1 files changed, 119 insertions, 12 deletions

diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
index 3ce5f4351156..6ba5a0305e25 100644
--- a/arch/s390/kvm/pv.c
+++ b/arch/s390/kvm/pv.c
@@ -5,6 +5,8 @@
  * Copyright IBM Corp. 2019, 2020
  *    Author(s): Janosch Frank <frankja@linux.ibm.com>
  */
+
+#include <linux/export.h>
 #include <linux/kvm.h>
 #include <linux/kvm_host.h>
 #include <linux/minmax.h>
@@ -18,6 +20,78 @@
 #include <linux/mmu_notifier.h>
 #include "kvm-s390.h"
 
+bool kvm_s390_pv_is_protected(struct kvm *kvm)
+{
+	lockdep_assert_held(&kvm->lock);
+	return !!kvm_s390_pv_get_handle(kvm);
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pv_is_protected);
+
+bool kvm_s390_pv_cpu_is_protected(struct kvm_vcpu *vcpu)
+{
+	lockdep_assert_held(&vcpu->mutex);
+	return !!kvm_s390_pv_cpu_get_handle(vcpu);
+}
+EXPORT_SYMBOL_GPL(kvm_s390_pv_cpu_is_protected);
+
+/**
+ * kvm_s390_pv_make_secure() - make one guest page secure
+ * @kvm: the guest
+ * @gaddr: the guest address that needs to be made secure
+ * @uvcb: the UVCB specifying which operation needs to be performed
+ *
+ * Context: needs to be called with kvm->srcu held.
+ * Return: 0 on success, < 0 in case of error.
+ */
+int kvm_s390_pv_make_secure(struct kvm *kvm, unsigned long gaddr, void *uvcb)
+{
+	unsigned long vmaddr;
+
+	lockdep_assert_held(&kvm->srcu);
+
+	vmaddr = gfn_to_hva(kvm, gpa_to_gfn(gaddr));
+	if (kvm_is_error_hva(vmaddr))
+		return -EFAULT;
+	return make_hva_secure(kvm->mm, vmaddr, uvcb);
+}
+
+int kvm_s390_pv_convert_to_secure(struct kvm *kvm, unsigned long gaddr)
+{
+	struct uv_cb_cts uvcb = {
+		.header.cmd = UVC_CMD_CONV_TO_SEC_STOR,
+		.header.len = sizeof(uvcb),
+		.guest_handle = kvm_s390_pv_get_handle(kvm),
+		.gaddr = gaddr,
+	};
+
+	return kvm_s390_pv_make_secure(kvm, gaddr, &uvcb);
+}
+
+/**
+ * kvm_s390_pv_destroy_page() - Destroy a guest page.
+ * @kvm: the guest
+ * @gaddr: the guest address to destroy
+ *
+ * An attempt will be made to destroy the given guest page. If the attempt
+ * fails, an attempt is made to export the page. If both attempts fail, an
+ * appropriate error is returned.
+ *
+ * Context: may sleep.
+ */
+int kvm_s390_pv_destroy_page(struct kvm *kvm, unsigned long gaddr)
+{
+	struct page *page;
+	int rc = 0;
+
+	mmap_read_lock(kvm->mm);
+	page = gfn_to_page(kvm, gpa_to_gfn(gaddr));
+	if (page)
+		rc = __kvm_s390_pv_destroy_page(page);
+	kvm_release_page_clean(page);
+	mmap_read_unlock(kvm->mm);
+	return rc;
+}
+
 /**
  * struct pv_vm_to_be_destroyed - Represents a protected VM that needs to
  * be destroyed
@@ -271,9 +345,10 @@ static int kvm_s390_pv_deinit_vm_fast(struct kvm *kvm, u16 *rc, u16 *rrc)
 	WRITE_ONCE(kvm->arch.gmap->guest_handle, 0);
 	KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM FAST: rc %x rrc %x",
 		     uvcb.header.rc, uvcb.header.rrc);
-	WARN_ONCE(cc, "protvirt destroy vm fast failed handle %llx rc %x rrc %x",
+	WARN_ONCE(cc && uvcb.header.rc != 0x104,
+		  "protvirt destroy vm fast failed handle %llx rc %x rrc %x",
 		  kvm_s390_pv_get_handle(kvm), uvcb.header.rc, uvcb.header.rrc);
-	/* Inteded memory leak on "impossible" error */
+	/* Intended memory leak on "impossible" error */
 	if (!cc)
 		kvm_s390_pv_dealloc_vm(kvm);
 	return cc ? -EIO : 0;
@@ -411,8 +486,12 @@ int kvm_s390_pv_deinit_cleanup_all(struct kvm *kvm, u16 *rc, u16 *rrc)
 	u16 _rc, _rrc;
 	int cc = 0;
 
-	/* Make sure the counter does not reach 0 before calling s390_uv_destroy_range */
-	atomic_inc(&kvm->mm->context.protected_count);
+	/*
+	 * Nothing to do if the counter was already 0. Otherwise make sure
+	 * the counter does not reach 0 before calling s390_uv_destroy_range.
+	 */
+	if (!atomic_inc_not_zero(&kvm->mm->context.protected_count))
+		return 0;
 
 	*rc = 1;
 	/* If the current VM is protected, destroy it */
@@ -545,6 +624,17 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
 	int cc, ret;
 	u16 dummy;
 
+	/* Add the notifier only once. No races because we hold kvm->lock */
+	if (kvm->arch.pv.mmu_notifier.ops != &kvm_s390_pv_mmu_notifier_ops) {
+		/* The notifier will be unregistered when the VM is destroyed */
+		kvm->arch.pv.mmu_notifier.ops = &kvm_s390_pv_mmu_notifier_ops;
+		ret = mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm);
+		if (ret) {
+			kvm->arch.pv.mmu_notifier.ops = NULL;
+			return ret;
+		}
+	}
+
 	ret = kvm_s390_pv_alloc_vm(kvm);
 	if (ret)
 		return ret;
@@ -557,12 +647,14 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
 	uvcb.conf_base_stor_origin =
 		virt_to_phys((void *)kvm->arch.pv.stor_base);
 	uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
+	uvcb.flags.ap_allow_instr = kvm->arch.model.uv_feat_guest.ap;
+	uvcb.flags.ap_instr_intr = kvm->arch.model.uv_feat_guest.ap_intr;
 
 	cc = uv_call_sched(0, (u64)&uvcb);
 	*rc = uvcb.header.rc;
 	*rrc = uvcb.header.rrc;
-	KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x",
-		     uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc);
+	KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x flags %04x",
+		     uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc, uvcb.flags.raw);
 
 	/* Outputs */
 	kvm->arch.pv.handle = uvcb.guest_handle;
@@ -578,11 +670,6 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc)
 		return -EIO;
 	}
 	kvm->arch.gmap->guest_handle = uvcb.guest_handle;
-	/* Add the notifier only once. No races because we hold kvm->lock */
-	if (kvm->arch.pv.mmu_notifier.ops != &kvm_s390_pv_mmu_notifier_ops) {
-		kvm->arch.pv.mmu_notifier.ops = &kvm_s390_pv_mmu_notifier_ops;
-		mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm);
-	}
 	return 0;
 }
 
@@ -616,11 +703,29 @@ static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
 		.tweak[0] = tweak,
 		.tweak[1] = offset,
 	};
-	int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
+	int ret = kvm_s390_pv_make_secure(kvm, addr, &uvcb);
+	unsigned long vmaddr;
+	bool unlocked;
 
 	*rc = uvcb.header.rc;
 	*rrc = uvcb.header.rrc;
 
+	if (ret == -ENXIO) {
+		mmap_read_lock(kvm->mm);
+		vmaddr = gfn_to_hva(kvm, gpa_to_gfn(addr));
+		if (kvm_is_error_hva(vmaddr)) {
+			ret = -EFAULT;
+		} else {
+			ret = fixup_user_fault(kvm->mm, vmaddr, FAULT_FLAG_WRITE, &unlocked);
+			if (!ret)
+				ret = __gmap_link(kvm->arch.gmap, addr, vmaddr);
+		}
+		mmap_read_unlock(kvm->mm);
+		if (!ret)
+			return -EAGAIN;
+		return ret;
+	}
+
 	if (ret && ret != -EAGAIN)
 		KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
 			     uvcb.gaddr, *rc, *rrc);
@@ -639,6 +744,8 @@ int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
 	KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
 		     addr, size);
 
+	guard(srcu)(&kvm->srcu);
+
 	while (offset < size) {
 		ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
 		if (ret == -EAGAIN) {