| Message ID | 20230613172054.3959700-24-quic_eberman@quicinc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Drivers for Gunyah hypervisor | expand |
On 6/13/23 12:20 PM, 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. > > Acked-by: Alex Elder <elder@linaro.org> I guess I don't mind upgrading this. It looks good to me. Reviewed-by: Alex Elder <elder@linaro.org> > 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 | 2 +- > drivers/virt/gunyah/Kconfig | 9 ++ > drivers/virt/gunyah/Makefile | 1 + > drivers/virt/gunyah/gunyah_irqfd.c | 180 +++++++++++++++++++++++ > include/uapi/linux/gunyah.h | 35 +++++ > 5 files changed, 226 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 b0c3bde105ae9..57a254827be26 100644 > --- a/Documentation/virt/gunyah/vm-manager.rst > +++ b/Documentation/virt/gunyah/vm-manager.rst > @@ -116,7 +116,7 @@ the VM *before* the VM starts. > The argument types are documented below: > > .. kernel-doc:: include/uapi/linux/gunyah.h > - :identifiers: gh_fn_vcpu_arg > + :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags > > Gunyah VCPU API Descriptions > ---------------------------- > diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig > index 0a58395f7d2c5..bc2c46d9df946 100644 > --- a/drivers/virt/gunyah/Kconfig > +++ b/drivers/virt/gunyah/Kconfig > @@ -39,3 +39,12 @@ 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 cc16b6c19db92..ad212a1cf9671 100644 > --- a/drivers/virt/gunyah/Makefile > +++ b/drivers/virt/gunyah/Makefile > @@ -7,3 +7,4 @@ gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o > obj-$(CONFIG_GUNYAH) += gunyah.o > > obj-$(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 0000000000000..3e954ebd20297 > --- /dev/null > +++ b/drivers/virt/gunyah/gunyah_irqfd.c > @@ -0,0 +1,180 @@ > +// 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/module.h> > +#include <linux/poll.h> > +#include <linux/printk.h> > + > +#include <uapi/linux/gunyah.h> > + > +struct gh_irqfd { > + struct gh_resource *ghrsc; > + struct gh_vm_resource_ticket ticket; > + struct gh_vm_function_instance *f; > + > + bool level; > + > + struct eventfd_ctx *ctx; > + wait_queue_entry_t wait; > + poll_table pt; > +}; > + > +static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) > +{ > + struct gh_irqfd *irqfd = container_of(wait, struct gh_irqfd, wait); > + __poll_t flags = key_to_poll(key); > + int ret = 0; > + > + if (flags & EPOLLIN) { > + if (irqfd->ghrsc) { > + ret = gh_hypercall_bell_send(irqfd->ghrsc->capid, 1, NULL); > + if (ret) > + pr_err_ratelimited("Failed to inject interrupt %d: %d\n", > + irqfd->ticket.label, ret); > + } else > + pr_err_ratelimited("Premature injection of interrupt\n"); > + } > + > + return 0; > +} > + > +static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) > +{ > + struct gh_irqfd *irq_ctx = container_of(pt, struct gh_irqfd, pt); > + > + add_wait_queue(wqh, &irq_ctx->wait); > +} > + > +static bool gh_irqfd_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc) > +{ > + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket); > + int ret; > + > + if (irqfd->ghrsc) { > + pr_warn("irqfd%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n", > + irqfd->ticket.label); > + return false; > + } > + > + irqfd->ghrsc = ghrsc; > + if (irqfd->level) { > + /* Configure the bell to trigger when bit 0 is asserted (see > + * irq_wakeup) and for bell to automatically clear bit 0 once > + * received by the VM (ack_mask). need to make sure bit 0 is cleared right away, > + * otherwise the line will never be deasserted. Emulating edge > + * trigger interrupt does not need to set either mask > + * because irq is listed only once per gh_hypercall_bell_send > + */ > + ret = gh_hypercall_bell_set_mask(irqfd->ghrsc->capid, 1, 1); > + if (ret) > + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n", > + irqfd->ticket.label); > + } > + > + return true; > +} > + > +static void gh_irqfd_unpopulate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc) > +{ > + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket); > + u64 cnt; > + > + eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt); > +} > + > +static long gh_irqfd_bind(struct gh_vm_function_instance *f) > +{ > + struct gh_fn_irqfd_arg *args = f->argp; > + struct gh_irqfd *irqfd; > + __poll_t events; > + struct fd fd; > + long r; > + > + if (f->arg_size != sizeof(*args)) > + return -EINVAL; > + > + /* All other flag bits are reserved for future use */ > + if (args->flags & ~GH_IRQFD_FLAGS_LEVEL) > + return -EINVAL; > + > + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); > + if (!irqfd) > + return -ENOMEM; > + > + irqfd->f = f; > + f->data = irqfd; > + > + fd = fdget(args->fd); > + if (!fd.file) { > + kfree(irqfd); > + return -EBADF; > + } > + > + irqfd->ctx = eventfd_ctx_fileget(fd.file); > + if (IS_ERR(irqfd->ctx)) { > + r = PTR_ERR(irqfd->ctx); > + goto err_fdput; > + } > + > + if (args->flags & GH_IRQFD_FLAGS_LEVEL) > + irqfd->level = true; > + > + init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup); > + init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc); > + > + irqfd->ticket.resource_type = GH_RESOURCE_TYPE_BELL_TX; > + irqfd->ticket.label = args->label; > + irqfd->ticket.owner = THIS_MODULE; > + irqfd->ticket.populate = gh_irqfd_populate; > + irqfd->ticket.unpopulate = gh_irqfd_unpopulate; > + > + r = gh_vm_add_resource_ticket(f->ghvm, &irqfd->ticket); > + if (r) > + goto err_ctx; > + > + events = vfs_poll(fd.file, &irqfd->pt); > + if (events & EPOLLIN) > + pr_warn("Premature injection of interrupt\n"); > + fdput(fd); > + > + return 0; > +err_ctx: > + eventfd_ctx_put(irqfd->ctx); > +err_fdput: > + fdput(fd); > + kfree(irqfd); > + return r; > +} > + > +static void gh_irqfd_unbind(struct gh_vm_function_instance *f) > +{ > + struct gh_irqfd *irqfd = f->data; > + > + gh_vm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket); > + eventfd_ctx_put(irqfd->ctx); > + kfree(irqfd); > +} > + > +static bool gh_irqfd_compare(const struct gh_vm_function_instance *f, > + const void *arg, size_t size) > +{ > + const struct gh_fn_irqfd_arg *instance = f->argp, > + *other = arg; > + > + if (sizeof(*other) != size) > + return false; > + > + return instance->label == other->label; > +} > + > +DECLARE_GH_VM_FUNCTION_INIT(irqfd, GH_FN_IRQFD, 2, gh_irqfd_bind, gh_irqfd_unbind, > + gh_irqfd_compare); > +MODULE_DESCRIPTION("Gunyah irqfd VM Function"); > +MODULE_LICENSE("GPL"); > diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h > index 434ffa8ffc783..0c480c622686a 100644 > --- a/include/uapi/linux/gunyah.h > +++ b/include/uapi/linux/gunyah.h > @@ -77,9 +77,12 @@ struct gh_vm_dtb_config { > * @GH_FN_VCPU: create a vCPU instance to control a vCPU > * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_vcpu_arg > * Return: file descriptor to manipulate the vcpu. > + * @GH_FN_IRQFD: register eventfd to assert a Gunyah doorbell > + * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_irqfd_arg > */ > enum gh_fn_type { > GH_FN_VCPU = 1, > + GH_FN_IRQFD, > }; > > #define GH_FN_MAX_ARG_SIZE 256 > @@ -99,6 +102,38 @@ struct gh_fn_vcpu_arg { > __u32 id; > }; > > +/** > + * enum gh_irqfd_flags - flags for use in gh_fn_irqfd_arg > + * @GH_IRQFD_FLAGS_LEVEL: make the interrupt operate like a level triggered > + * interrupt on guest side. Triggering IRQFD before > + * guest handles the interrupt causes interrupt to > + * stay asserted. > + */ > +enum gh_irqfd_flags { > + GH_IRQFD_FLAGS_LEVEL = 1UL << 0, > +}; > + > +/** > + * struct gh_fn_irqfd_arg - Arguments to create an irqfd function. > + * > + * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IRQFD. > + * > + * 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. > + * > + * @fd: an eventfd which when written to will raise a doorbell > + * @label: Label of the doorbell created on the guest VM > + * @flags: see &enum gh_irqfd_flags > + * @padding: padding bytes > + */ > +struct gh_fn_irqfd_arg { > + __u32 fd; > + __u32 label; > + __u32 flags; > + __u32 padding; > +}; > + > /** > * struct gh_fn_desc - Arguments to create a VM function > * @type: Type of the function. See &enum gh_fn_type.
diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst index b0c3bde105ae9..57a254827be26 100644 --- a/Documentation/virt/gunyah/vm-manager.rst +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -116,7 +116,7 @@ the VM *before* the VM starts. The argument types are documented below: .. kernel-doc:: include/uapi/linux/gunyah.h - :identifiers: gh_fn_vcpu_arg + :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags Gunyah VCPU API Descriptions ---------------------------- diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig index 0a58395f7d2c5..bc2c46d9df946 100644 --- a/drivers/virt/gunyah/Kconfig +++ b/drivers/virt/gunyah/Kconfig @@ -39,3 +39,12 @@ 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 cc16b6c19db92..ad212a1cf9671 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -7,3 +7,4 @@ gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o obj-$(CONFIG_GUNYAH) += gunyah.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 0000000000000..3e954ebd20297 --- /dev/null +++ b/drivers/virt/gunyah/gunyah_irqfd.c @@ -0,0 +1,180 @@ +// 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/module.h> +#include <linux/poll.h> +#include <linux/printk.h> + +#include <uapi/linux/gunyah.h> + +struct gh_irqfd { + struct gh_resource *ghrsc; + struct gh_vm_resource_ticket ticket; + struct gh_vm_function_instance *f; + + bool level; + + struct eventfd_ctx *ctx; + wait_queue_entry_t wait; + poll_table pt; +}; + +static int irqfd_wakeup(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key) +{ + struct gh_irqfd *irqfd = container_of(wait, struct gh_irqfd, wait); + __poll_t flags = key_to_poll(key); + int ret = 0; + + if (flags & EPOLLIN) { + if (irqfd->ghrsc) { + ret = gh_hypercall_bell_send(irqfd->ghrsc->capid, 1, NULL); + if (ret) + pr_err_ratelimited("Failed to inject interrupt %d: %d\n", + irqfd->ticket.label, ret); + } else + pr_err_ratelimited("Premature injection of interrupt\n"); + } + + return 0; +} + +static void irqfd_ptable_queue_proc(struct file *file, wait_queue_head_t *wqh, poll_table *pt) +{ + struct gh_irqfd *irq_ctx = container_of(pt, struct gh_irqfd, pt); + + add_wait_queue(wqh, &irq_ctx->wait); +} + +static bool gh_irqfd_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc) +{ + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket); + int ret; + + if (irqfd->ghrsc) { + pr_warn("irqfd%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n", + irqfd->ticket.label); + return false; + } + + irqfd->ghrsc = ghrsc; + if (irqfd->level) { + /* Configure the bell to trigger when bit 0 is asserted (see + * irq_wakeup) and for bell to automatically clear bit 0 once + * received by the VM (ack_mask). need to make sure bit 0 is cleared right away, + * otherwise the line will never be deasserted. Emulating edge + * trigger interrupt does not need to set either mask + * because irq is listed only once per gh_hypercall_bell_send + */ + ret = gh_hypercall_bell_set_mask(irqfd->ghrsc->capid, 1, 1); + if (ret) + pr_warn("irq %d couldn't be set as level triggered. Might cause IRQ storm if asserted\n", + irqfd->ticket.label); + } + + return true; +} + +static void gh_irqfd_unpopulate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc) +{ + struct gh_irqfd *irqfd = container_of(ticket, struct gh_irqfd, ticket); + u64 cnt; + + eventfd_ctx_remove_wait_queue(irqfd->ctx, &irqfd->wait, &cnt); +} + +static long gh_irqfd_bind(struct gh_vm_function_instance *f) +{ + struct gh_fn_irqfd_arg *args = f->argp; + struct gh_irqfd *irqfd; + __poll_t events; + struct fd fd; + long r; + + if (f->arg_size != sizeof(*args)) + return -EINVAL; + + /* All other flag bits are reserved for future use */ + if (args->flags & ~GH_IRQFD_FLAGS_LEVEL) + return -EINVAL; + + irqfd = kzalloc(sizeof(*irqfd), GFP_KERNEL); + if (!irqfd) + return -ENOMEM; + + irqfd->f = f; + f->data = irqfd; + + fd = fdget(args->fd); + if (!fd.file) { + kfree(irqfd); + return -EBADF; + } + + irqfd->ctx = eventfd_ctx_fileget(fd.file); + if (IS_ERR(irqfd->ctx)) { + r = PTR_ERR(irqfd->ctx); + goto err_fdput; + } + + if (args->flags & GH_IRQFD_FLAGS_LEVEL) + irqfd->level = true; + + init_waitqueue_func_entry(&irqfd->wait, irqfd_wakeup); + init_poll_funcptr(&irqfd->pt, irqfd_ptable_queue_proc); + + irqfd->ticket.resource_type = GH_RESOURCE_TYPE_BELL_TX; + irqfd->ticket.label = args->label; + irqfd->ticket.owner = THIS_MODULE; + irqfd->ticket.populate = gh_irqfd_populate; + irqfd->ticket.unpopulate = gh_irqfd_unpopulate; + + r = gh_vm_add_resource_ticket(f->ghvm, &irqfd->ticket); + if (r) + goto err_ctx; + + events = vfs_poll(fd.file, &irqfd->pt); + if (events & EPOLLIN) + pr_warn("Premature injection of interrupt\n"); + fdput(fd); + + return 0; +err_ctx: + eventfd_ctx_put(irqfd->ctx); +err_fdput: + fdput(fd); + kfree(irqfd); + return r; +} + +static void gh_irqfd_unbind(struct gh_vm_function_instance *f) +{ + struct gh_irqfd *irqfd = f->data; + + gh_vm_remove_resource_ticket(irqfd->f->ghvm, &irqfd->ticket); + eventfd_ctx_put(irqfd->ctx); + kfree(irqfd); +} + +static bool gh_irqfd_compare(const struct gh_vm_function_instance *f, + const void *arg, size_t size) +{ + const struct gh_fn_irqfd_arg *instance = f->argp, + *other = arg; + + if (sizeof(*other) != size) + return false; + + return instance->label == other->label; +} + +DECLARE_GH_VM_FUNCTION_INIT(irqfd, GH_FN_IRQFD, 2, gh_irqfd_bind, gh_irqfd_unbind, + gh_irqfd_compare); +MODULE_DESCRIPTION("Gunyah irqfd VM Function"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index 434ffa8ffc783..0c480c622686a 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -77,9 +77,12 @@ struct gh_vm_dtb_config { * @GH_FN_VCPU: create a vCPU instance to control a vCPU * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_vcpu_arg * Return: file descriptor to manipulate the vcpu. + * @GH_FN_IRQFD: register eventfd to assert a Gunyah doorbell + * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_irqfd_arg */ enum gh_fn_type { GH_FN_VCPU = 1, + GH_FN_IRQFD, }; #define GH_FN_MAX_ARG_SIZE 256 @@ -99,6 +102,38 @@ struct gh_fn_vcpu_arg { __u32 id; }; +/** + * enum gh_irqfd_flags - flags for use in gh_fn_irqfd_arg + * @GH_IRQFD_FLAGS_LEVEL: make the interrupt operate like a level triggered + * interrupt on guest side. Triggering IRQFD before + * guest handles the interrupt causes interrupt to + * stay asserted. + */ +enum gh_irqfd_flags { + GH_IRQFD_FLAGS_LEVEL = 1UL << 0, +}; + +/** + * struct gh_fn_irqfd_arg - Arguments to create an irqfd function. + * + * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IRQFD. + * + * 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. + * + * @fd: an eventfd which when written to will raise a doorbell + * @label: Label of the doorbell created on the guest VM + * @flags: see &enum gh_irqfd_flags + * @padding: padding bytes + */ +struct gh_fn_irqfd_arg { + __u32 fd; + __u32 label; + __u32 flags; + __u32 padding; +}; + /** * struct gh_fn_desc - Arguments to create a VM function * @type: Type of the function. See &enum gh_fn_type.