From 08fab50da669e5ee5a542592895fcb63be3cd7b1 Mon Sep 17 00:00:00 2001 From: Fei Li Date: Thu, 19 Jan 2017 17:02:26 +0100 Subject: [PATCH] KVM: s390: interface for suppressible I/O adapters In order to properly implement adapter-interruption suppression, we need a way for userspace to specify which adapters are subject to suppression. Let's convert the existing (and unused) 'pad' field into a 'flags' field and define a flag value for suppressible adapters. Besides, add documentation for the interface. Signed-off-by: Fei Li Reviewed-by: Cornelia Huck Signed-off-by: Christian Borntraeger --- Documentation/virtual/kvm/devices/s390_flic.txt | 12 +++++++++--- arch/s390/include/asm/kvm_host.h | 1 + arch/s390/include/uapi/asm/kvm.h | 4 +++- arch/s390/kvm/interrupt.c | 2 ++ 4 files changed, 15 insertions(+), 4 deletions(-) diff --git a/Documentation/virtual/kvm/devices/s390_flic.txt b/Documentation/virtual/kvm/devices/s390_flic.txt index 6b0e115301c8..e8ee3b6edb05 100644 --- a/Documentation/virtual/kvm/devices/s390_flic.txt +++ b/Documentation/virtual/kvm/devices/s390_flic.txt @@ -64,12 +64,18 @@ struct kvm_s390_io_adapter { __u8 isc; __u8 maskable; __u8 swap; - __u8 pad; + __u8 flags; }; id contains the unique id for the adapter, isc the I/O interruption subclass - to use, maskable whether this adapter may be masked (interrupts turned off) - and swap whether the indicators need to be byte swapped. + to use, maskable whether this adapter may be masked (interrupts turned off), + swap whether the indicators need to be byte swapped, and flags contains + further characteristics of the adapter. + Currently defined values for 'flags' are: + - KVM_S390_ADAPTER_SUPPRESSIBLE: adapter is subject to AIS + (adapter-interrupt-suppression) facility. This flag only has an effect if + the AIS capability is enabled. + Unknown flag values are ignored. KVM_DEV_FLIC_ADAPTER_MODIFY diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h index 1af090d93bf5..499c72c2280d 100644 --- a/arch/s390/include/asm/kvm_host.h +++ b/arch/s390/include/asm/kvm_host.h @@ -621,6 +621,7 @@ struct s390_io_adapter { bool maskable; bool masked; bool swap; + bool suppressible; struct rw_semaphore maps_lock; struct list_head maps; atomic_t nr_maps; diff --git a/arch/s390/include/uapi/asm/kvm.h b/arch/s390/include/uapi/asm/kvm.h index 5bd23cfd9ae5..5fa144d1df0a 100644 --- a/arch/s390/include/uapi/asm/kvm.h +++ b/arch/s390/include/uapi/asm/kvm.h @@ -41,9 +41,11 @@ struct kvm_s390_io_adapter { __u8 isc; __u8 maskable; __u8 swap; - __u8 pad; + __u8 flags; }; +#define KVM_S390_ADAPTER_SUPPRESSIBLE 0x01 + #define KVM_S390_IO_ADAPTER_MASK 1 #define KVM_S390_IO_ADAPTER_MAP 2 #define KVM_S390_IO_ADAPTER_UNMAP 3 diff --git a/arch/s390/kvm/interrupt.c b/arch/s390/kvm/interrupt.c index 311eef0df855..dba51ad62570 100644 --- a/arch/s390/kvm/interrupt.c +++ b/arch/s390/kvm/interrupt.c @@ -1997,6 +1997,8 @@ static int register_io_adapter(struct kvm_device *dev, adapter->maskable = adapter_info.maskable; adapter->masked = false; adapter->swap = adapter_info.swap; + adapter->suppressible = (adapter_info.flags) & + KVM_S390_ADAPTER_SUPPRESSIBLE; dev->kvm->arch.adapters[adapter->id] = adapter; return 0;