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authorShuo Liu <shuo.a.liu@intel.com>2021-02-07 11:10:38 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-02-09 10:58:19 +0100
commitaa3b483ff1d71c50b33db154048dff9a8f08ac71 (patch)
tree898df00c9a24bd0c5485e9ec47fb74f115e7323a /drivers/virt
parentd8ad515156b66e7e79a6e4c814f997ee54eb47c7 (diff)
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virt: acrn: Introduce irqfd
irqfd is a mechanism to inject a specific interrupt to a User VM using a decoupled eventfd mechanism. Vhost is a kernel-level virtio server which uses eventfd for interrupt injection. To support vhost on ACRN, irqfd is introduced in HSM. HSM provides ioctls to associate a virtual Message Signaled Interrupt (MSI) with an eventfd. The corresponding virtual MSI will be injected into a User VM once the eventfd got signal. Cc: Zhi Wang <zhi.a.wang@intel.com> Cc: Zhenyu Wang <zhenyuw@linux.intel.com> Cc: Yu Wang <yu1.wang@intel.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Zhi Wang <zhi.a.wang@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Shuo Liu <shuo.a.liu@intel.com> Link: https://lore.kernel.org/r/20210207031040.49576-17-shuo.a.liu@intel.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/virt')
-rw-r--r--drivers/virt/acrn/Makefile2
-rw-r--r--drivers/virt/acrn/acrn_drv.h10
-rw-r--r--drivers/virt/acrn/hsm.c7
-rw-r--r--drivers/virt/acrn/irqfd.c235
-rw-r--r--drivers/virt/acrn/vm.c3
5 files changed, 256 insertions, 1 deletions
diff --git a/drivers/virt/acrn/Makefile b/drivers/virt/acrn/Makefile
index 755b583b32ca..08ce641dcfa1 100644
--- a/drivers/virt/acrn/Makefile
+++ b/drivers/virt/acrn/Makefile
@@ -1,3 +1,3 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_ACRN_HSM) := acrn.o
-acrn-y := hsm.o vm.o mm.o ioreq.o ioeventfd.o
+acrn-y := hsm.o vm.o mm.o ioreq.o ioeventfd.o irqfd.o
diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h
index e3f8190bd972..1be54efa666c 100644
--- a/drivers/virt/acrn/acrn_drv.h
+++ b/drivers/virt/acrn/acrn_drv.h
@@ -159,6 +159,9 @@ extern rwlock_t acrn_vm_list_lock;
* @ioeventfds_lock: Lock to protect ioeventfds list
* @ioeventfds: List to link all hsm_ioeventfd
* @ioeventfd_client: I/O client for ioeventfds of the VM
+ * @irqfds_lock: Lock to protect irqfds list
+ * @irqfds: List to link all hsm_irqfd
+ * @irqfd_wq: Workqueue for irqfd async shutdown
*/
struct acrn_vm {
struct list_head list;
@@ -178,6 +181,9 @@ struct acrn_vm {
struct mutex ioeventfds_lock;
struct list_head ioeventfds;
struct acrn_ioreq_client *ioeventfd_client;
+ struct mutex irqfds_lock;
+ struct list_head irqfds;
+ struct workqueue_struct *irqfd_wq;
};
struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
@@ -214,4 +220,8 @@ int acrn_ioeventfd_init(struct acrn_vm *vm);
int acrn_ioeventfd_config(struct acrn_vm *vm, struct acrn_ioeventfd *args);
void acrn_ioeventfd_deinit(struct acrn_vm *vm);
+int acrn_irqfd_init(struct acrn_vm *vm);
+int acrn_irqfd_config(struct acrn_vm *vm, struct acrn_irqfd *args);
+void acrn_irqfd_deinit(struct acrn_vm *vm);
+
#endif /* __ACRN_HSM_DRV_H */
diff --git a/drivers/virt/acrn/hsm.c b/drivers/virt/acrn/hsm.c
index 0b4e88b0b6bc..93f6abe10fa6 100644
--- a/drivers/virt/acrn/hsm.c
+++ b/drivers/virt/acrn/hsm.c
@@ -115,6 +115,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
struct acrn_vm_memmap memmap;
struct acrn_msi_entry *msi;
struct acrn_pcidev *pcidev;
+ struct acrn_irqfd irqfd;
struct page *page;
u64 cstate_cmd;
int i, ret = 0;
@@ -347,6 +348,12 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
ret = acrn_ioeventfd_config(vm, &ioeventfd);
break;
+ case ACRN_IOCTL_IRQFD:
+ if (copy_from_user(&irqfd, (void __user *)ioctl_param,
+ sizeof(irqfd)))
+ return -EFAULT;
+ ret = acrn_irqfd_config(vm, &irqfd);
+ break;
default:
dev_dbg(acrn_dev.this_device, "Unknown IOCTL 0x%x!\n", cmd);
ret = -ENOTTY;
diff --git a/drivers/virt/acrn/irqfd.c b/drivers/virt/acrn/irqfd.c
new file mode 100644
index 000000000000..a8766d528e29
--- /dev/null
+++ b/drivers/virt/acrn/irqfd.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * ACRN HSM irqfd: use eventfd objects to inject virtual interrupts
+ *
+ * Copyright (C) 2020 Intel Corporation. All rights reserved.
+ *
+ * Authors:
+ * Shuo Liu <shuo.a.liu@intel.com>
+ * Yakui Zhao <yakui.zhao@intel.com>
+ */
+
+#include <linux/eventfd.h>
+#include <linux/file.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+
+#include "acrn_drv.h"
+
+static LIST_HEAD(acrn_irqfd_clients);
+static DEFINE_MUTEX(acrn_irqfds_mutex);
+
+/**
+ * struct hsm_irqfd - Properties of HSM irqfd
+ * @vm: Associated VM pointer
+ * @wait: Entry of wait-queue
+ * @shutdown: Async shutdown work
+ * @eventfd: Associated eventfd
+ * @list: Entry within &acrn_vm.irqfds of irqfds of a VM
+ * @pt: Structure for select/poll on the associated eventfd
+ * @msi: MSI data
+ */
+struct hsm_irqfd {
+ struct acrn_vm *vm;
+ wait_queue_entry_t wait;
+ struct work_struct shutdown;
+ struct eventfd_ctx *eventfd;
+ struct list_head list;
+ poll_table pt;
+ struct acrn_msi_entry msi;
+};
+
+static void acrn_irqfd_inject(struct hsm_irqfd *irqfd)
+{
+ struct acrn_vm *vm = irqfd->vm;
+
+ acrn_msi_inject(vm, irqfd->msi.msi_addr,
+ irqfd->msi.msi_data);
+}
+
+static void hsm_irqfd_shutdown(struct hsm_irqfd *irqfd)
+{
+ u64 cnt;
+
+ lockdep_assert_held(&irqfd->vm->irqfds_lock);
+
+ /* remove from wait queue */
+ list_del_init(&irqfd->list);
+ eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
+ eventfd_ctx_put(irqfd->eventfd);
+ kfree(irqfd);
+}
+
+static void hsm_irqfd_shutdown_work(struct work_struct *work)
+{
+ struct hsm_irqfd *irqfd;
+ struct acrn_vm *vm;
+
+ irqfd = container_of(work, struct hsm_irqfd, shutdown);
+ vm = irqfd->vm;
+ mutex_lock(&vm->irqfds_lock);
+ if (!list_empty(&irqfd->list))
+ hsm_irqfd_shutdown(irqfd);
+ mutex_unlock(&vm->irqfds_lock);
+}
+
+/* Called with wqh->lock held and interrupts disabled */
+static int hsm_irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode,
+ int sync, void *key)
+{
+ unsigned long poll_bits = (unsigned long)key;
+ struct hsm_irqfd *irqfd;
+ struct acrn_vm *vm;
+
+ irqfd = container_of(wait, struct hsm_irqfd, wait);
+ vm = irqfd->vm;
+ if (poll_bits & POLLIN)
+ /* An event has been signaled, inject an interrupt */
+ acrn_irqfd_inject(irqfd);
+
+ if (poll_bits & POLLHUP)
+ /* Do shutdown work in thread to hold wqh->lock */
+ queue_work(vm->irqfd_wq, &irqfd->shutdown);
+
+ return 0;
+}
+
+static void hsm_irqfd_poll_func(struct file *file, wait_queue_head_t *wqh,
+ poll_table *pt)
+{
+ struct hsm_irqfd *irqfd;
+
+ irqfd = container_of(pt, struct hsm_irqfd, pt);
+ add_wait_queue(wqh, &irqfd->wait);
+}
+
+/*
+ * Assign an eventfd to a VM and create a HSM irqfd associated with the
+ * eventfd. The properties of the HSM irqfd are built from a &struct
+ * acrn_irqfd.
+ */
+static int acrn_irqfd_assign(struct acrn_vm *vm, struct acrn_irqfd *args)
+{
+ struct eventfd_ctx *eventfd = NULL;
+ struct hsm_irqfd *irqfd, *tmp;
+ unsigned int events;
+ struct fd f;
+ int ret = 0;
+
+ irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL);
+ if (!irqfd)
+ return -ENOMEM;
+
+ irqfd->vm = vm;
+ memcpy(&irqfd->msi, &args->msi, sizeof(args->msi));
+ INIT_LIST_HEAD(&irqfd->list);
+ INIT_WORK(&irqfd->shutdown, hsm_irqfd_shutdown_work);
+
+ 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 custom wake-up handling to be notified whenever underlying
+ * eventfd is signaled.
+ */
+ init_waitqueue_func_entry(&irqfd->wait, hsm_irqfd_wakeup);
+ init_poll_funcptr(&irqfd->pt, hsm_irqfd_poll_func);
+
+ mutex_lock(&vm->irqfds_lock);
+ list_for_each_entry(tmp, &vm->irqfds, list) {
+ if (irqfd->eventfd != tmp->eventfd)
+ continue;
+ ret = -EBUSY;
+ mutex_unlock(&vm->irqfds_lock);
+ goto fail;
+ }
+ list_add_tail(&irqfd->list, &vm->irqfds);
+ mutex_unlock(&vm->irqfds_lock);
+
+ /* Check the pending event in this stage */
+ events = f.file->f_op->poll(f.file, &irqfd->pt);
+
+ if (events & POLLIN)
+ acrn_irqfd_inject(irqfd);
+
+ fdput(f);
+ return 0;
+fail:
+ if (eventfd && !IS_ERR(eventfd))
+ eventfd_ctx_put(eventfd);
+
+ fdput(f);
+out:
+ kfree(irqfd);
+ return ret;
+}
+
+static int acrn_irqfd_deassign(struct acrn_vm *vm,
+ struct acrn_irqfd *args)
+{
+ struct hsm_irqfd *irqfd, *tmp;
+ struct eventfd_ctx *eventfd;
+
+ eventfd = eventfd_ctx_fdget(args->fd);
+ if (IS_ERR(eventfd))
+ return PTR_ERR(eventfd);
+
+ mutex_lock(&vm->irqfds_lock);
+ list_for_each_entry_safe(irqfd, tmp, &vm->irqfds, list) {
+ if (irqfd->eventfd == eventfd) {
+ hsm_irqfd_shutdown(irqfd);
+ break;
+ }
+ }
+ mutex_unlock(&vm->irqfds_lock);
+ eventfd_ctx_put(eventfd);
+
+ return 0;
+}
+
+int acrn_irqfd_config(struct acrn_vm *vm, struct acrn_irqfd *args)
+{
+ int ret;
+
+ if (args->flags & ACRN_IRQFD_FLAG_DEASSIGN)
+ ret = acrn_irqfd_deassign(vm, args);
+ else
+ ret = acrn_irqfd_assign(vm, args);
+
+ return ret;
+}
+
+int acrn_irqfd_init(struct acrn_vm *vm)
+{
+ INIT_LIST_HEAD(&vm->irqfds);
+ mutex_init(&vm->irqfds_lock);
+ vm->irqfd_wq = alloc_workqueue("acrn_irqfd-%u", 0, 0, vm->vmid);
+ if (!vm->irqfd_wq)
+ return -ENOMEM;
+
+ dev_dbg(acrn_dev.this_device, "VM %u irqfd init.\n", vm->vmid);
+ return 0;
+}
+
+void acrn_irqfd_deinit(struct acrn_vm *vm)
+{
+ struct hsm_irqfd *irqfd, *next;
+
+ dev_dbg(acrn_dev.this_device, "VM %u irqfd deinit.\n", vm->vmid);
+ destroy_workqueue(vm->irqfd_wq);
+ mutex_lock(&vm->irqfds_lock);
+ list_for_each_entry_safe(irqfd, next, &vm->irqfds, list)
+ hsm_irqfd_shutdown(irqfd);
+ mutex_unlock(&vm->irqfds_lock);
+}
diff --git a/drivers/virt/acrn/vm.c b/drivers/virt/acrn/vm.c
index 2b322d956a8c..7804a2492ad7 100644
--- a/drivers/virt/acrn/vm.c
+++ b/drivers/virt/acrn/vm.c
@@ -51,6 +51,7 @@ struct acrn_vm *acrn_vm_create(struct acrn_vm *vm,
write_unlock_bh(&acrn_vm_list_lock);
acrn_ioeventfd_init(vm);
+ acrn_irqfd_init(vm);
dev_dbg(acrn_dev.this_device, "VM %u created.\n", vm->vmid);
return vm;
}
@@ -69,7 +70,9 @@ int acrn_vm_destroy(struct acrn_vm *vm)
write_unlock_bh(&acrn_vm_list_lock);
acrn_ioeventfd_deinit(vm);
+ acrn_irqfd_deinit(vm);
acrn_ioreq_deinit(vm);
+
if (vm->monitor_page) {
put_page(vm->monitor_page);
vm->monitor_page = NULL;