• Avi Kivity's avatar
    KVM: Per-vcpu inodes · bccf2150
    Avi Kivity authored
    Allocate a distinct inode for every vcpu in a VM.  This has the following
    benefits:
    
     - the filp cachelines are no longer bounced when f_count is incremented on
       every ioctl()
     - the API and internal code are distinctly clearer; for example, on the
       KVM_GET_REGS ioctl, there is no need to copy the vcpu number from
       userspace and then copy the registers back; the vcpu identity is derived
       from the fd used to make the call
    
    Right now the performance benefits are completely theoretical since (a) we
    don't support more than one vcpu per VM and (b) virtualization hardware
    inefficiencies completely everwhelm any cacheline bouncing effects.  But
    both of these will change, and we need to prepare the API today.
    Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
    bccf2150
vmx.c 52.3 KB