From patchwork Tue May 9 20:47:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 680257 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5EEA2C77B7C for ; Tue, 9 May 2023 20:52:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235687AbjEIUwh (ORCPT ); Tue, 9 May 2023 16:52:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235451AbjEIUwK (ORCPT ); Tue, 9 May 2023 16:52:10 -0400 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1F21C59CC; Tue, 9 May 2023 13:50:55 -0700 (PDT) Received: from pps.filterd (m0279865.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 349Ggu45001399; Tue, 9 May 2023 20:49:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding : content-type; s=qcppdkim1; bh=jaiGuT/zXyNNhB53SFr2NHGJ9XaZ7P6uE+ljZXKuZe8=; b=lH0QrVXhx7sNBm9r+Nw7G7unicU/OC6bm/tLDeKNFnRloWXQNjWGaGxnKofMfqW7OTZ7 g4kbWOMOS+e1wElWXye05P2ONajA1UoznX0pMQQG3e0FchHomrB7b5VkWzW/S6wkiTwt p+GBuWQCxmFZWc8Uu/+Rzg4VJHwyBxNkK9G9L+7tbhyz6KyW7ow0W6U2p4Xme4qDgkat taVq0xAdj8M/ggszgZfenaOiDiJoGRh6WtE+Y3qfA0DYCkStgYiKF8CqmXTG8sq7dDZ+ RGiP+CYhcTFp7DkkML80ErvGASzcN8KcHw1Oe/YE3lYeHo9SjQHw2XdW7pDXXlTqPKty yw== Received: from nasanppmta04.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qfsxj8f0c-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 May 2023 20:49:26 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA04.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 349KnQV0015266 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 9 May 2023 20:49:26 GMT Received: from hu-eberman-lv.qualcomm.com (10.49.16.6) by nasanex01b.na.qualcomm.com (10.46.141.250) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.986.42; Tue, 9 May 2023 13:49:25 -0700 From: Elliot Berman To: Alex Elder , Srinivas Kandagatla , Elliot Berman , Prakruthi Deepak Heragu , Jonathan Corbet CC: Murali Nalajala , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Dmitry Baryshkov , Bjorn Andersson , "Konrad Dybcio" , Arnd Bergmann , "Greg Kroah-Hartman" , Rob Herring , Krzysztof Kozlowski , Bagas Sanjaya , Will Deacon , Andy Gross , Catalin Marinas , Jassi Brar , , , , , Subject: [PATCH v13 22/24] virt: gunyah: Add irqfd interface Date: Tue, 9 May 2023 13:47:59 -0700 Message-ID: <20230509204801.2824351-23-quic_eberman@quicinc.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230509204801.2824351-1-quic_eberman@quicinc.com> References: <20230509204801.2824351-1-quic_eberman@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01c.na.qualcomm.com (10.47.97.35) To nasanex01b.na.qualcomm.com (10.46.141.250) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-ORIG-GUID: H8FjvL03_cWA-EFFIb9UBgXs7IdOK38J X-Proofpoint-GUID: H8FjvL03_cWA-EFFIb9UBgXs7IdOK38J X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.942,Hydra:6.0.573,FMLib:17.11.170.22 definitions=2023-05-09_13,2023-05-05_01,2023-02-09_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 adultscore=0 mlxlogscore=999 phishscore=0 spamscore=0 suspectscore=0 clxscore=1015 impostorscore=0 bulkscore=0 priorityscore=1501 mlxscore=0 lowpriorityscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2305090171 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org 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 Signed-off-by: Prakruthi Deepak Heragu Signed-off-by: Elliot Berman Acked-by: Alex Elder --- 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 6789d13fed14..c4960948c779 100644 --- a/Documentation/virt/gunyah/vm-manager.rst +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -115,7 +115,7 @@ 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 0a58395f7d2c..bc2c46d9df94 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 cc16b6c19db9..ad212a1cf967 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 000000000000..3e954ebd2029 --- /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 +#include +#include +#include +#include +#include +#include +#include + +#include + +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 434ffa8ffc78..0c480c622686 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.