• Jan Kiszka's avatar
    KVM: New guest debug interface · d0bfb940
    Jan Kiszka authored
    This rips out the support for KVM_DEBUG_GUEST and introduces a new IOCTL
    instead: KVM_SET_GUEST_DEBUG. The IOCTL payload consists of a generic
    part, controlling the "main switch" and the single-step feature. The
    arch specific part adds an x86 interface for intercepting both types of
    debug exceptions separately and re-injecting them when the host was not
    interested. Moveover, the foundation for guest debugging via debug
    registers is layed.
    
    To signal breakpoint events properly back to userland, an arch-specific
    data block is now returned along KVM_EXIT_DEBUG. For x86, the arch block
    contains the PC, the debug exception, and relevant debug registers to
    tell debug events properly apart.
    
    The availability of this new interface is signaled by
    KVM_CAP_SET_GUEST_DEBUG. Empty stubs for not yet supported archs are
    provided.
    
    Note that both SVM and VTX are supported, but only the latter was tested
    yet. Based on the experience with all those VTX corner case, I would be
    fairly surprised if SVM will work out of the box.
    Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
    Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
    d0bfb940
kvm.h 1.03 KB