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Tue, 13 Jun 2023 17:21:57 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, 13 Jun 2023 10:21:56 -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 , Conor Dooley , Bagas Sanjaya , Will Deacon , Andy Gross , Catalin Marinas , Jassi Brar , , , , , Subject: [PATCH v14 24/25] virt: gunyah: Add ioeventfd Date: Tue, 13 Jun 2023 10:20:52 -0700 Message-ID: <20230613172054.3959700-25-quic_eberman@quicinc.com> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230613172054.3959700-1-quic_eberman@quicinc.com> References: <20230613172054.3959700-1-quic_eberman@quicinc.com> MIME-Version: 1.0 X-Originating-IP: [10.49.16.6] X-ClientProxiedBy: nalasex01b.na.qualcomm.com (10.47.209.197) 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: iBjD5XAYBg7uZ5J1W_W3nFDmwKmfPylL X-Proofpoint-GUID: iBjD5XAYBg7uZ5J1W_W3nFDmwKmfPylL X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.254,Aquarius:18.0.957,Hydra:6.0.573,FMLib:17.11.176.26 definitions=2023-06-13_19,2023-06-12_02,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 bulkscore=0 adultscore=0 mlxscore=0 mlxlogscore=999 clxscore=1015 impostorscore=0 lowpriorityscore=0 suspectscore=0 priorityscore=1501 phishscore=0 malwarescore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2305260000 definitions=main-2306130153 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20230613_102208_088904_A810883D X-CRM114-Status: GOOD ( 32.88 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Allow userspace to attach an ioeventfd to an mmio address within the guest. Reviewed-by: Alex Elder Co-developed-by: Prakruthi Deepak Heragu Signed-off-by: Prakruthi Deepak Heragu Signed-off-by: Elliot Berman --- Documentation/virt/gunyah/vm-manager.rst | 2 +- drivers/virt/gunyah/Kconfig | 9 ++ drivers/virt/gunyah/Makefile | 1 + drivers/virt/gunyah/gunyah_ioeventfd.c | 130 +++++++++++++++++++++++ include/uapi/linux/gunyah.h | 37 +++++++ 5 files changed, 178 insertions(+), 1 deletion(-) create mode 100644 drivers/virt/gunyah/gunyah_ioeventfd.c diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst index 57a254827be26..415b11248e00b 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 gh_fn_irqfd_arg gh_irqfd_flags + :identifiers: gh_fn_vcpu_arg gh_fn_irqfd_arg gh_irqfd_flags gh_fn_ioeventfd_arg gh_ioeventfd_flags Gunyah VCPU API Descriptions ---------------------------- diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig index bc2c46d9df946..63bebc5b9f825 100644 --- a/drivers/virt/gunyah/Kconfig +++ b/drivers/virt/gunyah/Kconfig @@ -48,3 +48,12 @@ config GUNYAH_IRQFD on Gunyah virtual machine. Say Y/M here if unsure and you want to support Gunyah VMMs. + +config GUNYAH_IOEVENTFD + tristate "Gunyah ioeventfd interface" + depends on GUNYAH + help + Enable kernel support for creating ioeventfds which can alert userspace + when a Gunyah virtual machine accesses a memory address. + + 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 ad212a1cf9671..63ca11e747961 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_GUNYAH) += gunyah.o obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o obj-$(CONFIG_GUNYAH_IRQFD) += gunyah_irqfd.o +obj-$(CONFIG_GUNYAH_IOEVENTFD) += gunyah_ioeventfd.o diff --git a/drivers/virt/gunyah/gunyah_ioeventfd.c b/drivers/virt/gunyah/gunyah_ioeventfd.c new file mode 100644 index 0000000000000..5b1b9fd9ac3aa --- /dev/null +++ b/drivers/virt/gunyah/gunyah_ioeventfd.c @@ -0,0 +1,130 @@ +// 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 + +struct gh_ioeventfd { + struct gh_vm_function_instance *f; + struct gh_vm_io_handler io_handler; + + struct eventfd_ctx *ctx; +}; + +static int gh_write_ioeventfd(struct gh_vm_io_handler *io_dev, u64 addr, u32 len, u64 data) +{ + struct gh_ioeventfd *iofd = container_of(io_dev, struct gh_ioeventfd, io_handler); + + eventfd_signal(iofd->ctx, 1); + return 0; +} + +static struct gh_vm_io_handler_ops io_ops = { + .write = gh_write_ioeventfd, +}; + +static long gh_ioeventfd_bind(struct gh_vm_function_instance *f) +{ + const struct gh_fn_ioeventfd_arg *args = f->argp; + struct gh_ioeventfd *iofd; + struct eventfd_ctx *ctx; + int ret; + + if (f->arg_size != sizeof(*args)) + return -EINVAL; + + /* All other flag bits are reserved for future use */ + if (args->flags & ~GH_IOEVENTFD_FLAGS_DATAMATCH) + return -EINVAL; + + /* must be natural-word sized, or 0 to ignore length */ + switch (args->len) { + case 0: + case 1: + case 2: + case 4: + case 8: + break; + default: + return -EINVAL; + } + + /* check for range overflow */ + if (overflows_type(args->addr + args->len, u64)) + return -EINVAL; + + /* ioeventfd with no length can't be combined with DATAMATCH */ + if (!args->len && (args->flags & GH_IOEVENTFD_FLAGS_DATAMATCH)) + return -EINVAL; + + ctx = eventfd_ctx_fdget(args->fd); + if (IS_ERR(ctx)) + return PTR_ERR(ctx); + + iofd = kzalloc(sizeof(*iofd), GFP_KERNEL); + if (!iofd) { + ret = -ENOMEM; + goto err_eventfd; + } + + f->data = iofd; + iofd->f = f; + + iofd->ctx = ctx; + + if (args->flags & GH_IOEVENTFD_FLAGS_DATAMATCH) { + iofd->io_handler.datamatch = true; + iofd->io_handler.len = args->len; + iofd->io_handler.data = args->datamatch; + } + iofd->io_handler.addr = args->addr; + iofd->io_handler.ops = &io_ops; + + ret = gh_vm_add_io_handler(f->ghvm, &iofd->io_handler); + if (ret) + goto err_io_dev_add; + + return 0; + +err_io_dev_add: + kfree(iofd); +err_eventfd: + eventfd_ctx_put(ctx); + return ret; +} + +static void gh_ioevent_unbind(struct gh_vm_function_instance *f) +{ + struct gh_ioeventfd *iofd = f->data; + + eventfd_ctx_put(iofd->ctx); + gh_vm_remove_io_handler(iofd->f->ghvm, &iofd->io_handler); + kfree(iofd); +} + +static bool gh_ioevent_compare(const struct gh_vm_function_instance *f, + const void *arg, size_t size) +{ + const struct gh_fn_ioeventfd_arg *instance = f->argp, + *other = arg; + + if (sizeof(*other) != size) + return false; + + return instance->addr == other->addr; +} + +DECLARE_GH_VM_FUNCTION_INIT(ioeventfd, GH_FN_IOEVENTFD, 3, + gh_ioeventfd_bind, gh_ioevent_unbind, + gh_ioevent_compare); +MODULE_DESCRIPTION("Gunyah ioeventfd VM Function"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index 0c480c622686a..fa1cae7419d2b 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -79,10 +79,13 @@ struct gh_vm_dtb_config { * 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 + * @GH_FN_IOEVENTFD: register ioeventfd to trigger when VM faults on parameter + * &struct gh_fn_desc.arg is a pointer to &struct gh_fn_ioeventfd_arg */ enum gh_fn_type { GH_FN_VCPU = 1, GH_FN_IRQFD, + GH_FN_IOEVENTFD, }; #define GH_FN_MAX_ARG_SIZE 256 @@ -134,6 +137,40 @@ struct gh_fn_irqfd_arg { __u32 padding; }; +/** + * enum gh_ioeventfd_flags - flags for use in gh_fn_ioeventfd_arg + * @GH_IOEVENTFD_FLAGS_DATAMATCH: the event will be signaled only if the + * written value to the registered address is + * equal to &struct gh_fn_ioeventfd_arg.datamatch + */ +enum gh_ioeventfd_flags { + GH_IOEVENTFD_FLAGS_DATAMATCH = 1UL << 0, +}; + +/** + * struct gh_fn_ioeventfd_arg - Arguments to create an ioeventfd function + * @datamatch: data used when GH_IOEVENTFD_DATAMATCH is set + * @addr: Address in guest memory + * @len: Length of access + * @fd: When ioeventfd is matched, this eventfd is written + * @flags: See &enum gh_ioeventfd_flags + * @padding: padding bytes + * + * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_IOEVENTFD. + * + * Attaches an ioeventfd to a legal mmio address within the guest. A guest write + * in the registered address will signal the provided event instead of triggering + * an exit on the GH_VCPU_RUN ioctl. + */ +struct gh_fn_ioeventfd_arg { + __u64 datamatch; + __u64 addr; /* legal mmio address */ + __u32 len; /* 1, 2, 4, or 8 bytes; or 0 to ignore length */ + __s32 fd; + __u32 flags; + __u32 padding; +}; + /** * struct gh_fn_desc - Arguments to create a VM function * @type: Type of the function. See &enum gh_fn_type.