• Arjan van de Ven's avatar
    dmaengine: idxd: add a new security check to deal with a hardware erratum · e11452eb
    Arjan van de Ven authored
    On Sapphire Rapids and related platforms, the DSA and IAA devices have an
    erratum that causes direct access (for example, by using the ENQCMD or
    MOVDIR64 instructions) from untrusted applications to be a security problem.
    
    To solve this, add a flag to the PCI device enumeration and device structures
    to indicate the presence/absence of this security exposure. In the mmap()
    method of the device, this flag is then used to enforce that the user
    has the CAP_SYS_RAWIO capability.
    
    In a future patch, a write() based method will be added that allows untrusted
    applications submit work to the accelerator, where the kernel can do
    sanity checking on the user input to ensure secure operation of the accelerator.
    Signed-off-by: default avatarArjan van de Ven <arjan@linux.intel.com>
    e11452eb
idxd.h 20.3 KB