Merge tag 'kvm-s390-next-4.12-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux into HEAD

KVM: s390: Guarded storage fixup and keyless subset mode

- detect and use the keyless subset mode (guests without
  storage keys)
- fix vSIE support for sdnxc
- fix machine check data for guarded storage

9 files changed, 36 insertions, 9 deletions

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 552c319483c6..426614a882a9 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -122,6 +122,7 @@ struct esca_block {
 #define CPUSTAT_SLSR       0x00002000
 #define CPUSTAT_ZARCH      0x00000800
 #define CPUSTAT_MCDS       0x00000100
+#define CPUSTAT_KSS        0x00000200
 #define CPUSTAT_SM         0x00000080
 #define CPUSTAT_IBS        0x00000040
 #define CPUSTAT_GED2       0x00000010
@@ -185,6 +186,7 @@ struct kvm_s390_sie_block {
 #define ICPT_OPEREXC	0x2C
 #define ICPT_PARTEXEC	0x38
 #define ICPT_IOINST	0x40
+#define ICPT_KSS	0x5c
 	__u8	icptcode;		/* 0x0050 */
 	__u8	icptstatus;		/* 0x0051 */
 	__u16	ihcpu;			/* 0x0052 */
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index ace3bd315438..6f5167bc1928 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -75,6 +75,7 @@ struct sclp_info {
 	unsigned char has_pfmfi : 1;
 	unsigned char has_ibs : 1;
 	unsigned char has_skey : 1;
+	unsigned char has_kss : 1;
 	unsigned int ibc;
 	unsigned int mtid;
 	unsigned int mtid_cp;
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h
index 2c9ad251fa33..bf9267930939 100644
--- a/arch/s390/include/uapi/asm/kvm.h
+++ b/arch/s390/include/uapi/asm/kvm.h
@@ -119,6 +119,7 @@ struct kvm_s390_vm_cpu_machine {
 #define KVM_S390_VM_CPU_FEAT_CMMA	10
 #define KVM_S390_VM_CPU_FEAT_PFMFI	11
 #define KVM_S390_VM_CPU_FEAT_SIGPIF	12
+#define KVM_S390_VM_CPU_FEAT_KSS	13
 struct kvm_s390_vm_cpu_feat {
 	__u64 feat[16];
 };
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index f5378f336127..a4752bf6b526 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -426,6 +426,9 @@ int kvm_handle_sie_intercept(struct kvm_vcpu *vcpu)
 	case ICPT_PARTEXEC:
 		rc = handle_partial_execution(vcpu);
 		break;
+	case ICPT_KSS:
+		rc = kvm_s390_skey_check_enable(vcpu);
+		break;
 	default:
 		return -EOPNOTSUPP;
 	}
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 482673e3436d..caf15c8a8948 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -419,6 +419,8 @@ static int __write_machine_check(struct kvm_vcpu *vcpu,
 	/* take care of lazy register loading */
 	save_fpu_regs();
 	save_access_regs(vcpu->run->s.regs.acrs);
+	if (MACHINE_HAS_GS && vcpu->arch.gs_enabled)
+		save_gs_cb(current->thread.gs_cb);
 
 	/* Extended save area */
 	rc = read_guest_lc(vcpu, __LC_MCESAD, &ext_sa_addr,
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 11b7d6638991..8771fef112a1 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -300,6 +300,8 @@ static void kvm_s390_cpu_feat_init(void)
 		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_CEI);
 	if (sclp.has_ibs)
 		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_IBS);
+	if (sclp.has_kss)
+		allow_cpu_feat(KVM_S390_VM_CPU_FEAT_KSS);
 	/*
 	 * KVM_S390_VM_CPU_FEAT_SKEY: Wrong shadow of PTE.I bits will make
 	 * all skey handling functions read/set the skey from the PGSTE
@@ -2034,7 +2036,11 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu)
 	vcpu->arch.sie_block->sdnxo = ((unsigned long) &vcpu->run->s.regs.sdnx)
 					| SDNXC;
 	vcpu->arch.sie_block->riccbd = (unsigned long) &vcpu->run->s.regs.riccb;
-	vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
+
+	if (sclp.has_kss)
+		atomic_or(CPUSTAT_KSS, &vcpu->arch.sie_block->cpuflags);
+	else
+		vcpu->arch.sie_block->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
 
 	if (vcpu->kvm->arch.use_cmma) {
 		rc = kvm_s390_vcpu_setup_cmma(vcpu);
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index 455124fe0647..55f5c8457d6d 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -254,6 +254,7 @@ int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_stctl(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_lctl(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_eb(struct kvm_vcpu *vcpu);
+int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu);
 
 /* implemented in vsie.c */
 int kvm_s390_handle_vsie(struct kvm_vcpu *vcpu);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index 0ffe973535fa..c03106c428cf 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -198,18 +198,25 @@ static int handle_store_cpu_address(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
-static int __skey_check_enable(struct kvm_vcpu *vcpu)
+int kvm_s390_skey_check_enable(struct kvm_vcpu *vcpu)
 {
 	int rc = 0;
+	struct kvm_s390_sie_block *sie_block = vcpu->arch.sie_block;
 
 	trace_kvm_s390_skey_related_inst(vcpu);
-	if (!(vcpu->arch.sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)))
+	if (!(sie_block->ictl & (ICTL_ISKE | ICTL_SSKE | ICTL_RRBE)) &&
+	    !(atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS))
 		return rc;
 
 	rc = s390_enable_skey();
 	VCPU_EVENT(vcpu, 3, "enabling storage keys for guest: %d", rc);
-	if (!rc)
-		vcpu->arch.sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE | ICTL_RRBE);
+	if (!rc) {
+		if (atomic_read(&sie_block->cpuflags) & CPUSTAT_KSS)
+			atomic_andnot(CPUSTAT_KSS, &sie_block->cpuflags);
+		else
+			sie_block->ictl &= ~(ICTL_ISKE | ICTL_SSKE |
+					     ICTL_RRBE);
+	}
 	return rc;
 }
 
@@ -218,7 +225,7 @@ static int try_handle_skey(struct kvm_vcpu *vcpu)
 	int rc;
 
 	vcpu->stat.instruction_storage_key++;
-	rc = __skey_check_enable(vcpu);
+	rc = kvm_s390_skey_check_enable(vcpu);
 	if (rc)
 		return rc;
 	if (sclp.has_skey) {
@@ -916,7 +923,7 @@ static int handle_pfmf(struct kvm_vcpu *vcpu)
 		}
 
 		if (vcpu->run->s.regs.gprs[reg1] & PFMF_SK) {
-			int rc = __skey_check_enable(vcpu);
+			int rc = kvm_s390_skey_check_enable(vcpu);
 
 			if (rc)
 				return rc;
diff --git a/arch/s390/kvm/vsie.c b/arch/s390/kvm/vsie.c
index 2fafc2be777f..4719ecb9ab42 100644
--- a/arch/s390/kvm/vsie.c
+++ b/arch/s390/kvm/vsie.c
@@ -117,6 +117,8 @@ static int prepare_cpuflags(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 		newflags |= cpuflags & CPUSTAT_SM;
 	if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_IBS))
 		newflags |= cpuflags & CPUSTAT_IBS;
+	if (test_kvm_cpu_feat(vcpu->kvm, KVM_S390_VM_CPU_FEAT_KSS))
+		newflags |= cpuflags & CPUSTAT_KSS;
 
 	atomic_set(&scb_s->cpuflags, newflags);
 	return 0;
@@ -289,7 +291,9 @@ static int shadow_scb(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 	 * bits. Therefore we cannot provide interpretation and would later
 	 * have to provide own emulation handlers.
 	 */
-	scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
+	if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_KSS))
+		scb_s->ictl |= ICTL_ISKE | ICTL_SSKE | ICTL_RRBE;
+
 	scb_s->icpua = scb_o->icpua;
 
 	if (!(atomic_read(&scb_s->cpuflags) & CPUSTAT_SM))
@@ -627,7 +631,7 @@ static int pin_blocks(struct kvm_vcpu *vcpu, struct vsie_page *vsie_page)
 			rc = set_validity_icpt(scb_s, 0x10b0U);
 		if (rc)
 			goto unpin;
-		scb_s->sdnxo = hpa;
+		scb_s->sdnxo = hpa | sdnxc;
 	}
 	return 0;
 unpin: