| Message ID | 20230120224627.4053418-27-quic_eberman@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Drivers for gunyah hypervisor | expand |
On 20/01/2023 22:46, Elliot Berman wrote: > Enable support for creating irqfds which can raise an interrupt on a > Gunyah virtual machine. irqfds are exposed to userspace as a Gunyah VM > function with the name "irqfd". If the VM devicetree is not configured > to create a doorbell with the corresponding label, userspace will still > be able to assert the eventfd but no interrupt will be raised on the > guest. > > Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com> > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com> > --- > Documentation/virt/gunyah/vm-manager.rst | 22 +++ > drivers/virt/gunyah/Kconfig | 9 ++ > drivers/virt/gunyah/Makefile | 1 + > drivers/virt/gunyah/gunyah_irqfd.c | 166 +++++++++++++++++++++++ > include/linux/gunyah.h | 5 + > include/uapi/linux/gunyah.h | 11 +- > 6 files changed, 213 insertions(+), 1 deletion(-) > create mode 100644 drivers/virt/gunyah/gunyah_irqfd.c > > diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst > index d11267d59802..b6cf8db826b8 100644 > --- a/Documentation/virt/gunyah/vm-manager.rst > +++ b/Documentation/virt/gunyah/vm-manager.rst > @@ -142,3 +142,25 @@ The vcpu type will register with the VM Manager to expect to control > vCPU number `vcpu_id`. It returns a file descriptor allowing interaction with > the vCPU. See the Gunyah vCPU API description sections for interacting with > the Gunyah vCPU file descriptors. > + > +Type: "irqfd" > +^^^^^^^^^^^^^ > + > +:: > + > + struct gh_fn_irqfd_arg { > + __u32 fd; > + __u32 label; > + #define GH_IRQFD_LEVEL (1UL << 0) > + #define GH_IRQFD_DEASSIGN (1UL << 1) > + __u32 flags; > + }; > + > +Allows setting an eventfd to directly trigger a guest interrupt. > +irqfd.fd specifies the file descriptor to use as the eventfd. > +irqfd.label corresponds to the doorbell label used in the guest VM's devicetree. > +The irqfd is removed using the GH_IRQFD_DEASSIGN flag and specifying at least > +the irqfd.label. > + > +GH_IRQFD_LEVEL configures the corresponding doorbell to behave like a level > +triggered interrupt. > diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig > index 4c1c6110b50e..2cde24d429d1 100644 > --- a/drivers/virt/gunyah/Kconfig > +++ b/drivers/virt/gunyah/Kconfig > @@ -26,3 +26,12 @@ config GUNYAH_VCPU > VMMs can also handle stage 2 faults of the vCPUs. > > Say Y/M here if unsure and you want to support Gunyah VMMs. > + > +config GUNYAH_IRQFD > + tristate "Gunyah irqfd interface" > + depends on GUNYAH > + help > + Enable kernel support for creating irqfds which can raise an interrupt > + on Gunyah virtual machine. > + > + Say Y/M here if unsure and you want to support Gunyah VMMs. > diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile > index 2d1b604a7b03..6cf756bfa3c2 100644 > --- a/drivers/virt/gunyah/Makefile > +++ b/drivers/virt/gunyah/Makefile > @@ -7,3 +7,4 @@ gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o > obj-$(CONFIG_GUNYAH) += gunyah_rsc_mgr.o > > obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o > +obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o > diff --git a/drivers/virt/gunyah/gunyah_irqfd.c b/drivers/virt/gunyah/gunyah_irqfd.c > new file mode 100644 > index 000000000000..a3be9ca2377a > --- /dev/null > +++ b/drivers/virt/gunyah/gunyah_irqfd.c > @@ -0,0 +1,166 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. > + */ > + > +#include <linux/eventfd.h> > +#include <linux/file.h> > +#include <linux/fs.h> > +#include <linux/gunyah.h> > +#include <linux/gunyah_vm_mgr.h> > +#include <linux/kref.h> > +#include <linux/module.h> > +#include <linux/poll.h> > +#include <linux/printk.h> > + > +#include <uapi/linux/gunyah.h> > + > +struct gunyah_irqfd { > + struct gunyah_resource *ghrsc; > + struct gunyah_vm_resource_ticket ticket; > + struct gunyah_vm_function *f; > + > + struct kref kref; > + bool level; > + > + struct eventfd_ctx *ctx; > + wait_queue_entry_t wait; > + poll_table pt; > + struct fd fd; > +}; > + > +static void gh_irqfd_cleanup(struct kref *kref) > +{ > + struct gunyah_irqfd *irqfd = container_of(kref, struct gunyah_irqfd, kref); > + > + kfree(irqfd); > +} > + > +static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) > +{ > + struct gunyah_irqfd *irqfd = container_of(wait, struct gunyah_irqfd, wait); > + __poll_t flags = key_to_poll(key); > + u64 enable_mask = GH_DBL_NONBLOCK; > + u64 old_flags; > + int ret = 0; > + > + if (flags & EPOLLIN) { > + if (irqfd->ghrsc) { > + ret = gh_hypercall_dbl_send(irqfd->ghrsc->capid, enable_mask, &old_flags); > + if (ret) > + pr_err("Failed to assert irq %d\n", irqfd->f->fn.irqfd.label); > + } > + } > + > + return 0; > +} > + > +static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) > +{ > + struct gunyah_irqfd *irq_ctx = container_of(pt, struct gunyah_irqfd, pt); > + > + add_wait_queue(wqh, &irq_ctx->wait); > +} > + > +static int gunyah_irqfd_populate(struct gunyah_vm_resource_ticket *ticket, > + struct gunyah_resource *ghrsc) > +{ > + struct gunyah_irqfd *irqfd = container_of(ticket, struct gunyah_irqfd, ticket); > + u64 enable_mask = GH_DBL_NONBLOCK; > + u64 ack_mask = ~0; > + int ret = 0; > + > + irqfd->ghrsc = ghrsc; > + if (irqfd->level) { > + ret = gh_hypercall_dbl_set_mask(irqfd->ghrsc->capid, enable_mask, ack_mask); > + if (ret) > + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n", > + irqfd->f->fn.irqfd.label); > + } > + kref_get(&irqfd->kref); > + > + return 0; > +} > + > +static void gunyah_irqfd_unpopulate(struct gunyah_vm_resource_ticket *ticket, > + struct gunyah_resource *ghrsc) > +{ > + struct gunyah_irqfd *irqfd = container_of(ticket, struct gunyah_irqfd, ticket); > + u64 cnt; > + > + eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt); > + eventfd_ctx_put(irqfd->ctx); > + fdput(irqfd->fd); <-- > + irqfd->ctx = NULL; > + irqfd->fd.file = NULL; > + irqfd->ghrsc = NULL; --> How do we know that this is the last reference ? > + kref_put(&irqfd->kref, gh_irqfd_cleanup); > +} > + > +static long gunyah_irqfd_bind(struct gunyah_vm_function *f) > +{ > + __poll_t events; > + struct gunyah_irqfd *irqfd; > + long r; > + > + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); > + if (!irqfd) > + return -ENOMEM; > + > + irqfd->f = f; > + f->data = irqfd; > + > + irqfd->fd = fdget(f->fn.irqfd.fd); > + if (!irqfd->fd.file) { > + r = -EBADF; > + goto err_free; > + } > + > + irqfd->ctx = eventfd_ctx_fileget(irqfd->fd.file); > + if (IS_ERR(irqfd->ctx)) { > + r = PTR_ERR(irqfd->ctx); > + goto err_fdput; > + } > + > + if (f->fn.irqfd.flags & GH_IRQFD_LEVEL) > + irqfd->level = true; > + > + init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup); > + init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc); > + kref_init(&irqfd->kref); > + > + irqfd->ticket.resource_type = GUNYAH_RESOURCE_TYPE_BELL_TX; > + irqfd->ticket.label = f->fn.irqfd.label; > + irqfd->ticket.owner = THIS_MODULE; > + irqfd->ticket.populate = gunyah_irqfd_populate; > + irqfd->ticket.unpopulate = gunyah_irqfd_unpopulate; > + > + r = ghvm_add_resource_ticket(f->ghvm, &irqfd->ticket); > + if (r) > + goto err_ctx; > + > + events = vfs_poll(irqfd->fd.file, &irqfd->pt); > + if (events & EPOLLIN) > + pr_warn("Premature injection of interrupt\n"); > + > + return 0; > +err_ctx: kref_put missing? > + eventfd_ctx_put(irqfd->ctx); > +err_fdput: > + fdput(irqfd->fd); > +err_free: > + kfree(irqfd); > + return r; > +} > + > +static void gunyah_irqfd_release(struct gunyah_vm_function *f) > +{ > + struct gunyah_irqfd *irqfd = f->data; > + > + /* unpopulate will trigger clean up of the eventfd */ > + ghvm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket); > +} > + > +DECLARE_GUNYAH_VM_FUNCTION_INIT(irqfd, gunyah_irqfd_bind, gunyah_irqfd_release); > +MODULE_DESCRIPTION("Gunyah irqfds"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h > index ac4879940c10..6b363707a901 100644 > --- a/include/linux/gunyah.h > +++ b/include/linux/gunyah.h > @@ -33,6 +33,11 @@ struct gunyah_resource { > u32 rm_label; > }; > > +/** > + * Gunyah Doorbells > + */ > +#define GH_DBL_NONBLOCK BIT(32) > + > /** > * Gunyah Message Queues > */ > diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h > index b4afb11f538a..a947f0317ca9 100644 > --- a/include/uapi/linux/gunyah.h > +++ b/include/uapi/linux/gunyah.h > @@ -57,10 +57,19 @@ struct gh_fn_vcpu_arg { > __u32 vcpu_id; > }; > > +struct gh_fn_irqfd_arg { > + __u32 fd; > + __u32 label; > +#define GH_IRQFD_LEVEL (1UL << 0) > +#define GH_IRQFD_DEASSIGN (1UL << 1) > + __u32 flags; same issue here, this is not naturaly aligned. for details take a look at Documentation/driver-api/ioctl.rst > +}; > + > struct gh_vm_function { > char name[GUNYAH_FUNCTION_NAME_SIZE]; > union { > - struct gh_device_vcpu_arg vcpu; > + struct gh_fn_vcpu_arg vcpu; > + struct gh_fn_irqfd_arg irqfd; > char data[GUNYAH_FUNCTION_MAX_ARG_SIZE]; > }; > };
* Elliot Berman <quic_eberman@quicinc.com> [2023-01-20 14:46:25]: > +static int gunyah_irqfd_populate(struct gunyah_vm_resource_ticket *ticket, > + struct gunyah_resource *ghrsc) > +{ > + struct gunyah_irqfd *irqfd = container_of(ticket, struct gunyah_irqfd, ticket); > + u64 enable_mask = GH_DBL_NONBLOCK; > + u64 ack_mask = ~0; > + int ret = 0; > + > + irqfd->ghrsc = ghrsc; > + if (irqfd->level) { > + ret = gh_hypercall_dbl_set_mask(irqfd->ghrsc->capid, enable_mask, ack_mask); We probably want this mask set for both level and edge interrupts. > + if (ret) > + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n", > + irqfd->f->fn.irqfd.label); > + } > + kref_get(&irqfd->kref); Is this kref_get() really needed? > + > + return 0; > +} > +
diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst index d11267d59802..b6cf8db826b8 100644 --- a/Documentation/virt/gunyah/vm-manager.rst +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -142,3 +142,25 @@ The vcpu type will register with the VM Manager to expect to control vCPU number `vcpu_id`. It returns a file descriptor allowing interaction with the vCPU. See the Gunyah vCPU API description sections for interacting with the Gunyah vCPU file descriptors. + +Type: "irqfd" +^^^^^^^^^^^^^ + +:: + + struct gh_fn_irqfd_arg { + __u32 fd; + __u32 label; + #define GH_IRQFD_LEVEL (1UL << 0) + #define GH_IRQFD_DEASSIGN (1UL << 1) + __u32 flags; + }; + +Allows setting an eventfd to directly trigger a guest interrupt. +irqfd.fd specifies the file descriptor to use as the eventfd. +irqfd.label corresponds to the doorbell label used in the guest VM's devicetree. +The irqfd is removed using the GH_IRQFD_DEASSIGN flag and specifying at least +the irqfd.label. + +GH_IRQFD_LEVEL configures the corresponding doorbell to behave like a level +triggered interrupt. diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig index 4c1c6110b50e..2cde24d429d1 100644 --- a/drivers/virt/gunyah/Kconfig +++ b/drivers/virt/gunyah/Kconfig @@ -26,3 +26,12 @@ config GUNYAH_VCPU VMMs can also handle stage 2 faults of the vCPUs. Say Y/M here if unsure and you want to support Gunyah VMMs. + +config GUNYAH_IRQFD + tristate "Gunyah irqfd interface" + depends on GUNYAH + help + Enable kernel support for creating irqfds which can raise an interrupt + on Gunyah virtual machine. + + Say Y/M here if unsure and you want to support Gunyah VMMs. diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile index 2d1b604a7b03..6cf756bfa3c2 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -7,3 +7,4 @@ gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o obj-$(CONFIG_GUNYAH) += gunyah_rsc_mgr.o obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o +obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o diff --git a/drivers/virt/gunyah/gunyah_irqfd.c b/drivers/virt/gunyah/gunyah_irqfd.c new file mode 100644 index 000000000000..a3be9ca2377a --- /dev/null +++ b/drivers/virt/gunyah/gunyah_irqfd.c @@ -0,0 +1,166 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#include <linux/eventfd.h> +#include <linux/file.h> +#include <linux/fs.h> +#include <linux/gunyah.h> +#include <linux/gunyah_vm_mgr.h> +#include <linux/kref.h> +#include <linux/module.h> +#include <linux/poll.h> +#include <linux/printk.h> + +#include <uapi/linux/gunyah.h> + +struct gunyah_irqfd { + struct gunyah_resource *ghrsc; + struct gunyah_vm_resource_ticket ticket; + struct gunyah_vm_function *f; + + struct kref kref; + bool level; + + struct eventfd_ctx *ctx; + wait_queue_entry_t wait; + poll_table pt; + struct fd fd; +}; + +static void gh_irqfd_cleanup(struct kref *kref) +{ + struct gunyah_irqfd *irqfd = container_of(kref, struct gunyah_irqfd, kref); + + kfree(irqfd); +} + +static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) +{ + struct gunyah_irqfd *irqfd = container_of(wait, struct gunyah_irqfd, wait); + __poll_t flags = key_to_poll(key); + u64 enable_mask = GH_DBL_NONBLOCK; + u64 old_flags; + int ret = 0; + + if (flags & EPOLLIN) { + if (irqfd->ghrsc) { + ret = gh_hypercall_dbl_send(irqfd->ghrsc->capid, enable_mask, &old_flags); + if (ret) + pr_err("Failed to assert irq %d\n", irqfd->f->fn.irqfd.label); + } + } + + return 0; +} + +static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) +{ + struct gunyah_irqfd *irq_ctx = container_of(pt, struct gunyah_irqfd, pt); + + add_wait_queue(wqh, &irq_ctx->wait); +} + +static int gunyah_irqfd_populate(struct gunyah_vm_resource_ticket *ticket, + struct gunyah_resource *ghrsc) +{ + struct gunyah_irqfd *irqfd = container_of(ticket, struct gunyah_irqfd, ticket); + u64 enable_mask = GH_DBL_NONBLOCK; + u64 ack_mask = ~0; + int ret = 0; + + irqfd->ghrsc = ghrsc; + if (irqfd->level) { + ret = gh_hypercall_dbl_set_mask(irqfd->ghrsc->capid, enable_mask, ack_mask); + if (ret) + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n", + irqfd->f->fn.irqfd.label); + } + kref_get(&irqfd->kref); + + return 0; +} + +static void gunyah_irqfd_unpopulate(struct gunyah_vm_resource_ticket *ticket, + struct gunyah_resource *ghrsc) +{ + struct gunyah_irqfd *irqfd = container_of(ticket, struct gunyah_irqfd, ticket); + u64 cnt; + + eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt); + eventfd_ctx_put(irqfd->ctx); + fdput(irqfd->fd); + irqfd->ctx = NULL; + irqfd->fd.file = NULL; + irqfd->ghrsc = NULL; + kref_put(&irqfd->kref, gh_irqfd_cleanup); +} + +static long gunyah_irqfd_bind(struct gunyah_vm_function *f) +{ + __poll_t events; + struct gunyah_irqfd *irqfd; + long r; + + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); + if (!irqfd) + return -ENOMEM; + + irqfd->f = f; + f->data = irqfd; + + irqfd->fd = fdget(f->fn.irqfd.fd); + if (!irqfd->fd.file) { + r = -EBADF; + goto err_free; + } + + irqfd->ctx = eventfd_ctx_fileget(irqfd->fd.file); + if (IS_ERR(irqfd->ctx)) { + r = PTR_ERR(irqfd->ctx); + goto err_fdput; + } + + if (f->fn.irqfd.flags & GH_IRQFD_LEVEL) + irqfd->level = true; + + init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup); + init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc); + kref_init(&irqfd->kref); + + irqfd->ticket.resource_type = GUNYAH_RESOURCE_TYPE_BELL_TX; + irqfd->ticket.label = f->fn.irqfd.label; + irqfd->ticket.owner = THIS_MODULE; + irqfd->ticket.populate = gunyah_irqfd_populate; + irqfd->ticket.unpopulate = gunyah_irqfd_unpopulate; + + r = ghvm_add_resource_ticket(f->ghvm, &irqfd->ticket); + if (r) + goto err_ctx; + + events = vfs_poll(irqfd->fd.file, &irqfd->pt); + if (events & EPOLLIN) + pr_warn("Premature injection of interrupt\n"); + + return 0; +err_ctx: + eventfd_ctx_put(irqfd->ctx); +err_fdput: + fdput(irqfd->fd); +err_free: + kfree(irqfd); + return r; +} + +static void gunyah_irqfd_release(struct gunyah_vm_function *f) +{ + struct gunyah_irqfd *irqfd = f->data; + + /* unpopulate will trigger clean up of the eventfd */ + ghvm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket); +} + +DECLARE_GUNYAH_VM_FUNCTION_INIT(irqfd, gunyah_irqfd_bind, gunyah_irqfd_release); +MODULE_DESCRIPTION("Gunyah irqfds"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h index ac4879940c10..6b363707a901 100644 --- a/include/linux/gunyah.h +++ b/include/linux/gunyah.h @@ -33,6 +33,11 @@ struct gunyah_resource { u32 rm_label; }; +/** + * Gunyah Doorbells + */ +#define GH_DBL_NONBLOCK BIT(32) + /** * Gunyah Message Queues */ diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index b4afb11f538a..a947f0317ca9 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -57,10 +57,19 @@ struct gh_fn_vcpu_arg { __u32 vcpu_id; }; +struct gh_fn_irqfd_arg { + __u32 fd; + __u32 label; +#define GH_IRQFD_LEVEL (1UL << 0) +#define GH_IRQFD_DEASSIGN (1UL << 1) + __u32 flags; +}; + struct gh_vm_function { char name[GUNYAH_FUNCTION_NAME_SIZE]; union { - struct gh_device_vcpu_arg vcpu; + struct gh_fn_vcpu_arg vcpu; + struct gh_fn_irqfd_arg irqfd; char data[GUNYAH_FUNCTION_MAX_ARG_SIZE]; }; };