• Alex Bennée's avatar
    KVM: arm64: guest debug, add SW break point support · 4bd611ca
    Alex Bennée authored
    This adds support for SW breakpoints inserted by userspace.
    
    We do this by trapping all guest software debug exceptions to the
    hypervisor (MDCR_EL2.TDE). The exit handler sets an exit reason of
    KVM_EXIT_DEBUG with the kvm_debug_exit_arch structure holding the
    exception syndrome information.
    
    It will be up to userspace to extract the PC (via GET_ONE_REG) and
    determine if the debug event was for a breakpoint it inserted. If not
    userspace will need to re-inject the correct exception restart the
    hypervisor to deliver the debug exception to the guest.
    
    Any other guest software debug exception (e.g. single step or HW
    assisted breakpoints) will cause an error and the VM to be killed. This
    is addressed by later patches which add support for the other debug
    types.
    Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
    Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
    Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    4bd611ca
debug.c 2.52 KB