• Christoffer Dall's avatar
    KVM: ARM: User space API for getting/setting co-proc registers · 1138245c
    Christoffer Dall authored
    The following three ioctls are implemented:
     -  KVM_GET_REG_LIST
     -  KVM_GET_ONE_REG
     -  KVM_SET_ONE_REG
    
    Now we have a table for all the cp15 registers, we can drive a generic
    API.
    
    The register IDs carry the following encoding:
    
    ARM registers are mapped using the lower 32 bits.  The upper 16 of that
    is the register group type, or coprocessor number:
    
    ARM 32-bit CP15 registers have the following id bit patterns:
      0x4002 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3>
    
    ARM 64-bit CP15 registers have the following id bit patterns:
      0x4003 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3>
    
    For futureproofing, we need to tell QEMU about the CP15 registers the
    host lets the guest access.
    
    It will need this information to restore a current guest on a future
    CPU or perhaps a future KVM which allow some of these to be changed.
    
    We use a separate table for these, as they're only for the userspace API.
    Reviewed-by: default avatarWill Deacon <will.deacon@arm.com>
    Reviewed-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
    Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
    Signed-off-by: default avatarChristoffer Dall <c.dall@virtualopensystems.com>
    1138245c
guest.c 5.59 KB