• Thomas Gleixner's avatar
    x86/kvm: Use __xfer_to_guest_mode_work_pending() in kvm_run_vcpu() · f3020b88
    Thomas Gleixner authored
    The comments explicitely explain that the work flags check and handling in
    kvm_run_vcpu() is done with preemption and interrupts enabled as KVM
    invokes the check again right before entering guest mode with interrupts
    disabled which guarantees that the work flags are observed and handled
    before VMENTER.
    
    Nevertheless the flag pending check in kvm_run_vcpu() uses the helper
    variant which requires interrupts to be disabled triggering an instant
    lockdep splat. This was caught in testing before and then not fixed up in
    the patch before applying. :(
    
    Use the relaxed and intentionally racy __xfer_to_guest_mode_work_pending()
    instead.
    
    Fixes: 72c3c0fe ("x86/kvm: Use generic xfer to guest work function")
    Reported-by: Qian Cai <cai@lca.pw> writes:
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Link: https://lkml.kernel.org/r/87bljxa2sa.fsf@nanos.tec.linutronix.de
    
    f3020b88
x86.c 279 KB