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Commit d8346b7d authored by Cornelia Huck's avatar Cornelia Huck Committed by Marcelo Tosatti
Browse files

KVM: s390: Support for I/O interrupts. 



Add support for handling I/O interrupts (standard, subchannel-related
ones and rudimentary adapter interrupts).

The subchannel-identifying parameters are encoded into the interrupt
type.

I/O interrupts are floating, so they can't be injected on a specific
vcpu.

Reviewed-by: default avatarAlexander Graf <agraf@suse.de>
Reviewed-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent b1c571a5

Documentation/virtual/kvm/api.txt

+4 −0
Original line number Diff line number Diff line
@@ -2069,6 +2069,10 @@ KVM_S390_INT_VIRTIO (vm) - virtio external interrupt; external interrupt 
KVM_S390_INT_SERVICE (vm) - sclp external interrupt; sclp parameter in parm

KVM_S390_INT_EMERGENCY (vcpu) - sigp emergency; source cpu in parm

KVM_S390_INT_EXTERNAL_CALL (vcpu) - sigp external call; source cpu in parm

KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) - compound value to indicate an

    I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel);

    I/O interruption parameters in parm (subchannel) and parm64 (intparm,

    interruption subclass)



Note that the vcpu ioctl is asynchronous to vcpu execution.

arch/s390/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ struct kvm_s390_sie_block { 
	__u64	epoch;			/* 0x0038 */

	__u8	reserved40[4];		/* 0x0040 */

#define LCTL_CR0	0x8000

#define LCTL_CR6	0x0200

	__u16   lctl;			/* 0x0044 */

	__s16	icpua;			/* 0x0046 */

	__u32	ictl;			/* 0x0048 */
@@ -125,6 +126,7 @@ struct kvm_vcpu_stat { 
	u32 deliver_prefix_signal;

	u32 deliver_restart_signal;

	u32 deliver_program_int;

	u32 deliver_io_int;

	u32 exit_wait_state;

	u32 instruction_stidp;

	u32 instruction_spx;

arch/s390/kvm/interrupt.c

+101 −2
Original line number Diff line number Diff line
@@ -21,11 +21,26 @@ 
#include "gaccess.h"

#include "trace-s390.h"



#define IOINT_SCHID_MASK 0x0000ffff

#define IOINT_SSID_MASK 0x00030000

#define IOINT_CSSID_MASK 0x03fc0000

#define IOINT_AI_MASK 0x04000000



static int is_ioint(u64 type)

{

	return ((type & 0xfffe0000u) != 0xfffe0000u);

}



static int psw_extint_disabled(struct kvm_vcpu *vcpu)

{

	return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_EXT);

}



static int psw_ioint_disabled(struct kvm_vcpu *vcpu)

{

	return !(vcpu->arch.sie_block->gpsw.mask & PSW_MASK_IO);

}



static int psw_interrupts_disabled(struct kvm_vcpu *vcpu)

{

	if ((vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER) ||
@@ -67,7 +82,15 @@ static int __interrupt_is_deliverable(struct kvm_vcpu *vcpu, 
	case KVM_S390_SIGP_SET_PREFIX:

	case KVM_S390_RESTART:

		return 1;

	case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:

		if (psw_ioint_disabled(vcpu))

			return 0;

		if (vcpu->arch.sie_block->gcr[6] & inti->io.io_int_word)

			return 1;

		return 0;

	default:

		printk(KERN_WARNING "illegal interrupt type %llx\n",

		       inti->type);

		BUG();

	}

	return 0;
@@ -116,6 +139,12 @@ static void __set_intercept_indicator(struct kvm_vcpu *vcpu, 
	case KVM_S390_SIGP_STOP:

		__set_cpuflag(vcpu, CPUSTAT_STOP_INT);

		break;

	case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:

		if (psw_ioint_disabled(vcpu))

			__set_cpuflag(vcpu, CPUSTAT_IO_INT);

		else

			vcpu->arch.sie_block->lctl |= LCTL_CR6;

		break;

	default:

		BUG();

	}
@@ -297,6 +326,47 @@ static void __do_deliver_interrupt(struct kvm_vcpu *vcpu, 
			exception = 1;

		break;



	case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:

	{

		__u32 param0 = ((__u32)inti->io.subchannel_id << 16) |

			inti->io.subchannel_nr;

		__u64 param1 = ((__u64)inti->io.io_int_parm << 32) |

			inti->io.io_int_word;

		VCPU_EVENT(vcpu, 4, "interrupt: I/O %llx", inti->type);

		vcpu->stat.deliver_io_int++;

		trace_kvm_s390_deliver_interrupt(vcpu->vcpu_id, inti->type,

						 param0, param1);

		rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_ID,

				   inti->io.subchannel_id);

		if (rc == -EFAULT)

			exception = 1;



		rc = put_guest_u16(vcpu, __LC_SUBCHANNEL_NR,

				   inti->io.subchannel_nr);

		if (rc == -EFAULT)

			exception = 1;



		rc = put_guest_u32(vcpu, __LC_IO_INT_PARM,

				   inti->io.io_int_parm);

		if (rc == -EFAULT)

			exception = 1;



		rc = put_guest_u32(vcpu, __LC_IO_INT_WORD,

				   inti->io.io_int_word);

		if (rc == -EFAULT)

			exception = 1;



		rc = copy_to_guest(vcpu, __LC_IO_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_IO_NEW_PSW, sizeof(psw_t));

		if (rc == -EFAULT)

			exception = 1;

		break;

	}

	default:

		BUG();

	}
@@ -545,7 +615,7 @@ int kvm_s390_inject_vm(struct kvm *kvm, 
{

	struct kvm_s390_local_interrupt *li;

	struct kvm_s390_float_interrupt *fi;

	struct kvm_s390_interrupt_info *inti;

	struct kvm_s390_interrupt_info *inti, *iter;

	int sigcpu;



	inti = kzalloc(sizeof(*inti), GFP_KERNEL);
@@ -569,6 +639,22 @@ int kvm_s390_inject_vm(struct kvm *kvm, 
	case KVM_S390_SIGP_STOP:

	case KVM_S390_INT_EXTERNAL_CALL:

	case KVM_S390_INT_EMERGENCY:

		kfree(inti);

		return -EINVAL;

	case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:

		if (s390int->type & IOINT_AI_MASK)

			VM_EVENT(kvm, 5, "%s", "inject: I/O (AI)");

		else

			VM_EVENT(kvm, 5, "inject: I/O css %x ss %x schid %04x",

				 s390int->type & IOINT_CSSID_MASK,

				 s390int->type & IOINT_SSID_MASK,

				 s390int->type & IOINT_SCHID_MASK);

		inti->type = s390int->type;

		inti->io.subchannel_id = s390int->parm >> 16;

		inti->io.subchannel_nr = s390int->parm & 0x0000ffffu;

		inti->io.io_int_parm = s390int->parm64 >> 32;

		inti->io.io_int_word = s390int->parm64 & 0x00000000ffffffffull;

		break;

	default:

		kfree(inti);

		return -EINVAL;
@@ -579,7 +665,19 @@ int kvm_s390_inject_vm(struct kvm *kvm, 
	mutex_lock(&kvm->lock);

	fi = &kvm->arch.float_int;

	spin_lock(&fi->lock);

	if (!is_ioint(inti->type))

		list_add_tail(&inti->list, &fi->list);

	else {

		/* Keep I/O interrupts sorted in isc order. */

		list_for_each_entry(iter, &fi->list, list) {

			if (!is_ioint(iter->type))

				continue;

			if (iter->io.io_int_word <= inti->io.io_int_word)

				continue;

			break;

		}

		list_add_tail(&inti->list, &iter->list);

	}

	atomic_set(&fi->active, 1);

	sigcpu = find_first_bit(fi->idle_mask, KVM_MAX_VCPUS);

	if (sigcpu == KVM_MAX_VCPUS) {
@@ -653,6 +751,7 @@ int kvm_s390_inject_vcpu(struct kvm_vcpu *vcpu, 
		break;

	case KVM_S390_INT_VIRTIO:

	case KVM_S390_INT_SERVICE:

	case KVM_S390_INT_IO_MIN...KVM_S390_INT_IO_MAX:

	default:

		kfree(inti);

		return -EINVAL;

include/uapi/linux/kvm.h

+9 −0
Original line number Diff line number Diff line
@@ -401,6 +401,15 @@ struct kvm_s390_psw { 
#define KVM_S390_INT_SERVICE		0xffff2401u

#define KVM_S390_INT_EMERGENCY		0xffff1201u

#define KVM_S390_INT_EXTERNAL_CALL	0xffff1202u

/* Anything below 0xfffe0000u is taken by INT_IO */

#define KVM_S390_INT_IO(ai,cssid,ssid,schid)   \

	(((schid)) |			       \

	 ((ssid) << 16) |		       \

	 ((cssid) << 18) |		       \

	 ((ai) << 26))

#define KVM_S390_INT_IO_MIN		0x00000000u

#define KVM_S390_INT_IO_MAX		0xfffdffffu





struct kvm_s390_interrupt {

	__u32 type;