From patchwork Tue Jan 9 19:37:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Elliot Berman X-Patchwork-Id: 761566 Received: from mx0a-0031df01.pphosted.com (mx0a-0031df01.pphosted.com [205.220.168.131]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE01340BE8; Tue, 9 Jan 2024 19:38:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=quicinc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=quicinc.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=quicinc.com header.i=@quicinc.com header.b="nmVGxi57" Received: from pps.filterd (m0279862.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.24/8.17.1.24) with ESMTP id 409Er235000860; Tue, 9 Jan 2024 19:38:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h= from:date:subject:mime-version:content-type :content-transfer-encoding:message-id:references:in-reply-to:to :cc; s=qcppdkim1; bh=4lM0JVVYQLJT2z4piUn0A5bpNItJWqp93hg1dTCIGUo =; b=nmVGxi57i6Hz66foressk7Npgy0RWtWPIaPisAkL9t17w7/hZ/vJT+AcTIC 1mjxklx7iNIVxWkpBhIe7lQd3+//5JCgPBzxXYe1/XLt+HAooHTISas1kSr9iGtQ sGadnSnck/CX4NjQJZiJq7mJEH64a694u27OFKPY1ZivckYGRtu7CrUWW6UMAdCJ ELHX2uisxiYcxtR0apbZps8XOIXBV92xUdk+L6JHBCG5pFmVIUgys9An3pB7StXN QdydKoX3wKHvpROUyzOWo6KGO35r6A8jl6GjTBB7a2b6Bp3kg0H44nLAoCgO5U5f G+4MK3vdKHbDifxiZbB+EJpeTRg== Received: from nasanppmta04.qualcomm.com (i-global254.qualcomm.com [199.106.103.254]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3vh3me1851-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 09 Jan 2024 19:38:00 +0000 (GMT) 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 409JbxFE030438 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 9 Jan 2024 19:37:59 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 15.2.1118.40; Tue, 9 Jan 2024 11:37:58 -0800 From: Elliot Berman Date: Tue, 9 Jan 2024 11:37:53 -0800 Subject: [PATCH v16 15/34] virt: gunyah: Add proxy-scheduled vCPUs Precedence: bulk X-Mailing-List: linux-arm-msm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <20240109-gunyah-v16-15-634904bf4ce9@quicinc.com> References: <20240109-gunyah-v16-0-634904bf4ce9@quicinc.com> In-Reply-To: <20240109-gunyah-v16-0-634904bf4ce9@quicinc.com> To: Alex Elder , Srinivas Kandagatla , Murali Nalajal , Trilok Soni , Srivatsa Vaddagiri , Carl van Schaik , Philip Derrin , Prakruthi Deepak Heragu , Jonathan Corbet , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Catalin Marinas , Will Deacon , Konrad Dybcio , Bjorn Andersson , Dmitry Baryshkov , "Fuad Tabba" , Sean Christopherson , "Andrew Morton" CC: , , , , , , Elliot Berman X-Mailer: b4 0.13-dev 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: PxJYOU8rDFxI7KkcDCs-veyaHo31uZCZ X-Proofpoint-GUID: PxJYOU8rDFxI7KkcDCs-veyaHo31uZCZ X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-09_01,2023-12-07_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 phishscore=0 spamscore=0 priorityscore=1501 mlxlogscore=999 lowpriorityscore=0 mlxscore=0 suspectscore=0 impostorscore=0 clxscore=1015 adultscore=0 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2311290000 definitions=main-2401090158 Gunyah allows vCPUs that are configured as proxy-scheduled to be scheduled by another virtual machine (host) that holds capabilities to those vCPUs with suitable rights. Gunyah also supports configuring regions of a proxy-scheduled VM's address space to be virtualized by the host VM. This permits a host VMM to emulate MMIO devices in the proxy-scheduled VM. vCPUs are presented to the host as a Gunyah resource and represented to userspace as a Gunyah VM function. Creating the vcpu function on the VM will create a file descriptor that: - can handle an ioctl to run the vCPU. When called, Gunyah will directly context-switch to the selected vCPU and run it until one of the following events occurs: * the host vcpu's time slice ends * the host vcpu receives an interrupt or would have been pre-empted by the hypervisor * a fault occurs in the proxy-scheduled vcpu * a power management event, such as idle or cpu-off call in the vcpu - can be mmap'd to share the gunyah_vcpu_run structure with userspace. This allows the vcpu_run result codes to be accessed, and for arguments to vcpu_run to be passed, e.g. for resuming the vcpu when handling certain fault and exit cases. Co-developed-by: Prakruthi Deepak Heragu Signed-off-by: Prakruthi Deepak Heragu Signed-off-by: Elliot Berman --- drivers/virt/gunyah/Makefile | 2 +- drivers/virt/gunyah/gunyah_vcpu.c | 557 ++++++++++++++++++++++++++++++++++++++ drivers/virt/gunyah/vm_mgr.c | 5 + drivers/virt/gunyah/vm_mgr.h | 2 + include/uapi/linux/gunyah.h | 163 +++++++++++ 5 files changed, 728 insertions(+), 1 deletion(-) diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile index 47f1fae5419b..3f82af8c5ce7 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -2,4 +2,4 @@ gunyah_rsc_mgr-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o -obj-$(CONFIG_GUNYAH) += gunyah.o gunyah_rsc_mgr.o +obj-$(CONFIG_GUNYAH) += gunyah.o gunyah_rsc_mgr.o 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..b636b54dc9a1 --- /dev/null +++ b/drivers/virt/gunyah/gunyah_vcpu.c @@ -0,0 +1,557 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2022-2024 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "vm_mgr.h" + +#include + +#define MAX_VCPU_NAME 20 /* gh-vcpu:strlen(U32::MAX)+NUL */ + +/** + * struct gunyah_vcpu - Track an instance of gunyah vCPU + * @f: Function instance (how we get associated with the main VM) + * @rsc: Pointer to the Gunyah vCPU resource, will be NULL until VM starts + * @run_lock: One userspace thread at a time should run the vCPU + * @ghvm: Pointer to the main VM struct; quicker look up than going through + * @f->ghvm + * @vcpu_run: Pointer to page shared with userspace to communicate vCPU state + * @state: Our copy of the state of the vCPU, since userspace could trick + * kernel to behave incorrectly if we relied on @vcpu_run + * @mmio_read_len: Our copy of @vcpu_run->mmio.len; see also @state + * @mmio_addr: Our copy of @vcpu_run->mmio.phys_addr; see also @state + * @ready: if vCPU goes to sleep, hypervisor reports to us that it's sleeping + * and will signal interrupt (from @rsc) when it's time to wake up. + * This completion signals that we can run vCPU again. + * @nb: When VM exits, the status of VM is reported via @vcpu_run->status. + * We need to track overall VM status, and the nb gives us the updates from + * Resource Manager. + * @ticket: resource ticket to claim vCPU# for the VM + * @kref: Reference counter + */ +struct gunyah_vcpu { + struct gunyah_vm_function_instance *f; + struct gunyah_resource *rsc; + struct mutex run_lock; + struct gunyah_vm *ghvm; + + struct gunyah_vcpu_run *vcpu_run; + + /** + * Track why the vcpu_run hypercall returned. This mirrors the vcpu_run + * structure shared with userspace, except is used internally to avoid + * trusting userspace to not modify the vcpu_run structure. + */ + enum { + GUNYAH_VCPU_RUN_STATE_UNKNOWN = 0, + GUNYAH_VCPU_RUN_STATE_READY, + GUNYAH_VCPU_RUN_STATE_MMIO_READ, + GUNYAH_VCPU_RUN_STATE_MMIO_WRITE, + GUNYAH_VCPU_RUN_STATE_SYSTEM_DOWN, + } state; + u8 mmio_read_len; + u64 mmio_addr; + + struct completion ready; + + struct notifier_block nb; + struct gunyah_vm_resource_ticket ticket; + struct kref kref; +}; + +static void vcpu_release(struct kref *kref) +{ + struct gunyah_vcpu *vcpu = container_of(kref, struct gunyah_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 gunyah_vcpu_irq_handler(int irq, void *data) +{ + struct gunyah_vcpu *vcpu = data; + + complete(&vcpu->ready); + return IRQ_HANDLED; +} + +static void gunyah_handle_page_fault( + struct gunyah_vcpu *vcpu, + const struct gunyah_hypercall_vcpu_run_resp *vcpu_run_resp) +{ + u64 addr = vcpu_run_resp->state_data[0]; + + vcpu->vcpu_run->page_fault.resume_action = GUNYAH_VCPU_RESUME_FAULT; + vcpu->vcpu_run->page_fault.attempt = 0; + vcpu->vcpu_run->page_fault.phys_addr = addr; + vcpu->vcpu_run->exit_reason = GUNYAH_VCPU_EXIT_PAGE_FAULT; +} + +static void +gunyah_handle_mmio(struct gunyah_vcpu *vcpu, + const struct gunyah_hypercall_vcpu_run_resp *vcpu_run_resp) +{ + 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 == GUNYAH_VCPU_ADDRSPACE_VMMIO_READ) { + vcpu->vcpu_run->mmio.is_write = 0; + /* Record that we need to give vCPU user's supplied value next gunyah_vcpu_run() */ + vcpu->state = GUNYAH_VCPU_RUN_STATE_MMIO_READ; + vcpu->mmio_read_len = len; + } else { /* GUNYAH_VCPU_ADDRSPACE_VMMIO_WRITE */ + vcpu->vcpu_run->mmio.is_write = 1; + memcpy(vcpu->vcpu_run->mmio.data, &data, len); + vcpu->state = GUNYAH_VCPU_RUN_STATE_MMIO_WRITE; + } + + vcpu->vcpu_run->mmio.resume_action = 0; + vcpu->mmio_addr = vcpu->vcpu_run->mmio.phys_addr = addr; + vcpu->vcpu_run->mmio.len = len; + vcpu->vcpu_run->exit_reason = GUNYAH_VCPU_EXIT_MMIO; +} + +static int gunyah_handle_mmio_resume(struct gunyah_vcpu *vcpu, + unsigned long resume_data[3]) +{ + switch (vcpu->vcpu_run->mmio.resume_action) { + case GUNYAH_VCPU_RESUME_HANDLED: + if (vcpu->state == GUNYAH_VCPU_RUN_STATE_MMIO_READ) { + if (unlikely(vcpu->mmio_read_len > + sizeof(resume_data[0]))) + vcpu->mmio_read_len = sizeof(resume_data[0]); + memcpy(&resume_data[0], vcpu->vcpu_run->mmio.data, + vcpu->mmio_read_len); + } + resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_EMULATE; + break; + case GUNYAH_VCPU_RESUME_FAULT: + resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_FAULT; + break; + case GUNYAH_VCPU_RESUME_RETRY: + resume_data[1] = GUNYAH_ADDRSPACE_VMMIO_ACTION_RETRY; + break; + default: + return -EINVAL; + } + + return 0; +} + +static int gunyah_vcpu_rm_notification(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct gunyah_vcpu *vcpu = container_of(nb, struct gunyah_vcpu, nb); + struct gunyah_rm_vm_exited_payload *exit_payload = data; + + /* Wake up userspace waiting for the vCPU to be runnable again */ + if (action == GUNYAH_RM_NOTIFICATION_VM_EXITED && + le16_to_cpu(exit_payload->vmid) == vcpu->ghvm->vmid) + complete(&vcpu->ready); + + return NOTIFY_OK; +} + +static inline enum gunyah_vm_status +remap_vm_status(enum gunyah_rm_vm_status rm_status) +{ + switch (rm_status) { + case GUNYAH_RM_VM_STATUS_INIT_FAILED: + return GUNYAH_VM_STATUS_LOAD_FAILED; + case GUNYAH_RM_VM_STATUS_EXITED: + return GUNYAH_VM_STATUS_EXITED; + default: + return GUNYAH_VM_STATUS_CRASHED; + } +} + +/** + * gunyah_vcpu_check_system() - Check whether VM as a whole is running + * @vcpu: Pointer to gunyah_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 gunyah_vcpu_check_system(struct gunyah_vcpu *vcpu) + __must_hold(&vcpu->run_lock) +{ + bool ret = true; + + down_read(&vcpu->ghvm->status_lock); + if (likely(vcpu->ghvm->vm_status == GUNYAH_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 = GUNYAH_VCPU_EXIT_STATUS; + vcpu->state = GUNYAH_VCPU_RUN_STATE_SYSTEM_DOWN; + ret = false; +out: + up_read(&vcpu->ghvm->status_lock); + return ret; +} + +/** + * gunyah_vcpu_run() - Request Gunyah to begin scheduling this vCPU. + * @vcpu: The client descriptor that was obtained via gunyah_vcpu_alloc() + */ +static int gunyah_vcpu_run(struct gunyah_vcpu *vcpu) +{ + struct gunyah_hypercall_vcpu_run_resp vcpu_run_resp; + unsigned long resume_data[3] = { 0 }; + enum gunyah_error gunyah_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 GUNYAH_VCPU_RUN_STATE_UNKNOWN: + if (vcpu->ghvm->vm_status != GUNYAH_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 (!gunyah_vcpu_check_system(vcpu)) + goto out; + } + vcpu->state = GUNYAH_VCPU_RUN_STATE_READY; + break; + case GUNYAH_VCPU_RUN_STATE_MMIO_READ: + case GUNYAH_VCPU_RUN_STATE_MMIO_WRITE: + ret = gunyah_handle_mmio_resume(vcpu, resume_data); + if (ret) + goto out; + vcpu->state = GUNYAH_VCPU_RUN_STATE_READY; + break; + case GUNYAH_VCPU_RUN_STATE_SYSTEM_DOWN: + goto out; + default: + break; + } + + while (!ret && !signal_pending(current)) { + if (vcpu->vcpu_run->immediate_exit) { + ret = -EINTR; + goto out; + } + + gunyah_error = gunyah_hypercall_vcpu_run( + vcpu->rsc->capid, resume_data, &vcpu_run_resp); + if (gunyah_error == GUNYAH_ERROR_OK) { + memset(resume_data, 0, sizeof(resume_data)); + switch (vcpu_run_resp.state) { + case GUNYAH_VCPU_STATE_READY: + if (need_resched()) + schedule(); + break; + case GUNYAH_VCPU_STATE_POWERED_OFF: + /** + * vcpu might be off because the VM is shut down + * If so, it won't ever run again + */ + if (!gunyah_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 GUNYAH_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 VM status again. Completion + * might've come from VM exiting + */ + if (!ret && !gunyah_vcpu_check_system(vcpu)) + goto out; + break; + case GUNYAH_VCPU_STATE_BLOCKED: + schedule(); + break; + case GUNYAH_VCPU_ADDRSPACE_VMMIO_READ: + case GUNYAH_VCPU_ADDRSPACE_VMMIO_WRITE: + gunyah_handle_mmio(vcpu, &vcpu_run_resp); + goto out; + case GUNYAH_VCPU_ADDRSPACE_PAGE_FAULT: + gunyah_handle_page_fault(vcpu, &vcpu_run_resp); + goto out; + default: + pr_warn_ratelimited( + "Unknown vCPU state: %llx\n", + vcpu_run_resp.sized_state); + schedule(); + break; + } + } else if (gunyah_error == GUNYAH_ERROR_RETRY) { + schedule(); + } else { + ret = gunyah_error_remap(gunyah_error); + } + } + +out: + mutex_unlock(&vcpu->run_lock); + + if (signal_pending(current)) + return -ERESTARTSYS; + + return ret; +} + +static long gunyah_vcpu_ioctl(struct file *filp, unsigned int cmd, + unsigned long arg) +{ + struct gunyah_vcpu *vcpu = filp->private_data; + long ret = -ENOTTY; + + switch (cmd) { + case GUNYAH_VCPU_RUN: + ret = gunyah_vcpu_run(vcpu); + break; + case GUNYAH_VCPU_MMAP_SIZE: + ret = PAGE_SIZE; + break; + default: + break; + } + return ret; +} + +static int gunyah_vcpu_release(struct inode *inode, struct file *filp) +{ + struct gunyah_vcpu *vcpu = filp->private_data; + + gunyah_vm_put(vcpu->ghvm); + kref_put(&vcpu->kref, vcpu_release); + return 0; +} + +static vm_fault_t gunyah_vcpu_fault(struct vm_fault *vmf) +{ + struct gunyah_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 gunyah_vcpu_ops = { + .fault = gunyah_vcpu_fault, +}; + +static int gunyah_vcpu_mmap(struct file *file, struct vm_area_struct *vma) +{ + vma->vm_ops = &gunyah_vcpu_ops; + return 0; +} + +static const struct file_operations gunyah_vcpu_fops = { + .owner = THIS_MODULE, + .unlocked_ioctl = gunyah_vcpu_ioctl, + .release = gunyah_vcpu_release, + .llseek = noop_llseek, + .mmap = gunyah_vcpu_mmap, +}; + +static bool gunyah_vcpu_populate(struct gunyah_vm_resource_ticket *ticket, + struct gunyah_resource *ghrsc) +{ + struct gunyah_vcpu *vcpu = + container_of(ticket, struct gunyah_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, gunyah_vcpu_irq_handler, + IRQF_TRIGGER_RISING, "gunyah_vcpu", vcpu); + if (ret) + pr_warn("Failed to request vcpu irq %d: %d", vcpu->rsc->irq, + ret); + + enable_irq_wake(vcpu->rsc->irq); + +out: + mutex_unlock(&vcpu->run_lock); + return !ret; +} + +static void gunyah_vcpu_unpopulate(struct gunyah_vm_resource_ticket *ticket, + struct gunyah_resource *ghrsc) +{ + struct gunyah_vcpu *vcpu = + container_of(ticket, struct gunyah_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 gunyah_vcpu_bind(struct gunyah_vm_function_instance *f) +{ + struct gunyah_fn_vcpu_arg *arg = f->argp; + struct gunyah_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 = GUNYAH_RESOURCE_TYPE_VCPU; + vcpu->ticket.label = arg->id; + vcpu->ticket.owner = THIS_MODULE; + vcpu->ticket.populate = gunyah_vcpu_populate; + vcpu->ticket.unpopulate = gunyah_vcpu_unpopulate; + + r = gunyah_vm_add_resource_ticket(f->ghvm, &vcpu->ticket); + if (r) + goto err_destroy_page; + + if (!gunyah_vm_get(f->ghvm)) { + r = -ENODEV; + goto err_remove_resource_ticket; + } + vcpu->ghvm = f->ghvm; + + vcpu->nb.notifier_call = gunyah_vcpu_rm_notification; + /** + * Ensure we run after the vm_mgr handles the notification and does + * any necessary state changes. + */ + vcpu->nb.priority = -1; + r = gunyah_rm_notifier_register(f->rm, &vcpu->nb); + if (r) + goto err_put_gunyah_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, &gunyah_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: + gunyah_rm_notifier_unregister(f->rm, &vcpu->nb); +err_put_gunyah_vm: + gunyah_vm_put(vcpu->ghvm); +err_remove_resource_ticket: + gunyah_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 gunyah_vcpu_unbind(struct gunyah_vm_function_instance *f) +{ + struct gunyah_vcpu *vcpu = f->data; + + gunyah_rm_notifier_unregister(f->rm, &vcpu->nb); + gunyah_vm_remove_resource_ticket(vcpu->ghvm, &vcpu->ticket); + vcpu->f = NULL; + + kref_put(&vcpu->kref, vcpu_release); +} + +static bool gunyah_vcpu_compare(const struct gunyah_vm_function_instance *f, + const void *arg, size_t size) +{ + const struct gunyah_fn_vcpu_arg *instance = f->argp, *other = arg; + + if (sizeof(*other) != size) + return false; + + return instance->id == other->id; +} + +DECLARE_GUNYAH_VM_FUNCTION_INIT(vcpu, GUNYAH_FN_VCPU, 1, gunyah_vcpu_bind, + gunyah_vcpu_unbind, gunyah_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 5d4f413f7a76..db3d1d18ccb8 100644 --- a/drivers/virt/gunyah/vm_mgr.c +++ b/drivers/virt/gunyah/vm_mgr.c @@ -302,6 +302,11 @@ static int gunyah_vm_rm_notification_exited(struct gunyah_vm *ghvm, void *data) down_write(&ghvm->status_lock); ghvm->vm_status = GUNYAH_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(GUNYAH_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 190a95ee8da6..8c5b94101b2c 100644 --- a/drivers/virt/gunyah/vm_mgr.h +++ b/drivers/virt/gunyah/vm_mgr.h @@ -28,6 +28,7 @@ long gunyah_dev_vm_mgr_ioctl(struct gunyah_rm *rm, unsigned int cmd, * @vm_status: Current state of the VM, as last reported by RM * @vm_status_wait: Wait queue for status @vm_status changes * @status_lock: Serializing state transitions + * @exit_info: Breadcrumbs why VM is not running anymore * @kref: Reference counter for VM functions * @fn_lock: Serialization addition of functions * @functions: List of &struct gunyah_vm_function_instance that have been @@ -48,6 +49,7 @@ struct gunyah_vm { enum gunyah_rm_vm_status vm_status; wait_queue_head_t vm_status_wait; struct rw_semaphore status_lock; + struct gunyah_vm_exit_info exit_info; struct kref kref; struct mutex fn_lock; diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index 1b7cb5fde70a..46f7d3aa61d0 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -25,8 +25,33 @@ */ #define GUNYAH_VM_START _IO(GUNYAH_IOCTL_TYPE, 0x3) +/** + * enum gunyah_fn_type - Valid types of Gunyah VM functions + * @GUNYAH_FN_VCPU: create a vCPU instance to control a vCPU + * &struct gunyah_fn_desc.arg is a pointer to &struct gunyah_fn_vcpu_arg + * Return: file descriptor to manipulate the vcpu. + */ +enum gunyah_fn_type { + GUNYAH_FN_VCPU = 1, +}; + #define GUNYAH_FN_MAX_ARG_SIZE 256 +/** + * struct gunyah_fn_vcpu_arg - Arguments to create a vCPU. + * @id: vcpu id + * + * Create this function with &GUNYAH_VM_ADD_FUNCTION using type &GUNYAH_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 gunyah_fn_vcpu_arg { + __u32 id; +}; + /** * struct gunyah_fn_desc - Arguments to create a VM function * @type: Type of the function. See &enum gunyah_fn_type. @@ -43,4 +68,142 @@ struct gunyah_fn_desc { #define GUNYAH_VM_ADD_FUNCTION _IOW(GUNYAH_IOCTL_TYPE, 0x4, struct gunyah_fn_desc) #define GUNYAH_VM_REMOVE_FUNCTION _IOW(GUNYAH_IOCTL_TYPE, 0x7, struct gunyah_fn_desc) +/* + * ioctls for vCPU fds + */ + +/** + * enum gunyah_vm_status - Stores status reason why VM is not runnable (exited). + * @GUNYAH_VM_STATUS_LOAD_FAILED: VM didn't start because it couldn't be loaded. + * @GUNYAH_VM_STATUS_EXITED: VM requested shutdown/reboot. + * Use &struct gunyah_vm_exit_info.reason for further details. + * @GUNYAH_VM_STATUS_CRASHED: VM state is unknown and has crashed. + */ +enum gunyah_vm_status { + GUNYAH_VM_STATUS_LOAD_FAILED = 1, + GUNYAH_VM_STATUS_EXITED = 2, + GUNYAH_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 gunyah_vcpu_run < PAGE_SIZE. + */ +#define GUNYAH_VM_MAX_EXIT_REASON_SIZE 8u + +/** + * struct gunyah_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 gunyah_vm_exit_info { + __u16 type; + __u16 padding; + __u32 reason_size; + __u8 reason[GUNYAH_VM_MAX_EXIT_REASON_SIZE]; +}; + +/** + * enum gunyah_vcpu_exit - Stores reason why &GUNYAH_VCPU_RUN ioctl recently exited with status 0 + * @GUNYAH_VCPU_EXIT_UNKNOWN: Not used, status != 0 + * @GUNYAH_VCPU_EXIT_MMIO: vCPU performed a read or write that could not be handled + * by hypervisor or Linux. Use @struct gunyah_vcpu_run.mmio for + * details of the read/write. + * @GUNYAH_VCPU_EXIT_STATUS: vCPU not able to run because the VM has exited. + * Use @struct gunyah_vcpu_run.status for why VM has exited. + * @GUNYAH_VCPU_EXIT_PAGE_FAULT: vCPU tried to execute an instruction at an address + * for which memory hasn't been provided. Use + * @struct gunyah_vcpu_run.page_fault for details. + */ +enum gunyah_vcpu_exit { + GUNYAH_VCPU_EXIT_UNKNOWN, + GUNYAH_VCPU_EXIT_MMIO, + GUNYAH_VCPU_EXIT_STATUS, + GUNYAH_VCPU_EXIT_PAGE_FAULT, +}; + +/** + * enum gunyah_vcpu_resume_action - Provide resume action after an MMIO or page fault + * @GUNYAH_VCPU_RESUME_HANDLED: The mmio or page fault has been handled, continue + * normal operation of vCPU + * @GUNYAH_VCPU_RESUME_FAULT: The mmio or page fault could not be satisfied and + * inject the original fault back to the guest. + * @GUNYAH_VCPU_RESUME_RETRY: Retry the faulting instruction. Perhaps you added + * memory binding to satisfy the request. + */ +enum gunyah_vcpu_resume_action { + GUNYAH_VCPU_RESUME_HANDLED = 0, + GUNYAH_VCPU_RESUME_FAULT, + GUNYAH_VCPU_RESUME_RETRY, +}; + +/** + * struct gunyah_vcpu_run - Application code obtains a pointer to the gunyah_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 GUNYAH_VCPU_RUN returns successfully and gives reason why + * GUNYAH_VCPU_RUN has stopped running the vCPU. See &enum gunyah_vcpu_exit. + * @mmio: Used when exit_reason == GUNYAH_VCPU_EXIT_MMIO + * The guest has faulted on an memory-mapped I/O 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 + * @mmio.resume_action: See &enum gunyah_vcpu_resume_action + * @status: Used when exit_reason == GUNYAH_VCPU_EXIT_STATUS. + * The guest VM is no longer runnable. This struct informs why. + * @status.status: See &enum gunyah_vm_status for possible values + * @status.exit_info: Used when status == GUNYAH_VM_STATUS_EXITED + * @page_fault: Used when EXIT_REASON == GUNYAH_VCPU_EXIT_PAGE_FAULT + * The guest has faulted on a region that can only be provided + * by mapping memory at phys_addr. + * @page_fault.phys_addr: Address guest tried to access. + * @page_fault.attempt: Error code why Linux wasn't able to handle fault itself + * Typically, if no memory was mapped: -ENOENT, + * If permission bits weren't what the VM wanted: -EPERM + * @page_fault.resume_action: See &enum gunyah_vcpu_resume_action + */ +struct gunyah_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; + __u8 resume_action; + } mmio; + + struct { + enum gunyah_vm_status status; + struct gunyah_vm_exit_info exit_info; + } status; + + struct { + __u64 phys_addr; + __s32 attempt; + __u8 resume_action; + } page_fault; + }; +}; + +#define GUNYAH_VCPU_RUN _IO(GUNYAH_IOCTL_TYPE, 0x5) +#define GUNYAH_VCPU_MMAP_SIZE _IO(GUNYAH_IOCTL_TYPE, 0x6) + #endif