blob: 79b1202b1c628e92acb6a0bb928926c73d18a13e [file] [log] [blame]
// 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, bool skip_page_out)
{
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 = skip_page_out;
mutex_unlock(&kvm->arch.uvmem_lock);
pfn = gfn_to_pfn(kvm, gfn);
if (is_error_noslot_pfn(pfn))
continue;
kvm_release_pfn_clean(pfn);
}
}
unsigned long kvmppc_h_svm_init_abort(struct kvm *kvm)
{
int srcu_idx;
struct kvm_memory_slot *memslot;
/*
* Expect to be called only after INIT_START and before INIT_DONE.
* If INIT_DONE was completed, use normal VM termination sequence.
*/
if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
return H_UNSUPPORTED;
if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
return H_STATE;
srcu_idx = srcu_read_lock(&kvm->srcu);
kvm_for_each_memslot(memslot, kvm_memslots(kvm))
kvmppc_uvmem_drop_pages(memslot, kvm, false);
srcu_read_unlock(&kvm->srcu, srcu_idx);
kvm->arch.secure_guest = 0;
uv_svm_terminate(kvm->arch.lpid);
return H_PARAMETER;
}
/*
* 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)
goto out;
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);
}