• Vitaly Kuznetsov's avatar
    x86/hyper-v: Check for VP_INVAL in hyperv_flush_tlb_others() · 110d2a7f
    Vitaly Kuznetsov authored
    Commit 1268ed0c ("x86/hyper-v: Fix the circular dependency in IPI
     enlightenment") pre-filled hv_vp_index with VP_INVAL so it is now
    (theoretically) possible to observe hv_cpu_number_to_vp_number()
    returning VP_INVAL. We need to check for that in hyperv_flush_tlb_others().
    
    Not checking for VP_INVAL on the first call site where we do
    
     if (hv_cpu_number_to_vp_number(cpumask_last(cpus)) >= 64)
                            goto do_ex_hypercall;
    
    is OK, in case we're eligible for non-ex hypercall we'll catch the
    issue later in for_each_cpu() cycle and in case we'll be doing ex-
    hypercall cpumask_to_vpset() will fail.
    
    It would be nice to change hv_cpu_number_to_vp_number() return
    value's type to 'u32' but this will likely be a bigger change as
    all call sites need to be checked first.
    
    Fixes: 1268ed0c
    
     ("x86/hyper-v: Fix the circular dependency in IPI enlightenment")
    Signed-off-by: default avatarVitaly Kuznetsov <vkuznets@redhat.com>
    Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    Reviewed-by: default avatarMichael Kelley <mikelley@microsoft.com>
    Cc: "K. Y. Srinivasan" <kys@microsoft.com>
    Cc: Haiyang Zhang <haiyangz@microsoft.com>
    Cc: Stephen Hemminger <sthemmin@microsoft.com>
    Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com>
    Cc: devel@linuxdriverproject.org
    Cc: "H. Peter Anvin" <hpa@zytor.com>
    Link: https://lkml.kernel.org/r/20180709174012.17429-3-vkuznets@redhat.com
    110d2a7f
mmu.c 6.01 KB