• Jintack's avatar
    arm64: head.S: Fix CNTHCTL_EL2 access on VHE system · 1650ac49
    Jintack authored
    Bit positions of CNTHCTL_EL2 are changing depending on HCR_EL2.E2H bit.
    EL1PCEN and EL1PCTEN are 1st and 0th bits when E2H is not set, but they
    are 11th and 10th bits respectively when E2H is set.  Current code is
    unintentionally setting wrong bits to CNTHCTL_EL2 with E2H set.
    
    In fact, we don't need to set those two bits, which allow EL1 and EL0 to
    access physical timer and counter respectively, if E2H and TGE are set
    for the host kernel. They will be configured later as necessary. First,
    we don't need to configure those bits for EL1, since the host kernel
    runs in EL2.  It is a hypervisor's responsibility to configure them
    before entering a VM, which runs in EL0 and EL1. Second, EL0 accesses
    are configured in the later stage of boot process.
    Signed-off-by: default avatarJintack Lim <jintack@cs.columbia.edu>
    Acked-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    1650ac49
head.S 23.2 KB