Messages in this thread | | | From | "Michael Kelley (EOSG)" <> | Subject | RE: [PATCH 2/2] x86/hyper-v: check for VP_INVAL in hyperv_flush_tlb_others() | Date | Tue, 10 Jul 2018 19:41:09 +0000 |
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From: Vitaly Kuznetsov <vkuznets@redhat.com> Monday, July 9, 2018 10:40 AM > Commit 1268ed0c474a ("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: 1268ed0c474a ("x86/hyper-v: Fix the circular dependency in IPI enlightenment") > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > arch/x86/hyperv/mmu.c | 5 +++++ > 1 file changed, 5 insertions(+)
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
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