From patchwork Tue May 9 20:47:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 680303 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 12FE4C7EE2D for ; Tue, 9 May 2023 20:52:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235697AbjEIUwi (ORCPT ); Tue, 9 May 2023 16:52:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41248 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235319AbjEIUwK (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 157E77DAA; Tue, 9 May 2023 13:50:54 -0700 (PDT) Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 349KQao1000793; Tue, 9 May 2023 20:49:24 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=+b1Y4WibloG5vYjimbzGUNGeijsLea3VAcsuk4uFzcg=; b=fvaVbw8ZFofMQcPtoq1MF5ZV8ltTW75JtaTfbls4dtmGrsSyrfcZ6IWVCt1kFPehSpvH PfPHHXnW/XUVKgFmr8WAt69X9nPL3OBn8+blFASsOx5bg5/rTh00APofz3DKkqAilxcs Ms333tWxtaMYbGcua+NZm9fr7YUSq8fKCZCRtjC+U0HS1xKe/Rqhom/+Fd06d7saDsiK 2suwsmowr5TlAO1hnVa+2H+z6FNj5fbhYu9YveT6COhVfJc/fIbwFtsOn2vPIGA4iOEO 4qWc1ze38+P9Em0sNgGb1RJW2fSiffLbR2yNEbIj4c3VEWTxA0egO+CE16a42mg8vAJE OA== Received: from nasanppmta05.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3qf77ktu41-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 May 2023 20:49:24 +0000 Received: from nasanex01b.na.qualcomm.com (nasanex01b.na.qualcomm.com [10.46.141.250]) by NASANPPMTA05.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 349KnNiv003600 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 9 May 2023 20:49:23 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 13:49:22 -0700 From: Elliot Berman To: Alex Elder , Srinivas Kandagatla , Elliot Berman , Prakruthi Deepak Heragu , Jonathan Corbet , Catalin Marinas , Will Deacon 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 , Andy Gross , Jassi Brar , , , , , Subject: [PATCH v13 20/24] virt: gunyah: Add proxy-scheduled vCPUs Date: Tue, 9 May 2023 13:47:57 -0700 Message-ID: <20230509204801.2824351-21-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-GUID: s2Vo9njjaqDprpRu9nlNzcFUw4PxE1b2 X-Proofpoint-ORIG-GUID: s2Vo9njjaqDprpRu9nlNzcFUw4PxE1b2 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 mlxscore=0 malwarescore=0 suspectscore=0 adultscore=0 mlxlogscore=999 lowpriorityscore=0 phishscore=0 impostorscore=0 spamscore=0 clxscore=1015 bulkscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2304280000 definitions=main-2305090171 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Gunyah allows host virtual machines to schedule guest virtual machines and handle their MMIO accesses. vCPUs are presented to the host as a Gunyah resource and represented to userspace as a Gunyah VM function. Creating the vcpu VM function will create a file descriptor that: - can run an ioctl: GH_VCPU_RUN to schedule the guest vCPU until the next interrupt occurs on the host or when the guest vCPU can no longer be run. - can be mmap'd to share a gh_vcpu_run structure which can look up the reason why GH_VCPU_RUN returned and provide return values for MMIO access. 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 | 46 ++- arch/arm64/gunyah/gunyah_hypercall.c | 28 ++ drivers/virt/gunyah/Kconfig | 11 + drivers/virt/gunyah/Makefile | 2 + drivers/virt/gunyah/gunyah_vcpu.c | 468 +++++++++++++++++++++++ drivers/virt/gunyah/vm_mgr.c | 4 + drivers/virt/gunyah/vm_mgr.h | 1 + include/linux/gunyah.h | 24 ++ include/uapi/linux/gunyah.h | 128 +++++++ 9 files changed, 710 insertions(+), 2 deletions(-) create mode 100644 drivers/virt/gunyah/gunyah_vcpu.c diff --git a/Documentation/virt/gunyah/vm-manager.rst b/Documentation/virt/gunyah/vm-manager.rst index 3b51bab9d793..6789d13fed14 100644 --- a/Documentation/virt/gunyah/vm-manager.rst +++ b/Documentation/virt/gunyah/vm-manager.rst @@ -5,8 +5,7 @@ Virtual Machine Manager ======================= The Gunyah Virtual Machine Manager is a Linux driver to support launching -virtual machines using Gunyah. It presently supports launching non-proxy -scheduled Linux-like virtual machines. +virtual machines using Gunyah. Except for some basic information about the location of initial binaries, most of the configuration about a Gunyah virtual machine is described in the @@ -98,3 +97,46 @@ GH_VM_START ~~~~~~~~~~~ This ioctl starts the VM. + +GH_VM_ADD_FUNCTION +~~~~~~~~~~~~~~~~~~ + +This ioctl registers a Gunyah VM function with the VM manager. The VM function +is described with a &struct gh_fn_desc.type and some arguments for that type. +Typically, the function is added before the VM starts, but the function doesn't +"operate" until the VM starts with `GH_VM_START`_. For example, vCPU ioclts will +all return an error until the VM starts because the vCPUs don't exist until the +VM is started. This allows the VMM to set up all the kernel functions needed for +the VM *before* the VM starts. + +.. kernel-doc:: include/uapi/linux/gunyah.h + :identifiers: gh_fn_desc gh_fn_type + +The argument types are documented below: + +.. kernel-doc:: include/uapi/linux/gunyah.h + :identifiers: gh_fn_vcpu_arg + +Gunyah VCPU API Descriptions +---------------------------- + +A vCPU file descriptor is created after calling `GH_VM_ADD_FUNCTION` with the type `GH_FN_VCPU`. + +GH_VCPU_RUN +~~~~~~~~~~~ + +This ioctl is used to run a guest virtual cpu. While there are no +explicit parameters, there is an implicit parameter block that can be +obtained by mmap()ing the vcpu fd at offset 0, with the size given by +`GH_VCPU_MMAP_SIZE`_. The parameter block is formatted as a 'struct +gh_vcpu_run' (see below). + +GH_VCPU_MMAP_SIZE +~~~~~~~~~~~~~~~~~ + +The `GH_VCPU_RUN`_ ioctl communicates with userspace via a shared +memory region. This ioctl returns the size of that region. See the +`GH_VCPU_RUN`_ documentation for details. + +.. kernel-doc:: include/uapi/linux/gunyah.h + :identifiers: gh_vcpu_exit gh_vcpu_run gh_vm_status gh_vm_exit_info diff --git a/arch/arm64/gunyah/gunyah_hypercall.c b/arch/arm64/gunyah/gunyah_hypercall.c index 2b2a63e9b9e5..5f33f53e05a9 100644 --- a/arch/arm64/gunyah/gunyah_hypercall.c +++ b/arch/arm64/gunyah/gunyah_hypercall.c @@ -35,6 +35,7 @@ EXPORT_SYMBOL_GPL(arch_is_gh_guest); #define GH_HYPERCALL_HYP_IDENTIFY GH_HYPERCALL(0x8000) #define GH_HYPERCALL_MSGQ_SEND GH_HYPERCALL(0x801B) #define GH_HYPERCALL_MSGQ_RECV GH_HYPERCALL(0x801C) +#define GH_HYPERCALL_VCPU_RUN GH_HYPERCALL(0x8065) /** * gh_hypercall_hyp_identify() - Returns build information and feature flags @@ -83,5 +84,32 @@ enum gh_error gh_hypercall_msgq_recv(u64 capid, void *buff, size_t size, size_t } EXPORT_SYMBOL_GPL(gh_hypercall_msgq_recv); +enum gh_error gh_hypercall_vcpu_run(u64 capid, u64 *resume_data, + struct gh_hypercall_vcpu_run_resp *resp) +{ + struct arm_smccc_1_2_regs args = { + .a0 = GH_HYPERCALL_VCPU_RUN, + .a1 = capid, + .a2 = resume_data[0], + .a3 = resume_data[1], + .a4 = resume_data[2], + /* C language says this will be implictly zero. Gunyah requires 0, so be explicit */ + .a5 = 0, + }; + struct arm_smccc_1_2_regs res; + + arm_smccc_1_2_hvc(&args, &res); + + if (res.a0 == GH_ERROR_OK) { + resp->sized_state = res.a1; + resp->state_data[0] = res.a2; + resp->state_data[1] = res.a3; + resp->state_data[2] = res.a4; + } + + return res.a0; +} +EXPORT_SYMBOL_GPL(gh_hypercall_vcpu_run); + MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("Gunyah Hypervisor Hypercalls"); diff --git a/drivers/virt/gunyah/Kconfig b/drivers/virt/gunyah/Kconfig index 0421b751aad4..0a58395f7d2c 100644 --- a/drivers/virt/gunyah/Kconfig +++ b/drivers/virt/gunyah/Kconfig @@ -28,3 +28,14 @@ config GUNYAH_QCOM_PLATFORM extra platform-specific support. Say Y/M here to use Gunyah on Qualcomm platforms. + +config GUNYAH_VCPU + tristate "Runnable Gunyah vCPUs" + depends on GUNYAH + help + Enable kernel support for host-scheduled vCPUs running under Gunyah. + When selecting this option, userspace virtual machine managers (VMM) + can schedule the guest VM's vCPUs instead of using Gunyah's scheduler. + VMMs can also handle stage 2 faults of the vCPUs. + + 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 2aa9ff038ed0..cc16b6c19db9 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -5,3 +5,5 @@ obj-$(CONFIG_GUNYAH_QCOM_PLATFORM) += gunyah_qcom.o gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o obj-$(CONFIG_GUNYAH) += gunyah.o + +obj-$(CONFIG_GUNYAH_VCPU) += gunyah_vcpu.o diff --git a/drivers/virt/gunyah/gunyah_vcpu.c b/drivers/virt/gunyah/gunyah_vcpu.c new file mode 100644 index 000000000000..4f0bbd58a205 --- /dev/null +++ b/drivers/virt/gunyah/gunyah_vcpu.c @@ -0,0 +1,468 @@ +// 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 +#include + +#include "vm_mgr.h" + +#include + +#define MAX_VCPU_NAME 20 /* gh-vcpu:u32_max+NUL */ + +struct gh_vcpu { + struct gh_vm_function_instance *f; + struct gh_resource *rsc; + struct mutex run_lock; + /* Track why vcpu_run left last time around. */ + enum { + GH_VCPU_UNKNOWN = 0, + GH_VCPU_READY, + GH_VCPU_MMIO_READ, + GH_VCPU_SYSTEM_DOWN, + } state; + u8 mmio_read_len; + struct gh_vcpu_run *vcpu_run; + struct completion ready; + struct gh_vm *ghvm; + + struct notifier_block nb; + struct gh_vm_resource_ticket ticket; + struct kref kref; +}; + +static void vcpu_release(struct kref *kref) +{ + struct gh_vcpu *vcpu = container_of(kref, struct gh_vcpu, kref); + + free_page((unsigned long)vcpu->vcpu_run); + kfree(vcpu); +} + +/* + * When hypervisor allows us to schedule vCPU again, it gives us an interrupt + */ +static irqreturn_t gh_vcpu_irq_handler(int irq, void *data) +{ + struct gh_vcpu *vcpu = data; + + complete(&vcpu->ready); + return IRQ_HANDLED; +} + +static bool gh_handle_mmio(struct gh_vcpu *vcpu, + struct gh_hypercall_vcpu_run_resp *vcpu_run_resp) +{ + int ret = 0; + u64 addr = vcpu_run_resp->state_data[0], + len = vcpu_run_resp->state_data[1], + data = vcpu_run_resp->state_data[2]; + + if (WARN_ON(len > sizeof(u64))) + len = sizeof(u64); + + if (vcpu_run_resp->state == GH_VCPU_ADDRSPACE_VMMIO_READ) { + vcpu->vcpu_run->mmio.is_write = 0; + /* Record that we need to give vCPU user's supplied value next gh_vcpu_run() */ + vcpu->state = GH_VCPU_MMIO_READ; + vcpu->mmio_read_len = len; + } else { /* GH_VCPU_ADDRSPACE_VMMIO_WRITE */ + /* Try internal handlers first */ + ret = gh_vm_mmio_write(vcpu->f->ghvm, addr, len, data); + if (!ret) + return true; + + /* Give userspace the info */ + vcpu->vcpu_run->mmio.is_write = 1; + memcpy(vcpu->vcpu_run->mmio.data, &data, len); + } + + vcpu->vcpu_run->mmio.phys_addr = addr; + vcpu->vcpu_run->mmio.len = len; + vcpu->vcpu_run->exit_reason = GH_VCPU_EXIT_MMIO; + + return false; +} + +static int gh_vcpu_rm_notification(struct notifier_block *nb, unsigned long action, void *data) +{ + struct gh_vcpu *vcpu = container_of(nb, struct gh_vcpu, nb); + struct gh_rm_vm_exited_payload *exit_payload = data; + + if (action == GH_RM_NOTIFICATION_VM_EXITED && + le16_to_cpu(exit_payload->vmid) == vcpu->ghvm->vmid) + complete(&vcpu->ready); + + return NOTIFY_OK; +} + +static inline enum gh_vm_status remap_vm_status(enum gh_rm_vm_status rm_status) +{ + switch (rm_status) { + case GH_RM_VM_STATUS_INIT_FAILED: + return GH_VM_STATUS_LOAD_FAILED; + case GH_RM_VM_STATUS_EXITED: + return GH_VM_STATUS_EXITED; + default: + return GH_VM_STATUS_CRASHED; + } +} + +/** + * gh_vcpu_check_system() - Check whether VM as a whole is running + * @vcpu: Pointer to gh_vcpu + * + * Returns true if the VM is alive. + * Returns false if the vCPU is the VM is not alive (can only be that VM is shutting down). + */ +static bool gh_vcpu_check_system(struct gh_vcpu *vcpu) + __must_hold(&vcpu->run_lock) +{ + bool ret = true; + + down_read(&vcpu->ghvm->status_lock); + if (likely(vcpu->ghvm->vm_status == GH_RM_VM_STATUS_RUNNING)) + goto out; + + vcpu->vcpu_run->status.status = remap_vm_status(vcpu->ghvm->vm_status); + vcpu->vcpu_run->status.exit_info = vcpu->ghvm->exit_info; + vcpu->vcpu_run->exit_reason = GH_VCPU_EXIT_STATUS; + vcpu->state = GH_VCPU_SYSTEM_DOWN; + ret = false; +out: + up_read(&vcpu->ghvm->status_lock); + return ret; +} + +/** + * gh_vcpu_run() - Request Gunyah to begin scheduling this vCPU. + * @vcpu: The client descriptor that was obtained via gh_vcpu_alloc() + */ +static int gh_vcpu_run(struct gh_vcpu *vcpu) +{ + struct gh_hypercall_vcpu_run_resp vcpu_run_resp; + u64 state_data[3] = { 0 }; + enum gh_error gh_error; + int ret = 0; + + if (!vcpu->f) + return -ENODEV; + + if (mutex_lock_interruptible(&vcpu->run_lock)) + return -ERESTARTSYS; + + if (!vcpu->rsc) { + ret = -ENODEV; + goto out; + } + + switch (vcpu->state) { + case GH_VCPU_UNKNOWN: + if (vcpu->ghvm->vm_status != GH_RM_VM_STATUS_RUNNING) { + /* Check if VM is up. If VM is starting, will block until VM is fully up + * since that thread does down_write. + */ + if (!gh_vcpu_check_system(vcpu)) + goto out; + } + vcpu->state = GH_VCPU_READY; + break; + case GH_VCPU_MMIO_READ: + if (unlikely(vcpu->mmio_read_len > sizeof(state_data[0]))) + vcpu->mmio_read_len = sizeof(state_data[0]); + memcpy(&state_data[0], vcpu->vcpu_run->mmio.data, vcpu->mmio_read_len); + vcpu->state = GH_VCPU_READY; + break; + case GH_VCPU_SYSTEM_DOWN: + goto out; + default: + break; + } + + while (!ret && !signal_pending(current)) { + if (vcpu->vcpu_run->immediate_exit) { + ret = -EINTR; + goto out; + } + + gh_error = gh_hypercall_vcpu_run(vcpu->rsc->capid, state_data, &vcpu_run_resp); + if (gh_error == GH_ERROR_OK) { + switch (vcpu_run_resp.state) { + case GH_VCPU_STATE_READY: + if (need_resched()) + schedule(); + break; + case GH_VCPU_STATE_POWERED_OFF: + /* vcpu might be off because the VM is shut down. + * If so, it won't ever run again: exit back to user + */ + if (!gh_vcpu_check_system(vcpu)) + goto out; + /* Otherwise, another vcpu will turn it on (e.g. by PSCI) + * and hyp sends an interrupt to wake Linux up. + */ + fallthrough; + case GH_VCPU_STATE_EXPECTS_WAKEUP: + ret = wait_for_completion_interruptible(&vcpu->ready); + /* reinitialize completion before next hypercall. If we reinitialize + * after the hypercall, interrupt may have already come before + * re-initializing the completion and then end up waiting for + * event that already happened. + */ + reinit_completion(&vcpu->ready); + /* Check system status again. Completion might've + * come from gh_vcpu_rm_notification + */ + if (!ret && !gh_vcpu_check_system(vcpu)) + goto out; + break; + case GH_VCPU_STATE_BLOCKED: + schedule(); + break; + case GH_VCPU_ADDRSPACE_VMMIO_READ: + case GH_VCPU_ADDRSPACE_VMMIO_WRITE: + if (!gh_handle_mmio(vcpu, &vcpu_run_resp)) + goto out; + break; + default: + pr_warn_ratelimited("Unknown vCPU state: %llx\n", + vcpu_run_resp.sized_state); + schedule(); + break; + } + } else if (gh_error == GH_ERROR_RETRY) { + schedule(); + } else { + ret = gh_error_remap(gh_error); + } + } + +out: + mutex_unlock(&vcpu->run_lock); + + if (signal_pending(current)) + return -ERESTARTSYS; + + return ret; +} + +static long gh_vcpu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) +{ + struct gh_vcpu *vcpu = filp->private_data; + long ret = -EINVAL; + + switch (cmd) { + case GH_VCPU_RUN: + ret = gh_vcpu_run(vcpu); + break; + case GH_VCPU_MMAP_SIZE: + ret = PAGE_SIZE; + break; + default: + break; + } + return ret; +} + +static int gh_vcpu_release(struct inode *inode, struct file *filp) +{ + struct gh_vcpu *vcpu = filp->private_data; + + gh_vm_put(vcpu->ghvm); + kref_put(&vcpu->kref, vcpu_release); + return 0; +} + +static vm_fault_t gh_vcpu_fault(struct vm_fault *vmf) +{ + struct gh_vcpu *vcpu = vmf->vma->vm_file->private_data; + struct page *page = NULL; + + if (vmf->pgoff == 0) + page = virt_to_page(vcpu->vcpu_run); + + get_page(page); + vmf->page = page; + return 0; +} + +static const struct vm_operations_struct gh_vcpu_ops = { + .fault = gh_vcpu_fault, +}; + +static int gh_vcpu_mmap(struct file *file, struct vm_area_struct *vma) +{ + vma->vm_ops = &gh_vcpu_ops; + return 0; +} + +static const struct file_operations gh_vcpu_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = gh_vcpu_ioctl, + .release = gh_vcpu_release, + .llseek = noop_llseek, + .mmap = gh_vcpu_mmap, +}; + +static bool gh_vcpu_populate(struct gh_vm_resource_ticket *ticket, struct gh_resource *ghrsc) +{ + struct gh_vcpu *vcpu = container_of(ticket, struct gh_vcpu, ticket); + int ret; + + mutex_lock(&vcpu->run_lock); + if (vcpu->rsc) { + pr_warn("vcpu%d already got a Gunyah resource. Check if multiple resources with same label were configured.\n", + vcpu->ticket.label); + ret = -EEXIST; + goto out; + } + + vcpu->rsc = ghrsc; + init_completion(&vcpu->ready); + + ret = request_irq(vcpu->rsc->irq, gh_vcpu_irq_handler, IRQF_TRIGGER_RISING, "gh_vcpu", + vcpu); + if (ret) + pr_warn("Failed to request vcpu irq %d: %d", vcpu->rsc->irq, ret); + +out: + mutex_unlock(&vcpu->run_lock); + return !ret; +} + +static void gh_vcpu_unpopulate(struct gh_vm_resource_ticket *ticket, + struct gh_resource *ghrsc) +{ + struct gh_vcpu *vcpu = container_of(ticket, struct gh_vcpu, ticket); + + vcpu->vcpu_run->immediate_exit = true; + complete_all(&vcpu->ready); + mutex_lock(&vcpu->run_lock); + free_irq(vcpu->rsc->irq, vcpu); + vcpu->rsc = NULL; + mutex_unlock(&vcpu->run_lock); +} + +static long gh_vcpu_bind(struct gh_vm_function_instance *f) +{ + struct gh_fn_vcpu_arg *arg = f->argp; + struct gh_vcpu *vcpu; + char name[MAX_VCPU_NAME]; + struct file *file; + struct page *page; + int fd; + long r; + + if (f->arg_size != sizeof(*arg)) + return -EINVAL; + + vcpu = kzalloc(sizeof(*vcpu), GFP_KERNEL); + if (!vcpu) + return -ENOMEM; + + vcpu->f = f; + f->data = vcpu; + mutex_init(&vcpu->run_lock); + kref_init(&vcpu->kref); + + page = alloc_page(GFP_KERNEL | __GFP_ZERO); + if (!page) { + r = -ENOMEM; + goto err_destroy_vcpu; + } + vcpu->vcpu_run = page_address(page); + + vcpu->ticket.resource_type = GH_RESOURCE_TYPE_VCPU; + vcpu->ticket.label = arg->id; + vcpu->ticket.owner = THIS_MODULE; + vcpu->ticket.populate = gh_vcpu_populate; + vcpu->ticket.unpopulate = gh_vcpu_unpopulate; + + r = gh_vm_add_resource_ticket(f->ghvm, &vcpu->ticket); + if (r) + goto err_destroy_page; + + if (!gh_vm_get(f->ghvm)) { + r = -ENODEV; + goto err_remove_resource_ticket; + } + vcpu->ghvm = f->ghvm; + + vcpu->nb.notifier_call = gh_vcpu_rm_notification; + /* Ensure we run after the vm_mgr handles the notification and does + * any necessary state changes. We wake up to check the new state. + */ + vcpu->nb.priority = -1; + r = gh_rm_notifier_register(f->rm, &vcpu->nb); + if (r) + goto err_put_gh_vm; + + kref_get(&vcpu->kref); + + fd = get_unused_fd_flags(O_CLOEXEC); + if (fd < 0) { + r = fd; + goto err_notifier; + } + + snprintf(name, sizeof(name), "gh-vcpu:%u", vcpu->ticket.label); + file = anon_inode_getfile(name, &gh_vcpu_fops, vcpu, O_RDWR); + if (IS_ERR(file)) { + r = PTR_ERR(file); + goto err_put_fd; + } + + fd_install(fd, file); + + return fd; +err_put_fd: + put_unused_fd(fd); +err_notifier: + gh_rm_notifier_unregister(f->rm, &vcpu->nb); +err_put_gh_vm: + gh_vm_put(vcpu->ghvm); +err_remove_resource_ticket: + gh_vm_remove_resource_ticket(f->ghvm, &vcpu->ticket); +err_destroy_page: + free_page((unsigned long)vcpu->vcpu_run); +err_destroy_vcpu: + kfree(vcpu); + return r; +} + +static void gh_vcpu_unbind(struct gh_vm_function_instance *f) +{ + struct gh_vcpu *vcpu = f->data; + + gh_rm_notifier_unregister(f->rm, &vcpu->nb); + gh_vm_remove_resource_ticket(vcpu->f->ghvm, &vcpu->ticket); + vcpu->f = NULL; + + kref_put(&vcpu->kref, vcpu_release); +} + +static bool gh_vcpu_compare(const struct gh_vm_function_instance *f, + const void *arg, size_t size) +{ + const struct gh_fn_vcpu_arg *instance = f->argp, + *other = arg; + + if (sizeof(*other) != size) + return false; + + return instance->id == other->id; +} + +DECLARE_GH_VM_FUNCTION_INIT(vcpu, GH_FN_VCPU, 1, gh_vcpu_bind, gh_vcpu_unbind, gh_vcpu_compare); +MODULE_DESCRIPTION("Gunyah vCPU Function"); +MODULE_LICENSE("GPL"); diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c index 81b42ab675f6..e7844204c151 100644 --- a/drivers/virt/gunyah/vm_mgr.c +++ b/drivers/virt/gunyah/vm_mgr.c @@ -408,6 +408,10 @@ static int gh_vm_rm_notification_exited(struct gh_vm *ghvm, void *data) down_write(&ghvm->status_lock); ghvm->vm_status = GH_RM_VM_STATUS_EXITED; + ghvm->exit_info.type = le16_to_cpu(payload->exit_type); + ghvm->exit_info.reason_size = le32_to_cpu(payload->exit_reason_size); + memcpy(&ghvm->exit_info.reason, payload->exit_reason, + min(GH_VM_MAX_EXIT_REASON_SIZE, ghvm->exit_info.reason_size)); up_write(&ghvm->status_lock); wake_up(&ghvm->vm_status_wait); diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h index 3fc0f91dfd1a..fa2a61e10b57 100644 --- a/drivers/virt/gunyah/vm_mgr.h +++ b/drivers/virt/gunyah/vm_mgr.h @@ -45,6 +45,7 @@ struct gh_vm { enum gh_rm_vm_status vm_status; wait_queue_head_t vm_status_wait; struct rw_semaphore status_lock; + struct gh_vm_exit_info exit_info; struct work_struct free_work; struct kref kref; diff --git a/include/linux/gunyah.h b/include/linux/gunyah.h index 4b398b59c2c5..cd5704a82c6a 100644 --- a/include/linux/gunyah.h +++ b/include/linux/gunyah.h @@ -177,4 +177,28 @@ enum gh_error gh_hypercall_msgq_send(u64 capid, size_t size, void *buff, u64 tx_ enum gh_error gh_hypercall_msgq_recv(u64 capid, void *buff, size_t size, size_t *recv_size, bool *ready); +struct gh_hypercall_vcpu_run_resp { + union { + enum { + /* VCPU is ready to run */ + GH_VCPU_STATE_READY = 0, + /* VCPU is sleeping until an interrupt arrives */ + GH_VCPU_STATE_EXPECTS_WAKEUP = 1, + /* VCPU is powered off */ + GH_VCPU_STATE_POWERED_OFF = 2, + /* VCPU is blocked in EL2 for unspecified reason */ + GH_VCPU_STATE_BLOCKED = 3, + /* VCPU has returned for MMIO READ */ + GH_VCPU_ADDRSPACE_VMMIO_READ = 4, + /* VCPU has returned for MMIO WRITE */ + GH_VCPU_ADDRSPACE_VMMIO_WRITE = 5, + } state; + u64 sized_state; + }; + u64 state_data[3]; +}; + +enum gh_error gh_hypercall_vcpu_run(u64 capid, u64 *resume_data, + struct gh_hypercall_vcpu_run_resp *resp); + #endif diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index bb07118a351f..434ffa8ffc78 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -72,8 +72,33 @@ struct gh_vm_dtb_config { #define GH_VM_START _IO(GH_IOCTL_TYPE, 0x3) +/** + * enum gh_fn_type - Valid types of Gunyah VM functions + * @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. + */ +enum gh_fn_type { + GH_FN_VCPU = 1, +}; + #define GH_FN_MAX_ARG_SIZE 256 +/** + * struct gh_fn_vcpu_arg - Arguments to create a vCPU. + * @id: vcpu id + * + * Create this function with &GH_VM_ADD_FUNCTION using type &GH_FN_VCPU. + * + * 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. + */ +struct gh_fn_vcpu_arg { + __u32 id; +}; + /** * struct gh_fn_desc - Arguments to create a VM function * @type: Type of the function. See &enum gh_fn_type. @@ -90,4 +115,107 @@ struct gh_fn_desc { #define GH_VM_ADD_FUNCTION _IOW(GH_IOCTL_TYPE, 0x4, struct gh_fn_desc) #define GH_VM_REMOVE_FUNCTION _IOW(GH_IOCTL_TYPE, 0x7, struct gh_fn_desc) +/* + * ioctls for vCPU fds + */ + +/** + * enum gh_vm_status - Stores status reason why VM is not runnable (exited). + * @GH_VM_STATUS_LOAD_FAILED: VM didn't start because it couldn't be loaded. + * @GH_VM_STATUS_EXITED: VM requested shutdown/reboot. + * Use &struct gh_vm_exit_info.reason for further details. + * @GH_VM_STATUS_CRASHED: VM state is unknown and has crashed. + */ +enum gh_vm_status { + GH_VM_STATUS_LOAD_FAILED = 1, + GH_VM_STATUS_EXITED = 2, + GH_VM_STATUS_CRASHED = 3, +}; + +/* + * Gunyah presently sends max 4 bytes of exit_reason. + * If that changes, this macro can be safely increased without breaking + * userspace so long as struct gh_vcpu_run < PAGE_SIZE. + */ +#define GH_VM_MAX_EXIT_REASON_SIZE 8u + +/** + * struct gh_vm_exit_info - Reason for VM exit as reported by Gunyah + * See Gunyah documentation for values. + * @type: Describes how VM exited + * @padding: padding bytes + * @reason_size: Number of bytes valid for `reason` + * @reason: See Gunyah documentation for interpretation. Note: these values are + * not interpreted by Linux and need to be converted from little-endian + * as applicable. + */ +struct gh_vm_exit_info { + __u16 type; + __u16 padding; + __u32 reason_size; + __u8 reason[GH_VM_MAX_EXIT_REASON_SIZE]; +}; + +/** + * enum gh_vcpu_exit - Stores reason why &GH_VCPU_RUN ioctl recently exited with status 0 + * @GH_VCPU_EXIT_UNKNOWN: Not used, status != 0 + * @GH_VCPU_EXIT_MMIO: vCPU performed a read or write that could not be handled + * by hypervisor or Linux. Use @struct gh_vcpu_run.mmio for + * details of the read/write. + * @GH_VCPU_EXIT_STATUS: vCPU not able to run because the VM has exited. + * Use @struct gh_vcpu_run.status for why VM has exited. + */ +enum gh_vcpu_exit { + GH_VCPU_EXIT_UNKNOWN, + GH_VCPU_EXIT_MMIO, + GH_VCPU_EXIT_STATUS, +}; + +/** + * struct gh_vcpu_run - Application code obtains a pointer to the gh_vcpu_run + * structure by mmap()ing a vcpu fd. + * @immediate_exit: polled when scheduling the vcpu. If set, immediately returns -EINTR. + * @padding: padding bytes + * @exit_reason: Set when GH_VCPU_RUN returns successfully and gives reason why + * GH_VCPU_RUN has stopped running the vCPU. See &enum gh_vcpu_exit. + * @mmio: Used when exit_reason == GH_VCPU_EXIT_MMIO + * The guest has faulted on an memory-mapped I/O instruction that + * couldn't be satisfied by gunyah. + * @mmio.phys_addr: Address guest tried to access + * @mmio.data: the value that was written if `is_write == 1`. Filled by + * user for reads (`is_write == 0`). + * @mmio.len: Length of write. Only the first `len` bytes of `data` + * are considered by Gunyah. + * @mmio.is_write: 1 if VM tried to perform a write, 0 for a read + * @status: Used when exit_reason == GH_VCPU_EXIT_STATUS. + * The guest VM is no longer runnable. This struct informs why. + * @status.status: See &enum gh_vm_status for possible values + * @status.exit_info: Used when status == GH_VM_STATUS_EXITED + */ +struct gh_vcpu_run { + /* in */ + __u8 immediate_exit; + __u8 padding[7]; + + /* out */ + __u32 exit_reason; + + union { + struct { + __u64 phys_addr; + __u8 data[8]; + __u32 len; + __u8 is_write; + } mmio; + + struct { + enum gh_vm_status status; + struct gh_vm_exit_info exit_info; + } status; + }; +}; + +#define GH_VCPU_RUN _IO(GH_IOCTL_TYPE, 0x5) +#define GH_VCPU_MMAP_SIZE _IO(GH_IOCTL_TYPE, 0x6) + #endif