From: David Hildenbrand <david@redhat.com>
Date: Tue, 16 Jan 2018 18:15:26 +0100
Subject: KVM: s390: vsie: store guest addresses of satellite blocks in
 vsie_page
Git-commit: 15e5020e575d0c1a4eddd99bf7ffdc1f34a3b17d
Patch-mainline: v4.16-rc1
References: jsc#SLE-6412

This way, the values cannot change, even if another VCPU might try to
mess with the nested SCB currently getting executed by another VCPU.

We now always use the same gpa for pinning and unpinning a page (for
unpinning, it is only relevant to mark the guest page dirty for
migration).

Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20180116171526.12343-3-david@redhat.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 arch/s390/kvm/vsie.c |   37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -38,7 +38,13 @@ struct vsie_page {
 	struct gmap *gmap;			/* 0x0220 */
 	/* address of the last reported fault to guest2 */
 	unsigned long fault_addr;		/* 0x0228 */
-	__u8 reserved[0x0700 - 0x0230];		/* 0x0230 */
+	/* calculated guest addresses of satellite control blocks */
+	gpa_t sca_gpa;				/* 0x0230 */
+	gpa_t itdba_gpa;			/* 0x0238 */
+	gpa_t gvrd_gpa;				/* 0x0240 */
+	gpa_t riccbd_gpa;			/* 0x0248 */
+	gpa_t sdnx_gpa;				/* 0x0250 */
+	__u8 reserved[0x0700 - 0x0258];		/* 0x0258 */
 	struct kvm_s390_crypto_cb crycb;	/* 0x0700 */
 	__u8 fac[S390_ARCH_FAC_LIST_SIZE_BYTE];	/* 0x0800 */
 };
@@ -485,46 +491,42 @@ static void unpin_guest_page(struct kvm
 /* unpin all blocks previously pinned by pin_blocks(), marking them dirty */
 static void unpin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 {
-	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
 	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 	hpa_t hpa;
-	gpa_t gpa;
 
 	hpa = (u64) scb_s->scaoh << 32 | scb_s->scaol;
 	if (hpa) {
-		gpa = scb_o->scaol & ~0xfUL;
-		if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
-			gpa |= (u64) scb_o->scaoh << 32;
-		unpin_guest_page(vcpu->kvm, gpa, hpa);
+		unpin_guest_page(vcpu->kvm, vsie_page->sca_gpa, hpa);
+		vsie_page->sca_gpa = 0;
 		scb_s->scaol = 0;
 		scb_s->scaoh = 0;
 	}
 
 	hpa = scb_s->itdba;
 	if (hpa) {
-		gpa = scb_o->itdba & ~0xffUL;
-		unpin_guest_page(vcpu->kvm, gpa, hpa);
+		unpin_guest_page(vcpu->kvm, vsie_page->itdba_gpa, hpa);
+		vsie_page->itdba_gpa = 0;
 		scb_s->itdba = 0;
 	}
 
 	hpa = scb_s->gvrd;
 	if (hpa) {
-		gpa = scb_o->gvrd & ~0x1ffUL;
-		unpin_guest_page(vcpu->kvm, gpa, hpa);
+		unpin_guest_page(vcpu->kvm, vsie_page->gvrd_gpa, hpa);
+		vsie_page->gvrd_gpa = 0;
 		scb_s->gvrd = 0;
 	}
 
 	hpa = scb_s->riccbd;
 	if (hpa) {
-		gpa = scb_o->riccbd & ~0x3fUL;
-		unpin_guest_page(vcpu->kvm, gpa, hpa);
+		unpin_guest_page(vcpu->kvm, vsie_page->riccbd_gpa, hpa);
+		vsie_page->riccbd_gpa = 0;
 		scb_s->riccbd = 0;
 	}
 
 	hpa = scb_s->sdnxo;
 	if (hpa) {
-		gpa = scb_o->sdnxo;
-		unpin_guest_page(vcpu->kvm, gpa, hpa);
+		unpin_guest_page(vcpu->kvm, vsie_page->sdnx_gpa, hpa);
+		vsie_page->sdnx_gpa = 0;
 		scb_s->sdnxo = 0;
 	}
 }
@@ -569,6 +571,7 @@ static int pin_blocks(struct kvm_vcpu *v
 		}
 		if (rc)
 			goto unpin;
+		vsie_page->sca_gpa = gpa;
 		scb_s->scaoh = (u32)((u64)hpa >> 32);
 		scb_s->scaol = (u32)(u64)hpa;
 	}
@@ -585,6 +588,7 @@ static int pin_blocks(struct kvm_vcpu *v
 			rc = set_validity_icpt(scb_s, 0x0080U);
 			goto unpin;
 		}
+		vsie_page->itdba_gpa = gpa;
 		scb_s->itdba = hpa;
 	}
 
@@ -603,6 +607,7 @@ static int pin_blocks(struct kvm_vcpu *v
 			rc = set_validity_icpt(scb_s, 0x1310U);
 			goto unpin;
 		}
+		vsie_page->gvrd_gpa = gpa;
 		scb_s->gvrd = hpa;
 	}
 
@@ -619,6 +624,7 @@ static int pin_blocks(struct kvm_vcpu *v
 			goto unpin;
 		}
 		/* Validity 0x0044 will be checked by SIE */
+		vsie_page->riccbd_gpa = gpa;
 		scb_s->riccbd = hpa;
 	}
 	if ((scb_s->ecb & ECB_GS) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
@@ -646,6 +652,7 @@ static int pin_blocks(struct kvm_vcpu *v
 			rc = set_validity_icpt(scb_s, 0x10b0U);
 			goto unpin;
 		}
+		vsie_page->sdnx_gpa = gpa;
 		scb_s->sdnxo = hpa | sdnxc;
 	}
 	return 0;