When launching a virtual machine, Gunyah userspace allocates memory for the guest and informs Gunyah about these memory regions through SET_USER_MEMORY_REGION ioctl. Co-developed-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx> Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@xxxxxxxxxxx> Signed-off-by: Elliot Berman <quic_eberman@xxxxxxxxxxx> --- drivers/virt/gunyah/Makefile | 2 +- drivers/virt/gunyah/vm_mgr.c | 59 +++++++- drivers/virt/gunyah/vm_mgr.h | 26 ++++ drivers/virt/gunyah/vm_mgr_mm.c | 236 ++++++++++++++++++++++++++++++++ include/uapi/linux/gunyah.h | 37 +++++ 5 files changed, 356 insertions(+), 4 deletions(-) create mode 100644 drivers/virt/gunyah/vm_mgr_mm.c diff --git a/drivers/virt/gunyah/Makefile b/drivers/virt/gunyah/Makefile index e47e25895299..bacf78b8fa33 100644 --- a/drivers/virt/gunyah/Makefile +++ b/drivers/virt/gunyah/Makefile @@ -1,4 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 -gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o +gunyah-y += rsc_mgr.o rsc_mgr_rpc.o vm_mgr.o vm_mgr_mm.o obj-$(CONFIG_GUNYAH) += gunyah.o diff --git a/drivers/virt/gunyah/vm_mgr.c b/drivers/virt/gunyah/vm_mgr.c index a43401cb34f7..297427952b8c 100644 --- a/drivers/virt/gunyah/vm_mgr.c +++ b/drivers/virt/gunyah/vm_mgr.c @@ -15,6 +15,8 @@ #include "vm_mgr.h" +static void gh_vm_free(struct work_struct *work); + static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm) { struct gh_vm *ghvm; @@ -26,20 +28,72 @@ static __must_check struct gh_vm *gh_vm_alloc(struct gh_rm *rm) ghvm->parent = gh_rm_get(rm); ghvm->rm = rm; + mmgrab(current->mm); + ghvm->mm = current->mm; + mutex_init(&ghvm->mm_lock); + INIT_LIST_HEAD(&ghvm->memory_mappings); + INIT_WORK(&ghvm->free_work, gh_vm_free); + return ghvm; } -static int gh_vm_release(struct inode *inode, struct file *filp) +static long gh_vm_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) { struct gh_vm *ghvm = filp->private_data; + void __user *argp = (void __user *)arg; + long r; + + switch (cmd) { + case GH_VM_SET_USER_MEM_REGION: { + struct gh_userspace_memory_region region; + + /* only allow owner task to add memory */ + if (ghvm->mm != current->mm) + return -EPERM; + + if (copy_from_user(®ion, argp, sizeof(region))) + return -EFAULT; + + /* All other flag bits are reserved for future use */ + if (region.flags & ~(GH_MEM_ALLOW_READ | GH_MEM_ALLOW_WRITE | GH_MEM_ALLOW_EXEC)) + return -EINVAL; + + r = gh_vm_mem_alloc(ghvm, ®ion); + break; + } + default: + r = -ENOTTY; + break; + } + return r; +} + +static void gh_vm_free(struct work_struct *work) +{ + struct gh_vm *ghvm = container_of(work, struct gh_vm, free_work); + + gh_vm_mem_reclaim(ghvm); gh_rm_put(ghvm->rm); + mmdrop(ghvm->mm); kfree(ghvm); +} + +static int gh_vm_release(struct inode *inode, struct file *filp) +{ + struct gh_vm *ghvm = filp->private_data; + + /* VM will be reset and make RM calls which can interruptible sleep. + * Defer to a work so this thread can receive signal. + */ + schedule_work(&ghvm->free_work); return 0; } static const struct file_operations gh_vm_fops = { .owner = THIS_MODULE, + .unlocked_ioctl = gh_vm_ioctl, + .compat_ioctl = compat_ptr_ioctl, .release = gh_vm_release, .llseek = noop_llseek, }; @@ -77,8 +131,7 @@ static long gh_dev_ioctl_create_vm(struct gh_rm *rm, unsigned long arg) err_put_fd: put_unused_fd(fd); err_destroy_vm: - gh_rm_put(ghvm->rm); - kfree(ghvm); + gh_vm_free(&ghvm->free_work); return err; } diff --git a/drivers/virt/gunyah/vm_mgr.h b/drivers/virt/gunyah/vm_mgr.h index 1e94b58d7d34..434ef9f662a7 100644 --- a/drivers/virt/gunyah/vm_mgr.h +++ b/drivers/virt/gunyah/vm_mgr.h @@ -7,14 +7,40 @@ #define _GH_VM_MGR_H #include <linux/gunyah_rsc_mgr.h> +#include <linux/list.h> +#include <linux/miscdevice.h> +#include <linux/mutex.h> #include <uapi/linux/gunyah.h> long gh_dev_vm_mgr_ioctl(struct gh_rm *rm, unsigned int cmd, unsigned long arg); +enum gh_vm_mem_share_type { + VM_MEM_SHARE, + VM_MEM_LEND, +}; + +struct gh_vm_mem { + struct list_head list; + enum gh_vm_mem_share_type share_type; + struct gh_rm_mem_parcel parcel; + + __u64 guest_phys_addr; + struct page **pages; + unsigned long npages; +}; + struct gh_vm { struct gh_rm *rm; struct device *parent; + + struct work_struct free_work; + struct mm_struct *mm; /* userspace tied to this vm */ + struct mutex mm_lock; + struct list_head memory_mappings; }; +int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region); +void gh_vm_mem_reclaim(struct gh_vm *ghvm); + #endif diff --git a/drivers/virt/gunyah/vm_mgr_mm.c b/drivers/virt/gunyah/vm_mgr_mm.c new file mode 100644 index 000000000000..91109bbf36b3 --- /dev/null +++ b/drivers/virt/gunyah/vm_mgr_mm.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved. + */ + +#define pr_fmt(fmt) "gh_vm_mgr: " fmt + +#include <linux/gunyah_rsc_mgr.h> +#include <linux/mm.h> + +#include <uapi/linux/gunyah.h> + +#include "vm_mgr.h" + +static bool pages_are_mergeable(struct page *a, struct page *b) +{ + if (page_to_pfn(a) + 1 != page_to_pfn(b)) + return false; + if (!zone_device_pages_have_same_pgmap(a, b)) + return false; + return true; +} + +static bool gh_vm_mem_overlap(struct gh_vm_mem *a, u64 addr, u64 size) +{ + u64 a_end = a->guest_phys_addr + (a->npages << PAGE_SHIFT); + u64 end = addr + size; + + return a->guest_phys_addr < end && addr < a_end; +} + +static struct gh_vm_mem *__gh_vm_mem_find_by_label(struct gh_vm *ghvm, u32 label) + __must_hold(&ghvm->mm_lock) +{ + struct gh_vm_mem *mapping; + + list_for_each_entry(mapping, &ghvm->memory_mappings, list) + if (mapping->parcel.label == label) + return mapping; + + return NULL; +} + +static void gh_vm_mem_reclaim_mapping(struct gh_vm *ghvm, struct gh_vm_mem *mapping) + __must_hold(&ghvm->mm_lock) +{ + int ret = 0; + + if (mapping->parcel.mem_handle != GH_MEM_HANDLE_INVAL) { + ret = gh_rm_mem_reclaim(ghvm->rm, &mapping->parcel); + if (ret) + pr_warn("Failed to reclaim memory parcel for label %d: %d\n", + mapping->parcel.label, ret); + } + + if (!ret) { + unpin_user_pages(mapping->pages, mapping->npages); + account_locked_vm(ghvm->mm, mapping->npages, false); + } + + kfree(mapping->pages); + kfree(mapping->parcel.acl_entries); + kfree(mapping->parcel.mem_entries); + + list_del(&mapping->list); +} + +void gh_vm_mem_reclaim(struct gh_vm *ghvm) +{ + struct gh_vm_mem *mapping, *tmp; + + mutex_lock(&ghvm->mm_lock); + + list_for_each_entry_safe(mapping, tmp, &ghvm->memory_mappings, list) { + gh_vm_mem_reclaim_mapping(ghvm, mapping); + kfree(mapping); + } + + mutex_unlock(&ghvm->mm_lock); +} + +int gh_vm_mem_alloc(struct gh_vm *ghvm, struct gh_userspace_memory_region *region) +{ + struct gh_vm_mem *mapping, *tmp_mapping; + struct page *curr_page, *prev_page; + struct gh_rm_mem_parcel *parcel; + int i, j, pinned, ret = 0; + unsigned int gup_flags; + size_t entry_size; + u16 vmid; + + if (!region->memory_size || !PAGE_ALIGNED(region->memory_size) || + !PAGE_ALIGNED(region->userspace_addr) || + !PAGE_ALIGNED(region->guest_phys_addr)) + return -EINVAL; + + if (overflows_type(region->guest_phys_addr + region->memory_size, u64)) + return -EOVERFLOW; + + ret = mutex_lock_interruptible(&ghvm->mm_lock); + if (ret) + return ret; + + mapping = __gh_vm_mem_find_by_label(ghvm, region->label); + if (mapping) { + ret = -EEXIST; + goto unlock; + } + + list_for_each_entry(tmp_mapping, &ghvm->memory_mappings, list) { + if (gh_vm_mem_overlap(tmp_mapping, region->guest_phys_addr, + region->memory_size)) { + ret = -EEXIST; + goto unlock; + } + } + + mapping = kzalloc(sizeof(*mapping), GFP_KERNEL_ACCOUNT); + if (!mapping) { + ret = -ENOMEM; + goto unlock; + } + + mapping->guest_phys_addr = region->guest_phys_addr; + mapping->npages = region->memory_size >> PAGE_SHIFT; + parcel = &mapping->parcel; + parcel->label = region->label; + parcel->mem_handle = GH_MEM_HANDLE_INVAL; /* to be filled later by mem_share/mem_lend */ + parcel->mem_type = GH_RM_MEM_TYPE_NORMAL; + + ret = account_locked_vm(ghvm->mm, mapping->npages, true); + if (ret) + goto free_mapping; + + mapping->pages = kcalloc(mapping->npages, sizeof(*mapping->pages), GFP_KERNEL_ACCOUNT); + if (!mapping->pages) { + ret = -ENOMEM; + mapping->npages = 0; /* update npages for reclaim */ + goto unlock_pages; + } + + gup_flags = FOLL_LONGTERM; + if (region->flags & GH_MEM_ALLOW_WRITE) + gup_flags |= FOLL_WRITE; + + pinned = pin_user_pages_fast(region->userspace_addr, mapping->npages, + gup_flags, mapping->pages); + if (pinned < 0) { + ret = pinned; + goto free_pages; + } else if (pinned != mapping->npages) { + ret = -EFAULT; + mapping->npages = pinned; /* update npages for reclaim */ + goto unpin_pages; + } + + parcel->n_acl_entries = 2; + mapping->share_type = VM_MEM_SHARE; + parcel->acl_entries = kcalloc(parcel->n_acl_entries, sizeof(*parcel->acl_entries), + GFP_KERNEL); + if (!parcel->acl_entries) { + ret = -ENOMEM; + goto unpin_pages; + } + + /* acl_entries[0].vmid will be this VM's vmid. We'll fill it when the + * VM is starting and we know the VM's vmid. + */ + if (region->flags & GH_MEM_ALLOW_READ) + parcel->acl_entries[0].perms |= GH_RM_ACL_R; + if (region->flags & GH_MEM_ALLOW_WRITE) + parcel->acl_entries[0].perms |= GH_RM_ACL_W; + if (region->flags & GH_MEM_ALLOW_EXEC) + parcel->acl_entries[0].perms |= GH_RM_ACL_X; + + ret = gh_rm_get_vmid(ghvm->rm, &vmid); + if (ret) + goto free_acl; + + parcel->acl_entries[1].vmid = cpu_to_le16(vmid); + /* Host assumed to have all these permissions. Gunyah will not + * grant new permissions if host actually had less than RWX + */ + parcel->acl_entries[1].perms = GH_RM_ACL_R | GH_RM_ACL_W | GH_RM_ACL_X; + + parcel->n_mem_entries = 1; + for (i = 1; i < mapping->npages; i++) { + if (!pages_are_mergeable(mapping->pages[i - 1], mapping->pages[i])) + parcel->n_mem_entries++; + } + + parcel->mem_entries = kcalloc(parcel->n_mem_entries, + sizeof(parcel->mem_entries[0]), + GFP_KERNEL_ACCOUNT); + if (!parcel->mem_entries) { + ret = -ENOMEM; + goto free_acl; + } + + /* reduce number of entries by combining contiguous pages into single memory entry */ + prev_page = mapping->pages[0]; + parcel->mem_entries[0].phys_addr = cpu_to_le64(page_to_phys(prev_page)); + entry_size = PAGE_SIZE; + for (i = 1, j = 0; i < mapping->npages; i++) { + curr_page = mapping->pages[i]; + if (pages_are_mergeable(prev_page, curr_page)) { + entry_size += PAGE_SIZE; + } else { + parcel->mem_entries[j].size = cpu_to_le64(entry_size); + j++; + parcel->mem_entries[j].phys_addr = + cpu_to_le64(page_to_phys(curr_page)); + entry_size = PAGE_SIZE; + } + + prev_page = curr_page; + } + parcel->mem_entries[j].size = cpu_to_le64(entry_size); + + list_add(&mapping->list, &ghvm->memory_mappings); + mutex_unlock(&ghvm->mm_lock); + return 0; +free_acl: + kfree(parcel->acl_entries); +unpin_pages: + unpin_user_pages(mapping->pages, pinned); +free_pages: + kfree(mapping->pages); +unlock_pages: + account_locked_vm(ghvm->mm, mapping->npages, false); +free_mapping: + kfree(mapping); +unlock: + mutex_unlock(&ghvm->mm_lock); + return ret; +} diff --git a/include/uapi/linux/gunyah.h b/include/uapi/linux/gunyah.h index 86b9cb60118d..91d6dd26fcc8 100644 --- a/include/uapi/linux/gunyah.h +++ b/include/uapi/linux/gunyah.h @@ -20,4 +20,41 @@ */ #define GH_CREATE_VM _IO(GH_IOCTL_TYPE, 0x0) /* Returns a Gunyah VM fd */ +/* + * ioctls for VM fds + */ + +/** + * enum gh_mem_flags - Possible flags on &struct gh_userspace_memory_region + * @GH_MEM_ALLOW_READ: Allow guest to read the memory + * @GH_MEM_ALLOW_WRITE: Allow guest to write to the memory + * @GH_MEM_ALLOW_EXEC: Allow guest to execute instructions in the memory + */ +enum gh_mem_flags { + GH_MEM_ALLOW_READ = 1UL << 0, + GH_MEM_ALLOW_WRITE = 1UL << 1, + GH_MEM_ALLOW_EXEC = 1UL << 2, +}; + +/** + * struct gh_userspace_memory_region - Userspace memory descripion for GH_VM_SET_USER_MEM_REGION + * @label: Identifer to the region which is unique to the VM. + * @flags: Flags for memory parcel behavior. See &enum gh_mem_flags. + * @guest_phys_addr: Location of the memory region in guest's memory space (page-aligned) + * @memory_size: Size of the region (page-aligned) + * @userspace_addr: Location of the memory region in caller (userspace)'s memory + * + * See Documentation/virt/gunyah/vm-manager.rst for further details. + */ +struct gh_userspace_memory_region { + __u32 label; + __u32 flags; + __u64 guest_phys_addr; + __u64 memory_size; + __u64 userspace_addr; +}; + +#define GH_VM_SET_USER_MEM_REGION _IOW(GH_IOCTL_TYPE, 0x1, \ + struct gh_userspace_memory_region) + #endif -- 2.40.0