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KVM: s390: Support for I/O interrupts.
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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: Alexander Graf <agraf@suse.de>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
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Cornelia Huck authored and Marcelo Tosatti committed Jan 7, 2013
1 parent b1c571a commit d8346b7
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Showing 4 changed files with 116 additions and 2 deletions.
4 changes: 4 additions & 0 deletions Documentation/virtual/kvm/api.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -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.

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2 changes: 2 additions & 0 deletions arch/s390/include/asm/kvm_host.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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 */
Expand Down Expand Up @@ -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;
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103 changes: 101 additions & 2 deletions arch/s390/kvm/interrupt.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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) ||
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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();
}
Expand Down Expand Up @@ -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();
}
Expand Down Expand Up @@ -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);
Expand All @@ -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;
Expand All @@ -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);
list_add_tail(&inti->list, &fi->list);
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) {
Expand Down Expand Up @@ -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;
Expand Down
9 changes: 9 additions & 0 deletions include/uapi/linux/kvm.h
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Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand Down

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