• Carsten Otte's avatar
    KVM: s390: interrupt subsystem, cpu timer, waitpsw · ba5c1e9b
    Carsten Otte authored
    This patch contains the s390 interrupt subsystem (similar to in kernel apic)
    including timer interrupts (similar to in-kernel-pit) and enabled wait
    (similar to in kernel hlt).
    
    In order to achieve that, this patch also introduces intercept handling
    for instruction intercepts, and it implements load control instructions.
    
    This patch introduces an ioctl KVM_S390_INTERRUPT which is valid for both
    the vm file descriptors and the vcpu file descriptors. In case this ioctl is
    issued against a vm file descriptor, the interrupt is considered floating.
    Floating interrupts may be delivered to any virtual cpu in the configuration.
    
    The following interrupts are supported:
    SIGP STOP       - interprocessor signal that stops a remote cpu
    SIGP SET PREFIX - interprocessor signal that sets the prefix register of a
                      (stopped) remote cpu
    INT EMERGENCY   - interprocessor interrupt, usually used to signal need_reshed
                      and for smp_call_function() in the guest.
    PROGRAM INT     - exception during program execution such as page fault, illegal
                      instruction and friends
    RESTART         - interprocessor signal that starts a stopped cpu
    INT VIRTIO      - floating interrupt for virtio signalisation
    INT SERVICE     - floating interrupt for signalisations from the system
                      service processor
    
    struct kvm_s390_interrupt, which is submitted as ioctl parameter when injecting
    an interrupt, also carrys parameter data for interrupts along with the interrupt
    type. Interrupts on s390 usually have a state that represents the current
    operation, or identifies which device has caused the interruption on s390.
    
    kvm_s390_handle_wait() does handle waitpsw in two flavors: in case of a
    disabled wait (that is, disabled for interrupts), we exit to userspace. In case
    of an enabled wait we set up a timer that equals the cpu clock comparator value
    and sleep on a wait queue.
    
    [christian: change virtio interrupt to 0x2603]
    Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Signed-off-by: default avatarCarsten Otte <cotte@de.ibm.com>
    Signed-off-by: default avatarChristian Borntraeger <borntraeger@de.ibm.com>
    Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
    ba5c1e9b
intercept.c 4.48 KB