+ if (args->flags & GZVM_IRQFD_FLAG_DEASSIGN)
+ return gzvm_irqfd_deassign(gzvm, args);
+
+ return gzvm_irqfd_assign(gzvm, args);
+}
+
+/**
+ * gzvm_vm_irqfd_init() - Initialize irqfd data structure per VM
+ *
+ * @gzvm: Pointer to struct gzvm.
+ *
+ * Return:
+ * * 0 - Success.
+ * * Negative - Failure.
+ */
+int gzvm_vm_irqfd_init(struct gzvm *gzvm)
+{
+ mutex_init(&gzvm->irq_lock);
+
+ spin_lock_init(&gzvm->irqfds.lock);
+ INIT_LIST_HEAD(&gzvm->irqfds.items);
+ if (init_srcu_struct(&gzvm->irq_srcu))
+ return -EINVAL;
+ INIT_HLIST_HEAD(&gzvm->irq_ack_notifier_list);
+
+ return 0;
+}
+
+/**
+ * gzvm_vm_irqfd_release() - This function is called as the gzvm VM fd is being
+ * released. Shutdown all irqfds that still remain open.
+ * @gzvm: Pointer to gzvm.
+ */
+void gzvm_vm_irqfd_release(struct gzvm *gzvm)
+{
+ struct gzvm_kernel_irqfd *irqfd, *tmp;
+
+ spin_lock_irq(&gzvm->irqfds.lock);
+
+ list_for_each_entry_safe(irqfd, tmp, &gzvm->irqfds.items, list)
+ irqfd_deactivate(irqfd);
+
+ spin_unlock_irq(&gzvm->irqfds.lock);
+
+ /*
+ * Block until we know all outstanding shutdown jobs have completed.
+ */
+ flush_workqueue(irqfd_cleanup_wq);
+}
+
+/**
+ * gzvm_drv_irqfd_init() - Erase flushing work items when a VM exits.
+ *
+ * Return:
+ * * 0 - Success.
+ * * Negative - Failure.
+ *
+ * Create a host-wide workqueue for issuing deferred shutdown requests
+ * aggregated from all vm* instances. We need our own isolated
+ * queue to ease flushing work items when a VM exits.
+ */
+int gzvm_drv_irqfd_init(void)
+{
+ irqfd_cleanup_wq = alloc_workqueue("gzvm-irqfd-cleanup", 0, 0);
+ if (!irqfd_cleanup_wq)
+ return -ENOMEM;
+
+ return 0;
+}
+
+void gzvm_drv_irqfd_exit(void)
+{
+ destroy_workqueue(irqfd_cleanup_wq);
+}
@@ -97,16 +97,26 @@ static struct miscdevice gzvm_dev = {
static int gzvm_drv_probe(struct platform_device *pdev)
{
+ int ret;
+
if (gzvm_arch_probe() != 0) {
dev_err(&pdev->dev, "Not found available conduit\n");
return -ENODEV;
}
- return misc_register(&gzvm_dev);
+ ret = misc_register(&gzvm_dev);
+ if (ret)
+ return ret;
+
+ ret = gzvm_drv_irqfd_init();
+ if (ret)
+ return ret;
+ return 0;
}
static int gzvm_drv_remove(struct platform_device *pdev)
{
+ gzvm_drv_irqfd_exit();
gzvm_destroy_all_vms();
misc_deregister(&gzvm_dev);
return 0;
@@ -228,6 +228,7 @@ int gzvm_vm_ioctl_create_vcpu(struct gzvm *gzvm, u32 cpuid)
ret = -ENOMEM;
goto free_vcpu;
}
+ vcpu->hwstate = (void *)vcpu->run + PAGE_SIZE;
vcpu->vcpuid = cpuid;
vcpu->gzvm = gzvm;
mutex_init(&vcpu->lock);
@@ -213,6 +213,16 @@ static long gzvm_vm_ioctl(struct file *filp, unsigned int ioctl,
ret = gzvm_vm_ioctl_create_device(gzvm, argp);
break;
}
+ case GZVM_IRQFD: {
+ struct gzvm_irqfd data;
+
+ if (copy_from_user(&data, argp, sizeof(data))) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = gzvm_irqfd(gzvm, &data);
+ break;
+ }
case GZVM_ENABLE_CAP: {
struct gzvm_enable_cap cap;
@@ -236,6 +246,7 @@ static void gzvm_destroy_vm(struct gzvm *gzvm)
mutex_lock(&gzvm->lock);
+ gzvm_vm_irqfd_release(gzvm);
gzvm_destroy_vcpus(gzvm);
gzvm_arch_destroy_vm(gzvm->vm_id);
@@ -281,6 +292,13 @@ static struct gzvm *gzvm_create_vm(unsigned long vm_type)
gzvm->mm = current->mm;
mutex_init(&gzvm->lock);
+ ret = gzvm_vm_irqfd_init(gzvm);
+ if (ret) {
+ pr_err("Failed to initialize irqfd\n");
+ kfree(gzvm);
+ return ERR_PTR(ret);
+ }
+
mutex_lock(&gzvm_list_lock);
list_add(&gzvm->vm_list, &gzvm_list);
mutex_unlock(&gzvm_list_lock);
@@ -10,6 +10,7 @@
#include <linux/mm.h>
#include <linux/mutex.h>
#include <linux/gzvm.h>
+#include <linux/srcu.h>
/*
* For the normal physical address, the highest 12 bits should be zero, so we
@@ -30,6 +31,7 @@
#define ERR_NOT_SUPPORTED (-24)
#define ERR_NOT_IMPLEMENTED (-27)
#define ERR_FAULT (-40)
+#define GZVM_IRQFD_RESAMPLE_IRQ_SOURCE_ID 1
/*
* The following data structures are for data transferring between driver and
@@ -73,6 +75,7 @@ struct gzvm_vcpu {
/* lock of vcpu*/
struct mutex lock;
struct gzvm_vcpu_run *run;
+ struct gzvm_vcpu_hwstate *hwstate;
};
struct gzvm {
@@ -82,8 +85,23 @@ struct gzvm {
struct gzvm_memslot memslot[GZVM_MAX_MEM_REGION];
/* lock for list_add*/
struct mutex lock;
+
+ struct {
+ /* lock for irqfds list operation */
+ spinlock_t lock;
+ struct list_head items;
+ struct list_head resampler_list;
+ /* lock for irqfds resampler */
+ struct mutex resampler_lock;
+ } irqfds;
+
struct list_head vm_list;
u16 vm_id;
+
+ struct hlist_head irq_ack_notifier_list;
+ struct srcu_struct irq_srcu;
+ /* lock for irq injection */
+ struct mutex irq_lock;
};
long gzvm_dev_ioctl_check_extension(struct gzvm *gzvm, unsigned long args);
@@ -124,4 +142,11 @@ int gzvm_arch_create_device(u16 vm_id, struct gzvm_create_device *gzvm_dev);
int gzvm_arch_inject_irq(struct gzvm *gzvm, unsigned int vcpu_idx,
u32 irq, bool level);
+void gzvm_notify_acked_irq(struct gzvm *gzvm, unsigned int gsi);
+int gzvm_irqfd(struct gzvm *gzvm, struct gzvm_irqfd *args);
+int gzvm_drv_irqfd_init(void);
+void gzvm_drv_irqfd_exit(void);
+int gzvm_vm_irqfd_init(struct gzvm *gzvm);
+void gzvm_vm_irqfd_release(struct gzvm *gzvm);
+
#endif /* __GZVM_DRV_H__ */
@@ -309,4 +309,30 @@ struct gzvm_one_reg {
#define GZVM_REG_GENERIC 0x0000000000000000ULL
+#define GZVM_IRQFD_FLAG_DEASSIGN BIT(0)
+/*
+ * GZVM_IRQFD_FLAG_RESAMPLE indicates resamplefd is valid and specifies
+ * the irqfd to operate in resampling mode for level triggered interrupt
+ * emulation.
+ */
+#define GZVM_IRQFD_FLAG_RESAMPLE BIT(1)
+
+/**
+ * struct gzvm_irqfd: gzvm irqfd descriptor
+ * @fd: File descriptor.
+ * @gsi: Used for level IRQ fast-path.
+ * @flags: FLAG_DEASSIGN or FLAG_RESAMPLE.
+ * @resamplefd: The file descriptor of the resampler.
+ * @pad: Reserved for future-proof.
+ */
+struct gzvm_irqfd {
+ __u32 fd;
+ __u32 gsi;
+ __u32 flags;
+ __u32 resamplefd;
+ __u8 pad[16];
+};
+
+#define GZVM_IRQFD _IOW(GZVM_IOC_MAGIC, 0x76, struct gzvm_irqfd)
+
#endif /* __GZVM_H__ */