• Marc Zyngier's avatar
    KVM: arm64: vgic-v4: Move the GICv4 residency flow to be driven by vcpu_load/put · 8e01d9a3
    Marc Zyngier authored
    When the VHE code was reworked, a lot of the vgic stuff was moved around,
    but the GICv4 residency code did stay untouched, meaning that we come
    in and out of residency on each flush/sync, which is obviously suboptimal.
    
    To address this, let's move things around a bit:
    
    - Residency entry (flush) moves to vcpu_load
    - Residency exit (sync) moves to vcpu_put
    - On blocking (entry to WFI), we "put"
    - On unblocking (exit from WFI), we "load"
    
    Because these can nest (load/block/put/load/unblock/put, for example),
    we now have per-VPE tracking of the residency state.
    
    Additionally, vgic_v4_put gains a "need doorbell" parameter, which only
    gets set to true when blocking because of a WFI. This allows a finer
    control of the doorbell, which now also gets disabled as soon as
    it gets signaled.
    Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
    Link: https://lore.kernel.org/r/20191027144234.8395-2-maz@kernel.org
    8e01d9a3
vgic.c 25.9 KB