Merge tag 'kvm-ppc-uvmem-5.5-2' of...

Merge tag 'kvm-ppc-uvmem-5.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into HEAD

KVM: Add support for secure guests under the Protected Execution
Framework (PEF) Ultravisor on POWER.

This enables secure memory to be represented as device memory,
which provides a way for the host to keep track of which pages of a
secure guest have been moved into secure memory managed by the
ultravisor and are no longer accessible by the host, and manage
movement of pages between secure and normal memory.

Documentation/virt/kvm/api.txt

@@ -4149,6 +4149,24 @@ 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,
+unpins the VPA pages and releases all the device pages that are used to
+track the secure pages by hypervisor.
 
 5. The kvm_run structure
 ------------------------

arch/powerpc/Kconfig

@@ -451,6 +451,23 @@ 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 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). On 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

arch/powerpc/include/asm/hvcall.h

@@ -342,6 +342,15 @@
 #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
+#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
 #define H_SET_MODE_RESOURCE_SET_DAWR		2

arch/powerpc/include/asm/kvm_book3s_uvmem.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_KVM_BOOK3S_UVMEM_H__
+#define __ASM_KVM_BOOK3S_UVMEM_H__
+
+#ifdef CONFIG_PPC_UV
+int kvmppc_uvmem_init(void);
+void kvmppc_uvmem_free(void);
+int kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot);
+void kvmppc_uvmem_slot_free(struct kvm *kvm,
+			    const struct kvm_memory_slot *slot);
+unsigned long kvmppc_h_svm_page_in(struct kvm *kvm,
+				   unsigned long gra,
+				   unsigned long flags,
+				   unsigned long page_shift);
+unsigned long kvmppc_h_svm_page_out(struct kvm *kvm,
+				    unsigned long gra,
+				    unsigned long flags,
+				    unsigned long page_shift);
+unsigned long kvmppc_h_svm_init_start(struct kvm *kvm);
+unsigned long kvmppc_h_svm_init_done(struct kvm *kvm);
+int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn);
+void kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
+			     struct kvm *kvm);
+#else
+static inline int kvmppc_uvmem_init(void)
+{
+	return 0;
+}
+
+static inline void kvmppc_uvmem_free(void) { }
+
+static inline int
+kvmppc_uvmem_slot_init(struct kvm *kvm, const struct kvm_memory_slot *slot)
+{
+	return 0;
+}
+
+static inline void
+kvmppc_uvmem_slot_free(struct kvm *kvm, const struct kvm_memory_slot *slot) { }
+
+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;
+}
+
+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;
+}
+
+static inline int kvmppc_send_page_to_uv(struct kvm *kvm, unsigned long gfn)
+{
+	return -EFAULT;
+}
+
+static inline void
+kvmppc_uvmem_drop_pages(const struct kvm_memory_slot *free,
+			struct kvm *kvm) { }
+#endif /* CONFIG_PPC_UV */
+#endif /* __ASM_KVM_BOOK3S_UVMEM_H__ */

arch/powerpc/include/asm/kvm_host.h

@@ -275,6 +275,10 @@ 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 */
@@ -330,6 +334,8 @@ struct kvm_arch {
 #endif
 	struct kvmppc_ops *kvm_ops;
 #ifdef CONFIG_KVM_BOOK3S_HV_POSSIBLE
+	struct mutex uvmem_lock;
+	struct list_head uvmem_pfns;
 	struct mutex mmu_setup_lock;	/* nests inside vcpu mutexes */
 	u64 l1_ptcr;
 	int max_nested_lpid;

arch/powerpc/include/asm/kvm_ppc.h

@@ -322,6 +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;

arch/powerpc/include/asm/ultravisor-api.h

@@ -26,8 +26,14 @@
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
 #define UV_ESM				0xF110
+#define UV_REGISTER_MEM_SLOT		0xF120
+#define UV_UNREGISTER_MEM_SLOT		0xF124
+#define UV_PAGE_IN			0xF128
+#define UV_PAGE_OUT			0xF12C
 #define UV_SHARE_PAGE			0xF130
 #define UV_UNSHARE_PAGE			0xF134
 #define UV_UNSHARE_ALL_PAGES		0xF140
+#define UV_PAGE_INVAL			0xF138
+#define UV_SVM_TERMINATE		0xF13C
 
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */

arch/powerpc/include/asm/ultravisor.h

@@ -46,4 +46,40 @@ static inline int uv_unshare_all_pages(void)
 	return ucall_norets(UV_UNSHARE_ALL_PAGES);
 }
 
+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);
+}
+
+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);
+}
+
+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);
+}
+
+static inline int uv_svm_terminate(u64 lpid)
+{
+	return ucall_norets(UV_SVM_TERMINATE, lpid);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */

arch/powerpc/kvm/Makefile

@@ -71,6 +71,9 @@ kvm-hv-y += \
 	book3s_64_mmu_radix.o \
 	book3s_hv_nested.o
 
+kvm-hv-$(CONFIG_PPC_UV) += \
+	book3s_hv_uvmem.o
+
 kvm-hv-$(CONFIG_PPC_TRANSACTIONAL_MEM) += \
 	book3s_hv_tm.o
 

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_book3s_uvmem.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 (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return kvmppc_send_page_to_uv(kvm, gfn);
+
 	/* 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 (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE) {
+		uv_page_inval(kvm->arch.lpid, gpa, PAGE_SHIFT);
+		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 (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		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 (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		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 (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return ret;
+
 	ptep = __find_linux_pte(kvm->arch.pgtable, gpa, NULL, &shift);
 	if (ptep && pte_present(*ptep) && pte_dirty(*ptep)) {
 		ret = 1;
@@ -1082,6 +1101,12 @@ void kvmppc_radix_flush_memslot(struct kvm *kvm,
 	unsigned long gpa;
 	unsigned int shift;
 
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START)
+		kvmppc_uvmem_drop_pages(memslot, kvm);
+
+	if (kvm->arch.secure_guest & KVMPPC_SECURE_INIT_DONE)
+		return;
+
 	gpa = memslot->base_gfn << PAGE_SHIFT;
 	spin_lock(&kvm->mmu_lock);
 	for (n = memslot->npages; n; --n) {

arch/powerpc/kvm/book3s_hv.c

@@ -72,6 +72,9 @@
 #include <asm/xics.h>
 #include <asm/xive.h>
 #include <asm/hw_breakpoint.h>
+#include <asm/kvm_host.h>
+#include <asm/kvm_book3s_uvmem.h>
+#include <asm/ultravisor.h>
 
 #include "book3s.h"
 
@@ -1070,6 +1073,25 @@ 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;
+	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;
 	}
@@ -4494,6 +4516,29 @@ 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;
+
+	switch (change) {
+	case KVM_MR_CREATE:
+		if (kvmppc_uvmem_slot_init(kvm, new))
+			return;
+		uv_register_mem_slot(kvm->arch.lpid,
+				     new->base_gfn << PAGE_SHIFT,
+				     new->npages * PAGE_SIZE,
+				     0, new->id);
+		break;
+	case KVM_MR_DELETE:
+		uv_unregister_mem_slot(kvm->arch.lpid, old->id);
+		kvmppc_uvmem_slot_free(kvm, old);
+		break;
+	default:
+		/* TODO: Handle KVM_MR_MOVE */
+		break;
+	}
 }
 
 /*
@@ -4767,6 +4812,8 @@ static int kvmppc_core_init_vm_hv(struct kvm *kvm)
 	char buf[32];
 	int ret;
 
+	mutex_init(&kvm->arch.uvmem_lock);
+	INIT_LIST_HEAD(&kvm->arch.uvmem_pfns);
 	mutex_init(&kvm->arch.mmu_setup_lock);
 
 	/* Allocate the guest's logical partition ID */
@@ -4936,8 +4983,10 @@ 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);
 
 	kvmppc_free_pimap(kvm);
@@ -5377,6 +5426,94 @@ static int kvmhv_store_to_eaddr(struct kvm_vcpu *vcpu, ulong *eaddr, void *ptr,
 	return rc;
 }
 
+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;
+}
+
+/*
+ *  IOCTL handler to turn off secure mode of guest
+ *
+ * - Release all device pages
+ * - Issue ucall to terminate the guest on the UV side
+ * - Unpin the VPA pages.
+ * - Reinit the partition scoped page tables
+ */
+static int kvmhv_svm_off(struct kvm *kvm)
+{
+	struct kvm_vcpu *vcpu;
+	int mmu_was_ready;
+	int srcu_idx;
+	int ret = 0;
+	int i;
+
+	if (!(kvm->arch.secure_guest & KVMPPC_SECURE_INIT_START))
+		return ret;
+
+	mutex_lock(&kvm->arch.mmu_setup_lock);
+	mmu_was_ready = kvm->arch.mmu_ready;
+	if (kvm->arch.mmu_ready) {
+		kvm->arch.mmu_ready = 0;
+		/* order mmu_ready vs. vcpus_running */
+		smp_mb();
+		if (atomic_read(&kvm->arch.vcpus_running)) {
+			kvm->arch.mmu_ready = 1;
+			ret = -EBUSY;
+			goto out;
+		}
+	}
+
+	srcu_idx = srcu_read_lock(&kvm->srcu);
+	for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
+		struct kvm_memory_slot *memslot;
+		struct kvm_memslots *slots = __kvm_memslots(kvm, i);
+
+		if (!slots)
+			continue;
+
+		kvm_for_each_memslot(memslot, slots) {
+			kvmppc_uvmem_drop_pages(memslot, kvm);
+			uv_unregister_mem_slot(kvm->arch.lpid, memslot->id);
+		}
+	}
+	srcu_read_unlock(&kvm->srcu, srcu_idx);
+
+	ret = uv_svm_terminate(kvm->arch.lpid);
+	if (ret != U_SUCCESS) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	/*
+	 * When secure guest is reset, all the guest pages are sent
+	 * to UV via UV_PAGE_IN before the non-boot vcpus get a
+	 * chance to run and unpin their VPA pages. Unpinning of all
+	 * VPA pages is done here explicitly so that VPA pages
+	 * can be migrated to the secure side.
+	 *
+	 * This is required to for the secure SMP guest to reboot
+	 * correctly.
+	 */
+	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);
+	}
+
+	kvmppc_setup_partition_table(kvm);
+	kvm->arch.secure_guest = 0;
+	kvm->arch.mmu_ready = mmu_was_ready;
+out:
+	mutex_unlock(&kvm->arch.mmu_setup_lock);
+	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,
@@ -5420,6 +5557,7 @@ 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)
@@ -5528,11 +5666,16 @@ static int kvmppc_book3s_init_hv(void)
 			no_mixing_hpt_and_radix = true;
 	}
 
+	r = kvmppc_uvmem_init();
+	if (r < 0)
+		pr_err("KVM-HV: kvmppc_uvmem_init failed %d\n", r);
+
 	return r;
 }
 
 static void kvmppc_book3s_exit_hv(void)
 {
+	kvmppc_uvmem_free();
 	kvmppc_free_host_rm_ops();
 	if (kvmppc_radix_possible())
 		kvmppc_radix_exit();

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"
@@ -2413,6 +2415,16 @@ 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);

include/uapi/linux/kvm.h

@@ -1348,6 +1348,7 @@ 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)

mm/ksm.c

@@ -2478,6 +2478,7 @@ int ksm_madvise(struct vm_area_struct *vma, unsigned long start,
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(ksm_madvise);
 
 int __ksm_enter(struct mm_struct *mm)
 {