Using indirect pointers in an ioctl command argument means that the layout is architecture specific, in particular we can't use the same one from 32-bit compat tasks. The general recommendation is to have __u64 members and use u64_to_user_ptr() to access it from the kernel if we are unable to avoid the pointers altogether.

Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") Reported-by: Arnd Bergmann arnd@kernel.org Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmai... Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/xen/privcmd.c | 2 +- include/uapi/xen/privcmd.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 120af57999fc..5095bd1abea5 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -935,7 +935,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd) return -ENOMEM; dm_op = kirqfd + 1;

- if (copy_from_user(dm_op, irqfd->dm_op, irqfd->size)) { + if (copy_from_user(dm_op, u64_to_user_ptr(irqfd->dm_op), irqfd->size)) { ret = -EFAULT; goto error_kfree; } diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h index 375718ba4ab6..b143fafce84d 100644 --- a/include/uapi/xen/privcmd.h +++ b/include/uapi/xen/privcmd.h @@ -102,7 +102,7 @@ struct privcmd_mmap_resource { #define PRIVCMD_IRQFD_FLAG_DEASSIGN (1 << 0)

struct privcmd_irqfd { - void __user *dm_op; + __u64 dm_op; __u32 size; /* Size of structure pointed by dm_op */ __u32 fd; __u32 flags;

_IOC() an internal helper that we should not use in driver code. In particular, we got the data direction wrong here, which breaks a number of tools, as having "_IOC_NONE" should never be paired with a nonzero size.

Use _IOW() instead.

Fixes: f8941e6c4c71 ("xen: privcmd: Add support for irqfd") Reported-by: Arnd Bergmann arnd@kernel.org Closes: https://lore.kernel.org/all/268a2031-63b8-4c7d-b1e5-8ab83ca80b4a@app.fastmai... Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- include/uapi/xen/privcmd.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h index b143fafce84d..e145bca5105c 100644 --- a/include/uapi/xen/privcmd.h +++ b/include/uapi/xen/privcmd.h @@ -138,6 +138,6 @@ struct privcmd_irqfd { #define IOCTL_PRIVCMD_MMAP_RESOURCE \ _IOC(_IOC_NONE, 'P', 7, sizeof(struct privcmd_mmap_resource)) #define IOCTL_PRIVCMD_IRQFD \ - _IOC(_IOC_NONE, 'P', 8, sizeof(struct privcmd_irqfd)) + _IOW('P', 8, struct privcmd_irqfd)

#endif /* __LINUX_PUBLIC_PRIVCMD_H__ */

Currently the handling of events is supported either in the kernel or userspace, but not both.

In order to support fast delivery of interrupts from the guest to the backend, we need to handle the Queue notify part of Virtio protocol in kernel and the rest in userspace.

Update the interrupt handler registration flag to IRQF_SHARED for event channels, which would allow multiple entities to bind their interrupt handler for the same event channel port.

Also increment the reference count of irq_info when multiple entities try to bind event channel to irqchip, so the unbinding happens only after all the users are gone.

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/xen/events/events_base.c | 3 ++- drivers/xen/evtchn.c | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/xen/events/events_base.c b/drivers/xen/events/events_base.c index c7715f8bd452..d72fb26cc051 100644 --- a/drivers/xen/events/events_base.c +++ b/drivers/xen/events/events_base.c @@ -1238,7 +1238,8 @@ static int bind_evtchn_to_irq_chip(evtchn_port_t evtchn, struct irq_chip *chip, bind_evtchn_to_cpu(evtchn, 0, false); } else { struct irq_info *info = info_for_irq(irq); - WARN_ON(info == NULL || info->type != IRQT_EVTCHN); + if (!WARN_ON(!info || info->type != IRQT_EVTCHN)) + info->refcnt++; }

out: diff --git a/drivers/xen/evtchn.c b/drivers/xen/evtchn.c index c99415a70051..43f77915feb5 100644 --- a/drivers/xen/evtchn.c +++ b/drivers/xen/evtchn.c @@ -397,7 +397,7 @@ static int evtchn_bind_to_user(struct per_user_data *u, evtchn_port_t port) if (rc < 0) goto err;

- rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, 0, + rc = bind_evtchn_to_irqhandler_lateeoi(port, evtchn_interrupt, IRQF_SHARED, u->name, evtchn); if (rc < 0) goto err;

Virtio guests send VIRTIO_MMIO_QUEUE_NOTIFY notification when they need to notify the backend of an update to the status of the virtqueue. The backend or another entity, polls the MMIO address for updates to know when the notification is sent.

It works well if the backend does this polling by itself. But as we move towards generic backend implementations, we end up implementing this in a separate user-space program.

Generally, the Virtio backends are implemented to work with the Eventfd based mechanism. In order to make such backends work with Xen, another software layer needs to do the polling and send an event via eventfd to the backend once the notification from guest is received. This results in an extra context switch.

This is not a new problem in Linux though. It is present with other hypervisors like KVM, etc. as well. The generic solution implemented in the kernel for them is to provide an IOCTL call to pass the address to poll and eventfd, which lets the kernel take care of polling and raise an event on the eventfd, instead of handling this in user space (which involves an extra context switch).

This patch adds similar support for xen.

Inspired by existing implementations for KVM, etc..

This also copies ioreq.h header file (only struct ioreq and related macros) from Xen's source tree (Top commit 5d84f07fe6bf ("xen/pci: drop remaining uses of bool_t")).

Signed-off-by: Viresh Kumar viresh.kumar@linaro.org --- drivers/xen/Kconfig | 8 +- drivers/xen/privcmd.c | 405 +++++++++++++++++++++++++++++- include/uapi/xen/privcmd.h | 18 ++ include/xen/interface/hvm/ioreq.h | 51 ++++ 4 files changed, 476 insertions(+), 6 deletions(-) create mode 100644 include/xen/interface/hvm/ioreq.h

diff --git a/drivers/xen/Kconfig b/drivers/xen/Kconfig index d43153fec18e..d5989871dd5d 100644 --- a/drivers/xen/Kconfig +++ b/drivers/xen/Kconfig @@ -269,12 +269,12 @@ config XEN_PRIVCMD disaggregated Xen setups this driver might be needed for other domains, too.

-config XEN_PRIVCMD_IRQFD - bool "Xen irqfd support" +config XEN_PRIVCMD_EVENTFD + bool "Xen Ioeventfd and irqfd support" depends on XEN_PRIVCMD && XEN_VIRTIO && EVENTFD help - Using the irqfd mechanism a virtio backend running in a daemon can - speed up interrupt injection into a guest. + Using the ioeventfd / irqfd mechanism a virtio backend running in a + daemon can speed up interrupt delivery from / to a guest.

config XEN_ACPI_PROCESSOR tristate "Xen ACPI processor" diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 5095bd1abea5..121e258077ea 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -29,15 +29,18 @@ #include <linux/seq_file.h> #include <linux/miscdevice.h> #include <linux/moduleparam.h> +#include <linux/virtio_mmio.h>

#include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h>

#include <xen/xen.h> +#include <xen/events.h> #include <xen/privcmd.h> #include <xen/interface/xen.h> #include <xen/interface/memory.h> #include <xen/interface/hvm/dm_op.h> +#include <xen/interface/hvm/ioreq.h> #include <xen/features.h> #include <xen/page.h> #include <xen/xen-ops.h> @@ -782,6 +785,7 @@ static long privcmd_ioctl_mmap_resource(struct file *file, goto out;

pages = vma->vm_private_data; + for (i = 0; i < kdata.num; i++) { xen_pfn_t pfn = page_to_xen_pfn(pages[i / XEN_PFN_PER_PAGE]); @@ -838,7 +842,7 @@ static long privcmd_ioctl_mmap_resource(struct file *file, return rc; }

-#ifdef CONFIG_XEN_PRIVCMD_IRQFD +#ifdef CONFIG_XEN_PRIVCMD_EVENTFD /* Irqfd support */ static struct workqueue_struct *irqfd_cleanup_wq; static DEFINE_MUTEX(irqfds_lock); @@ -1079,6 +1083,389 @@ static void privcmd_irqfd_exit(void)

destroy_workqueue(irqfd_cleanup_wq); } + +/* Ioeventfd Support */ +#define QUEUE_NOTIFY_VQ_MASK 0xFFFF + +static DEFINE_MUTEX(ioreq_lock); +static LIST_HEAD(ioreq_list); + +/* per-eventfd structure */ +struct privcmd_kernel_ioeventfd { + struct eventfd_ctx *eventfd; + struct list_head list; + u64 addr; + unsigned int addr_len; + unsigned int vq; +}; + +/* per-guest CPU / port structure */ +struct ioreq_port { + int vcpu; + unsigned int port; + struct privcmd_kernel_ioreq *kioreq; +}; + +/* per-guest structure */ +struct privcmd_kernel_ioreq { + domid_t dom; + unsigned int vcpus; + u64 uioreq; + struct ioreq *ioreq; + spinlock_t lock; /* Protects ioeventfds list */ + struct list_head ioeventfds; + struct list_head list; + struct ioreq_port ports[0]; +}; + +static irqreturn_t ioeventfd_interrupt(int irq, void *dev_id) +{ + struct ioreq_port *port = dev_id; + struct privcmd_kernel_ioreq *kioreq = port->kioreq; + struct ioreq *ioreq = &kioreq->ioreq[port->vcpu]; + struct privcmd_kernel_ioeventfd *kioeventfd; + unsigned int state = STATE_IOREQ_READY; + + if (ioreq->state != STATE_IOREQ_READY || + ioreq->type != IOREQ_TYPE_COPY || ioreq->dir != IOREQ_WRITE) + return IRQ_NONE; + + /* + * We need a barrier, smp_mb(), here to ensure reads are finished before + * `state` is updated. Since the lock implementation ensures that + * appropriate barrier will be added anyway, we can avoid adding + * explicit barrier here. + * + * Ideally we don't need to update `state` within the locks, but we do + * that here to avoid adding explicit barrier. + */ + + spin_lock(&kioreq->lock); + ioreq->state = STATE_IOREQ_INPROCESS; + + list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) { + if (ioreq->addr == kioeventfd->addr + VIRTIO_MMIO_QUEUE_NOTIFY && + ioreq->size == kioeventfd->addr_len && + (ioreq->data & QUEUE_NOTIFY_VQ_MASK) == kioeventfd->vq) { + eventfd_signal(kioeventfd->eventfd, 1); + state = STATE_IORESP_READY; + break; + } + } + spin_unlock(&kioreq->lock); + + /* + * We need a barrier, smp_mb(), here to ensure writes are finished + * before `state` is updated. Since the lock implementation ensures that + * appropriate barrier will be added anyway, we can avoid adding + * explicit barrier here. + */ + + ioreq->state = state; + + if (state == STATE_IORESP_READY) { + notify_remote_via_evtchn(port->port); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static void ioreq_free(struct privcmd_kernel_ioreq *kioreq) +{ + struct ioreq_port *ports = kioreq->ports; + int i; + + lockdep_assert_held(&ioreq_lock); + + list_del(&kioreq->list); + + for (i = kioreq->vcpus - 1; i >= 0; i--) + unbind_from_irqhandler(irq_from_evtchn(ports[i].port), &ports[i]); + + kfree(kioreq); +} + +static +struct privcmd_kernel_ioreq *alloc_ioreq(struct privcmd_ioeventfd *ioeventfd) +{ + struct privcmd_kernel_ioreq *kioreq; + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + struct page **pages; + unsigned int *ports; + int ret, size, i; + + lockdep_assert_held(&ioreq_lock); + + size = struct_size(kioreq, ports, ioeventfd->vcpus); + kioreq = kzalloc(size, GFP_KERNEL); + if (!kioreq) + return ERR_PTR(-ENOMEM); + + kioreq->dom = ioeventfd->dom; + kioreq->vcpus = ioeventfd->vcpus; + kioreq->uioreq = ioeventfd->ioreq; + spin_lock_init(&kioreq->lock); + INIT_LIST_HEAD(&kioreq->ioeventfds); + + /* The memory for ioreq server must have been mapped earlier */ + mmap_write_lock(mm); + vma = find_vma(mm, (unsigned long)ioeventfd->ioreq); + if (!vma) { + pr_err("Failed to find vma for ioreq page!\n"); + mmap_write_unlock(mm); + ret = -EFAULT; + goto error_kfree; + } + + pages = vma->vm_private_data; + kioreq->ioreq = (struct ioreq *)(page_to_virt(pages[0])); + mmap_write_unlock(mm); + + size = sizeof(*ports) * kioreq->vcpus; + ports = kzalloc(size, GFP_KERNEL); + if (!ports) { + ret = -ENOMEM; + goto error_kfree; + } + + if (copy_from_user(ports, u64_to_user_ptr(ioeventfd->ports), size)) { + ret = -EFAULT; + goto error_kfree_ports; + } + + for (i = 0; i < kioreq->vcpus; i++) { + kioreq->ports[i].vcpu = i; + kioreq->ports[i].port = ports[i]; + kioreq->ports[i].kioreq = kioreq; + + ret = bind_evtchn_to_irqhandler_lateeoi(ports[i], + ioeventfd_interrupt, IRQF_SHARED, "ioeventfd", + &kioreq->ports[i]); + if (ret < 0) + goto error_unbind; + } + + kfree(ports); + + list_add_tail(&kioreq->list, &ioreq_list); + + return kioreq; + +error_unbind: + while (--i >= 0) + unbind_from_irqhandler(irq_from_evtchn(ports[i]), &kioreq->ports[i]); +error_kfree_ports: + kfree(ports); +error_kfree: + kfree(kioreq); + return ERR_PTR(ret); +} + +static struct privcmd_kernel_ioreq * +get_ioreq(struct privcmd_ioeventfd *ioeventfd, struct eventfd_ctx *eventfd) +{ + struct privcmd_kernel_ioreq *kioreq; + unsigned long flags; + + list_for_each_entry(kioreq, &ioreq_list, list) { + struct privcmd_kernel_ioeventfd *kioeventfd; + + /* + * kioreq fields can be accessed here without a lock as they are + * never updated after being added to the ioreq_list. + */ + if (kioreq->uioreq != ioeventfd->ioreq) { + continue; + } else if (kioreq->dom != ioeventfd->dom || + kioreq->vcpus != ioeventfd->vcpus) { + pr_err("Invalid ioeventfd configuration mismatch, dom (%u vs %u), vcpus (%u vs %u)\n", + kioreq->dom, ioeventfd->dom, kioreq->vcpus, + ioeventfd->vcpus); + return ERR_PTR(-EINVAL); + } + + /* Look for a duplicate eventfd for the same guest */ + spin_lock_irqsave(&kioreq->lock, flags); + list_for_each_entry(kioeventfd, &kioreq->ioeventfds, list) { + if (eventfd == kioeventfd->eventfd) { + spin_unlock_irqrestore(&kioreq->lock, flags); + return ERR_PTR(-EBUSY); + } + } + spin_unlock_irqrestore(&kioreq->lock, flags); + + return kioreq; + } + + /* Matching kioreq isn't found, allocate a new one */ + return alloc_ioreq(ioeventfd); +} + +static void ioeventfd_free(struct privcmd_kernel_ioeventfd *kioeventfd) +{ + list_del(&kioeventfd->list); + eventfd_ctx_put(kioeventfd->eventfd); + kfree(kioeventfd); +} + +static int privcmd_ioeventfd_assign(struct privcmd_ioeventfd *ioeventfd) +{ + struct privcmd_kernel_ioeventfd *kioeventfd; + struct privcmd_kernel_ioreq *kioreq; + unsigned long flags; + struct fd f; + int ret; + + /* Check for range overflow */ + if (ioeventfd->addr + ioeventfd->addr_len < ioeventfd->addr) + return -EINVAL; + + /* Vhost requires us to support length 1, 2, 4, and 8 */ + if (!(ioeventfd->addr_len == 1 || ioeventfd->addr_len == 2 || + ioeventfd->addr_len == 4 || ioeventfd->addr_len == 8)) + return -EINVAL; + + /* 4096 vcpus limit enough ? */ + if (!ioeventfd->vcpus || ioeventfd->vcpus > 4096) + return -EINVAL; + + kioeventfd = kzalloc(sizeof(*kioeventfd), GFP_KERNEL); + if (!kioeventfd) + return -ENOMEM; + + f = fdget(ioeventfd->event_fd); + if (!f.file) { + ret = -EBADF; + goto error_kfree; + } + + kioeventfd->eventfd = eventfd_ctx_fileget(f.file); + fdput(f); + + if (IS_ERR(kioeventfd->eventfd)) { + ret = PTR_ERR(kioeventfd->eventfd); + goto error_kfree; + } + + kioeventfd->addr = ioeventfd->addr; + kioeventfd->addr_len = ioeventfd->addr_len; + kioeventfd->vq = ioeventfd->vq; + + mutex_lock(&ioreq_lock); + kioreq = get_ioreq(ioeventfd, kioeventfd->eventfd); + if (IS_ERR(kioreq)) { + mutex_unlock(&ioreq_lock); + ret = PTR_ERR(kioreq); + goto error_eventfd; + } + + spin_lock_irqsave(&kioreq->lock, flags); + list_add_tail(&kioeventfd->list, &kioreq->ioeventfds); + spin_unlock_irqrestore(&kioreq->lock, flags); + + mutex_unlock(&ioreq_lock); + + return 0; + +error_eventfd: + eventfd_ctx_put(kioeventfd->eventfd); + +error_kfree: + kfree(kioeventfd); + return ret; +} + +static int privcmd_ioeventfd_deassign(struct privcmd_ioeventfd *ioeventfd) +{ + struct privcmd_kernel_ioreq *kioreq, *tkioreq; + struct eventfd_ctx *eventfd; + unsigned long flags; + int ret = 0; + + eventfd = eventfd_ctx_fdget(ioeventfd->event_fd); + if (IS_ERR(eventfd)) + return PTR_ERR(eventfd); + + mutex_lock(&ioreq_lock); + list_for_each_entry_safe(kioreq, tkioreq, &ioreq_list, list) { + struct privcmd_kernel_ioeventfd *kioeventfd, *tmp; + /* + * kioreq fields can be accessed here without a lock as they are + * never updated after being added to the ioreq_list. + */ + if (kioreq->dom != ioeventfd->dom || + kioreq->uioreq != ioeventfd->ioreq || + kioreq->vcpus != ioeventfd->vcpus) + continue; + + spin_lock_irqsave(&kioreq->lock, flags); + list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list) { + if (eventfd == kioeventfd->eventfd) { + ioeventfd_free(kioeventfd); + spin_unlock_irqrestore(&kioreq->lock, flags); + + if (list_empty(&kioreq->ioeventfds)) + ioreq_free(kioreq); + goto unlock; + } + } + spin_unlock_irqrestore(&kioreq->lock, flags); + break; + } + + pr_err("Ioeventfd isn't already assigned, dom: %u, addr: %llu\n", + ioeventfd->dom, ioeventfd->addr); + ret = -ENODEV; + +unlock: + mutex_unlock(&ioreq_lock); + eventfd_ctx_put(eventfd); + + return ret; +} + +static long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata) +{ + struct privcmd_data *data = file->private_data; + struct privcmd_ioeventfd ioeventfd; + + if (copy_from_user(&ioeventfd, udata, sizeof(ioeventfd))) + return -EFAULT; + + /* No other flags should be set */ + if (ioeventfd.flags & ~PRIVCMD_IOEVENTFD_FLAG_DEASSIGN) + return -EINVAL; + + /* If restriction is in place, check the domid matches */ + if (data->domid != DOMID_INVALID && data->domid != ioeventfd.dom) + return -EPERM; + + if (ioeventfd.flags & PRIVCMD_IOEVENTFD_FLAG_DEASSIGN) + return privcmd_ioeventfd_deassign(&ioeventfd); + + return privcmd_ioeventfd_assign(&ioeventfd); +} + +static void privcmd_ioeventfd_exit(void) +{ + struct privcmd_kernel_ioreq *kioreq, *tmp; + unsigned long flags; + + mutex_lock(&ioreq_lock); + list_for_each_entry_safe(kioreq, tmp, &ioreq_list, list) { + struct privcmd_kernel_ioeventfd *kioeventfd, *tmp; + + spin_lock_irqsave(&kioreq->lock, flags); + list_for_each_entry_safe(kioeventfd, tmp, &kioreq->ioeventfds, list) + ioeventfd_free(kioeventfd); + spin_unlock_irqrestore(&kioreq->lock, flags); + + ioreq_free(kioreq); + } + mutex_unlock(&ioreq_lock); +} #else static inline long privcmd_ioctl_irqfd(struct file *file, void __user *udata) { @@ -1093,7 +1480,16 @@ static inline int privcmd_irqfd_init(void) static inline void privcmd_irqfd_exit(void) { } -#endif /* CONFIG_XEN_PRIVCMD_IRQFD */ + +static inline long privcmd_ioctl_ioeventfd(struct file *file, void __user *udata) +{ + return -EOPNOTSUPP; +} + +static inline void privcmd_ioeventfd_exit(void) +{ +} +#endif /* CONFIG_XEN_PRIVCMD_EVENTFD */

static long privcmd_ioctl(struct file *file, unsigned int cmd, unsigned long data) @@ -1134,6 +1530,10 @@ static long privcmd_ioctl(struct file *file, ret = privcmd_ioctl_irqfd(file, udata); break;

+ case IOCTL_PRIVCMD_IOEVENTFD: + ret = privcmd_ioctl_ioeventfd(file, udata); + break; + default: break; } @@ -1278,6 +1678,7 @@ static int __init privcmd_init(void)

static void __exit privcmd_exit(void) { + privcmd_ioeventfd_exit(); privcmd_irqfd_exit(); misc_deregister(&privcmd_dev); misc_deregister(&xen_privcmdbuf_dev); diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h index e145bca5105c..8b8c5d1420fe 100644 --- a/include/uapi/xen/privcmd.h +++ b/include/uapi/xen/privcmd.h @@ -110,6 +110,22 @@ struct privcmd_irqfd { __u8 pad[2]; };

+/* For privcmd_ioeventfd::flags */ +#define PRIVCMD_IOEVENTFD_FLAG_DEASSIGN (1 << 0) + +struct privcmd_ioeventfd { + __u64 ioreq; + __u64 ports; + __u64 addr; + __u32 addr_len; + __u32 event_fd; + __u32 vcpus; + __u32 vq; + __u32 flags; + domid_t dom; + __u8 pad[2]; +}; + /* * @cmd: IOCTL_PRIVCMD_HYPERCALL * @arg: &privcmd_hypercall_t @@ -139,5 +155,7 @@ struct privcmd_irqfd { _IOC(_IOC_NONE, 'P', 7, sizeof(struct privcmd_mmap_resource)) #define IOCTL_PRIVCMD_IRQFD \ _IOW('P', 8, struct privcmd_irqfd) +#define IOCTL_PRIVCMD_IOEVENTFD \ + _IOW('P', 9, struct privcmd_ioeventfd)

#endif /* __LINUX_PUBLIC_PRIVCMD_H__ */ diff --git a/include/xen/interface/hvm/ioreq.h b/include/xen/interface/hvm/ioreq.h new file mode 100644 index 000000000000..b02cfeae7eb5 --- /dev/null +++ b/include/xen/interface/hvm/ioreq.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: MIT */ +/* + * ioreq.h: I/O request definitions for device models + * Copyright (c) 2004, Intel Corporation. + */ + +#ifndef __XEN_PUBLIC_HVM_IOREQ_H__ +#define __XEN_PUBLIC_HVM_IOREQ_H__ + +#define IOREQ_READ 1 +#define IOREQ_WRITE 0 + +#define STATE_IOREQ_NONE 0 +#define STATE_IOREQ_READY 1 +#define STATE_IOREQ_INPROCESS 2 +#define STATE_IORESP_READY 3 + +#define IOREQ_TYPE_PIO 0 /* pio */ +#define IOREQ_TYPE_COPY 1 /* mmio ops */ +#define IOREQ_TYPE_PCI_CONFIG 2 +#define IOREQ_TYPE_TIMEOFFSET 7 +#define IOREQ_TYPE_INVALIDATE 8 /* mapcache */ + +/* + * VMExit dispatcher should cooperate with instruction decoder to + * prepare this structure and notify service OS and DM by sending + * virq. + * + * For I/O type IOREQ_TYPE_PCI_CONFIG, the physical address is formatted + * as follows: + * + * 63....48|47..40|39..35|34..32|31........0 + * SEGMENT |BUS |DEV |FN |OFFSET + */ +struct ioreq { + uint64_t addr; /* physical address */ + uint64_t data; /* data (or paddr of data) */ + uint32_t count; /* for rep prefixes */ + uint32_t size; /* size in bytes */ + uint32_t vp_eport; /* evtchn for notifications to/from device model */ + uint16_t _pad0; + uint8_t state:4; + uint8_t data_is_ptr:1; /* if 1, data above is the guest paddr + * of the real data to use. */ + uint8_t dir:1; /* 1=read, 0=write */ + uint8_t df:1; + uint8_t _pad1:1; + uint8_t type; /* I/O type */ +}; + +#endif /* __XEN_PUBLIC_HVM_IOREQ_H__ */