1 files changed, 55 insertions, 36 deletions

diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 751348348477..ec772700ff96 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -28,13 +28,23 @@ struct vsie_page {
 	 * the same offset as that in struct sie_page!
 	 */
 	struct mcck_volatile_info mcck_info;    /* 0x0200 */
-	/* the pinned originial scb */
+	/*
+	 * The pinned original scb. Be aware that other VCPUs can modify
+	 * it while we read from it. Values that are used for conditions or
+	 * are reused conditionally, should be accessed via READ_ONCE.
+	 */
 	struct kvm_s390_sie_block *scb_o;	/* 0x0218 */
 	/* the shadow gmap in use by the 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 */
 };
@@ -140,12 +150,13 @@ static int shadow_crycb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 {
 	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
-	u32 crycb_addr = scb_o->crycbd & 0x7ffffff8U;
+	const uint32_t crycbd_o = READ_ONCE(scb_o->crycbd);
+	const u32 crycb_addr = crycbd_o & 0x7ffffff8U;
 	unsigned long *b1, *b2;
 	u8 ecb3_flags;
 
 	scb_s->crycbd = 0;
-	if (!(scb_o->crycbd & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
+	if (!(crycbd_o & vcpu->arch.sie_block->crycbd & CRYCB_FORMAT1))
 		return 0;
 	/* format-1 is supported with message-security-assist extension 3 */
 	if (!test_kvm_facility(vcpu->kvm, 76))
@@ -183,12 +194,15 @@ static void prepare_ibc(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 {
 	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
 	struct kvm_s390_sie_block *scb_o = vsie_page->scb_o;
+	/* READ_ONCE does not work on bitfields - use a temporary variable */
+	const uint32_t __new_ibc = scb_o->ibc;
+	const uint32_t new_ibc = READ_ONCE(__new_ibc) & 0x0fffU;
 	__u64 min_ibc = (sclp.ibc >> 16) & 0x0fffU;
 
 	scb_s->ibc = 0;
 	/* ibc installed in g2 and requested for g3 */
-	if (vcpu->kvm->arch.model.ibc && (scb_o->ibc & 0x0fffU)) {
-		scb_s->ibc = scb_o->ibc & 0x0fffU;
+	if (vcpu->kvm->arch.model.ibc && new_ibc) {
+		scb_s->ibc = new_ibc;
 		/* takte care of the minimum ibc level of the machine */
 		if (scb_s->ibc < min_ibc)
 			scb_s->ibc = min_ibc;
@@ -259,6 +273,10 @@ static int shadow_scb(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;
+	/* READ_ONCE does not work on bitfields - use a temporary variable */
+	const uint32_t __new_prefix = scb_o->prefix;
+	const uint32_t new_prefix = READ_ONCE(__new_prefix);
+	const bool wants_tx = READ_ONCE(scb_o->ecb) & ECB_TE;
 	bool had_tx = scb_s->ecb & ECB_TE;
 	unsigned long new_mso = 0;
 	int rc;
@@ -306,14 +324,14 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	scb_s->icpua = scb_o->icpua;
 
 	if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
-		new_mso = scb_o->mso & 0xfffffffffff00000UL;
+		new_mso = READ_ONCE(scb_o->mso) & 0xfffffffffff00000UL;
 	/* if the hva of the prefix changes, we have to remap the prefix */
-	if (scb_s->mso != new_mso || scb_s->prefix != scb_o->prefix)
+	if (scb_s->mso != new_mso || scb_s->prefix != new_prefix)
 		prefix_unmapped(vsie_page);
 	 /* SIE will do mso/msl validity and exception checks for us */
 	scb_s->msl = scb_o->msl & 0xfffffffffff00000UL;
 	scb_s->mso = new_mso;
-	scb_s->prefix = scb_o->prefix;
+	scb_s->prefix = new_prefix;
 
 	/* We have to definetly flush the tlb if this scb never ran */
 	if (scb_s->ihcpu != 0xffffU)
@@ -325,11 +343,11 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_ESOP))
 		scb_s->ecb |= scb_o->ecb & ECB_HOSTPROTINT;
 	/* transactional execution */
-	if (test_kvm_facility(vcpu->kvm, 73)) {
+	if (test_kvm_facility(vcpu->kvm, 73) && wants_tx) {
 		/* remap the prefix is tx is toggled on */
-		if ((scb_o->ecb & ECB_TE) && !had_tx)
+		if (!had_tx)
 			prefix_unmapped(vsie_page);
-		scb_s->ecb |= scb_o->ecb & ECB_TE;
+		scb_s->ecb |= ECB_TE;
 	}
 	/* branch prediction */
 	if (test_kvm_facility(vcpu->kvm, 82))
@@ -473,46 +491,42 @@ static void unpin_guest_page(struct kvm *kvm, gpa_t gpa, hpa_t hpa)
 /* 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;
 	}
 }
@@ -539,9 +553,9 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	gpa_t gpa;
 	int rc = 0;
 
-	gpa = scb_o->scaol & ~0xfUL;
+	gpa = READ_ONCE(scb_o->scaol) & ~0xfUL;
 	if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_64BSCAO))
-		gpa |= (u64) scb_o->scaoh << 32;
+		gpa |= (u64) READ_ONCE(scb_o->scaoh) << 32;
 	if (gpa) {
 		if (!(gpa & ~0x1fffUL))
 			rc = set_validity_icpt(scb_s, 0x0038U);
@@ -557,11 +571,12 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 		}
 		if (rc)
 			goto unpin;
+		vsie_page->sca_gpa = gpa;
 		scb_s->scaoh = (u32)((u64)hpa >> 32);
 		scb_s->scaol = (u32)(u64)hpa;
 	}
 
-	gpa = scb_o->itdba & ~0xffUL;
+	gpa = READ_ONCE(scb_o->itdba) & ~0xffUL;
 	if (gpa && (scb_s->ecb & ECB_TE)) {
 		if (!(gpa & ~0x1fffU)) {
 			rc = set_validity_icpt(scb_s, 0x0080U);
@@ -573,10 +588,11 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 			rc = set_validity_icpt(scb_s, 0x0080U);
 			goto unpin;
 		}
+		vsie_page->itdba_gpa = gpa;
 		scb_s->itdba = hpa;
 	}
 
-	gpa = scb_o->gvrd & ~0x1ffUL;
+	gpa = READ_ONCE(scb_o->gvrd) & ~0x1ffUL;
 	if (gpa && (scb_s->eca & ECA_VX) && !(scb_s->ecd & ECD_HOSTREGMGMT)) {
 		if (!(gpa & ~0x1fffUL)) {
 			rc = set_validity_icpt(scb_s, 0x1310U);
@@ -591,10 +607,11 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 			rc = set_validity_icpt(scb_s, 0x1310U);
 			goto unpin;
 		}
+		vsie_page->gvrd_gpa = gpa;
 		scb_s->gvrd = hpa;
 	}
 
-	gpa = scb_o->riccbd & ~0x3fUL;
+	gpa = READ_ONCE(scb_o->riccbd) & ~0x3fUL;
 	if (gpa && (scb_s->ecb3 & ECB3_RI)) {
 		if (!(gpa & ~0x1fffUL)) {
 			rc = set_validity_icpt(scb_s, 0x0043U);
@@ -607,13 +624,14 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 			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)) {
 		unsigned long sdnxc;
 
-		gpa = scb_o->sdnxo & ~0xfUL;
-		sdnxc = scb_o->sdnxo & 0xfUL;
+		gpa = READ_ONCE(scb_o->sdnxo) & ~0xfUL;
+		sdnxc = READ_ONCE(scb_o->sdnxo) & 0xfUL;
 		if (!gpa || !(gpa & ~0x1fffUL)) {
 			rc = set_validity_icpt(scb_s, 0x10b0U);
 			goto unpin;
@@ -634,6 +652,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 			rc = set_validity_icpt(scb_s, 0x10b0U);
 			goto unpin;
 		}
+		vsie_page->sdnx_gpa = gpa;
 		scb_s->sdnxo = hpa | sdnxc;
 	}
 	return 0;
@@ -778,7 +797,7 @@ static void retry_vsie_icpt(struct vsie_page *vsie_page)
 static int handle_stfle(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 {
 	struct kvm_s390_sie_block *scb_s = &vsie_page->scb_s;
-	__u32 fac = vsie_page->scb_o->fac & 0x7ffffff8U;
+	__u32 fac = READ_ONCE(vsie_page->scb_o->fac) & 0x7ffffff8U;
 
 	if (fac && test_kvm_facility(vcpu->kvm, 7)) {
 		retry_vsie_icpt(vsie_page);
@@ -904,7 +923,7 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu,
 	 * External calls have to lead to a kick of the vcpu and
 	 * therefore the vsie -> Simulate Wait state.
 	 */
-	atomic_or(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
+	kvm_s390_set_cpuflags(vcpu, CPUSTAT_WAIT);
 	/*
 	 * We have to adjust the g3 epoch by the g2 epoch. The epoch will
 	 * automatically be adjusted on tod clock changes via kvm_sync_clock.
@@ -926,7 +945,7 @@ static void register_shadow_scb(struct kvm_vcpu *vcpu,
  */
 static void unregister_shadow_scb(struct kvm_vcpu *vcpu)
 {
-	atomic_andnot(CPUSTAT_WAIT, &vcpu->arch.sie_block->cpuflags);
+	kvm_s390_clear_cpuflags(vcpu, CPUSTAT_WAIT);
 	WRITE_ONCE(vcpu->arch.vsie_block, NULL);
 }