Merge tag 'kvm-s390-next-20141107' of...

Merge tag 'kvm-s390-next-20141107' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Fixes for kvm/next (3.19) and stable

1. We should flush TLBs for load control instruction emulation (stable)
2. A workaround for a compiler bug that renders ACCESS_ONCE broken (stable)
3. Fix program check handling for load control
4. Documentation Fix

Documentation/virtual/kvm/devices/vm.txt

@@ -12,14 +12,14 @@ specific.
 1. GROUP: KVM_S390_VM_MEM_CTRL
 Architectures: s390
 
-1.1. ATTRIBUTE: KVM_S390_VM_MEM_CTRL
+1.1. ATTRIBUTE: KVM_S390_VM_MEM_ENABLE_CMMA
 Parameters: none
-Returns: -EBUSY if already a vcpus is defined, otherwise 0
+Returns: -EBUSY if a vcpu is already defined, otherwise 0
 
-Enables CMMA for the virtual machine
+Enables Collaborative Memory Management Assist (CMMA) for the virtual machine.
 
-1.2. ATTRIBUTE: KVM_S390_VM_CLR_CMMA
-Parameteres: none
+1.2. ATTRIBUTE: KVM_S390_VM_MEM_CLR_CMMA
+Parameters: none
 Returns: 0
 
 Clear the CMMA status for all guest pages, so any pages the guest marked

arch/s390/kvm/gaccess.c

@@ -227,10 +227,12 @@ static void ipte_lock_simple(struct kvm_vcpu *vcpu)
 		goto out;
 	ic = &vcpu->kvm->arch.sca->ipte_control;
 	do {
-		old = ACCESS_ONCE(*ic);
+		old = *ic;
+		barrier();
 		while (old.k) {
 			cond_resched();
-			old = ACCESS_ONCE(*ic);
+			old = *ic;
+			barrier();
 		}
 		new = old;
 		new.k = 1;
@@ -249,7 +251,9 @@ static void ipte_unlock_simple(struct kvm_vcpu *vcpu)
 		goto out;
 	ic = &vcpu->kvm->arch.sca->ipte_control;
 	do {
-		new = old = ACCESS_ONCE(*ic);
+		old = *ic;
+		barrier();
+		new = old;
 		new.k = 0;
 	} while (cmpxchg(&ic->val, old.val, new.val) != old.val);
 	wake_up(&vcpu->kvm->arch.ipte_wq);
@@ -263,10 +267,12 @@ static void ipte_lock_siif(struct kvm_vcpu *vcpu)
 
 	ic = &vcpu->kvm->arch.sca->ipte_control;
 	do {
-		old = ACCESS_ONCE(*ic);
+		old = *ic;
+		barrier();
 		while (old.kg) {
 			cond_resched();
-			old = ACCESS_ONCE(*ic);
+			old = *ic;
+			barrier();
 		}
 		new = old;
 		new.k = 1;
@@ -280,7 +286,9 @@ static void ipte_unlock_siif(struct kvm_vcpu *vcpu)
 
 	ic = &vcpu->kvm->arch.sca->ipte_control;
 	do {
-		new = old = ACCESS_ONCE(*ic);
+		old = *ic;
+		barrier();
+		new = old;
 		new.kh--;
 		if (!new.kh)
 			new.k = 0;

arch/s390/kvm/priv.c

@@ -762,8 +762,8 @@ int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu)
 {
 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
-	u32 val = 0;
-	int reg, rc;
+	int reg, rc, nr_regs;
+	u32 ctl_array[16];
 	u64 ga;
 
 	vcpu->stat.instruction_lctl++;
@@ -779,19 +779,20 @@ int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu)
 	VCPU_EVENT(vcpu, 5, "lctl r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
 	trace_kvm_s390_handle_lctl(vcpu, 0, reg1, reg3, ga);
 
+	nr_regs = ((reg3 - reg1) & 0xf) + 1;
+	rc = read_guest(vcpu, ga, ctl_array, nr_regs * sizeof(u32));
+	if (rc)
+		return kvm_s390_inject_prog_cond(vcpu, rc);
 	reg = reg1;
+	nr_regs = 0;
 	do {
-		rc = read_guest(vcpu, ga, &val, sizeof(val));
-		if (rc)
-			return kvm_s390_inject_prog_cond(vcpu, rc);
 		vcpu->arch.sie_block->gcr[reg] &= 0xffffffff00000000ul;
-		vcpu->arch.sie_block->gcr[reg] |= val;
-		ga += 4;
+		vcpu->arch.sie_block->gcr[reg] |= ctl_array[nr_regs++];
 		if (reg == reg3)
 			break;
 		reg = (reg + 1) % 16;
 	} while (1);
-
+	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	return 0;
 }
 
@@ -799,9 +800,9 @@ int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu)
 {
 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
+	int reg, rc, nr_regs;
+	u32 ctl_array[16];
 	u64 ga;
-	u32 val;
-	int reg, rc;
 
 	vcpu->stat.instruction_stctl++;
 
@@ -817,26 +818,24 @@ int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu)
 	trace_kvm_s390_handle_stctl(vcpu, 0, reg1, reg3, ga);
 
 	reg = reg1;
+	nr_regs = 0;
 	do {
-		val = vcpu->arch.sie_block->gcr[reg] &  0x00000000fffffffful;
-		rc = write_guest(vcpu, ga, &val, sizeof(val));
-		if (rc)
-			return kvm_s390_inject_prog_cond(vcpu, rc);
-		ga += 4;
+		ctl_array[nr_regs++] = vcpu->arch.sie_block->gcr[reg];
 		if (reg == reg3)
 			break;
 		reg = (reg + 1) % 16;
 	} while (1);
-
-	return 0;
+	rc = write_guest(vcpu, ga, ctl_array, nr_regs * sizeof(u32));
+	return rc ? kvm_s390_inject_prog_cond(vcpu, rc) : 0;
 }
 
 static int handle_lctlg(struct kvm_vcpu *vcpu)
 {
 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
-	u64 ga, val;
-	int reg, rc;
+	int reg, rc, nr_regs;
+	u64 ctl_array[16];
+	u64 ga;
 
 	vcpu->stat.instruction_lctlg++;
 
@@ -848,22 +847,22 @@ static int handle_lctlg(struct kvm_vcpu *vcpu)
 	if (ga & 7)
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-	reg = reg1;
-
 	VCPU_EVENT(vcpu, 5, "lctlg r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
 	trace_kvm_s390_handle_lctl(vcpu, 1, reg1, reg3, ga);
 
+	nr_regs = ((reg3 - reg1) & 0xf) + 1;
+	rc = read_guest(vcpu, ga, ctl_array, nr_regs * sizeof(u64));
+	if (rc)
+		return kvm_s390_inject_prog_cond(vcpu, rc);
+	reg = reg1;
+	nr_regs = 0;
 	do {
-		rc = read_guest(vcpu, ga, &val, sizeof(val));
-		if (rc)
-			return kvm_s390_inject_prog_cond(vcpu, rc);
-		vcpu->arch.sie_block->gcr[reg] = val;
-		ga += 8;
+		vcpu->arch.sie_block->gcr[reg] = ctl_array[nr_regs++];
 		if (reg == reg3)
 			break;
 		reg = (reg + 1) % 16;
 	} while (1);
-
+	kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
 	return 0;
 }
 
@@ -871,8 +870,9 @@ static int handle_stctg(struct kvm_vcpu *vcpu)
 {
 	int reg1 = (vcpu->arch.sie_block->ipa & 0x00f0) >> 4;
 	int reg3 = vcpu->arch.sie_block->ipa & 0x000f;
-	u64 ga, val;
-	int reg, rc;
+	int reg, rc, nr_regs;
+	u64 ctl_array[16];
+	u64 ga;
 
 	vcpu->stat.instruction_stctg++;
 
@@ -884,23 +884,19 @@ static int handle_stctg(struct kvm_vcpu *vcpu)
 	if (ga & 7)
 		return kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
 
-	reg = reg1;
-
 	VCPU_EVENT(vcpu, 5, "stctg r1:%x, r3:%x, addr:%llx", reg1, reg3, ga);
 	trace_kvm_s390_handle_stctl(vcpu, 1, reg1, reg3, ga);
 
+	reg = reg1;
+	nr_regs = 0;
 	do {
-		val = vcpu->arch.sie_block->gcr[reg];
-		rc = write_guest(vcpu, ga, &val, sizeof(val));
-		if (rc)
-			return kvm_s390_inject_prog_cond(vcpu, rc);
-		ga += 8;
+		ctl_array[nr_regs++] = vcpu->arch.sie_block->gcr[reg];
 		if (reg == reg3)
 			break;
 		reg = (reg + 1) % 16;
 	} while (1);
-
-	return 0;
+	rc = write_guest(vcpu, ga, ctl_array, nr_regs * sizeof(u64));
+	return rc ? kvm_s390_inject_prog_cond(vcpu, rc) : 0;
 }
 
 static const intercept_handler_t eb_handlers[256] = {