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Commit 4953919f authored by David Hildenbrand's avatar David Hildenbrand Committed by Christian Borntraeger
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KVM: s390: interpretive execution of SIGP EXTERNAL CALL 



If the sigp interpretation facility is installed, most SIGP EXTERNAL CALL
operations will be interpreted instead of intercepted. A partial execution
interception will occurr at the sending cpu only if the target cpu is in the
wait state ("W" bit in the cpuflags set). Instruction interception will only
happen in error cases (e.g. cpu addr invalid).

As a sending cpu might set the external call interrupt pending flags at the
target cpu at every point in time, we can't handle this kind of interrupt using
our kvm interrupt injection mechanism. The injection will be done automatically
by the SIE when preparing the start of the target cpu.

Signed-off-by: default avatarDavid Hildenbrand <dahi@linux.vnet.ibm.com>
Reviewed-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
CC: Thomas Huth <thuth@linux.vnet.ibm.com>
[Adopt external call injection to check for sigp interpretion]
Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
parent d26b8655

arch/s390/include/asm/kvm_host.h

+3 −1
Original line number Diff line number Diff line
@@ -32,8 +32,10 @@ 
#define KVM_NR_IRQCHIPS 1

#define KVM_IRQCHIP_NUM_PINS 4096



#define SIGP_CTRL_C	0x00800000



struct sca_entry {

	atomic_t scn;

	atomic_t ctrl;

	__u32	reserved;

	__u64	sda;

	__u64	reserved2[2];

arch/s390/kvm/intercept.c

+4 −0
Original line number Diff line number Diff line
@@ -272,6 +272,8 @@ static int handle_external_interrupt(struct kvm_vcpu *vcpu) 
		irq.type = KVM_S390_INT_CPU_TIMER;

		break;

	case EXT_IRQ_EXTERNAL_CALL:

		if (kvm_s390_si_ext_call_pending(vcpu))

			return 0;

		irq.type = KVM_S390_INT_EXTERNAL_CALL;

		irq.parm = vcpu->arch.sie_block->extcpuaddr;

		break;
@@ -323,6 +325,8 @@ static int handle_partial_execution(struct kvm_vcpu *vcpu) 
{

	if (vcpu->arch.sie_block->ipa == 0xb254)	/* MVPG */

		return handle_mvpg_pei(vcpu);

	if (vcpu->arch.sie_block->ipa >> 8 == 0xae)	/* SIGP */

		return kvm_s390_handle_sigp_pei(vcpu);



	return -EOPNOTSUPP;

}

arch/s390/kvm/interrupt.c

+26 −4
Original line number Diff line number Diff line
@@ -148,8 +148,7 @@ static void __unset_cpu_idle(struct kvm_vcpu *vcpu) 


static void __reset_intercept_indicators(struct kvm_vcpu *vcpu)

{

	atomic_clear_mask(CPUSTAT_ECALL_PEND |

		CPUSTAT_IO_INT | CPUSTAT_EXT_INT | CPUSTAT_STOP_INT,

	atomic_clear_mask(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 | ICTL_STCTL | ICTL_PINT);
@@ -524,6 +523,20 @@ static void deliver_ckc_interrupt(struct kvm_vcpu *vcpu) 
	}

}



/* Check whether SIGP interpretation facility has an external call pending */

int kvm_s390_si_ext_call_pending(struct kvm_vcpu *vcpu)

{

	atomic_t *sigp_ctrl = &vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].ctrl;



	if (!psw_extint_disabled(vcpu) &&

	    (vcpu->arch.sie_block->gcr[0] & 0x2000ul) &&

	    (atomic_read(sigp_ctrl) & SIGP_CTRL_C) &&

	    (atomic_read(&vcpu->arch.sie_block->cpuflags) & CPUSTAT_ECALL_PEND))

		return 1;



	return 0;

}



int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu)

{

	struct kvm_s390_local_interrupt *li = &vcpu->arch.local_int;
@@ -554,6 +567,9 @@ int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu) 
	if (!rc && kvm_cpu_has_pending_timer(vcpu))

		rc = 1;



	if (!rc && kvm_s390_si_ext_call_pending(vcpu))

		rc = 1;



	return rc;

}
@@ -610,7 +626,8 @@ int kvm_s390_handle_wait(struct kvm_vcpu *vcpu) 
	while (list_empty(&vcpu->arch.local_int.list) &&

		list_empty(&vcpu->arch.local_int.float_int->list) &&

		(!vcpu->arch.local_int.timer_due) &&

		!signal_pending(current)) {

		!signal_pending(current) &&

		!kvm_s390_si_ext_call_pending(vcpu)) {

		set_current_state(TASK_INTERRUPTIBLE);

		spin_unlock_bh(&vcpu->arch.local_int.lock);

		spin_unlock(&vcpu->arch.local_int.float_int->lock);
@@ -667,6 +684,11 @@ void kvm_s390_clear_local_irqs(struct kvm_vcpu *vcpu) 
	}

	atomic_set(&li->active, 0);

	spin_unlock_bh(&li->lock);



	/* clear pending external calls set by sigp interpretation facility */

	atomic_clear_mask(CPUSTAT_ECALL_PEND, &vcpu->arch.sie_block->cpuflags);

	atomic_clear_mask(SIGP_CTRL_C,

			  &vcpu->kvm->arch.sca->cpu[vcpu->vcpu_id].ctrl);

}



void kvm_s390_deliver_pending_interrupts(struct kvm_vcpu *vcpu)

arch/s390/kvm/kvm-s390.c

+1 −1
Original line number Diff line number Diff line
@@ -633,7 +633,7 @@ int kvm_arch_vcpu_setup(struct kvm_vcpu *vcpu) 
		vcpu->arch.sie_block->ecb |= 0x10;



	vcpu->arch.sie_block->ecb2  = 8;

	vcpu->arch.sie_block->eca   = 0xC1002000U;

	vcpu->arch.sie_block->eca   = 0xD1002000U;

	if (sclp_has_siif())

		vcpu->arch.sie_block->eca |= 1;

	vcpu->arch.sie_block->fac   = (int) (long) vfacilities;

arch/s390/kvm/kvm-s390.h

+2 −0
Original line number Diff line number Diff line
@@ -154,6 +154,7 @@ int kvm_s390_handle_eb(struct kvm_vcpu *vcpu); 


/* implemented in sigp.c */

int kvm_s390_handle_sigp(struct kvm_vcpu *vcpu);

int kvm_s390_handle_sigp_pei(struct kvm_vcpu *vcpu);



/* implemented in kvm-s390.c */

long kvm_arch_fault_in_page(struct kvm_vcpu *vcpu, gpa_t gpa, int writable);
@@ -214,6 +215,7 @@ static inline int kvm_s390_inject_prog_cond(struct kvm_vcpu *vcpu, int rc) 
int kvm_cpu_has_interrupt(struct kvm_vcpu *vcpu);

int psw_extint_disabled(struct kvm_vcpu *vcpu);

void kvm_s390_destroy_adapters(struct kvm *kvm);

int kvm_s390_si_ext_call_pending(struct kvm_vcpu *vcpu);



/* implemented in guestdbg.c */

void kvm_s390_backup_guest_per_regs(struct kvm_vcpu *vcpu);