diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_hv_uvmem.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_hv_uvmem.c | 785 |
1 files changed, 785 insertions, 0 deletions
diff --git a/arch/powerpc/kvm/book3s_hv_uvmem.c b/arch/powerpc/kvm/book3s_hv_uvmem.c new file mode 100644 index 000000000000..2de264fc3156 --- /dev/null +++ b/arch/powerpc/kvm/book3s_hv_uvmem.c @@ -0,0 +1,785 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Secure pages management: Migration of pages between normal and secure + * memory of KVM guests. + * + * Copyright 2018 Bharata B Rao, IBM Corp. <bharata@linux.ibm.com> + */ + +/* + * A pseries guest can be run as secure guest on Ultravisor-enabled + * POWER platforms. On such platforms, this driver will be used to manage + * the movement of guest pages between the normal memory managed by + * hypervisor (HV) and secure memory managed by Ultravisor (UV). + * + * The page-in or page-out requests from UV will come to HV as hcalls and + * HV will call back into UV via ultracalls to satisfy these page requests. + * + * Private ZONE_DEVICE memory equal to the amount of secure memory + * available in the platform for running secure guests is hotplugged. + * Whenever a page belonging to the guest becomes secure, a page from this + * private device memory is used to represent and track that secure page + * on the HV side. Some pages (like virtio buffers, VPA pages etc) are + * shared between UV and HV. However such pages aren't represented by + * device private memory and mappings to shared memory exist in both + * UV and HV page tables. + */ + +/* + * Notes on locking + * + * kvm->arch.uvmem_lock is a per-guest lock that prevents concurrent + * page-in and page-out requests for the same GPA. Concurrent accesses + * can either come via UV (guest vCPUs requesting for same page) + * or when HV and guest simultaneously access the same page. + * This mutex serializes the migration of page from HV(normal) to + * UV(secure) and vice versa. So the serialization points are around + * migrate_vma routines and page-in/out routines. + * + * Per-guest mutex comes with a cost though. Mainly it serializes the + * fault path as page-out can occur when HV faults on accessing secure + * guest pages. Currently UV issues page-in requests for all the guest + * PFNs one at a time during early boot (UV_ESM uvcall), so this is + * not a cause for concern. Also currently the number of page-outs caused + * by HV touching secure pages is very very low. If an when UV supports + * overcommitting, then we might see concurrent guest driven page-outs. + * + * Locking order + * + * 1. kvm->srcu - Protects KVM memslots + * 2. kvm->mm->mmap_sem - find_vma, migrate_vma_pages and helpers, ksm_madvise + * 3. kvm->arch.uvmem_lock - protects read/writes to uvmem slots thus acting + * as sync-points for page-in/out + */ + +/* + * Notes on page size + * + * Currently UV uses 2MB mappings internally, but will issue H_SVM_PAGE_IN + * and H_SVM_PAGE_OUT hcalls in PAGE_SIZE(64K) granularity. HV tracks + * secure GPAs at 64K page size and maintains one device PFN for each + * 64K secure GPA. UV_PAGE_IN and UV_PAGE_OUT calls by HV are also issued + * for 64K page at a time. + * + * HV faulting on secure pages: When HV touches any secure page, it + * faults and issues a UV_PAGE_OUT request with 64K page size. Currently + * UV splits and remaps the 2MB page if necessary and copies out the + * required 64K page contents. + * + * Shared pages: Whenever guest shares a secure page, UV will split and + * remap the 2MB page if required and issue H_SVM_PAGE_IN with 64K page size. + * + * HV invalidating a page: When a regular page belonging to secure + * guest gets unmapped, HV informs UV with UV_PAGE_INVAL of 64K + * page size. Using 64K page size is correct here because any non-secure + * page will essentially be of 64K page size. Splitting by UV during sharing + * and page-out ensures this. + * + * Page fault handling: When HV handles page fault of a page belonging + * to secure guest, it sends that to UV with a 64K UV_PAGE_IN request. + * Using 64K size is correct here too as UV would have split the 2MB page + * into 64k mappings and would have done page-outs earlier. + * + * In summary, the current secure pages handling code in HV assumes + * 64K page size and in fact fails any page-in/page-out requests of + * non-64K size upfront. If and when UV starts supporting multiple + * page-sizes, we need to break this assumption. + */ + +#include <linux/pagemap.h> +#include <linux/migrate.h> +#include <linux/kvm_host.h> +#include <linux/ksm.h> +#include <asm/ultravisor.h> +#include <asm/mman.h> +#include <asm/kvm_ppc.h> + +static struct dev_pagemap kvmppc_uvmem_pgmap; +static unsigned long *kvmppc_uvmem_bitmap; +static DEFINE_SPINLOCK(kvmppc_uvmem_bitmap_lock); + +#define KVMPPC_UVMEM_PFN (1UL << 63) + +struct kvmppc_uvmem_slot { + struct list_head list; + unsigned long nr_pfns; + unsigned long base_pfn; + unsigned long *pfns; +}; + +struct kvmppc_uvmem_page_pvt { + struct kvm *kvm; + unsigned long gpa; + bool skip_page_out; +}; + +int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot) +{ + struct kvmppc_uvmem_slot *p; + + p = kzalloc(sizeof(*p), GFP_KERNEL); + if (!p) + return -ENOMEM; + p->pfns = vzalloc(array_size(slot->npages, sizeof(*p->pfns))); + if (!p->pfns) { + kfree(p); + return -ENOMEM; + } + p->nr_pfns = slot->npages; + p->base_pfn = slot->base_gfn; + + mutex_lock(&kvm->arch.uvmem_lock); + list_add(&p->list, &kvm->arch.uvmem_pfns); + mutex_unlock(&kvm->arch.uvmem_lock); + + return 0; +} + +/* + * All device PFNs are already released by the time we come here. + */ +void kvmppc_uvmem_slot_free(struct kvm *kvm, const struct kvm_memory_slot *slot) +{ + struct kvmppc_uvmem_slot *p, *next; + + mutex_lock(&kvm->arch.uvmem_lock); + list_for_each_entry_safe(p, next, &kvm->arch.uvmem_pfns, list) { + if (p->base_pfn == slot->base_gfn) { + vfree(p->pfns); + list_del(&p->list); + kfree(p); + break; + } + } + mutex_unlock(&kvm->arch.uvmem_lock); +} + +static void kvmppc_uvmem_pfn_insert(unsigned long gfn, unsigned long uvmem_pfn, + struct kvm *kvm) +{ + struct kvmppc_uvmem_slot *p; + + list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) { + if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) { + unsigned long index = gfn - p->base_pfn; + + p->pfns[index] = uvmem_pfn | KVMPPC_UVMEM_PFN; + return; + } + } +} + +static void kvmppc_uvmem_pfn_remove(unsigned long gfn, struct kvm *kvm) +{ + struct kvmppc_uvmem_slot *p; + + list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) { + if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) { + p->pfns[gfn - p->base_pfn] = 0; + return; + } + } +} + +static bool kvmppc_gfn_is_uvmem_pfn(unsigned long gfn, struct kvm *kvm, + unsigned long *uvmem_pfn) +{ + struct kvmppc_uvmem_slot *p; + + list_for_each_entry(p, &kvm->arch.uvmem_pfns, list) { + if (gfn >= p->base_pfn && gfn < p->base_pfn + p->nr_pfns) { + unsigned long index = gfn - p->base_pfn; + + if (p->pfns[index] & KVMPPC_UVMEM_PFN) { + if (uvmem_pfn) + *uvmem_pfn = p->pfns[index] & + ~KVMPPC_UVMEM_PFN; + return true; + } else + return false; + } + } + return false; +} + +unsigned long kvmppc_h_svm_init_start(struct kvm *kvm) +{ + struct kvm_memslots *slots; + struct kvm_memory_slot *memslot; + int ret = H_SUCCESS; + int srcu_idx; + + if (!kvmppc_uvmem_bitmap) + return H_UNSUPPORTED; + + /* Only radix guests can be secure guests */ + if (!kvm_is_radix(kvm)) + return H_UNSUPPORTED; + + srcu_idx = srcu_read_lock(&kvm->srcu); + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) { + if (kvmppc_uvmem_slot_init(kvm, memslot)) { + ret = H_PARAMETER; + goto out; + } + ret = uv_register_mem_slot(kvm->arch.lpid, + memslot->base_gfn << PAGE_SHIFT, + memslot->npages * PAGE_SIZE, + 0, memslot->id); + if (ret < 0) { + kvmppc_uvmem_slot_free(kvm, memslot); + ret = H_PARAMETER; + goto out; + } + } + kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_START; +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + +unsigned long kvmppc_h_svm_init_done(struct kvm *kvm) +{ + if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)) + return H_UNSUPPORTED; + + kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_DONE; + pr_info("LPID %d went secure\n", kvm->arch.lpid); + return H_SUCCESS; +} + +/* + * Drop device pages that we maintain for the secure guest + * + * We first mark the pages to be skipped from UV_PAGE_OUT when there + * is HV side fault on these pages. Next we *get* these pages, forcing + * fault on them, do fault time migration to replace the device PTEs in + * QEMU page table with normal PTEs from newly allocated pages. + */ +void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free, + struct kvm *kvm) +{ + int i; + struct kvmppc_uvmem_page_pvt *pvt; + unsigned long pfn, uvmem_pfn; + unsigned long gfn = free->base_gfn; + + for (i = free->npages; i; --i, ++gfn) { + struct page *uvmem_page; + + mutex_lock(&kvm->arch.uvmem_lock); + if (!kvmppc_gfn_is_uvmem_pfn(gfn, kvm, &uvmem_pfn)) { + mutex_unlock(&kvm->arch.uvmem_lock); + continue; + } + + uvmem_page = pfn_to_page(uvmem_pfn); + pvt = uvmem_page->zone_device_data; + pvt->skip_page_out = true; + mutex_unlock(&kvm->arch.uvmem_lock); + + pfn = gfn_to_pfn(kvm, gfn); + if (is_error_noslot_pfn(pfn)) + continue; + kvm_release_pfn_clean(pfn); + } +} + +/* + * Get a free device PFN from the pool + * + * Called when a normal page is moved to secure memory (UV_PAGE_IN). Device + * PFN will be used to keep track of the secure page on HV side. + * + * Called with kvm->arch.uvmem_lock held + */ +static struct page *kvmppc_uvmem_get_page(unsigned long gpa, struct kvm *kvm) +{ + struct page *dpage = NULL; + unsigned long bit, uvmem_pfn; + struct kvmppc_uvmem_page_pvt *pvt; + unsigned long pfn_last, pfn_first; + + pfn_first = kvmppc_uvmem_pgmap.res.start >> PAGE_SHIFT; + pfn_last = pfn_first + + (resource_size(&kvmppc_uvmem_pgmap.res) >> PAGE_SHIFT); + + spin_lock(&kvmppc_uvmem_bitmap_lock); + bit = find_first_zero_bit(kvmppc_uvmem_bitmap, + pfn_last - pfn_first); + if (bit >= (pfn_last - pfn_first)) + goto out; + bitmap_set(kvmppc_uvmem_bitmap, bit, 1); + spin_unlock(&kvmppc_uvmem_bitmap_lock); + + pvt = kzalloc(sizeof(*pvt), GFP_KERNEL); + if (!pvt) + goto out_clear; + + uvmem_pfn = bit + pfn_first; + kvmppc_uvmem_pfn_insert(gpa >> PAGE_SHIFT, uvmem_pfn, kvm); + + pvt->gpa = gpa; + pvt->kvm = kvm; + + dpage = pfn_to_page(uvmem_pfn); + dpage->zone_device_data = pvt; + get_page(dpage); + lock_page(dpage); + return dpage; +out_clear: + spin_lock(&kvmppc_uvmem_bitmap_lock); + bitmap_clear(kvmppc_uvmem_bitmap, bit, 1); +out: + spin_unlock(&kvmppc_uvmem_bitmap_lock); + return NULL; +} + +/* + * Alloc a PFN from private device memory pool and copy page from normal + * memory to secure memory using UV_PAGE_IN uvcall. + */ +static int +kvmppc_svm_page_in(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long gpa, struct kvm *kvm, + unsigned long page_shift, bool *downgrade) +{ + unsigned long src_pfn, dst_pfn = 0; + struct migrate_vma mig; + struct page *spage; + unsigned long pfn; + struct page *dpage; + int ret = 0; + + memset(&mig, 0, sizeof(mig)); + mig.vma = vma; + mig.start = start; + mig.end = end; + mig.src = &src_pfn; + mig.dst = &dst_pfn; + + /* + * We come here with mmap_sem write lock held just for + * ksm_madvise(), otherwise we only need read mmap_sem. + * Hence downgrade to read lock once ksm_madvise() is done. + */ + ret = ksm_madvise(vma, vma->vm_start, vma->vm_end, + MADV_UNMERGEABLE, &vma->vm_flags); + downgrade_write(&kvm->mm->mmap_sem); + *downgrade = true; + if (ret) + return ret; + + ret = migrate_vma_setup(&mig); + if (ret) + return ret; + + if (!(*mig.src & MIGRATE_PFN_MIGRATE)) { + ret = -1; + goto out_finalize; + } + + dpage = kvmppc_uvmem_get_page(gpa, kvm); + if (!dpage) { + ret = -1; + goto out_finalize; + } + + pfn = *mig.src >> MIGRATE_PFN_SHIFT; + spage = migrate_pfn_to_page(*mig.src); + if (spage) + uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, + page_shift); + + *mig.dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED; + migrate_vma_pages(&mig); +out_finalize: + migrate_vma_finalize(&mig); + return ret; +} + +/* + * Shares the page with HV, thus making it a normal page. + * + * - If the page is already secure, then provision a new page and share + * - If the page is a normal page, share the existing page + * + * In the former case, uses dev_pagemap_ops.migrate_to_ram handler + * to unmap the device page from QEMU's page tables. + */ +static unsigned long +kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift) +{ + + int ret = H_PARAMETER; + struct page *uvmem_page; + struct kvmppc_uvmem_page_pvt *pvt; + unsigned long pfn; + unsigned long gfn = gpa >> page_shift; + int srcu_idx; + unsigned long uvmem_pfn; + + srcu_idx = srcu_read_lock(&kvm->srcu); + mutex_lock(&kvm->arch.uvmem_lock); + if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, &uvmem_pfn)) { + uvmem_page = pfn_to_page(uvmem_pfn); + pvt = uvmem_page->zone_device_data; + pvt->skip_page_out = true; + } + +retry: + mutex_unlock(&kvm->arch.uvmem_lock); + pfn = gfn_to_pfn(kvm, gfn); + if (is_error_noslot_pfn(pfn)) + goto out; + + mutex_lock(&kvm->arch.uvmem_lock); + if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, &uvmem_pfn)) { + uvmem_page = pfn_to_page(uvmem_pfn); + pvt = uvmem_page->zone_device_data; + pvt->skip_page_out = true; + kvm_release_pfn_clean(pfn); + goto retry; + } + + if (!uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift)) + ret = H_SUCCESS; + kvm_release_pfn_clean(pfn); + mutex_unlock(&kvm->arch.uvmem_lock); +out: + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + +/* + * H_SVM_PAGE_IN: Move page from normal memory to secure memory. + * + * H_PAGE_IN_SHARED flag makes the page shared which means that the same + * memory in is visible from both UV and HV. + */ +unsigned long +kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa, + unsigned long flags, unsigned long page_shift) +{ + bool downgrade = false; + unsigned long start, end; + struct vm_area_struct *vma; + int srcu_idx; + unsigned long gfn = gpa >> page_shift; + int ret; + + if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)) + return H_UNSUPPORTED; + + if (page_shift != PAGE_SHIFT) + return H_P3; + + if (flags & ~H_PAGE_IN_SHARED) + return H_P2; + + if (flags & H_PAGE_IN_SHARED) + return kvmppc_share_page(kvm, gpa, page_shift); + + ret = H_PARAMETER; + srcu_idx = srcu_read_lock(&kvm->srcu); + down_write(&kvm->mm->mmap_sem); + + start = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(start)) + goto out; + + mutex_lock(&kvm->arch.uvmem_lock); + /* Fail the page-in request of an already paged-in page */ + if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL)) + goto out_unlock; + + end = start + (1UL << page_shift); + vma = find_vma_intersection(kvm->mm, start, end); + if (!vma || vma->vm_start > start || vma->vm_end < end) + goto out_unlock; + + if (!kvmppc_svm_page_in(vma, start, end, gpa, kvm, page_shift, + &downgrade)) + ret = H_SUCCESS; +out_unlock: + mutex_unlock(&kvm->arch.uvmem_lock); +out: + if (downgrade) + up_read(&kvm->mm->mmap_sem); + else + up_write(&kvm->mm->mmap_sem); + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + +/* + * Provision a new page on HV side and copy over the contents + * from secure memory using UV_PAGE_OUT uvcall. + */ +static int +kvmppc_svm_page_out(struct vm_area_struct *vma, unsigned long start, + unsigned long end, unsigned long page_shift, + struct kvm *kvm, unsigned long gpa) +{ + unsigned long src_pfn, dst_pfn = 0; + struct migrate_vma mig; + struct page *dpage, *spage; + struct kvmppc_uvmem_page_pvt *pvt; + unsigned long pfn; + int ret = U_SUCCESS; + + memset(&mig, 0, sizeof(mig)); + mig.vma = vma; + mig.start = start; + mig.end = end; + mig.src = &src_pfn; + mig.dst = &dst_pfn; + + mutex_lock(&kvm->arch.uvmem_lock); + /* The requested page is already paged-out, nothing to do */ + if (!kvmppc_gfn_is_uvmem_pfn(gpa >> page_shift, kvm, NULL)) + goto out; + + ret = migrate_vma_setup(&mig); + if (ret) + return ret; + + spage = migrate_pfn_to_page(*mig.src); + if (!spage || !(*mig.src & MIGRATE_PFN_MIGRATE)) + goto out_finalize; + + if (!is_zone_device_page(spage)) + goto out_finalize; + + dpage = alloc_page_vma(GFP_HIGHUSER, vma, start); + if (!dpage) { + ret = -1; + goto out_finalize; + } + + lock_page(dpage); + pvt = spage->zone_device_data; + pfn = page_to_pfn(dpage); + + /* + * This function is used in two cases: + * - When HV touches a secure page, for which we do UV_PAGE_OUT + * - When a secure page is converted to shared page, we *get* + * the page to essentially unmap the device page. In this + * case we skip page-out. + */ + if (!pvt->skip_page_out) + ret = uv_page_out(kvm->arch.lpid, pfn << page_shift, + gpa, 0, page_shift); + + if (ret == U_SUCCESS) + *mig.dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED; + else { + unlock_page(dpage); + __free_page(dpage); + goto out_finalize; + } + + migrate_vma_pages(&mig); +out_finalize: + migrate_vma_finalize(&mig); +out: + mutex_unlock(&kvm->arch.uvmem_lock); + return ret; +} + +/* + * Fault handler callback that gets called when HV touches any page that + * has been moved to secure memory, we ask UV to give back the page by + * issuing UV_PAGE_OUT uvcall. + * + * This eventually results in dropping of device PFN and the newly + * provisioned page/PFN gets populated in QEMU page tables. + */ +static vm_fault_t kvmppc_uvmem_migrate_to_ram(struct vm_fault *vmf) +{ + struct kvmppc_uvmem_page_pvt *pvt = vmf->page->zone_device_data; + + if (kvmppc_svm_page_out(vmf->vma, vmf->address, + vmf->address + PAGE_SIZE, PAGE_SHIFT, + pvt->kvm, pvt->gpa)) + return VM_FAULT_SIGBUS; + else + return 0; +} + +/* + * Release the device PFN back to the pool + * + * Gets called when secure page becomes a normal page during H_SVM_PAGE_OUT. + * Gets called with kvm->arch.uvmem_lock held. + */ +static void kvmppc_uvmem_page_free(struct page *page) +{ + unsigned long pfn = page_to_pfn(page) - + (kvmppc_uvmem_pgmap.res.start >> PAGE_SHIFT); + struct kvmppc_uvmem_page_pvt *pvt; + + spin_lock(&kvmppc_uvmem_bitmap_lock); + bitmap_clear(kvmppc_uvmem_bitmap, pfn, 1); + spin_unlock(&kvmppc_uvmem_bitmap_lock); + + pvt = page->zone_device_data; + page->zone_device_data = NULL; + kvmppc_uvmem_pfn_remove(pvt->gpa >> PAGE_SHIFT, pvt->kvm); + kfree(pvt); +} + +static const struct dev_pagemap_ops kvmppc_uvmem_ops = { + .page_free = kvmppc_uvmem_page_free, + .migrate_to_ram = kvmppc_uvmem_migrate_to_ram, +}; + +/* + * H_SVM_PAGE_OUT: Move page from secure memory to normal memory. + */ +unsigned long +kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gpa, + unsigned long flags, unsigned long page_shift) +{ + unsigned long gfn = gpa >> page_shift; + unsigned long start, end; + struct vm_area_struct *vma; + int srcu_idx; + int ret; + + if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)) + return H_UNSUPPORTED; + + if (page_shift != PAGE_SHIFT) + return H_P3; + + if (flags) + return H_P2; + + ret = H_PARAMETER; + srcu_idx = srcu_read_lock(&kvm->srcu); + down_read(&kvm->mm->mmap_sem); + start = gfn_to_hva(kvm, gfn); + if (kvm_is_error_hva(start)) + goto out; + + end = start + (1UL << page_shift); + vma = find_vma_intersection(kvm->mm, start, end); + if (!vma || vma->vm_start > start || vma->vm_end < end) + goto out; + + if (!kvmppc_svm_page_out(vma, start, end, page_shift, kvm, gpa)) + ret = H_SUCCESS; +out: + up_read(&kvm->mm->mmap_sem); + srcu_read_unlock(&kvm->srcu, srcu_idx); + return ret; +} + +int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn) +{ + unsigned long pfn; + int ret = U_SUCCESS; + + pfn = gfn_to_pfn(kvm, gfn); + if (is_error_noslot_pfn(pfn)) + return -EFAULT; + + mutex_lock(&kvm->arch.uvmem_lock); + if (kvmppc_gfn_is_uvmem_pfn(gfn, kvm, NULL)) + goto out; + + ret = uv_page_in(kvm->arch.lpid, pfn << PAGE_SHIFT, gfn << PAGE_SHIFT, + 0, PAGE_SHIFT); +out: + kvm_release_pfn_clean(pfn); + mutex_unlock(&kvm->arch.uvmem_lock); + return (ret == U_SUCCESS) ? RESUME_GUEST : -EFAULT; +} + +static u64 kvmppc_get_secmem_size(void) +{ + struct device_node *np; + int i, len; + const __be32 *prop; + u64 size = 0; + + np = of_find_compatible_node(NULL, NULL, "ibm,uv-firmware"); + if (!np) + goto out; + + prop = of_get_property(np, "secure-memory-ranges", &len); + if (!prop) + goto out_put; + + for (i = 0; i < len / (sizeof(*prop) * 4); i++) + size += of_read_number(prop + (i * 4) + 2, 2); + +out_put: + of_node_put(np); +out: + return size; +} + +int kvmppc_uvmem_init(void) +{ + int ret = 0; + unsigned long size; + struct resource *res; + void *addr; + unsigned long pfn_last, pfn_first; + + size = kvmppc_get_secmem_size(); + if (!size) { + /* + * Don't fail the initialization of kvm-hv module if + * the platform doesn't export ibm,uv-firmware node. + * Let normal guests run on such PEF-disabled platform. + */ + pr_info("KVMPPC-UVMEM: No support for secure guests\n"); + goto out; + } + + res = request_free_mem_region(&iomem_resource, size, "kvmppc_uvmem"); + if (IS_ERR(res)) { + ret = PTR_ERR(res); + goto out; + } + + kvmppc_uvmem_pgmap.type = MEMORY_DEVICE_PRIVATE; + kvmppc_uvmem_pgmap.res = *res; + kvmppc_uvmem_pgmap.ops = &kvmppc_uvmem_ops; + addr = memremap_pages(&kvmppc_uvmem_pgmap, NUMA_NO_NODE); + if (IS_ERR(addr)) { + ret = PTR_ERR(addr); + goto out_free_region; + } + + pfn_first = res->start >> PAGE_SHIFT; + pfn_last = pfn_first + (resource_size(res) >> PAGE_SHIFT); + kvmppc_uvmem_bitmap = kcalloc(BITS_TO_LONGS(pfn_last - pfn_first), + sizeof(unsigned long), GFP_KERNEL); + if (!kvmppc_uvmem_bitmap) { + ret = -ENOMEM; + goto out_unmap; + } + + pr_info("KVMPPC-UVMEM: Secure Memory size 0x%lx\n", size); + return ret; +out_unmap: + memunmap_pages(&kvmppc_uvmem_pgmap); +out_free_region: + release_mem_region(res->start, size); +out: + return ret; +} + +void kvmppc_uvmem_free(void) +{ + memunmap_pages(&kvmppc_uvmem_pgmap); + release_mem_region(kvmppc_uvmem_pgmap.res.start, + resource_size(&kvmppc_uvmem_pgmap.res)); + kfree(kvmppc_uvmem_bitmap); +} |