[PATCH v6 0/7] KVMPPC driver to manage secure guest pages

[PATCH v6 0/7] KVMPPC driver to manage secure guest pages

[Bharata B Rao]

Hi,

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 char device. 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. The movement
of pages between normal and secure memory is done via
migrate_vma_pages().

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.

These patches are against Christoph Hellwig's migrate_vma-cleanup.2
branch
(http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/migrate_vma-cleanup.2)

plus

Claudio Carvalho's base ultravisor enablement patchset
(https://lore.kernel.org/linuxppc-dev/20190808040555.2371-1-cclaudio@linux.ibm.com/T/#t)

These patches along with Claudio's above patches are required to
run a secure pseries guest on KVM.

Changes in v6
=============
Updated the driver to account for the changes in HMM and migrate_vma()
by Christoph Hellwig.
 - Not using any HMM routines any more.
 - Switched to using migrate_vma_pages()

v5: https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg153294.html

Anshuman Khandual (1):
  KVM: PPC: Ultravisor: Add PPC_UV config option

Bharata B Rao (6):
  kvmppc: Driver to manage pages of secure guest
  kvmppc: Shared pages support for secure guests
  kvmppc: H_SVM_INIT_START and H_SVM_INIT_DONE hcalls
  kvmppc: Handle memory plug/unplug to secure VM
  kvmppc: Radix changes for secure guest
  kvmppc: Support reset of secure guest

 Documentation/virtual/kvm/api.txt          |  18 +
 arch/powerpc/Kconfig                       |  18 +
 arch/powerpc/include/asm/hvcall.h          |   9 +
 arch/powerpc/include/asm/kvm_book3s_devm.h |  48 ++
 arch/powerpc/include/asm/kvm_host.h        |  28 +
 arch/powerpc/include/asm/kvm_ppc.h         |   2 +
 arch/powerpc/include/asm/ultravisor-api.h  |   6 +
 arch/powerpc/include/asm/ultravisor.h      |  36 ++
 arch/powerpc/kvm/Makefile                  |   3 +
 arch/powerpc/kvm/book3s_64_mmu_radix.c     |  22 +
 arch/powerpc/kvm/book3s_hv.c               | 115 ++++
 arch/powerpc/kvm/book3s_hv_devm.c          | 668 +++++++++++++++++++++
 arch/powerpc/kvm/powerpc.c                 |  12 +
 include/uapi/linux/kvm.h                   |   1 +
 14 files changed, 986 insertions(+)
 create mode 100644 arch/powerpc/include/asm/kvm_book3s_devm.h
 create mode 100644 arch/powerpc/kvm/book3s_hv_devm.c

-- 
2.21.0

[PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Bharata B Rao]

KVMPPC driver 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

Private ZONE_DEVICE memory equal to the amount of secure memory
available in the platform for running secure guests is created
via a char device. 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. The movement
of pages between normal and secure memory is done via
migrate_vma_pages() using UV_PAGE_IN and UV_PAGE_OUT ucalls.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
---
 arch/powerpc/include/asm/hvcall.h          |   4 +
 arch/powerpc/include/asm/kvm_book3s_devm.h |  29 ++
 arch/powerpc/include/asm/kvm_host.h        |  12 +
 arch/powerpc/include/asm/ultravisor-api.h  |   2 +
 arch/powerpc/include/asm/ultravisor.h      |  14 +
 arch/powerpc/kvm/Makefile                  |   3 +
 arch/powerpc/kvm/book3s_hv.c               |  19 +
 arch/powerpc/kvm/book3s_hv_devm.c          | 492 +++++++++++++++++++++
 8 files changed, 575 insertions(+)
 create mode 100644 arch/powerpc/include/asm/kvm_book3s_devm.h
 create mode 100644 arch/powerpc/kvm/book3s_hv_devm.c

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 463c63a9fcf1..2f6b952deb0f 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -337,6 +337,10 @@
 #define H_TLB_INVALIDATE	0xF808
 #define H_COPY_TOFROM_GUEST	0xF80C
 
+/* Platform-specific hcalls used by the Ultravisor */
+#define H_SVM_PAGE_IN		0xEF00
+#define H_SVM_PAGE_OUT		0xEF04
+
 /* 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_book3s_devm.h b/arch/powerpc/include/asm/kvm_book3s_devm.h
new file mode 100644
index 000000000000..21f3de5f2acb
--- /dev/null
+++ b/arch/powerpc/include/asm/kvm_book3s_devm.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __POWERPC_KVM_PPC_HMM_H__
+#define __POWERPC_KVM_PPC_HMM_H__
+
+#ifdef CONFIG_PPC_UV
+extern unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
+					  unsigned long gra,
+					  unsigned long flags,
+					  unsigned long page_shift);
+extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
+					  unsigned long gra,
+					  unsigned long flags,
+					  unsigned long page_shift);
+#else
+static inline unsigned long
+kvmppc_h_svm_page_in(struct kvm *kvm, 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 long gra,
+		      unsigned long flags, unsigned long page_shift)
+{
+	return H_UNSUPPORTED;
+}
+#endif /* CONFIG_PPC_UV */
+#endif /* __POWERPC_KVM_PPC_HMM_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 4bb552d639b8..86bbe607ad7e 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -849,4 +849,16 @@ 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_UV
+extern int kvmppc_devm_init(void);
+extern void kvmppc_devm_free(void);
+#else
+static inline int kvmppc_devm_init(void)
+{
+	return 0;
+}
+
+static inline void kvmppc_devm_free(void) {}
+#endif /* CONFIG_PPC_UV */
+
 #endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index 6a0f9c74f959..1cd1f595fd81 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -25,5 +25,7 @@
 /* opcodes */
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
+#define UV_PAGE_IN			0xF128
+#define UV_PAGE_OUT			0xF12C
 
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index 6fe1f365dec8..d668a59e099b 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -19,4 +19,18 @@ static inline int uv_register_pate(u64 lpid, u64 dw0, u64 dw1)
 	return ucall_norets(UV_WRITE_PATE, lpid, dw0, dw1);
 }
 
+static inline int uv_page_in(u64 lpid, u64 src_ra, u64 dst_gpa, u64 flags,
+			     u64 page_shift)
+{
+	return ucall_norets(UV_PAGE_IN, lpid, src_ra, dst_gpa, flags,
+			    page_shift);
+}
+
+static inline int uv_page_out(u64 lpid, u64 dst_ra, u64 src_gpa, u64 flags,
+			      u64 page_shift)
+{
+	return ucall_norets(UV_PAGE_OUT, lpid, dst_ra, src_gpa, flags,
+			    page_shift);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 4c67cc79de7c..16b40590e67c 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -71,6 +71,9 @@ kvm-hv-y += \
 	book3s_64_mmu_radix.o \
 	book3s_hv_nested.o
 
+kvm-hv-$(CONFIG_PPC_UV) += \
+	book3s_hv_devm.o
+
 kvm-hv-$(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 ec1804f822af..00b43ee8b693 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -72,6 +72,8 @@
 #include <asm/xics.h>
 #include <asm/xive.h>
 #include <asm/hw_breakpoint.h>
+#include <asm/kvm_host.h>
+#include <asm/kvm_book3s_devm.h>
 
 #include "book3s.h"
 
@@ -1075,6 +1077,18 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 					 kvmppc_get_gpr(vcpu, 5),
 					 kvmppc_get_gpr(vcpu, 6));
 		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));
+		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));
+		break;
 	default:
 		return RESUME_HOST;
 	}
@@ -5510,11 +5524,16 @@ static int kvmppc_book3s_init_hv(void)
 			no_mixing_hpt_and_radix = true;
 	}
 
+	r = kvmppc_devm_init();
+	if (r < 0)
+		pr_err("KVM-HV: kvmppc_devm_init failed %d\n", r);
+
 	return r;
 }
 
 static void kvmppc_book3s_exit_hv(void)
 {
+	kvmppc_devm_free();
 	kvmppc_free_host_rm_ops();
 	if (kvmppc_radix_possible())
 		kvmppc_radix_exit();
diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c
new file mode 100644
index 000000000000..2e6c077bd22e
--- /dev/null
+++ b/arch/powerpc/kvm/book3s_hv_devm.c
@@ -0,0 +1,492 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver to manage page migration between normal and secure
+ * memory.
+ *
+ * Copyright 2018 Bharata B Rao, IBM Corp. <bharata@linux.ibm.com>
+ */
+
+/*
+ * 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).
+ *
+ * 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.
+ *
+ * Private ZONE_DEVICE memory equal to the amount of secure memory
+ * available in the platform for running secure guests is created
+ * via a char device. 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.
+ *
+ * For each page that gets moved into secure memory, a device PFN is used
+ * on the HV side and migration PTE corresponding to that PFN would be
+ * populated in the QEMU page tables. Device PFNs are stored in the rmap
+ * array. Whenever a guest page becomes secure, device PFN allocated for
+ * the same will be populated in the corresponding slot in the rmap
+ * array. The overloading of rmap array's usage which otherwise is
+ * used primarily by HPT guests means that this feature (secure
+ * guest on PEF platforms) is available only for Radix MMU guests.
+ * Also the same rmap array is used differently by nested HPT guests.
+ * Hence a secure guest can't have nested guests.
+ */
+
+#include <linux/pagemap.h>
+#include <linux/migrate.h>
+#include <linux/kvm_host.h>
+#include <linux/sched/mm.h>
+#include <asm/ultravisor.h>
+
+struct kvmppc_devm_device {
+	struct device dev;
+	dev_t devt;
+	struct dev_pagemap pagemap;
+	unsigned long pfn_first, pfn_last;
+	unsigned long *pfn_bitmap;
+};
+
+
+static struct kvmppc_devm_device kvmppc_devm;
+spinlock_t kvmppc_devm_lock;
+
+struct kvmppc_devm_page_pvt {
+	unsigned long *rmap;
+	unsigned int lpid;
+	unsigned long gpa;
+};
+
+struct kvmppc_devm_copy_args {
+	unsigned long *rmap;
+	unsigned int lpid;
+	unsigned long gpa;
+	unsigned long page_shift;
+};
+
+/*
+ * Bits 60:56 in the rmap entry will be used to identify the
+ * different uses/functions of rmap. This definition with move
+ * to a proper header when all other functions are defined.
+ */
+#define KVMPPC_PFN_DEVM		(0x2ULL << 56)
+
+static inline bool kvmppc_is_devm_pfn(unsigned long pfn)
+{
+	return !!(pfn & KVMPPC_PFN_DEVM);
+}
+
+/*
+ * 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.
+ *
+ * @rmap here is the slot in the rmap array that corresponds to @gpa.
+ * Thus a non-zero rmap entry indicates that the corresonding guest
+ * page has become secure, and is not mapped on the HV side.
+ *
+ * NOTE: In this and subsequent functions, we pass around and access
+ * individual elements of kvm_memory_slot->arch.rmap[] without any
+ * protection. Should we use lock_rmap() here?
+ */
+static struct page *kvmppc_devm_get_page(unsigned long *rmap,
+					unsigned long gpa, unsigned int lpid)
+{
+	struct page *dpage = NULL;
+	unsigned long bit, devm_pfn;
+	unsigned long nr_pfns = kvmppc_devm.pfn_last -
+				kvmppc_devm.pfn_first;
+	unsigned long flags;
+	struct kvmppc_devm_page_pvt *pvt;
+
+	if (kvmppc_is_devm_pfn(*rmap))
+		return NULL;
+
+	spin_lock_irqsave(&kvmppc_devm_lock, flags);
+	bit = find_first_zero_bit(kvmppc_devm.pfn_bitmap, nr_pfns);
+	if (bit >= nr_pfns)
+		goto out;
+
+	bitmap_set(kvmppc_devm.pfn_bitmap, bit, 1);
+	devm_pfn = bit + kvmppc_devm.pfn_first;
+	dpage = pfn_to_page(devm_pfn);
+
+	if (!trylock_page(dpage))
+		goto out_clear;
+
+	*rmap = devm_pfn | KVMPPC_PFN_DEVM;
+	pvt = kzalloc(sizeof(*pvt), GFP_ATOMIC);
+	if (!pvt)
+		goto out_unlock;
+	pvt->rmap = rmap;
+	pvt->gpa = gpa;
+	pvt->lpid = lpid;
+	dpage->zone_device_data = pvt;
+	spin_unlock_irqrestore(&kvmppc_devm_lock, flags);
+
+	get_page(dpage);
+	return dpage;
+
+out_unlock:
+	unlock_page(dpage);
+out_clear:
+	bitmap_clear(kvmppc_devm.pfn_bitmap,
+		     devm_pfn - kvmppc_devm.pfn_first, 1);
+out:
+	spin_unlock_irqrestore(&kvmppc_devm_lock, flags);
+	return NULL;
+}
+
+/*
+ * Release the device PFN back to the pool
+ *
+ * Gets called when secure page becomes a normal page during UV_PAGE_OUT.
+ */
+static void kvmppc_devm_put_page(struct page *page)
+{
+	unsigned long pfn = page_to_pfn(page);
+	unsigned long flags;
+	struct kvmppc_devm_page_pvt *pvt;
+
+	spin_lock_irqsave(&kvmppc_devm_lock, flags);
+	pvt = (struct kvmppc_devm_page_pvt *)page->zone_device_data;
+	page->zone_device_data = 0;
+
+	bitmap_clear(kvmppc_devm.pfn_bitmap,
+		     pfn - kvmppc_devm.pfn_first, 1);
+	*(pvt->rmap) = 0;
+	spin_unlock_irqrestore(&kvmppc_devm_lock, flags);
+	kfree(pvt);
+}
+
+/*
+ * Alloc a PFN from private device memory pool and copy page from normal
+ * memory to secure memory.
+ */
+static int
+kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig,
+				   struct kvmppc_devm_copy_args *args)
+{
+	struct page *spage = migrate_pfn_to_page(*mig->src);
+	unsigned long pfn = *mig->src >> MIGRATE_PFN_SHIFT;
+	struct page *dpage;
+
+	*mig->dst = 0;
+	if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE))
+		return 0;
+
+	dpage = kvmppc_devm_get_page(args->rmap, args->gpa, args->lpid);
+	if (!dpage)
+		return -EINVAL;
+
+	if (spage)
+		uv_page_in(args->lpid, pfn << args->page_shift,
+			   args->gpa, 0, args->page_shift);
+
+	*mig->dst = migrate_pfn(page_to_pfn(dpage)) | MIGRATE_PFN_LOCKED;
+	return 0;
+}
+
+/*
+ * 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_devm_copy_args args;
+	struct migrate_vma mig;
+	struct vm_area_struct *vma;
+	int srcu_idx;
+	unsigned long gfn = gpa >> page_shift;
+	struct kvm_memory_slot *slot;
+	unsigned long *rmap;
+	int ret;
+
+	if (page_shift != PAGE_SHIFT)
+		return H_P3;
+
+	if (flags)
+		return H_P2;
+
+	ret = H_PARAMETER;
+	down_read(&kvm->mm->mmap_sem);
+	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);
+	if (kvm_is_error_hva(addr))
+		goto out;
+
+	end = addr + (1UL << page_shift);
+	vma = find_vma_intersection(kvm->mm, addr, end);
+	if (!vma || vma->vm_start > addr || vma->vm_end < end)
+		goto out;
+
+	args.rmap = rmap;
+	args.lpid = kvm->arch.lpid;
+	args.gpa = gpa;
+	args.page_shift = page_shift;
+
+	memset(&mig, 0, sizeof(mig));
+	mig.vma = vma;
+	mig.start = addr;
+	mig.end = end;
+	mig.src = &src_pfn;
+	mig.dst = &dst_pfn;
+
+	if (migrate_vma_setup(&mig))
+		goto out;
+
+	if (kvmppc_devm_migrate_alloc_and_copy(&mig, &args))
+		goto out_finalize;
+
+	migrate_vma_pages(&mig);
+	ret = H_SUCCESS;
+out_finalize:
+	migrate_vma_finalize(&mig);
+out:
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+	up_read(&kvm->mm->mmap_sem);
+	return ret;
+}
+
+/*
+ * Provision a new page on HV side and copy over the contents
+ * from secure memory.
+ */
+static int
+kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig)
+{
+	struct page *dpage, *spage;
+	struct kvmppc_devm_page_pvt *pvt;
+	unsigned long pfn;
+	int ret = U_SUCCESS;
+
+	spage = migrate_pfn_to_page(*mig->src);
+	if (!spage || !(*mig->src & MIGRATE_PFN_MIGRATE))
+		return 0;
+	if (!is_zone_device_page(spage))
+		return 0;
+
+	dpage = alloc_page_vma(GFP_HIGHUSER, mig->vma, mig->start);
+	if (!dpage)
+		return -EINVAL;
+	lock_page(dpage);
+	pvt = (struct kvmppc_devm_page_pvt *)spage->zone_device_data;
+
+	pfn = page_to_pfn(dpage);
+	ret = uv_page_out(pvt->lpid, pfn << PAGE_SHIFT,
+			  pvt->gpa, 0, PAGE_SHIFT);
+	if (ret == U_SUCCESS)
+		*mig->dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED;
+	return 0;
+}
+
+/*
+ * 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.
+ *
+ * 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_devm_migrate_to_ram(struct vm_fault *vmf)
+{
+	unsigned long src_pfn, dst_pfn = 0;
+	struct migrate_vma mig;
+	int ret = 0;
+
+	memset(&mig, 0, sizeof(mig));
+	mig.vma = vmf->vma;
+	mig.start = vmf->address;
+	mig.end = vmf->address + PAGE_SIZE;
+	mig.src = &src_pfn;
+	mig.dst = &dst_pfn;
+
+	if (migrate_vma_setup(&mig)) {
+		ret = VM_FAULT_SIGBUS;
+		goto out;
+	}
+
+	if (kvmppc_devm_fault_migrate_alloc_and_copy(&mig)) {
+		ret = VM_FAULT_SIGBUS;
+		goto out_finalize;
+	}
+
+	migrate_vma_pages(&mig);
+out_finalize:
+	migrate_vma_finalize(&mig);
+out:
+	return ret;
+}
+
+static void kvmppc_devm_page_free(struct page *page)
+{
+	kvmppc_devm_put_page(page);
+}
+
+static const struct dev_pagemap_ops kvmppc_devm_ops = {
+	.page_free = kvmppc_devm_page_free,
+	.migrate_to_ram	= kvmppc_devm_migrate_to_ram,
+};
+
+/*
+ * 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)
+{
+	struct migrate_vma mig;
+	unsigned long addr, end;
+	struct vm_area_struct *vma;
+	unsigned long src_pfn, dst_pfn = 0;
+	int srcu_idx;
+	int ret;
+
+	if (page_shift != PAGE_SHIFT)
+		return H_P3;
+
+	if (flags)
+		return H_P2;
+
+	ret = H_PARAMETER;
+	down_read(&kvm->mm->mmap_sem);
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	addr = gfn_to_hva(kvm, gpa >> page_shift);
+	if (kvm_is_error_hva(addr))
+		goto out;
+
+	end = addr + (1UL << page_shift);
+	vma = find_vma_intersection(kvm->mm, addr, end);
+	if (!vma || vma->vm_start > addr || vma->vm_end < end)
+		goto out;
+
+	memset(&mig, 0, sizeof(mig));
+	mig.vma = vma;
+	mig.start = addr;
+	mig.end = end;
+	mig.src = &src_pfn;
+	mig.dst = &dst_pfn;
+	if (migrate_vma_setup(&mig))
+		goto out;
+
+	if (kvmppc_devm_fault_migrate_alloc_and_copy(&mig))
+		goto out_finalize;
+
+	migrate_vma_pages(&mig);
+	ret = H_SUCCESS;
+out_finalize:
+	migrate_vma_finalize(&mig);
+out:
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+	up_read(&kvm->mm->mmap_sem);
+	return ret;
+}
+
+static u64 kvmppc_get_secmem_size(void)
+{
+	struct device_node *np;
+	int i, len;
+	const __be32 *prop;
+	u64 size = 0;
+
+	np = of_find_node_by_path("/ibm,ultravisor/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;
+}
+
+static int kvmppc_devm_pages_init(void)
+{
+	unsigned long nr_pfns = kvmppc_devm.pfn_last -
+				kvmppc_devm.pfn_first;
+
+	kvmppc_devm.pfn_bitmap = kcalloc(BITS_TO_LONGS(nr_pfns),
+				 sizeof(unsigned long), GFP_KERNEL);
+	if (!kvmppc_devm.pfn_bitmap)
+		return -ENOMEM;
+
+	spin_lock_init(&kvmppc_devm_lock);
+
+	return 0;
+}
+
+static void kvmppc_devm_release(struct device *dev)
+{
+	unregister_chrdev_region(kvmppc_devm.devt, 1);
+}
+
+int kvmppc_devm_init(void)
+{
+	int ret = 0;
+	unsigned long size;
+	struct resource *res;
+	void *addr;
+
+	size = kvmppc_get_secmem_size();
+	if (!size) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	ret = alloc_chrdev_region(&kvmppc_devm.devt, 0, 1,
+				"kvmppc-devm");
+	if (ret)
+		goto out;
+
+	dev_set_name(&kvmppc_devm.dev, "kvmppc_devm_device%d", 0);
+	kvmppc_devm.dev.release = kvmppc_devm_release;
+	device_initialize(&kvmppc_devm.dev);
+	res = devm_request_free_mem_region(&kvmppc_devm.dev,
+		&iomem_resource, size);
+	if (IS_ERR(res)) {
+		ret = PTR_ERR(res);
+		goto out_unregister;
+	}
+
+	kvmppc_devm.pagemap.type = MEMORY_DEVICE_PRIVATE;
+	kvmppc_devm.pagemap.res = *res;
+	kvmppc_devm.pagemap.ops = &kvmppc_devm_ops;
+	addr = devm_memremap_pages(&kvmppc_devm.dev, &kvmppc_devm.pagemap);
+	if (IS_ERR(addr)) {
+		ret = PTR_ERR(addr);
+		goto out_unregister;
+	}
+
+	kvmppc_devm.pfn_first = res->start >> PAGE_SHIFT;
+	kvmppc_devm.pfn_last = kvmppc_devm.pfn_first +
+			(resource_size(res) >> PAGE_SHIFT);
+	ret = kvmppc_devm_pages_init();
+	if (ret < 0)
+		goto out_unregister;
+
+	pr_info("KVMPPC-DEVM: Secure Memory size 0x%lx\n", size);
+	return ret;
+
+out_unregister:
+	put_device(&kvmppc_devm.dev);
+out:
+	return ret;
+}
+
+void kvmppc_devm_free(void)
+{
+	kfree(kvmppc_devm.pfn_bitmap);
+	put_device(&kvmppc_devm.dev);
+}
-- 
2.21.0

[PATCH v6 2/7] kvmppc: Shared pages support for secure guests

[Bharata B Rao]

A secure guest will share some of its pages with hypervisor (Eg. virtio
bounce buffers etc). Support sharing of pages between hypervisor and
ultravisor.

Once a secure page is converted to shared page, stop tracking that page
as a device page.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
---
 arch/powerpc/include/asm/hvcall.h |  3 ++
 arch/powerpc/kvm/book3s_hv_devm.c | 67 +++++++++++++++++++++++++++++--
 2 files changed, 67 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 2f6b952deb0f..05b8536f6653 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -337,6 +337,9 @@
 #define H_TLB_INVALIDATE	0xF808
 #define H_COPY_TOFROM_GUEST	0xF80C
 
+/* Flags for H_SVM_PAGE_IN */
+#define H_PAGE_IN_SHARED        0x1
+
 /* Platform-specific hcalls used by the Ultravisor */
 #define H_SVM_PAGE_IN		0xEF00
 #define H_SVM_PAGE_OUT		0xEF04
diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c
index 2e6c077bd22e..c9189e58401d 100644
--- a/arch/powerpc/kvm/book3s_hv_devm.c
+++ b/arch/powerpc/kvm/book3s_hv_devm.c
@@ -55,6 +55,7 @@ struct kvmppc_devm_page_pvt {
 	unsigned long *rmap;
 	unsigned int lpid;
 	unsigned long gpa;
+	bool skip_page_out;
 };
 
 struct kvmppc_devm_copy_args {
@@ -188,6 +189,54 @@ kvmppc_devm_migrate_alloc_and_copy(struct migrate_vma *mig,
 	return 0;
 }
 
+/*
+ * 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 the dev_pagemap_ops migrate_to_ram handler to
+ * release the device page.
+ */
+static unsigned long
+kvmppc_share_page(struct kvm *kvm, unsigned long gpa, unsigned long page_shift)
+{
+
+	int ret = H_PARAMETER;
+	struct page *devm_page;
+	struct kvmppc_devm_page_pvt *pvt;
+	unsigned long pfn;
+	unsigned long *rmap;
+	struct kvm_memory_slot *slot;
+	unsigned long gfn = gpa >> page_shift;
+	int srcu_idx;
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	slot = gfn_to_memslot(kvm, gfn);
+	if (!slot)
+		goto out;
+
+	rmap = &slot->arch.rmap[gfn - slot->base_gfn];
+	if (kvmppc_is_devm_pfn(*rmap)) {
+		devm_page = pfn_to_page(*rmap & ~KVMPPC_PFN_DEVM);
+		pvt = (struct kvmppc_devm_page_pvt *)
+			devm_page->zone_device_data;
+		pvt->skip_page_out = true;
+	}
+
+	pfn = gfn_to_pfn(kvm, gpa >> page_shift);
+	if (is_error_noslot_pfn(pfn))
+		goto out;
+
+	ret = uv_page_in(kvm->arch.lpid, pfn << page_shift, gpa, 0, page_shift);
+	if (ret == U_SUCCESS)
+		ret = H_SUCCESS;
+	kvm_release_pfn_clean(pfn);
+out:
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+	return ret;
+}
+
 /*
  * Move page from normal memory to secure memory.
  */
@@ -209,9 +258,12 @@ kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gpa,
 	if (page_shift != PAGE_SHIFT)
 		return H_P3;
 
-	if (flags)
+	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;
 	down_read(&kvm->mm->mmap_sem);
 	srcu_idx = srcu_read_lock(&kvm->srcu);
@@ -279,8 +331,17 @@ kvmppc_devm_fault_migrate_alloc_and_copy(struct migrate_vma *mig)
 	pvt = (struct kvmppc_devm_page_pvt *)spage->zone_device_data;
 
 	pfn = page_to_pfn(dpage);
-	ret = uv_page_out(pvt->lpid, pfn << PAGE_SHIFT,
-			  pvt->gpa, 0, PAGE_SHIFT);
+
+	/*
+	 * This same function is used in two cases:
+	 * - When HV touches a secure page, for which we do page-out
+	 * - When a secure page is converted to shared page, we touch
+	 *   the page to essentially discard the device page. In this
+	 *   case we skip page-out.
+	 */
+	if (!pvt->skip_page_out)
+		ret = uv_page_out(pvt->lpid, pfn << PAGE_SHIFT,
+				  pvt->gpa, 0, PAGE_SHIFT);
 	if (ret == U_SUCCESS)
 		*mig->dst = migrate_pfn(pfn) | MIGRATE_PFN_LOCKED;
 	return 0;
-- 
2.21.0

[PATCH v6 3/7] kvmppc: H_SVM_INIT_START and H_SVM_INIT_DONE hcalls

[Bharata B Rao]

H_SVM_INIT_START: Initiate securing a VM
H_SVM_INIT_DONE: Conclude securing a VM

As part of H_SVM_INIT_START, register all existing memslots with
the UV. H_SVM_INIT_DONE call by UV informs HV that transition of
the guest to secure mode is complete.

These two states (transition to secure mode STARTED and transition
to secure mode COMPLETED) are recorded in kvm->arch.secure_guest.
Setting these states will cause the assembly code that enters the
guest to call the UV_RETURN ucall instead of trying to enter the
guest directly.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/include/asm/hvcall.h          |  2 ++
 arch/powerpc/include/asm/kvm_book3s_devm.h | 12 ++++++++
 arch/powerpc/include/asm/kvm_host.h        |  4 +++
 arch/powerpc/include/asm/ultravisor-api.h  |  1 +
 arch/powerpc/include/asm/ultravisor.h      |  7 +++++
 arch/powerpc/kvm/book3s_hv.c               |  7 +++++
 arch/powerpc/kvm/book3s_hv_devm.c          | 34 ++++++++++++++++++++++
 7 files changed, 67 insertions(+)

diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 05b8536f6653..fa7695928e30 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -343,6 +343,8 @@
 /* Platform-specific hcalls used by the Ultravisor */
 #define H_SVM_PAGE_IN		0xEF00
 #define H_SVM_PAGE_OUT		0xEF04
+#define H_SVM_INIT_START	0xEF08
+#define H_SVM_INIT_DONE		0xEF0C
 
 /* Values for 2nd argument to H_SET_MODE */
 #define H_SET_MODE_RESOURCE_SET_CIABR		1
diff --git a/arch/powerpc/include/asm/kvm_book3s_devm.h b/arch/powerpc/include/asm/kvm_book3s_devm.h
index 21f3de5f2acb..8c7aacabb2e0 100644
--- a/arch/powerpc/include/asm/kvm_book3s_devm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_devm.h
@@ -11,6 +11,8 @@ extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
 					  unsigned long gra,
 					  unsigned long flags,
 					  unsigned long page_shift);
+extern unsigned long kvmppc_h_svm_init_start(struct kvm *kvm);
+extern unsigned long kvmppc_h_svm_init_done(struct kvm *kvm);
 #else
 static inline unsigned long
 kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gra,
@@ -25,5 +27,15 @@ kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gra,
 {
 	return H_UNSUPPORTED;
 }
+
+static inline unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
+{
+	return H_UNSUPPORTED;
+}
+
+static inline unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
+{
+	return H_UNSUPPORTED;
+}
 #endif /* CONFIG_PPC_UV */
 #endif /* __POWERPC_KVM_PPC_HMM_H__ */
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 86bbe607ad7e..1827c22909cd 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -261,6 +261,10 @@ struct kvm_hpt_info {
 
 struct kvm_resize_hpt;
 
+/* Flag values for kvm_arch.secure_guest */
+#define KVMPPC_SECURE_INIT_START	0x1 /* H_SVM_INIT_START has been called */
+#define KVMPPC_SECURE_INIT_DONE		0x2 /* H_SVM_INIT_DONE completed */
+
 struct kvm_arch {
 	unsigned int lpid;
 	unsigned int smt_mode;		/* # vcpus per virtual core */
diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index 1cd1f595fd81..c578d9b13a56 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -25,6 +25,7 @@
 /* opcodes */
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
+#define UV_REGISTER_MEM_SLOT		0xF120
 #define UV_PAGE_IN			0xF128
 #define UV_PAGE_OUT			0xF12C
 
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index d668a59e099b..8a722c575c56 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -33,4 +33,11 @@ static inline int uv_page_out(u64 lpid, u64 dst_ra, u64 src_gpa, u64 flags,
 			    page_shift);
 }
 
+static inline int uv_register_mem_slot(u64 lpid, u64 start_gpa, u64 size,
+				       u64 flags, u64 slotid)
+{
+	return ucall_norets(UV_REGISTER_MEM_SLOT, lpid, start_gpa,
+			    size, flags, slotid);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 00b43ee8b693..33b8ebffbef0 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1089,6 +1089,13 @@ int kvmppc_pseries_do_hcall(struct kvm_vcpu *vcpu)
 					    kvmppc_get_gpr(vcpu, 5),
 					    kvmppc_get_gpr(vcpu, 6));
 		break;
+	case H_SVM_INIT_START:
+		ret = kvmppc_h_svm_init_start(vcpu->kvm);
+		break;
+	case H_SVM_INIT_DONE:
+		ret = kvmppc_h_svm_init_done(vcpu->kvm);
+		break;
+
 	default:
 		return RESUME_HOST;
 	}
diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c
index c9189e58401d..c55bb5f57928 100644
--- a/arch/powerpc/kvm/book3s_hv_devm.c
+++ b/arch/powerpc/kvm/book3s_hv_devm.c
@@ -65,6 +65,40 @@ struct kvmppc_devm_copy_args {
 	unsigned long page_shift;
 };
 
+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;
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	slots = kvm_memslots(kvm);
+	kvm_for_each_memslot(memslot, slots) {
+		ret = uv_register_mem_slot(kvm->arch.lpid,
+					   memslot->base_gfn << PAGE_SHIFT,
+					   memslot->npages * PAGE_SIZE,
+					   0, memslot->id);
+		if (ret < 0) {
+			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;
+	return H_SUCCESS;
+}
+
 /*
  * Bits 60:56 in the rmap entry will be used to identify the
  * different uses/functions of rmap. This definition with move
-- 
2.21.0

[PATCH v6 4/7] kvmppc: Handle memory plug/unplug to secure VM

[Bharata B Rao]

Register the new memslot with UV during plug and unregister
the memslot during unplug.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
---
 arch/powerpc/include/asm/ultravisor-api.h |  1 +
 arch/powerpc/include/asm/ultravisor.h     |  5 +++++
 arch/powerpc/kvm/book3s_hv.c              | 19 +++++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index c578d9b13a56..46b1ee381695 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -26,6 +26,7 @@
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
 #define UV_REGISTER_MEM_SLOT		0xF120
+#define UV_UNREGISTER_MEM_SLOT		0xF124
 #define UV_PAGE_IN			0xF128
 #define UV_PAGE_OUT			0xF12C
 
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index 8a722c575c56..79c415bf5ee8 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -40,4 +40,9 @@ static inline int uv_register_mem_slot(u64 lpid, u64 start_gpa, u64 size,
 			    size, flags, slotid);
 }
 
+static inline int uv_unregister_mem_slot(u64 lpid, u64 slotid)
+{
+	return ucall_norets(UV_UNREGISTER_MEM_SLOT, lpid, slotid);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 33b8ebffbef0..13e31ef3583e 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -74,6 +74,7 @@
 #include <asm/hw_breakpoint.h>
 #include <asm/kvm_host.h>
 #include <asm/kvm_book3s_devm.h>
+#include <asm/ultravisor.h>
 
 #include "book3s.h"
 
@@ -4504,6 +4505,24 @@ static void kvmppc_core_commit_memory_region_hv(struct kvm *kvm,
 	if (change == KVM_MR_FLAGS_ONLY && kvm_is_radix(kvm) &&
 	    ((new->flags ^ old->flags) & KVM_MEM_LOG_DIRTY_PAGES))
 		kvmppc_radix_flush_memslot(kvm, old);
+	/*
+	 * If UV hasn't yet called H_SVM_INIT_START, don't register memslots.
+	 */
+	if (!kvm->arch.secure_guest)
+		return;
+
+	/*
+	 * TODO: Handle KVM_MR_MOVE
+	 */
+	if (change == KVM_MR_CREATE) {
+		uv_register_mem_slot(kvm->arch.lpid,
+					   new->base_gfn << PAGE_SHIFT,
+					   new->npages * PAGE_SIZE,
+					   0,
+					   new->id);
+	} else if (change == KVM_MR_DELETE) {
+		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
+	}
 }
 
 /*
-- 
2.21.0

[PATCH v6 5/7] kvmppc: Radix changes for secure guest

[Bharata B Rao]

- After the guest becomes secure, when we handle a page fault of a page
  belonging to SVM in HV, send that page to UV via UV_PAGE_IN.
- Whenever a page is unmapped on the HV side, inform UV via UV_PAGE_INVAL.
- Ensure all those routines that walk the secondary page tables of
  the guest don't do so in case of secure VM. For secure guest, the
  active secondary page tables are in secure memory and the secondary
  page tables in HV are freed when guest becomes secure.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
---
 arch/powerpc/include/asm/kvm_host.h       | 12 ++++++++++++
 arch/powerpc/include/asm/ultravisor-api.h |  1 +
 arch/powerpc/include/asm/ultravisor.h     |  5 +++++
 arch/powerpc/kvm/book3s_64_mmu_radix.c    | 22 ++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_devm.c         | 20 ++++++++++++++++++++
 5 files changed, 60 insertions(+)

diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 1827c22909cd..db680d7f5779 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -856,6 +856,8 @@ static inline void kvm_arch_vcpu_block_finish(struct kvm_vcpu *vcpu) {}
 #ifdef CONFIG_PPC_UV
 extern int kvmppc_devm_init(void);
 extern void kvmppc_devm_free(void);
+extern bool kvmppc_is_guest_secure(struct kvm *kvm);
+extern int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gpa);
 #else
 static inline int kvmppc_devm_init(void)
 {
@@ -863,6 +865,16 @@ static inline int kvmppc_devm_init(void)
 }
 
 static inline void kvmppc_devm_free(void) {}
+
+static inline bool kvmppc_is_guest_secure(struct kvm *kvm)
+{
+	return false;
+}
+
+static inline int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gpa)
+{
+	return -EFAULT;
+}
 #endif /* CONFIG_PPC_UV */
 
 #endif /* __POWERPC_KVM_HOST_H__ */
diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index 46b1ee381695..cf200d4ce703 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -29,5 +29,6 @@
 #define UV_UNREGISTER_MEM_SLOT		0xF124
 #define UV_PAGE_IN			0xF128
 #define UV_PAGE_OUT			0xF12C
+#define UV_PAGE_INVAL			0xF138
 
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index 79c415bf5ee8..640db659c8c8 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -45,4 +45,9 @@ static inline int uv_unregister_mem_slot(u64 lpid, u64 slotid)
 	return ucall_norets(UV_UNREGISTER_MEM_SLOT, lpid, slotid);
 }
 
+static inline int uv_page_inval(u64 lpid, u64 gpa, u64 page_shift)
+{
+	return ucall_norets(UV_PAGE_INVAL, lpid, gpa, page_shift);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index 2d415c36a61d..93ad34e63045 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -19,6 +19,8 @@
 #include <asm/pgtable.h>
 #include <asm/pgalloc.h>
 #include <asm/pte-walk.h>
+#include <asm/ultravisor.h>
+#include <asm/kvm_host.h>
 
 /*
  * Supported radix tree geometry.
@@ -915,6 +917,9 @@ int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	if (!(dsisr & DSISR_PRTABLE_FAULT))
 		gpa |= ea & 0xfff;
 
+	if (kvmppc_is_guest_secure(kvm))
+		return kvmppc_send_page_to_uv(kvm, gpa & PAGE_MASK);
+
 	/* Get the corresponding memslot */
 	memslot = gfn_to_memslot(kvm, gfn);
 
@@ -972,6 +977,11 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	unsigned long gpa = gfn << PAGE_SHIFT;
 	unsigned int shift;
 
+	if (kvmppc_is_guest_secure(kvm)) {
+		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SIZE);
+		return 0;
+	}
+
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep))
 		kvmppc_unmap_pte(kvm, ptep, gpa, shift, memslot,
@@ -989,6 +999,9 @@ int kvm_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	int ref = 0;
 	unsigned long old, *rmapp;
 
+	if (kvmppc_is_guest_secure(kvm))
+		return ref;
+
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_young(*ptep)) {
 		old = kvmppc_radix_update_pte(kvm, ptep, _PAGE_ACCESSED, 0,
@@ -1013,6 +1026,9 @@ int kvm_test_age_radix(struct kvm *kvm, struct kvm_memory_slot *memslot,
 	unsigned int shift;
 	int ref = 0;
 
+	if (kvmppc_is_guest_secure(kvm))
+		return ref;
+
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_young(*ptep))
 		ref = 1;
@@ -1030,6 +1046,9 @@ static int kvm_radix_test_clear_dirty(struct kvm *kvm,
 	int ret = 0;
 	unsigned long old, *rmapp;
 
+	if (kvmppc_is_guest_secure(kvm))
+		return ret;
+
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
 		ret = 1;
@@ -1082,6 +1101,9 @@ void kvmppc_radix_flush_memslot(struct kvm *kvm,
 	unsigned long gpa;
 	unsigned int shift;
 
+	if (kvmppc_is_guest_secure(kvm))
+		return;
+
 	gpa = memslot->base_gfn << PAGE_SHIFT;
 	spin_lock(&kvm->mmu_lock);
 	for (n = memslot->npages; n; --n) {
diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c
index c55bb5f57928..9c4b05cd5b0a 100644
--- a/arch/powerpc/kvm/book3s_hv_devm.c
+++ b/arch/powerpc/kvm/book3s_hv_devm.c
@@ -65,6 +65,11 @@ struct kvmppc_devm_copy_args {
 	unsigned long page_shift;
 };
 
+bool kvmppc_is_guest_secure(struct kvm *kvm)
+{
+	return !!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE);
+}
+
 unsigned long kvmppc_h_svm_init_start(struct kvm *kvm)
 {
 	struct kvm_memslots *slots;
@@ -483,6 +488,21 @@ kvmppc_h_svm_page_out(struct kvm *kvm, unsigned long gpa,
 	return ret;
 }
 
+int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gpa)
+{
+	unsigned long pfn;
+	int ret;
+
+	pfn = gfn_to_pfn(kvm, gpa >> PAGE_SHIFT);
+	if (is_error_noslot_pfn(pfn))
+		return -EFAULT;
+
+	ret = uv_page_in(kvm->arch.lpid, pfn << PAGE_SHIFT, gpa, 0, PAGE_SHIFT);
+	kvm_release_pfn_clean(pfn);
+
+	return (ret == U_SUCCESS) ? RESUME_GUEST : -EFAULT;
+}
+
 static u64 kvmppc_get_secmem_size(void)
 {
 	struct device_node *np;
-- 
2.21.0

[PATCH v6 6/7] kvmppc: Support reset of secure guest

[Bharata B Rao]

Add support for reset of secure guest via a new ioctl KVM_PPC_SVM_OFF.
This ioctl will be issued by QEMU during reset and includes the
the following steps:

- Ask UV to terminate the guest via UV_SVM_TERMINATE ucall
- Unpin the VPA pages so that they can be migrated back to secure
  side when guest becomes secure again. This is required because
  pinned pages can't be migrated.
- Reinitialize guest's partitioned scoped page tables. These are
  freed when guest become secure (H_SVM_INIT_DONE)
- Release all device pages of the secure guest.

After these steps, guest is ready to issue UV_ESM call once again
to switch to secure mode.

Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
	[Implementation of uv_svm_terminate() and its call from
	guest shutdown path]
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
	[Unpinning of VPA pages]
---
 Documentation/virtual/kvm/api.txt          | 18 ++++++
 arch/powerpc/include/asm/kvm_book3s_devm.h |  7 +++
 arch/powerpc/include/asm/kvm_ppc.h         |  2 +
 arch/powerpc/include/asm/ultravisor-api.h  |  1 +
 arch/powerpc/include/asm/ultravisor.h      |  5 ++
 arch/powerpc/kvm/book3s_hv.c               | 70 ++++++++++++++++++++++
 arch/powerpc/kvm/book3s_hv_devm.c          | 61 +++++++++++++++++++
 arch/powerpc/kvm/powerpc.c                 | 12 ++++
 include/uapi/linux/kvm.h                   |  1 +
 9 files changed, 177 insertions(+)

diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index e54a3f51ddc5..6fdd140dd9af 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -4111,6 +4111,24 @@ Valid values for 'action':
 #define KVM_PMU_EVENT_ALLOW 0
 #define KVM_PMU_EVENT_DENY 1
 
+4.121 KVM_PPC_SVM_OFF
+
+Capability: basic
+Architectures: powerpc
+Type: vm ioctl
+Parameters: none
+Returns: 0 on successful completion,
+Errors:
+  EINVAL:    if ultravisor failed to terminate the secure guest
+  ENOMEM:    if hypervisor failed to allocate new radix page tables for guest
+
+This ioctl is used to turn off the secure mode of the guest or transition
+the guest from secure mode to normal mode. This is invoked when the guest
+is reset. This has no effect if called for a normal guest.
+
+This ioctl issues an ultravisor call to terminate the secure guest,
+unpin the VPA pages, reinitialize guest's partition scoped page
+tables and releases all the HMM pages that is associated with this guest.
 
 5. The kvm_run structure
 ------------------------
diff --git a/arch/powerpc/include/asm/kvm_book3s_devm.h b/arch/powerpc/include/asm/kvm_book3s_devm.h
index 8c7aacabb2e0..6d97da320400 100644
--- a/arch/powerpc/include/asm/kvm_book3s_devm.h
+++ b/arch/powerpc/include/asm/kvm_book3s_devm.h
@@ -13,6 +13,8 @@ extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
 					  unsigned long page_shift);
 extern unsigned long kvmppc_h_svm_init_start(struct kvm *kvm);
 extern unsigned long kvmppc_h_svm_init_done(struct kvm *kvm);
+extern void kvmppc_devm_free_memslot_pfns(struct kvm *kvm,
+		struct kvm_memslots *slots);
 #else
 static inline unsigned long
 kvmppc_h_svm_page_in(struct kvm *kvm, unsigned long gra,
@@ -37,5 +39,10 @@ static inline unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
 {
 	return H_UNSUPPORTED;
 }
+
+static inline void kvmppc_devm_free_memslot_pfns(struct kvm *kvm,
+		struct kvm_memslots *slots)
+{
+}
 #endif /* CONFIG_PPC_UV */
 #endif /* __POWERPC_KVM_PPC_HMM_H__ */
diff --git a/arch/powerpc/include/asm/kvm_ppc.h b/arch/powerpc/include/asm/kvm_ppc.h
index 2484e6a8f5ca..e4093d067354 100644
--- a/arch/powerpc/include/asm/kvm_ppc.h
+++ b/arch/powerpc/include/asm/kvm_ppc.h
@@ -177,6 +177,7 @@ extern void kvm_spapr_tce_release_iommu_group(struct kvm *kvm,
 extern int kvmppc_switch_mmu_to_hpt(struct kvm *kvm);
 extern int kvmppc_switch_mmu_to_radix(struct kvm *kvm);
 extern void kvmppc_setup_partition_table(struct kvm *kvm);
+extern int kvmppc_reinit_partition_table(struct kvm *kvm);
 
 extern long kvm_vm_ioctl_create_spapr_tce(struct kvm *kvm,
 				struct kvm_create_spapr_tce_64 *args);
@@ -321,6 +322,7 @@ struct kvmppc_ops {
 			       int size);
 	int (*store_to_eaddr)(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr,
 			      int size);
+	int (*svm_off)(struct kvm *kvm);
 };
 
 extern struct kvmppc_ops *kvmppc_hv_ops;
diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h
index cf200d4ce703..3a27a0c0be05 100644
--- a/arch/powerpc/include/asm/ultravisor-api.h
+++ b/arch/powerpc/include/asm/ultravisor-api.h
@@ -30,5 +30,6 @@
 #define UV_PAGE_IN			0xF128
 #define UV_PAGE_OUT			0xF12C
 #define UV_PAGE_INVAL			0xF138
+#define UV_SVM_TERMINATE		0xF13C
 
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */
diff --git a/arch/powerpc/include/asm/ultravisor.h b/arch/powerpc/include/asm/ultravisor.h
index 640db659c8c8..03d4fd49fa0d 100644
--- a/arch/powerpc/include/asm/ultravisor.h
+++ b/arch/powerpc/include/asm/ultravisor.h
@@ -50,4 +50,9 @@ static inline int uv_page_inval(u64 lpid, u64 gpa, u64 page_shift)
 	return ucall_norets(UV_PAGE_INVAL, lpid, gpa, page_shift);
 }
 
+static inline int uv_svm_terminate(u64 lpid)
+{
+	return ucall_norets(UV_SVM_TERMINATE, lpid);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 13e31ef3583e..b348452b2a93 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -2433,6 +2433,15 @@ static void unpin_vpa(struct kvm *kvm, struct kvmppc_vpa *vpa)
 					vpa->dirty);
 }
 
+static void unpin_vpa_reset(struct kvm *kvm, struct kvmppc_vpa *vpa)
+{
+	unpin_vpa(kvm, vpa);
+	vpa->gpa = 0;
+	vpa->pinned_addr = NULL;
+	vpa->dirty = false;
+	vpa->update_pending = 0;
+}
+
 static void kvmppc_core_vcpu_free_hv(struct kvm_vcpu *vcpu)
 {
 	spin_lock(&vcpu->arch.vpa_update_lock);
@@ -4578,6 +4587,22 @@ void kvmppc_setup_partition_table(struct kvm *kvm)
 	kvmhv_set_ptbl_entry(kvm->arch.lpid, dw0, dw1);
 }
 
+/*
+ * Called from KVM_PPC_SVM_OFF ioctl at guest reset time when secure
+ * guest is converted back to normal guest.
+ */
+int kvmppc_reinit_partition_table(struct kvm *kvm)
+{
+	int ret;
+
+	ret = kvmppc_init_vm_radix(kvm);
+	if (ret)
+		return ret;
+
+	kvmppc_setup_partition_table(kvm);
+	return 0;
+}
+
 /*
  * Set up HPT (hashed page table) and RMA (real-mode area).
  * Must be called with kvm->arch.mmu_setup_lock held.
@@ -4965,6 +4990,7 @@ static void kvmppc_core_destroy_vm_hv(struct kvm *kvm)
 		if (nesting_enabled(kvm))
 			kvmhv_release_all_nested(kvm);
 		kvm->arch.process_table = 0;
+		uv_svm_terminate(kvm->arch.lpid);
 		kvmhv_set_ptbl_entry(kvm->arch.lpid, 0, 0);
 	}
 	kvmppc_free_lpid(kvm->arch.lpid);
@@ -5406,6 +5432,49 @@ static int kvmhv_store_to_eaddr(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr,
 	return rc;
 }
 
+/*
+ *  IOCTL handler to turn off secure mode of guest
+ *
+ * - Issue ucall to terminate the guest on the UV side
+ * - Unpin the VPA pages (Enables these pages to be migrated back
+ *   when VM becomes secure again)
+ * - Recreate partition table as the guest is transitioning back to
+ *   normal mode
+ * - Release all HMM pages
+ */
+static int kvmhv_svm_off(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int ret = 0;
+	int i;
+
+	if (kvmppc_is_guest_secure(kvm)) {
+		ret = uv_svm_terminate(kvm->arch.lpid);
+		if (ret != U_SUCCESS) {
+			ret = -EINVAL;
+			goto out;
+		}
+
+		kvm_for_each_vcpu(i, vcpu, kvm) {
+			spin_lock(&vcpu->arch.vpa_update_lock);
+			unpin_vpa_reset(kvm, &vcpu->arch.dtl);
+			unpin_vpa_reset(kvm, &vcpu->arch.slb_shadow);
+			unpin_vpa_reset(kvm, &vcpu->arch.vpa);
+			spin_unlock(&vcpu->arch.vpa_update_lock);
+		}
+
+		ret = kvmppc_reinit_partition_table(kvm);
+		if (ret)
+			goto out;
+		kvm->arch.secure_guest = 0;
+		for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++)
+			kvmppc_devm_free_memslot_pfns(kvm,
+			__kvm_memslots(kvm, i));
+	}
+out:
+	return ret;
+}
+
 static struct kvmppc_ops kvm_ops_hv = {
 	.get_sregs = kvm_arch_vcpu_ioctl_get_sregs_hv,
 	.set_sregs = kvm_arch_vcpu_ioctl_set_sregs_hv,
@@ -5448,6 +5517,7 @@ static struct kvmppc_ops kvm_ops_hv = {
 	.enable_nested = kvmhv_enable_nested,
 	.load_from_eaddr = kvmhv_load_from_eaddr,
 	.store_to_eaddr = kvmhv_store_to_eaddr,
+	.svm_off = kvmhv_svm_off,
 };
 
 static int kvm_init_subcore_bitmap(void)
diff --git a/arch/powerpc/kvm/book3s_hv_devm.c b/arch/powerpc/kvm/book3s_hv_devm.c
index 9c4b05cd5b0a..1a33283192c2 100644
--- a/arch/powerpc/kvm/book3s_hv_devm.c
+++ b/arch/powerpc/kvm/book3s_hv_devm.c
@@ -38,6 +38,8 @@
 #include <linux/kvm_host.h>
 #include <linux/sched/mm.h>
 #include <asm/ultravisor.h>
+#include <asm/kvm_ppc.h>
+#include <asm/kvm_book3s.h>
 
 struct kvmppc_devm_device {
 	struct device dev;
@@ -101,6 +103,12 @@ unsigned long kvmppc_h_svm_init_done(struct kvm *kvm)
 		return H_UNSUPPORTED;
 
 	kvm->arch.secure_guest |= KVMPPC_SECURE_INIT_DONE;
+	if (kvm_is_radix(kvm)) {
+		pr_info("LPID %d went secure, freeing HV side radix pgtables\n",
+			kvm->arch.lpid);
+		kvmppc_free_radix(kvm);
+	}
+
 	return H_SUCCESS;
 }
 
@@ -116,6 +124,59 @@ static inline bool kvmppc_is_devm_pfn(unsigned long pfn)
 	return !!(pfn & KVMPPC_PFN_DEVM);
 }
 
+/*
+ * 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.
+ */
+static void kvmppc_devm_drop_pages(struct kvm_memory_slot *free,
+				   struct kvm *kvm)
+{
+	int i;
+	struct kvmppc_devm_page_pvt *pvt;
+	unsigned long pfn;
+
+	for (i = 0; i < free->npages; i++) {
+		unsigned long *rmap = &free->arch.rmap[i];
+		struct page *devm_page;
+
+		if (kvmppc_is_devm_pfn(*rmap)) {
+			devm_page = pfn_to_page(*rmap & ~KVMPPC_PFN_DEVM);
+			pvt = (struct kvmppc_devm_page_pvt *)
+				devm_page->zone_device_data;
+			pvt->skip_page_out = true;
+
+			pfn = gfn_to_pfn(kvm, pvt->gpa >> PAGE_SHIFT);
+			if (is_error_noslot_pfn(pfn))
+				continue;
+			kvm_release_pfn_clean(pfn);
+		}
+	}
+}
+
+/*
+ * Called from KVM_PPC_SVM_OFF ioctl when secure guest is reset
+ *
+ * UV has already cleaned up the guest, we release any device pages
+ * that we maintain
+ */
+void kvmppc_devm_free_memslot_pfns(struct kvm *kvm, struct kvm_memslots *slots)
+{
+	struct kvm_memory_slot *memslot;
+	int srcu_idx;
+
+	if (!slots)
+		return;
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	kvm_for_each_memslot(memslot, slots)
+		kvmppc_devm_drop_pages(memslot, kvm);
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+}
+
 /*
  * Get a free device PFN from the pool
  *
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 0dba7eb24f92..77dceaa8fb55 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -31,6 +31,8 @@
 #include <asm/hvcall.h>
 #include <asm/plpar_wrappers.h>
 #endif
+#include <asm/ultravisor.h>
+#include <asm/kvm_host.h>
 
 #include "timing.h"
 #include "irq.h"
@@ -2415,6 +2417,16 @@ long kvm_arch_vm_ioctl(struct file *filp,
 			r = -EFAULT;
 		break;
 	}
+	case KVM_PPC_SVM_OFF: {
+		struct kvm *kvm = filp->private_data;
+
+		r = 0;
+		if (!kvm->arch.kvm_ops->svm_off)
+			goto out;
+
+		r = kvm->arch.kvm_ops->svm_off(kvm);
+		break;
+	}
 	default: {
 		struct kvm *kvm = filp->private_data;
 		r = kvm->arch.kvm_ops->arch_vm_ioctl(filp, ioctl, arg);
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index a7c19540ce21..07041a64e21f 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1332,6 +1332,7 @@ struct kvm_s390_ucas_mapping {
 #define KVM_PPC_GET_CPU_CHAR	  _IOR(KVMIO,  0xb1, struct kvm_ppc_cpu_char)
 /* Available with KVM_CAP_PMU_EVENT_FILTER */
 #define KVM_SET_PMU_EVENT_FILTER  _IOW(KVMIO,  0xb2, struct kvm_pmu_event_filter)
+#define KVM_PPC_SVM_OFF		  _IO(KVMIO,  0xb3)
 
 /* ioctl for vm fd */
 #define KVM_CREATE_DEVICE	  _IOWR(KVMIO,  0xe0, struct kvm_create_device)
-- 
2.21.0

[PATCH v6 7/7] KVM: PPC: Ultravisor: Add PPC_UV config option

[Bharata B Rao]

From: Anshuman Khandual <khandual@linux.vnet.ibm.com>

CONFIG_PPC_UV adds support for ultravisor.

Signed-off-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>
Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
[ Update config help and commit message ]
Signed-off-by: Claudio Carvalho <cclaudio@linux.ibm.com>
---
 arch/powerpc/Kconfig | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index d8dcd8820369..8b36ca5ed3b0 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -448,6 +448,24 @@ config PPC_TRANSACTIONAL_MEM
 	help
 	  Support user-mode Transactional Memory on POWERPC.
 
+config PPC_UV
+	bool "Ultravisor support"
+	depends on KVM_BOOK3S_HV_POSSIBLE
+	select ZONE_DEVICE
+	select MIGRATE_VMA_HELPER
+	select DEV_PAGEMAP_OPS
+	select DEVICE_PRIVATE
+	select MEMORY_HOTPLUG
+	select MEMORY_HOTREMOVE
+	default n
+	help
+	  This option paravirtualizes the kernel to run in POWER platforms that
+	  supports the Protected Execution Facility (PEF). In such platforms,
+	  the ultravisor firmware runs at a privilege level above the
+	  hypervisor.
+
+	  If unsure, say "N".
+
 config LD_HEAD_STUB_CATCH
 	bool "Reserve 256 bytes to cope with linker stubs in HEAD text" if EXPERT
 	depends on PPC64
-- 
2.21.0

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Christoph Hellwig]

> +#ifdef CONFIG_PPC_UV
> +extern unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
> +					  unsigned long gra,
> +					  unsigned long flags,
> +					  unsigned long page_shift);
> +extern unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
> +					  unsigned long gra,
> +					  unsigned long flags,
> +					  unsigned long page_shift);

No need for externs on function declarations.

> +struct kvmppc_devm_device {
> +	struct device dev;
> +	dev_t devt;
> +	struct dev_pagemap pagemap;
> +	unsigned long pfn_first, pfn_last;
> +	unsigned long *pfn_bitmap;
> +};

We shouldn't really need this conaining structucture given that there
is only a single global instance of it anyway.

> +struct kvmppc_devm_copy_args {
> +	unsigned long *rmap;
> +	unsigned int lpid;
> +	unsigned long gpa;
> +	unsigned long page_shift;
> +};

Do we really need this args structure?  It is just used in a single
function call where passing the arguments might be cleaner.

> +static void kvmppc_devm_put_page(struct page *page)
> +{
> +	unsigned long pfn = page_to_pfn(page);
> +	unsigned long flags;
> +	struct kvmppc_devm_page_pvt *pvt;
> +
> +	spin_lock_irqsave(&kvmppc_devm_lock, flags);
> +	pvt = (struct kvmppc_devm_page_pvt *)page->zone_device_data;

No need for the cast.

> +	page->zone_device_data = 0;

This should be NULL.

> +
> +	bitmap_clear(kvmppc_devm.pfn_bitmap,
> +		     pfn - kvmppc_devm.pfn_first, 1);
> +	*(pvt->rmap) = 0;

No need for the braces.

> +	dpage = alloc_page_vma(GFP_HIGHUSER, mig->vma, mig->start);
> +	if (!dpage)
> +		return -EINVAL;
> +	lock_page(dpage);
> +	pvt = (struct kvmppc_devm_page_pvt *)spage->zone_device_data;

No need for the cast here.

> +static void kvmppc_devm_page_free(struct page *page)
> +{
> +	kvmppc_devm_put_page(page);
> +}

This seems to be the only caller of kvmppc_devm_put_page, any reason
not to just merge the two functions?

> +static int kvmppc_devm_pages_init(void)
> +{
> +	unsigned long nr_pfns = kvmppc_devm.pfn_last -
> +				kvmppc_devm.pfn_first;
> +
> +	kvmppc_devm.pfn_bitmap = kcalloc(BITS_TO_LONGS(nr_pfns),
> +				 sizeof(unsigned long), GFP_KERNEL);
> +	if (!kvmppc_devm.pfn_bitmap)
> +		return -ENOMEM;
> +
> +	spin_lock_init(&kvmppc_devm_lock);

Just initialize the spinlock using DEFINE_SPINLOCK() at compile time.
The rest of the function is so trivial that it can be inlined into the
caller.

Also is kvmppc_devm_lock such a good name?  This mostly just protects
the allocation bitmap, so reflecting that in the name might be a good
idea.

> +int kvmppc_devm_init(void)
> +{
> +	int ret = 0;
> +	unsigned long size;
> +	struct resource *res;
> +	void *addr;
> +
> +	size = kvmppc_get_secmem_size();
> +	if (!size) {
> +		ret = -ENODEV;
> +		goto out;
> +	}
> +
> +	ret = alloc_chrdev_region(&kvmppc_devm.devt, 0, 1,
> +				"kvmppc-devm");
> +	if (ret)
> +		goto out;
> +
> +	dev_set_name(&kvmppc_devm.dev, "kvmppc_devm_device%d", 0);
> +	kvmppc_devm.dev.release = kvmppc_devm_release;
> +	device_initialize(&kvmppc_devm.dev);
> +	res = devm_request_free_mem_region(&kvmppc_devm.dev,
> +		&iomem_resource, size);
> +	if (IS_ERR(res)) {
> +		ret = PTR_ERR(res);
> +		goto out_unregister;
> +	}
> +
> +	kvmppc_devm.pagemap.type = MEMORY_DEVICE_PRIVATE;
> +	kvmppc_devm.pagemap.res = *res;
> +	kvmppc_devm.pagemap.ops = &kvmppc_devm_ops;
> +	addr = devm_memremap_pages(&kvmppc_devm.dev, &kvmppc_devm.pagemap);
> +	if (IS_ERR(addr)) {
> +		ret = PTR_ERR(addr);
> +		goto out_unregister;
> +	}

It seems a little silly to allocate a struct device just so that we can
pass it to devm_request_free_mem_region and devm_memremap_pages.  I think
we should just create non-dev_ versions of those as well.

> +
> +	kvmppc_devm.pfn_first = res->start >> PAGE_SHIFT;
> +	kvmppc_devm.pfn_last = kvmppc_devm.pfn_first +
> +			(resource_size(res) >> PAGE_SHIFT);

pfn_last is only used to calculat a size.  Also I think we could
just use kvmppc_devm.pagemap.res directly instead of copying these
values out.  the ">> PAGE_SHIFT" is cheap enough.

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Bharata B Rao]

On Sat, Aug 10, 2019 at 12:58:19PM +0200, Christoph Hellwig wrote:
> 
> > +int kvmppc_devm_init(void)
> > +{
> > +	int ret = 0;
> > +	unsigned long size;
> > +	struct resource *res;
> > +	void *addr;
> > +
> > +	size = kvmppc_get_secmem_size();
> > +	if (!size) {
> > +		ret = -ENODEV;
> > +		goto out;
> > +	}
> > +
> > +	ret = alloc_chrdev_region(&kvmppc_devm.devt, 0, 1,
> > +				"kvmppc-devm");
> > +	if (ret)
> > +		goto out;
> > +
> > +	dev_set_name(&kvmppc_devm.dev, "kvmppc_devm_device%d", 0);
> > +	kvmppc_devm.dev.release = kvmppc_devm_release;
> > +	device_initialize(&kvmppc_devm.dev);
> > +	res = devm_request_free_mem_region(&kvmppc_devm.dev,
> > +		&iomem_resource, size);
> > +	if (IS_ERR(res)) {
> > +		ret = PTR_ERR(res);
> > +		goto out_unregister;
> > +	}
> > +
> > +	kvmppc_devm.pagemap.type = MEMORY_DEVICE_PRIVATE;
> > +	kvmppc_devm.pagemap.res = *res;
> > +	kvmppc_devm.pagemap.ops = &kvmppc_devm_ops;
> > +	addr = devm_memremap_pages(&kvmppc_devm.dev, &kvmppc_devm.pagemap);
> > +	if (IS_ERR(addr)) {
> > +		ret = PTR_ERR(addr);
> > +		goto out_unregister;
> > +	}
> 
> It seems a little silly to allocate a struct device just so that we can
> pass it to devm_request_free_mem_region and devm_memremap_pages.  I think
> we should just create non-dev_ versions of those as well.

There is no reason for us to create a device really. If non-dev versions
of the above two routines are present, I can switch.

I will take care of the rest of your comments. Thanks for the review.

Regards,
Bharata.

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Thiago Jung Bauermann]

Hello Bharata,

I have just a couple of small comments.

Bharata B Rao <bharata@linux.ibm.com> writes:

> +/*
> + * 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.
> + *
> + * @rmap here is the slot in the rmap array that corresponds to @gpa.
> + * Thus a non-zero rmap entry indicates that the corresonding guest

Typo: corresponding

> +static u64 kvmppc_get_secmem_size(void)
> +{
> +	struct device_node *np;
> +	int i, len;
> +	const __be32 *prop;
> +	u64 size = 0;
> +
> +	np = of_find_node_by_path("/ibm,ultravisor/ibm,uv-firmware");
> +	if (!np)
> +		goto out;

I believe that in general we try to avoid hard-coding the path when a
node is accessed and searched instead via its compatible property.

-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Suraj Jitindar Singh]

On Fri, 2019-08-09 at 14:11 +0530, Bharata B Rao wrote:
> KVMPPC driver 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
> 
> Private ZONE_DEVICE memory equal to the amount of secure memory
> available in the platform for running secure guests is created
> via a char device. 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. The movement
> of pages between normal and secure memory is done via
> migrate_vma_pages() using UV_PAGE_IN and UV_PAGE_OUT ucalls.

Hi Bharata,

please see my patch where I define the bits which define the type of
the rmap entry:
https://patchwork.ozlabs.org/patch/1149791/

Please add an entry for the devm pfn type like:
#define KVMPPC_RMAP_PFN_DEVM 0x0200000000000000 /* secure guest devm
pfn */

And the following in the appropriate header file

static inline bool kvmppc_rmap_is_pfn_demv(unsigned long *rmapp)
{
	return !!((*rmapp & KVMPPC_RMAP_TYPE_MASK) ==
KVMPPC_RMAP_PFN_DEVM));
}

Also see comment below.

Thanks,
Suraj

> 
> Signed-off-by: Bharata B Rao <bharata@linux.ibm.com>
> ---
>  arch/powerpc/include/asm/hvcall.h          |   4 +
>  arch/powerpc/include/asm/kvm_book3s_devm.h |  29 ++
>  arch/powerpc/include/asm/kvm_host.h        |  12 +
>  arch/powerpc/include/asm/ultravisor-api.h  |   2 +
>  arch/powerpc/include/asm/ultravisor.h      |  14 +
>  arch/powerpc/kvm/Makefile                  |   3 +
>  arch/powerpc/kvm/book3s_hv.c               |  19 +
>  arch/powerpc/kvm/book3s_hv_devm.c          | 492
> +++++++++++++++++++++
>  8 files changed, 575 insertions(+)
>  create mode 100644 arch/powerpc/include/asm/kvm_book3s_devm.h
>  create mode 100644 arch/powerpc/kvm/book3s_hv_devm.c
> 
[snip]
> +
> +struct kvmppc_devm_page_pvt {
> +	unsigned long *rmap;
> +	unsigned int lpid;
> +	unsigned long gpa;
> +};
> +
> +struct kvmppc_devm_copy_args {
> +	unsigned long *rmap;
> +	unsigned int lpid;
> +	unsigned long gpa;
> +	unsigned long page_shift;
> +};
> +
> +/*
> + * Bits 60:56 in the rmap entry will be used to identify the
> + * different uses/functions of rmap. This definition with move
> + * to a proper header when all other functions are defined.
> + */
> +#define KVMPPC_PFN_DEVM		(0x2ULL << 56)
> +
> +static inline bool kvmppc_is_devm_pfn(unsigned long pfn)
> +{
> +	return !!(pfn & KVMPPC_PFN_DEVM);
> +}
> +
> +/*
> + * 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.
> + *
> + * @rmap here is the slot in the rmap array that corresponds to
> @gpa.
> + * Thus a non-zero rmap entry indicates that the corresonding guest
> + * page has become secure, and is not mapped on the HV side.
> + *
> + * NOTE: In this and subsequent functions, we pass around and access
> + * individual elements of kvm_memory_slot->arch.rmap[] without any
> + * protection. Should we use lock_rmap() here?
> + */
> +static struct page *kvmppc_devm_get_page(unsigned long *rmap,
> +					unsigned long gpa, unsigned
> int lpid)
> +{
> +	struct page *dpage = NULL;
> +	unsigned long bit, devm_pfn;
> +	unsigned long nr_pfns = kvmppc_devm.pfn_last -
> +				kvmppc_devm.pfn_first;
> +	unsigned long flags;
> +	struct kvmppc_devm_page_pvt *pvt;
> +
> +	if (kvmppc_is_devm_pfn(*rmap))
> +		return NULL;
> +
> +	spin_lock_irqsave(&kvmppc_devm_lock, flags);
> +	bit = find_first_zero_bit(kvmppc_devm.pfn_bitmap, nr_pfns);
> +	if (bit >= nr_pfns)
> +		goto out;
> +
> +	bitmap_set(kvmppc_devm.pfn_bitmap, bit, 1);
> +	devm_pfn = bit + kvmppc_devm.pfn_first;
> +	dpage = pfn_to_page(devm_pfn);
> +
> +	if (!trylock_page(dpage))
> +		goto out_clear;
> +
> +	*rmap = devm_pfn | KVMPPC_PFN_DEVM;
> +	pvt = kzalloc(sizeof(*pvt), GFP_ATOMIC);
> +	if (!pvt)
> +		goto out_unlock;
> +	pvt->rmap = rmap;

Am I missing something, why does the rmap need to be stored in pvt?
Given the gpa is already stored and this is enough to get back to the
rmap entry, right?

> +	pvt->gpa = gpa;
> +	pvt->lpid = lpid;
> +	dpage->zone_device_data = pvt;
> +	spin_unlock_irqrestore(&kvmppc_devm_lock, flags);
> +
> +	get_page(dpage);
> +	return dpage;
> +
> +out_unlock:
> +	unlock_page(dpage);
> +out_clear:
> +	bitmap_clear(kvmppc_devm.pfn_bitmap,
> +		     devm_pfn - kvmppc_devm.pfn_first, 1);
> +out:
> +	spin_unlock_irqrestore(&kvmppc_devm_lock, flags);
> +	return NULL;
> +}
> +
> 
[snip]

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Bharata B Rao]

On Tue, Aug 20, 2019 at 04:22:15PM +1000, Suraj Jitindar Singh wrote:
> On Fri, 2019-08-09 at 14:11 +0530, Bharata B Rao wrote:
> > KVMPPC driver 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
> > 
> > Private ZONE_DEVICE memory equal to the amount of secure memory
> > available in the platform for running secure guests is created
> > via a char device. 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. The movement
> > of pages between normal and secure memory is done via
> > migrate_vma_pages() using UV_PAGE_IN and UV_PAGE_OUT ucalls.
> 
> Hi Bharata,
> 
> please see my patch where I define the bits which define the type of
> the rmap entry:
> https://patchwork.ozlabs.org/patch/1149791/
> 
> Please add an entry for the devm pfn type like:
> #define KVMPPC_RMAP_PFN_DEVM 0x0200000000000000 /* secure guest devm
> pfn */
> 
> And the following in the appropriate header file
> 
> static inline bool kvmppc_rmap_is_pfn_demv(unsigned long *rmapp)
> {
> 	return !!((*rmapp & KVMPPC_RMAP_TYPE_MASK) ==
> KVMPPC_RMAP_PFN_DEVM));
> }
> 

Sure, I have the equivalents defined locally, will move to appropriate
headers.

> Also see comment below.
> 
> > +static struct page *kvmppc_devm_get_page(unsigned long *rmap,
> > +					unsigned long gpa, unsigned
> > int lpid)
> > +{
> > +	struct page *dpage = NULL;
> > +	unsigned long bit, devm_pfn;
> > +	unsigned long nr_pfns = kvmppc_devm.pfn_last -
> > +				kvmppc_devm.pfn_first;
> > +	unsigned long flags;
> > +	struct kvmppc_devm_page_pvt *pvt;
> > +
> > +	if (kvmppc_is_devm_pfn(*rmap))
> > +		return NULL;
> > +
> > +	spin_lock_irqsave(&kvmppc_devm_lock, flags);
> > +	bit = find_first_zero_bit(kvmppc_devm.pfn_bitmap, nr_pfns);
> > +	if (bit >= nr_pfns)
> > +		goto out;
> > +
> > +	bitmap_set(kvmppc_devm.pfn_bitmap, bit, 1);
> > +	devm_pfn = bit + kvmppc_devm.pfn_first;
> > +	dpage = pfn_to_page(devm_pfn);
> > +
> > +	if (!trylock_page(dpage))
> > +		goto out_clear;
> > +
> > +	*rmap = devm_pfn | KVMPPC_PFN_DEVM;
> > +	pvt = kzalloc(sizeof(*pvt), GFP_ATOMIC);
> > +	if (!pvt)
> > +		goto out_unlock;
> > +	pvt->rmap = rmap;
> 
> Am I missing something, why does the rmap need to be stored in pvt?
> Given the gpa is already stored and this is enough to get back to the
> rmap entry, right?

I use rmap entry to note that this guest page is secure and is being
represented by device memory page on the HV side. When the page becomes
normal again, I need to undo that from dev_pagemap_ops.page_free()
where I don't have gpa.

Regards,
Bharata.

Re: [PATCH v6 1/7] kvmppc: Driver to manage pages of secure guest

[Bharata B Rao]

On Tue, Aug 20, 2019 at 12:04:33AM -0300, Thiago Jung Bauermann wrote:
> 
> Hello Bharata,
> 
> I have just a couple of small comments.
> 
> Bharata B Rao <bharata@linux.ibm.com> writes:
> 
> > +/*
> > + * 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.
> > + *
> > + * @rmap here is the slot in the rmap array that corresponds to @gpa.
> > + * Thus a non-zero rmap entry indicates that the corresonding guest
> 
> Typo: corresponding
> 
> > +static u64 kvmppc_get_secmem_size(void)
> > +{
> > +	struct device_node *np;
> > +	int i, len;
> > +	const __be32 *prop;
> > +	u64 size = 0;
> > +
> > +	np = of_find_node_by_path("/ibm,ultravisor/ibm,uv-firmware");
> > +	if (!np)
> > +		goto out;
> 
> I believe that in general we try to avoid hard-coding the path when a
> node is accessed and searched instead via its compatible property.

Thanks, will switch to of_find_compatible_node().

Regards,
Bharata.