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| author | Halil Pasic <pasic@linux.vnet.ibm.com> | 2016-01-25 19:10:40 +0100 |
|---|---|---|
| committer | Cornelia Huck <cornelia.huck@de.ibm.com> | 2016-04-20 14:27:32 +0200 |
| commit | 6d28f789bf81540d4069342b1a28bfd41dab38a3 (patch) | |
| tree | 81573b9b5e05e974806c9b0473b8abd3800afe5a /arch/s390 | |
| parent | dad7eefbd048a2f44c990303751159671e988d13 (diff) | |
| download | linux-stable-6d28f789bf81540d4069342b1a28bfd41dab38a3.tar.gz linux-stable-6d28f789bf81540d4069342b1a28bfd41dab38a3.tar.bz2 linux-stable-6d28f789bf81540d4069342b1a28bfd41dab38a3.zip | |
KVM: s390: add clear I/O irq operation for FLIC
Introduce a FLIC operation for clearing I/O interrupts for a subchannel.
Rationale: According to the platform specification, pending I/O
interruption requests have to be revoked in certain situations. For
instance, according to the Principles of Operation (page 17-27), a
subchannel put into the installed parameters initialized state is in the
same state as after an I/O system reset (just parameters possibly changed).
This implies that any I/O interrupts for that subchannel are no longer
pending (as I/O system resets clear I/O interrupts). Therefore, we need an
interface to clear pending I/O interrupts.
Signed-off-by: Halil Pasic <pasic@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/include/uapi/asm/kvm.h | 1 | ||||
| -rw-r--r-- | arch/s390/kvm/interrupt.c | 25 |
2 files changed, 26 insertions, 0 deletions
diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 347fe5afa419..3b8e99ef9d58 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -25,6 +25,7 @@ #define KVM_DEV_FLIC_APF_DISABLE_WAIT 5 #define KVM_DEV_FLIC_ADAPTER_REGISTER 6 #define KVM_DEV_FLIC_ADAPTER_MODIFY 7 +#define KVM_DEV_FLIC_CLEAR_IO_IRQ 8 /* * We can have up to 4*64k pending subchannels + 8 adapter interrupts, * as well as up to ASYNC_PF_PER_VCPU*KVM_MAX_VCPUS pfault done interrupts. diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 4c2cdb2dcfc8..e55040467eb5 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -2034,6 +2034,27 @@ static int modify_io_adapter(struct kvm_device *dev, return ret; } +static int clear_io_irq(struct kvm *kvm, struct kvm_device_attr *attr) + +{ + const u64 isc_mask = 0xffUL << 24; /* all iscs set */ + u32 schid; + + if (attr->flags) + return -EINVAL; + if (attr->attr != sizeof(schid)) + return -EINVAL; + if (copy_from_user(&schid, (void __user *) attr->addr, sizeof(schid))) + return -EFAULT; + kfree(kvm_s390_get_io_int(kvm, isc_mask, schid)); + /* + * If userspace is conforming to the architecture, we can have at most + * one pending I/O interrupt per subchannel, so this is effectively a + * clear all. + */ + return 0; +} + static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { int r = 0; @@ -2067,6 +2088,9 @@ static int flic_set_attr(struct kvm_device *dev, struct kvm_device_attr *attr) case KVM_DEV_FLIC_ADAPTER_MODIFY: r = modify_io_adapter(dev, attr); break; + case KVM_DEV_FLIC_CLEAR_IO_IRQ: + r = clear_io_irq(dev->kvm, attr); + break; default: r = -EINVAL; } @@ -2085,6 +2109,7 @@ static int flic_has_attr(struct kvm_device *dev, case KVM_DEV_FLIC_APF_DISABLE_WAIT: case KVM_DEV_FLIC_ADAPTER_REGISTER: case KVM_DEV_FLIC_ADAPTER_MODIFY: + case KVM_DEV_FLIC_CLEAR_IO_IRQ: return 0; } return -ENXIO; |