HMM driver for KVM PPC to manage page transitions of
secure guest via H_SVM_PAGE_IN and H_SVM_PAGE_OUT hcalls.
H_SVM_PAGE_IN: Move the content of a normal page to secure page
H_SVM_PAGE_OUT: Move the content of a secure page to normal page
Signed-off-by: Bharata B Rao <bharata@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/hvcall.h | 4 +
arch/powerpc/include/asm/kvm_host.h | 14 +
arch/powerpc/include/asm/kvm_ppc.h | 28 ++
arch/powerpc/include/asm/ucall-api.h | 22 ++
arch/powerpc/kvm/Makefile | 3 +
arch/powerpc/kvm/book3s_hv.c | 21 ++
arch/powerpc/kvm/book3s_hv_hmm.c | 457 +++++++++++++++++++++++++++
7 files changed, 549 insertions(+)
create mode 100644 arch/powerpc/include/asm/ucall-api.h
create mode 100644 arch/powerpc/kvm/book3s_hv_hmm.c
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 33a4fc891947..c900f47c0a9f 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -336,6 +336,10 @@
#define H_ENTER_NESTED 0xF804
#define H_TLB_INVALIDATE 0xF808
+/* Platform-specific hcalls used by the Ultravisor */
+#define H_SVM_PAGE_IN 0xFF00
+#define H_SVM_PAGE_OUT 0xFF04
+
/* Values for 2nd argument to H_SET_MODE */
#define H_SET_MODE_RESOURCE_SET_CIABR 1
#define H_SET_MODE_RESOURCE_SET_DAWR 2
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index fac6f631ed29..729bdea22250 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -842,4 +842,18 @@ static inline void kvm_arch_vcpu_blocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_unblocking(struct kvm_vcpu *vcpu) {}
static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
+#ifdef CONFIG_PPC_SVM
+extern int kvmppc_hmm_init(void);
+extern void kvmppc_hmm_free(void);
+extern void kvmppc_hmm_release_pfns(struct kvm_memory_slot *free);
+#else
+static inline int kvmppc_hmm_init(void)
+{
+ return 0;
+}
+
+static inline void kvmppc_hmm_free(void) {}
+static inline void kvmppc_hmm_release_pfns(struct kvm_memory_slot *free) {}
+#endif /* CONFIG_PPC_SVM */
+
#endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 9b89b1918dfc..659c80982497 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -908,4 +908,32 @@ static inline ulong kvmppc_get_ea_indexed(struct kvm_vcpu *vcpu, int ra, int rb)
extern void xics_wake_cpu(int cpu);
+#ifdef CONFIG_PPC_SVM
+extern unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
+ unsigned int lpid,
+ unsigned long gra,
+ unsigned long flags,
+ unsigned long page_shift);
+extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
+ unsigned int lpid,
+ unsigned long gra,
+ unsigned long flags,
+ unsigned long page_shift);
+#else
+static inline unsigned long
+kvmppc_h_svm_page_in(struct kvm *kvm, unsigned int lpid,
+ unsigned long gra, unsigned long flags,
+ unsigned long page_shift)
+{
+ return H_UNSUPPORTED;
+}
+
+static inline unsigned long
+kvmppc_h_svm_page_out(struct kvm *kvm, unsigned int lpid,
+ unsigned long gra, unsigned long flags,
+ unsigned long page_shift)
+{
+ return H_UNSUPPORTED;
+}
+#endif
#endif /* __POWERPC_KVM_PPC_H__ */
diff --git a/arch/powerpc/include/asm/ucall-api.h b/arch/powerpc/include/asm/ucall-api.h
new file mode 100644
index 000000000000..a84dc2abd172
--- /dev/null
+++ b/arch/powerpc/include/asm/ucall-api.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_UCALL_API_H
+#define _ASM_POWERPC_UCALL_API_H
+
+#define U_SUCCESS 0
+
+/*
+ * TODO: Dummy uvcalls, will be replaced by real calls
+ */
+static inline int uv_page_in(u64 lpid, u64 src_ra, u64 dst_gpa, u64 flags,
+ u64 page_shift)
+{
+ return U_SUCCESS;
+}
+
+static inline int uv_page_out(u64 lpid, u64 dst_ra, u64 src_gpa, u64 flags,
+ u64 page_shift)
+{
+ return U_SUCCESS;
+}
+
+#endif /* _ASM_POWERPC_UCALL_API_H */
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 64f1135e7732..a9547318662e 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -76,6 +76,9 @@ kvm-hv-y += \
book3s_64_mmu_radix.o \
book3s_hv_nested.o
+kvm-hv-$(CONFIG_PPC_SVM) += \
+ book3s_hv_hmm.o
+
kvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
book3s_hv_tm.o
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index d65b961661fb..7e413605e7c4 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -74,6 +74,7 @@
#include <asm/opal.h>
#include <asm/xics.h>
#include <asm/xive.h>
+#include <asm/kvm_host.h>
#include "book3s.h"
@@ -991,6 +992,20 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
if (nesting_enabled(vcpu->kvm))
ret = kvmhv_do_nested_tlbie(vcpu);
break;
+ case H_SVM_PAGE_IN:
+ ret = kvmppc_h_svm_page_in(vcpu->kvm,
+ kvmppc_get_gpr(vcpu, 4),
+ kvmppc_get_gpr(vcpu, 5),
+ kvmppc_get_gpr(vcpu, 6),
+ kvmppc_get_gpr(vcpu, 7));
+ break;
+ case H_SVM_PAGE_OUT:
+ ret = kvmppc_h_svm_page_out(vcpu->kvm,
+ kvmppc_get_gpr(vcpu, 4),
+ kvmppc_get_gpr(vcpu, 5),
+ kvmppc_get_gpr(vcpu, 6),
+ kvmppc_get_gpr(vcpu, 7));
+ break;
default:
return RESUME_HOST;
@@ -4345,6 +4360,7 @@ static void kvmppc_core_free_memslot_hv(struct kvm_memory_slot *free,
struct kvm_memory_slot *dont)
{
if (!dont || free->arch.rmap != dont->arch.rmap) {
+ kvmppc_hmm_release_pfns(free);
vfree(free->arch.rmap);
free->arch.rmap = NULL;
}
@@ -5357,11 +5373,16 @@ static int kvmppc_book3s_init_hv(void)
no_mixing_hpt_and_radix = true;
}
+ r = kvmppc_hmm_init();
+ if (r < 0)
+ pr_err("KVM-HV: kvmppc_hmm_init failed %d\n", r);
+
return r;
}
static void kvmppc_book3s_exit_hv(void)
{
+ kvmppc_hmm_free();
kvmppc_free_host_rm_ops();
if (kvmppc_radix_possible())
kvmppc_radix_exit();
diff --git a/arch/powerpc/kvm/book3s_hv_hmm.c b/arch/powerpc/kvm/book3s_hv_hmm.c
new file mode 100644
index 000000000000..5f2a924a4f16
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_hmm.c
@@ -0,0 +1,457 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * HMM driver to manage page migration between normal and secure
+ * memory.
+ *
+ * Based on Jérôme Glisse's HMM dummy driver.
+ *
+ * Copyright 2018 Bharata B Rao, IBM Corp. <bharata@xxxxxxxxxxxxx>
+ */
+
+/*
+ * A pseries guest can be run as a 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).
+ *
+ * Private ZONE_DEVICE memory equal to the amount of secure memory
+ * available in the platform for running secure guests is created
+ * via a HMM device. The movement of pages between normal and secure
+ * memory is done by ->alloc_and_copy() callback routine of migrate_vma().
+ *
+ * The page-in or page-out requests from UV will come to HV as hcalls and
+ * HV will call back into UV via uvcalls to satisfy these page requests.
+ *
+ * For each page that gets moved into secure memory, a HMM PFN is used
+ * on the HV side and HMM migration PTE corresponding to that PFN would be
+ * populated in the QEMU page tables.
+ */
+
+#include <linux/hmm.h>
+#include <linux/kvm_host.h>
+#include <linux/sched/mm.h>
+#include <asm/ucall-api.h>
+
+struct kvmppc_hmm_device {
+ struct hmm_device *device;
+ struct hmm_devmem *devmem;
+ unsigned long *pfn_bitmap;
+};
+
+static struct kvmppc_hmm_device kvmppc_hmm;
+spinlock_t kvmppc_hmm_lock;
+
+struct kvmppc_hmm_page_pvt {
+ unsigned long *rmap;
+ unsigned int lpid;
+ unsigned long gpa;
+};
+
+struct kvmppc_hmm_migrate_args {
+ unsigned long *rmap;
+ unsigned int lpid;
+ unsigned long gpa;
+ unsigned long page_shift;
+};
+
+#define KVMPPC_PFN_HMM (0x1ULL << 61)
+
+static inline bool kvmppc_is_hmm_pfn(unsigned long pfn)
+{
+ return !!(pfn & KVMPPC_PFN_HMM);
+}
+
+void kvmppc_hmm_release_pfns(struct kvm_memory_slot *free)
+{
+ int i;
+
+ for (i = 0; i < free->npages; i++) {
+ unsigned long *rmap = &free->arch.rmap[i];
+
+ if (kvmppc_is_hmm_pfn(*rmap))
+ put_page(pfn_to_page(*rmap & ~KVMPPC_PFN_HMM));
+ }
+}
+
+/*
+ * Get a free HMM PFN from the pool
+ *
+ * Called when a normal page is moved to secure memory (UV_PAGE_IN). HMM
+ * PFN will be used to keep track of the secure page on HV side.
+ */
+/*
+ * TODO: In this and subsequent functions, we pass around and access
+ * individual elements of kvm_memory_slot->arch.rmap[] without any
+ * protection. Figure out the safe way to access this.
+ */
+static struct page *kvmppc_hmm_get_page(unsigned long *rmap,
+ unsigned long gpa, unsigned int lpid)
+{
+ struct page *dpage = NULL;
+ unsigned long bit, hmm_pfn;
+ unsigned long nr_pfns = kvmppc_hmm.devmem->pfn_last -
+ kvmppc_hmm.devmem->pfn_first;
+ unsigned long flags;
+ struct kvmppc_hmm_page_pvt *pvt;
+
+ if (kvmppc_is_hmm_pfn(*rmap))
+ return NULL;
+
+ spin_lock_irqsave(&kvmppc_hmm_lock, flags);
+ bit = find_first_zero_bit(kvmppc_hmm.pfn_bitmap, nr_pfns);
+ if (bit >= nr_pfns)
+ goto out;
+
+ bitmap_set(kvmppc_hmm.pfn_bitmap, bit, 1);
+ hmm_pfn = bit + kvmppc_hmm.devmem->pfn_first;
+ dpage = pfn_to_page(hmm_pfn);
+
+ if (!trylock_page(dpage))
+ goto out_clear;
+
+ *rmap = hmm_pfn | KVMPPC_PFN_HMM;
+ pvt = kzalloc(sizeof(*pvt), GFP_ATOMIC);
+ if (!pvt)
+ goto out_unlock;
+ pvt->rmap = rmap;
+ pvt->gpa = gpa;
+ pvt->lpid = lpid;
+ hmm_devmem_page_set_drvdata(dpage, (unsigned long)pvt);
+ spin_unlock_irqrestore(&kvmppc_hmm_lock, flags);
+
+ get_page(dpage);
+ return dpage;
+
+out_unlock:
+ unlock_page(dpage);
+out_clear:
+ bitmap_clear(kvmppc_hmm.pfn_bitmap,
+ hmm_pfn - kvmppc_hmm.devmem->pfn_first, 1);
+out:
+ spin_unlock_irqrestore(&kvmppc_hmm_lock, flags);
+ return NULL;
+}
+
+/*
+ * Release the HMM PFN back to the pool
+ *
+ * Called when secure page becomes a normal page during UV_PAGE_OUT.
+ */
+static void kvmppc_hmm_put_page(struct page *page)
+{
+ unsigned long pfn = page_to_pfn(page);
+ unsigned long flags;
+ struct kvmppc_hmm_page_pvt *pvt;
+
+ spin_lock_irqsave(&kvmppc_hmm_lock, flags);
+ pvt = (struct kvmppc_hmm_page_pvt *)hmm_devmem_page_get_drvdata(page);
+ hmm_devmem_page_set_drvdata(page, 0);
+
+ bitmap_clear(kvmppc_hmm.pfn_bitmap,
+ pfn - kvmppc_hmm.devmem->pfn_first, 1);
+ *(pvt->rmap) = 0;
+ spin_unlock_irqrestore(&kvmppc_hmm_lock, flags);
+ kfree(pvt);
+}
+
+/*
+ * migrate_vma() callback to move page from normal memory to secure memory.
+ *
+ * We don't capture the return value of uv_page_in() here because when
+ * UV asks for a page and then fails to copy it over, we don't care.
+ */
+static void
+kvmppc_hmm_migrate_alloc_and_copy(struct vm_area_struct *vma,
+ const unsigned long *src_pfn,
+ unsigned long *dst_pfn,
+ unsigned long start,
+ unsigned long end,
+ void *private)
+{
+ struct kvmppc_hmm_migrate_args *args = private;
+ struct page *spage = migrate_pfn_to_page(*src_pfn);
+ unsigned long pfn = *src_pfn >> MIGRATE_PFN_SHIFT;
+ struct page *dpage;
+
+ *dst_pfn = 0;
+ if (!(*src_pfn & MIGRATE_PFN_MIGRATE))
+ return;
+
+ dpage = kvmppc_hmm_get_page(args->rmap, args->gpa, args->lpid);
+ if (!dpage)
+ return;
+
+ if (spage)
+ uv_page_in(args->lpid, pfn << args->page_shift,
+ args->gpa, 0, args->page_shift);
+
+ *dst_pfn = migrate_pfn(page_to_pfn(dpage)) |
+ MIGRATE_PFN_DEVICE | MIGRATE_PFN_LOCKED;
+}
+
+/*
+ * This migrate_vma() callback is typically used to updated device
+ * page tables after successful migration. We have nothing to do here.
+ *
+ * Also as we don't care if UV successfully copied over the page in
+ * kvmppc_hmm_migrate_alloc_and_copy(), we don't bother to check
+ * dst_pfn for any errors here.
+ */
+static void
+kvmppc_hmm_migrate_finalize_and_map(struct vm_area_struct *vma,
+ const unsigned long *src_pfn,
+ const unsigned long *dst_pfn,
+ unsigned long start,
+ unsigned long end,
+ void *private)
+{
+}
+
+static const struct migrate_vma_ops kvmppc_hmm_migrate_ops = {
+ .alloc_and_copy = kvmppc_hmm_migrate_alloc_and_copy,
+ .finalize_and_map = kvmppc_hmm_migrate_finalize_and_map,
+};
+
+/*
+ * Move page from normal memory to secure memory.
+ */
+unsigned long
+kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
+ unsigned long flags, unsigned long page_shift)
+{
+ unsigned long addr, end;
+ unsigned long src_pfn, dst_pfn;
+ struct kvmppc_hmm_migrate_args args;
+ struct mm_struct *mm = get_task_mm(current);
+ struct vm_area_struct *vma;
+ int srcu_idx;
+ unsigned long gfn = gpa >> page_shift;
+ struct kvm_memory_slot *slot;
+ unsigned long *rmap;
+ int ret = H_SUCCESS;
+
+ if (page_shift != PAGE_SHIFT)
+ return H_P3;
+
+ srcu_idx = srcu_read_lock(&kvm->srcu);
+ slot = gfn_to_memslot(kvm, gfn);
+ rmap = &slot->arch.rmap[gfn - slot->base_gfn];
+ addr = gfn_to_hva(kvm, gpa >> page_shift);
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ if (kvm_is_error_hva(addr))
+ return H_PARAMETER;
+
+ end = addr + (1UL << page_shift);
+
+ if (flags)
+ return H_P2;
+
+ args.rmap = rmap;
+ args.lpid = kvm->arch.lpid;
+ args.gpa = gpa;
+ args.page_shift = page_shift;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma_intersection(mm, addr, end);
+ if (!vma || vma->vm_start > addr || vma->vm_end < end) {
+ ret = H_PARAMETER;
+ goto out;
+ }
+ ret = migrate_vma(&kvmppc_hmm_migrate_ops, vma, addr, end,
+ &src_pfn, &dst_pfn, &args);
+ if (ret < 0)
+ ret = H_PARAMETER;
+out:
+ up_read(&mm->mmap_sem);
+ return ret;
+}
+
+static void
+kvmppc_hmm_fault_migrate_alloc_and_copy(struct vm_area_struct *vma,
+ const unsigned long *src_pfn,
+ unsigned long *dst_pfn,
+ unsigned long start,
+ unsigned long end,
+ void *private)
+{
+ struct page *dpage, *spage;
+ struct kvmppc_hmm_page_pvt *pvt;
+ unsigned long pfn;
+ int ret = U_SUCCESS;
+
+ *dst_pfn = MIGRATE_PFN_ERROR;
+ spage = migrate_pfn_to_page(*src_pfn);
+ if (!spage || !(*src_pfn & MIGRATE_PFN_MIGRATE))
+ return;
+ if (!is_zone_device_page(spage))
+ return;
+ dpage = hmm_vma_alloc_locked_page(vma, start);
+ if (!dpage)
+ return;
+ pvt = (struct kvmppc_hmm_page_pvt *)
+ hmm_devmem_page_get_drvdata(spage);
+
+ pfn = page_to_pfn(dpage);
+ ret = uv_page_out(pvt->lpid, pfn << PAGE_SHIFT,
+ pvt->gpa, 0, PAGE_SHIFT);
+ if (ret == U_SUCCESS)
+ *dst_pfn = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED;
+}
+
+/*
+ * This migrate_vma() callback is typically used to updated device
+ * page tables after successful migration. We have nothing to do here.
+ */
+static void
+kvmppc_hmm_fault_migrate_finalize_and_map(struct vm_area_struct *vma,
+ const unsigned long *src_pfn,
+ const unsigned long *dst_pfn,
+ unsigned long start,
+ unsigned long end,
+ void *private)
+{
+}
+
+static const struct migrate_vma_ops kvmppc_hmm_fault_migrate_ops = {
+ .alloc_and_copy = kvmppc_hmm_fault_migrate_alloc_and_copy,
+ .finalize_and_map = kvmppc_hmm_fault_migrate_finalize_and_map,
+};
+
+/*
+ * Fault handler callback when HV touches any page that has been
+ * moved to secure memory, we ask UV to give back the page by
+ * issuing a UV_PAGE_OUT uvcall.
+ */
+static int kvmppc_hmm_devmem_fault(struct hmm_devmem *devmem,
+ struct vm_area_struct *vma,
+ unsigned long addr,
+ const struct page *page,
+ unsigned int flags,
+ pmd_t *pmdp)
+{
+ unsigned long end = addr + PAGE_SIZE;
+ unsigned long src_pfn, dst_pfn = 0;
+
+ if (migrate_vma(&kvmppc_hmm_fault_migrate_ops, vma, addr, end,
+ &src_pfn, &dst_pfn, NULL))
+ return VM_FAULT_SIGBUS;
+ if (dst_pfn == MIGRATE_PFN_ERROR)
+ return VM_FAULT_SIGBUS;
+ return 0;
+}
+
+static void kvmppc_hmm_devmem_free(struct hmm_devmem *devmem,
+ struct page *page)
+{
+ kvmppc_hmm_put_page(page);
+}
+
+static const struct hmm_devmem_ops kvmppc_hmm_devmem_ops = {
+ .free = kvmppc_hmm_devmem_free,
+ .fault = kvmppc_hmm_devmem_fault,
+};
+
+/*
+ * 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 addr, end;
+ struct mm_struct *mm = get_task_mm(current);
+ struct vm_area_struct *vma;
+ unsigned long src_pfn, dst_pfn = 0;
+ int srcu_idx;
+ int ret = H_SUCCESS;
+
+ if (page_shift != PAGE_SHIFT)
+ return H_P3;
+
+ if (flags)
+ return H_P2;
+
+ srcu_idx = srcu_read_lock(&kvm->srcu);
+ addr = gfn_to_hva(kvm, gpa >> page_shift);
+ srcu_read_unlock(&kvm->srcu, srcu_idx);
+ if (kvm_is_error_hva(addr))
+ return H_PARAMETER;
+
+ end = addr + (1UL << page_shift);
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma_intersection(mm, addr, end);
+ if (!vma || vma->vm_start > addr || vma->vm_end < end) {
+ ret = H_PARAMETER;
+ goto out;
+ }
+ ret = migrate_vma(&kvmppc_hmm_fault_migrate_ops, vma, addr, end,
+ &src_pfn, &dst_pfn, NULL);
+ if (ret < 0)
+ ret = H_PARAMETER;
+out:
+ up_read(&mm->mmap_sem);
+ return ret;
+}
+
+/*
+ * TODO: Number of secure pages and the page size order would probably come
+ * via DT or via some uvcall. Return 8G for now.
+ */
+static unsigned long kvmppc_get_secmem_size(void)
+{
+ return (1UL << 33);
+}
+
+static int kvmppc_hmm_pages_init(void)
+{
+ unsigned long nr_pfns = kvmppc_hmm.devmem->pfn_last -
+ kvmppc_hmm.devmem->pfn_first;
+
+ kvmppc_hmm.pfn_bitmap = kcalloc(BITS_TO_LONGS(nr_pfns),
+ sizeof(unsigned long), GFP_KERNEL);
+ if (!kvmppc_hmm.pfn_bitmap)
+ return -ENOMEM;
+
+ spin_lock_init(&kvmppc_hmm_lock);
+
+ return 0;
+}
+
+int kvmppc_hmm_init(void)
+{
+ int ret = 0;
+ unsigned long size = kvmppc_get_secmem_size();
+
+ kvmppc_hmm.device = hmm_device_new(NULL);
+ if (IS_ERR(kvmppc_hmm.device)) {
+ ret = PTR_ERR(kvmppc_hmm.device);
+ goto out;
+ }
+
+ kvmppc_hmm.devmem = hmm_devmem_add(&kvmppc_hmm_devmem_ops,
+ &kvmppc_hmm.device->device, size);
+ if (IS_ERR(kvmppc_hmm.devmem)) {
+ ret = PTR_ERR(kvmppc_hmm.devmem);
+ goto out_device;
+ }
+ ret = kvmppc_hmm_pages_init();
+ if (ret < 0)
+ goto out_devmem;
+
+ return ret;
+
+out_devmem:
+ hmm_devmem_remove(kvmppc_hmm.devmem);
+out_device:
+ hmm_device_put(kvmppc_hmm.device);
+out:
+ return ret;
+}
+
+void kvmppc_hmm_free(void)
+{
+ kfree(kvmppc_hmm.pfn_bitmap);
+ hmm_devmem_remove(kvmppc_hmm.devmem);
+ hmm_device_put(kvmppc_hmm.device);
+}
--
2.17.1
