Patchwork [v2,2/7] s390/kvm: Add support for machine checks.

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Submitter Cornelia Huck
Date Sept. 4, 2012, 3:13 p.m.
Message ID <1346771610-52423-3-git-send-email-cornelia.huck@de.ibm.com>
Download mbox | patch
Permalink /patch/181621/
State New
Headers show

Comments

Cornelia Huck - Sept. 4, 2012, 3:13 p.m.
Add support for injecting machine checks (only repressible
conditions for now).

This is a bit more involved than I/O interrupts, for these reasons:

- Machine checks come in both floating and cpu varieties.
- We don't have a bit for machine checks enabling, but have to use
  a roundabout approach with trapping PSW changing instructions and
  watching for opened machine checks.

Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
 arch/s390/include/asm/kvm_host.h |   8 +++
 arch/s390/kvm/intercept.c        |   2 +
 arch/s390/kvm/interrupt.c        | 111 ++++++++++++++++++++++++++++++++
 arch/s390/kvm/kvm-s390.h         |   3 +
 arch/s390/kvm/priv.c             | 133 +++++++++++++++++++++++++++++++++++++++
 arch/s390/kvm/trace-s390.h       |   6 +-
 include/linux/kvm.h              |   1 +
 7 files changed, 261 insertions(+), 3 deletions(-)
Heiko Carstens - Sept. 5, 2012, 7:22 a.m.
On Tue, Sep 04, 2012 at 05:13:25PM +0200, Cornelia Huck wrote:

Just some quick comments:

[...]

>  int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
>  {
>  	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
> @@ -648,6 +747,12 @@ int kvm_s390_inject_vm(struct kvm *kvm,
>  	case KVM_S390_INT_EMERGENCY:
>  		kfree(inti);
>  		return -EINVAL;
> +	case KVM_S390_MCHK:
> +		VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
> +			 s390int->parm64);
> +		inti->type = s390int->type;
> +		inti->mchk.mcic = s390int->parm64;
> +		break;

The kvm_s390_interrupt struct seems to be inappropriate to pass machine check
data around.
E.g. if you want to inject an uncorrectable storage error, because the host
failed to swap in a page, you must also pass a failing storage address which
doesn't fit into this structure.
Just something you should consider. ;)

> +static int handle_lpswe(struct kvm_vcpu *vcpu)
> +{
> +	int base2 = vcpu->arch.sie_block->ipb >> 28;
> +	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);

Sooner or later we need helper functions which extract the significant parts
of an instruction.
Maybay something like insn_[type]_get_base2(...) or simply structures like
struct insn_[type], which allow to easily access parts of an instruction.

> +	u64 addr;
> +	u64 new_psw[2];

psw_t?

> +
> +	addr = disp2;
> +	if (base2)
> +		addr += vcpu->run->s.regs.gprs[base2];
> +	
> +	if (addr & 7) {
> +		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
> +		goto out;
> +	}
> +
> +	if (copy_from_guest(vcpu, new_psw, addr, sizeof(*new_psw))) {

I assume that should be sizeof(new_psw). Did that ever work?!

> +	if ((vcpu->arch.sie_block->gpsw.mask & 0xb80800fe7fffffff) ||
> +	    (((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
> +	      0x0000000010000000) &&
> +	     (vcpu->arch.sie_block->gpsw.addr & 0xffffffff80000000)) ||
> +	    (!(vcpu->arch.sie_block->gpsw.mask & 0x0000000180000000) &&
> +	     (vcpu->arch.sie_block->gpsw.addr & 0xfffffffffff00000)) ||
> +	    ((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
> +	     0x0000000100000000)) {

This is not very readable...

Please make use of the PSW defines in ptrace.h and add new ones if needed.
Also please make use of (move) the PSW32 defines in compat.h.
Cornelia Huck - Sept. 5, 2012, 8:39 a.m.
On Wed, 5 Sep 2012 09:22:32 +0200
Heiko Carstens <heiko.carstens@de.ibm.com> wrote:

> On Tue, Sep 04, 2012 at 05:13:25PM +0200, Cornelia Huck wrote:
> 
> Just some quick comments:
> 
> [...]
> 
> >  int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
> >  {
> >  	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
> > @@ -648,6 +747,12 @@ int kvm_s390_inject_vm(struct kvm *kvm,
> >  	case KVM_S390_INT_EMERGENCY:
> >  		kfree(inti);
> >  		return -EINVAL;
> > +	case KVM_S390_MCHK:
> > +		VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
> > +			 s390int->parm64);
> > +		inti->type = s390int->type;
> > +		inti->mchk.mcic = s390int->parm64;
> > +		break;
> 
> The kvm_s390_interrupt struct seems to be inappropriate to pass machine check
> data around.
> E.g. if you want to inject an uncorrectable storage error, because the host
> failed to swap in a page, you must also pass a failing storage address which
> doesn't fit into this structure.
> Just something you should consider. ;)

Sigh, it seems we might want a KVM_S390_INTERRUPT2 taking a larger and
more complex structure later on...

kvm_s390_interrupt should be fine for our current needs, though,
expecially as machine checks are currently only injected in-kernel.

> 
> > +static int handle_lpswe(struct kvm_vcpu *vcpu)
> > +{
> > +	int base2 = vcpu->arch.sie_block->ipb >> 28;
> > +	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
> 
> Sooner or later we need helper functions which extract the significant parts
> of an instruction.
> Maybay something like insn_[type]_get_base2(...) or simply structures like
> struct insn_[type], which allow to easily access parts of an instruction.

Agree on helper functions, not sure about the use of structures for
that. Let's see how it looks coded up.

> 
> > +	u64 addr;
> > +	u64 new_psw[2];
> 
> psw_t?
> 
> > +
> > +	addr = disp2;
> > +	if (base2)
> > +		addr += vcpu->run->s.regs.gprs[base2];
> > +	
> > +	if (addr & 7) {
> > +		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
> > +		goto out;
> > +	}
> > +
> > +	if (copy_from_guest(vcpu, new_psw, addr, sizeof(*new_psw))) {
> 
> I assume that should be sizeof(new_psw). Did that ever work?!

No, because the code was never hit since the code for ICTL was
incorrect... The guest kernel just does a good job at keeping machine
checks open nearly all of the time :)

> 
> > +	if ((vcpu->arch.sie_block->gpsw.mask & 0xb80800fe7fffffff) ||
> > +	    (((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
> > +	      0x0000000010000000) &&
> > +	     (vcpu->arch.sie_block->gpsw.addr & 0xffffffff80000000)) ||
> > +	    (!(vcpu->arch.sie_block->gpsw.mask & 0x0000000180000000) &&
> > +	     (vcpu->arch.sie_block->gpsw.addr & 0xfffffffffff00000)) ||
> > +	    ((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
> > +	     0x0000000100000000)) {
> 
> This is not very readable...

It's straight from the PoP's discussion of invalid bits.

> 
> Please make use of the PSW defines in ptrace.h and add new ones if needed.
> Also please make use of (move) the PSW32 defines in compat.h.

I'll check these.

Patch

diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index e47f697..556774d 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -77,8 +77,10 @@  struct kvm_s390_sie_block {
 	__u8	reserved40[4];		/* 0x0040 */
 #define LCTL_CR0	0x8000
 #define LCTL_CR6	0x0200
+#define LCTL_CR14	0x0002
 	__u16   lctl;			/* 0x0044 */
 	__s16	icpua;			/* 0x0046 */
+#define ICTL_LPSW 0x02000000
 	__u32	ictl;			/* 0x0048 */
 	__u32	eca;			/* 0x004c */
 	__u8	icptcode;		/* 0x0050 */
@@ -189,6 +191,11 @@  struct kvm_s390_emerg_info {
 	__u16 code;
 };
 
+struct kvm_s390_mchk_info {
+	__u64 cr14;
+	__u64 mcic;
+};
+
 struct kvm_s390_interrupt_info {
 	struct list_head list;
 	u64	type;
@@ -199,6 +206,7 @@  struct kvm_s390_interrupt_info {
 		struct kvm_s390_emerg_info emerg;
 		struct kvm_s390_extcall_info extcall;
 		struct kvm_s390_prefix_info prefix;
+		struct kvm_s390_mchk_info mchk;
 	};
 };
 
diff --git a/arch/s390/kvm/intercept.c b/arch/s390/kvm/intercept.c
index 22798ec..ec1177f 100644
--- a/arch/s390/kvm/intercept.c
+++ b/arch/s390/kvm/intercept.c
@@ -106,10 +106,12 @@  static int handle_lctl(struct kvm_vcpu *vcpu)
 
 static intercept_handler_t instruction_handlers[256] = {
 	[0x01] = kvm_s390_handle_01,
+	[0x82] = kvm_s390_handle_lpsw,
 	[0x83] = kvm_s390_handle_diag,
 	[0xae] = kvm_s390_handle_sigp,
 	[0xb2] = kvm_s390_handle_b2,
 	[0xb7] = handle_lctl,
+	[0xb9] = kvm_s390_handle_b9,
 	[0xe5] = kvm_s390_handle_e5,
 	[0xeb] = handle_lctlg,
 };
diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c
index 1dccfe7..edc065f 100644
--- a/arch/s390/kvm/interrupt.c
+++ b/arch/s390/kvm/interrupt.c
@@ -41,6 +41,11 @@  static int psw_ioint_disabled(struct kvm_vcpu *vcpu)
 	return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO);
 }
 
+static int psw_mchk_disabled(struct kvm_vcpu *vcpu)
+{
+	return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK);
+}
+
 static int psw_interrupts_disabled(struct kvm_vcpu *vcpu)
 {
 	if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) ||
@@ -82,6 +87,12 @@  static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu,
 	case KVM_S390_SIGP_SET_PREFIX:
 	case KVM_S390_RESTART:
 		return 1;
+	case KVM_S390_MCHK:
+		if (psw_mchk_disabled(vcpu))
+			return 0;
+		if (vcpu->arch.sie_block->gcr[14] & inti->mchk.cr14)
+			return 1;
+		return 0;
 	default:
 		if (is_ioint(inti->type)) {
 			if (psw_ioint_disabled(vcpu))
@@ -119,6 +130,7 @@  static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)
 		CPUSTAT_IO_INT | CPUSTAT_EXT_INT | CPUSTAT_STOP_INT,
 		&vcpu->arch.sie_block->cpuflags);
 	vcpu->arch.sie_block->lctl = 0x0000;
+	vcpu->arch.sie_block->ictl &= ~ICTL_LPSW;
 }
 
 static void __set_cpuflag(struct kvm_vcpu *vcpu, u32 flag)
@@ -142,6 +154,12 @@  static void __set_intercept_indicator(struct kvm_vcpu *vcpu,
 	case KVM_S390_SIGP_STOP:
 		__set_cpuflag(vcpu, CPUSTAT_STOP_INT);
 		break;
+	case KVM_S390_MCHK:
+		if (psw_mchk_disabled(vcpu))
+			vcpu->arch.sie_block->ictl |= ICTL_LPSW;
+		else
+			vcpu->arch.sie_block->lctl |= LCTL_CR14;
+		break;
 	default:
 		if (is_ioint(inti->type)) {
 			if (psw_ioint_disabled(vcpu))
@@ -330,6 +348,32 @@  static void __do_deliver_interrupt(struct kvm_vcpu *vcpu,
 			exception = 1;
 		break;
 
+	case KVM_S390_MCHK:
+		VCPU_EVENT(vcpu, 4, "interrupt: machine check mcic=%llx",
+			   inti->mchk.mcic);
+		trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,
+						 inti->mchk.cr14,
+						 inti->mchk.mcic);
+		rc = kvm_s390_vcpu_store_status(vcpu,
+						KVM_S390_STORE_STATUS_PREFIXED);
+		if (rc == -EFAULT)
+			exception = 1;
+
+		rc = put_guest_u64(vcpu, __LC_MCCK_CODE, inti->mchk.mcic);
+		if (rc == -EFAULT)
+			exception = 1;
+		
+		rc = copy_to_guest(vcpu, __LC_MCK_OLD_PSW,
+				   &vcpu->arch.sie_block->gpsw, sizeof(psw_t));
+		if (rc == -EFAULT)
+			exception = 1;
+		
+		rc = copy_from_guest(vcpu, &vcpu->arch.sie_block->gpsw,
+				     __LC_MCK_NEW_PSW, sizeof(psw_t));
+		if (rc == -EFAULT)
+			exception = 1;
+		break;
+
 	default:
 		if (is_ioint(inti->type)) {
 			__u32 param0 = ((__u32)inti->io.subchannel_id << 16) |
@@ -595,6 +639,61 @@  void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)
 	}
 }
 
+void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu)
+{
+	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
+	struct kvm_s390_float_interrupt *fi = vcpu->arch.local_int.float_int;
+	struct kvm_s390_interrupt_info  *n, *inti = NULL;
+	int deliver;
+
+	__reset_intercept_indicators(vcpu);
+	if (atomic_read(&li->active)) {
+		do {
+			deliver = 0;
+			spin_lock_bh(&li->lock);
+			list_for_each_entry_safe(inti, n, &li->list, list) {
+				if ((inti->type == KVM_S390_MCHK) &&
+				    __interrupt_is_deliverable(vcpu, inti)) {
+					list_del(&inti->list);
+					deliver = 1;
+					break;
+				}
+				__set_intercept_indicator(vcpu, inti);
+			}
+			if (list_empty(&li->list))
+				atomic_set(&li->active, 0);
+			spin_unlock_bh(&li->lock);
+			if (deliver) {
+				__do_deliver_interrupt(vcpu, inti);
+				kfree(inti);
+			}
+		} while (deliver);
+	}
+
+	if (atomic_read(&fi->active)) {
+		do {
+			deliver = 0;
+			spin_lock(&fi->lock);
+			list_for_each_entry_safe(inti, n, &fi->list, list) {
+				if ((inti->type == KVM_S390_MCHK) &&
+				    __interrupt_is_deliverable(vcpu, inti)) {
+					list_del(&inti->list);
+					deliver = 1;
+					break;
+				}
+				__set_intercept_indicator(vcpu, inti);
+			}
+			if (list_empty(&fi->list))
+				atomic_set(&fi->active, 0);
+			spin_unlock(&fi->lock);
+			if (deliver) {
+				__do_deliver_interrupt(vcpu, inti);
+				kfree(inti);
+			}
+		} while (deliver);
+	}
+}
+
 int kvm_s390_inject_program_int(struct kvm_vcpu *vcpu, u16 code)
 {
 	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
@@ -648,6 +747,12 @@  int kvm_s390_inject_vm(struct kvm *kvm,
 	case KVM_S390_INT_EMERGENCY:
 		kfree(inti);
 		return -EINVAL;
+	case KVM_S390_MCHK:
+		VM_EVENT(kvm, 5, "inject: machine check parm64:%llx",
+			 s390int->parm64);
+		inti->type = s390int->type;
+		inti->mchk.mcic = s390int->parm64;
+		break;
 	default:
 		if (!is_ioint(s390int->type)) {
 			kfree(inti);
@@ -740,6 +845,12 @@  int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
 		VCPU_EVENT(vcpu, 3, "inject: type %x", s390int->type);
 		inti->type = s390int->type;
 		break;
+	case KVM_S390_MCHK:
+		VCPU_EVENT(vcpu, 5, "inject: machine check parm64:%llx",
+			   s390int->parm64);
+		inti->type = s390int->type;
+		inti->mchk.mcic = s390int->parm64;
+		break;
 	case KVM_S390_INT_VIRTIO:
 	case KVM_S390_INT_SERVICE:
 	default:
diff --git a/arch/s390/kvm/kvm-s390.h b/arch/s390/kvm/kvm-s390.h
index d75bc5e..b1e1cb6 100644
--- a/arch/s390/kvm/kvm-s390.h
+++ b/arch/s390/kvm/kvm-s390.h
@@ -69,6 +69,7 @@  int kvm_s390_handle_wait(struct kvm_vcpu *vcpu);
 enum hrtimer_restart kvm_s390_idle_wakeup(struct hrtimer *timer);
 void kvm_s390_tasklet(unsigned long parm);
 void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu);
+void kvm_s390_deliver_pending_machine_checks(struct kvm_vcpu *vcpu);
 int kvm_s390_inject_vm(struct kvm *kvm,
 		struct kvm_s390_interrupt *s390int);
 int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu,
@@ -80,6 +81,8 @@  int kvm_s390_inject_sigp_stop(struct kvm_vcpu *vcpu, int action);
 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_e5(struct kvm_vcpu *vcpu);
 int kvm_s390_handle_01(struct kvm_vcpu *vcpu);
+int kvm_s390_handle_b9(struct kvm_vcpu *vcpu);
+int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu);
 
 /* implemented in sigp.c */
 int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);
diff --git a/arch/s390/kvm/priv.c b/arch/s390/kvm/priv.c
index ed256fd..7e7263c 100644
--- a/arch/s390/kvm/priv.c
+++ b/arch/s390/kvm/priv.c
@@ -176,6 +176,101 @@  static int handle_stfl(struct kvm_vcpu *vcpu)
 	return 0;
 }
 
+static void handle_new_psw(struct kvm_vcpu *vcpu)
+{
+	/* Check whether the new psw is enabled for machine checks. */
+	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_MCHECK)
+		kvm_s390_deliver_pending_machine_checks(vcpu);
+}
+
+int kvm_s390_handle_lpsw(struct kvm_vcpu *vcpu)
+{
+	int base2 = vcpu->arch.sie_block->ipb >> 28;
+	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
+	u64 addr;
+	u64 uninitialized_var(new_psw);
+
+	if (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE)
+		return kvm_s390_inject_program_int(vcpu,
+						   PGM_PRIVILEGED_OPERATION);
+
+	addr = disp2;
+	if (base2)
+		addr += vcpu->run->s.regs.gprs[base2];
+
+	if (addr & 7) {
+		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+		goto out;
+	}
+
+	if (get_guest_u64(vcpu, addr, &new_psw)) {
+		kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+		goto out;
+	}
+
+	if (!(new_psw & 0x0008000000000000)) {
+		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+		goto out;
+	}
+
+	vcpu->arch.sie_block->gpsw.mask = new_psw & 0xfff7ffff80000000;
+	vcpu->arch.sie_block->gpsw.addr = new_psw & 0x000000007fffffff;
+
+	if ((vcpu->arch.sie_block->gpsw.mask & 0xb80800fe00000000) ||
+	    (!(vcpu->arch.sie_block->gpsw.mask & 0x0000000180000000) &&
+	     (vcpu->arch.sie_block->gpsw.addr & 0x000000007ff00000)) ||
+	    ((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
+	     0x0000000100000000)) {
+		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+		goto out;
+	}
+
+	handle_new_psw(vcpu);
+out:
+	return 0;
+}
+
+static int handle_lpswe(struct kvm_vcpu *vcpu)
+{
+	int base2 = vcpu->arch.sie_block->ipb >> 28;
+	int disp2 = ((vcpu->arch.sie_block->ipb & 0x0fff0000) >> 16);
+	u64 addr;
+	u64 new_psw[2];
+
+	addr = disp2;
+	if (base2)
+		addr += vcpu->run->s.regs.gprs[base2];
+	
+	if (addr & 7) {
+		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+		goto out;
+	}
+
+	if (copy_from_guest(vcpu, new_psw, addr, sizeof(*new_psw))) {
+		kvm_s390_inject_program_int(vcpu, PGM_ADDRESSING);
+		goto out;
+	}
+
+	vcpu->arch.sie_block->gpsw.mask = new_psw[0];
+	vcpu->arch.sie_block->gpsw.addr = new_psw[1];
+
+	if ((vcpu->arch.sie_block->gpsw.mask & 0xb80800fe7fffffff) ||
+	    (((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
+	      0x0000000010000000) &&
+	     (vcpu->arch.sie_block->gpsw.addr & 0xffffffff80000000)) ||
+	    (!(vcpu->arch.sie_block->gpsw.mask & 0x0000000180000000) &&
+	     (vcpu->arch.sie_block->gpsw.addr & 0xfffffffffff00000)) ||
+	    ((vcpu->arch.sie_block->gpsw.mask & 0x0000000110000000) ==
+	     0x0000000100000000)) {
+		kvm_s390_inject_program_int(vcpu, PGM_SPECIFICATION);
+		goto out;
+	}
+	
+	handle_new_psw(vcpu);
+out:
+	return 0;
+}
+
 static int handle_stidp(struct kvm_vcpu *vcpu)
 {
 	int base2 = vcpu->arch.sie_block->ipb >> 28;
@@ -309,6 +404,7 @@  static intercept_handler_t priv_handlers[256] = {
 	[0x5f] = handle_chsc,
 	[0x7d] = handle_stsi,
 	[0xb1] = handle_stfl,
+	[0xb2] = handle_lpswe,
 };
 
 int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
@@ -333,6 +429,43 @@  int kvm_s390_handle_b2(struct kvm_vcpu *vcpu)
 	return -EOPNOTSUPP;
 }
 
+static int handle_epsw(struct kvm_vcpu *vcpu)
+{
+	int reg1, reg2;
+
+	reg1 = (vcpu->arch.sie_block->ipb & 0x00f00000) >> 24;
+	reg2 = (vcpu->arch.sie_block->ipb & 0x000f0000) >> 16;
+	vcpu->run->s.regs.gprs[reg1] &= 0xffffffff00000000;
+	vcpu->run->s.regs.gprs[reg1] |= vcpu->arch.sie_block->gpsw.mask >> 32;
+	if (reg2) {
+		vcpu->run->s.regs.gprs[reg2] &= 0xffffffff00000000;
+		vcpu->run->s.regs.gprs[reg2] |=
+			vcpu->arch.sie_block->gpsw.mask & 0x00000000ffffffff;
+	}
+	return 0;
+}
+
+static intercept_handler_t b9_handlers[256] = {
+	[0x8d] = handle_epsw,
+};
+
+int kvm_s390_handle_b9(struct kvm_vcpu *vcpu)
+{
+	intercept_handler_t handler;
+
+	/* This is handled just as for the B2 instructions. */
+	handler = b9_handlers[vcpu->arch.sie_block->ipa & 0x00ff];
+	if (handler) {
+		if ((handler != handle_epsw) &&
+		    (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PSTATE))
+			return kvm_s390_inject_program_int(vcpu,
+						   PGM_PRIVILEGED_OPERATION);
+		else
+			return handler(vcpu);
+	}
+	return -EOPNOTSUPP;
+}
+
 static int handle_tprot(struct kvm_vcpu *vcpu)
 {
 	int base1 = (vcpu->arch.sie_block->ipb & 0xf0000000) >> 28;
diff --git a/arch/s390/kvm/trace-s390.h b/arch/s390/kvm/trace-s390.h
index 90fdf85..95fbc1a 100644
--- a/arch/s390/kvm/trace-s390.h
+++ b/arch/s390/kvm/trace-s390.h
@@ -141,13 +141,13 @@  TRACE_EVENT(kvm_s390_inject_vcpu,
  * Trace point for the actual delivery of interrupts.
  */
 TRACE_EVENT(kvm_s390_deliver_interrupt,
-	    TP_PROTO(unsigned int id, __u64 type, __u32 data0, __u64 data1),
+	    TP_PROTO(unsigned int id, __u64 type, __u64 data0, __u64 data1),
 	    TP_ARGS(id, type, data0, data1),
 
 	    TP_STRUCT__entry(
 		    __field(int, id)
 		    __field(__u32, inttype)
-		    __field(__u32, data0)
+		    __field(__u64, data0)
 		    __field(__u64, data1)
 		    ),
 
@@ -159,7 +159,7 @@  TRACE_EVENT(kvm_s390_deliver_interrupt,
 		    ),
 
 	    TP_printk("deliver interrupt (vcpu %d): type:%x (%s) "	\
-		      "data:%08x %016llx",
+		      "data:%08llx %016llx",
 		      __entry->id, __entry->inttype,
 		      __print_symbolic(__entry->inttype, kvm_s390_int_type),
 		      __entry->data0, __entry->data1)
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 5a36e65..6bd6062 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -392,6 +392,7 @@  struct kvm_s390_psw {
 #define KVM_S390_PROGRAM_INT		0xfffe0001u
 #define KVM_S390_SIGP_SET_PREFIX	0xfffe0002u
 #define KVM_S390_RESTART		0xfffe0003u
+#define KVM_S390_MCHK			0xfffe1000u
 #define KVM_S390_INT_VIRTIO		0xffff2603u
 #define KVM_S390_INT_SERVICE		0xffff2401u
 #define KVM_S390_INT_EMERGENCY		0xffff1201u