Messages in this thread | | | Subject | Re: [PATCH v2 2/5] x86/mce/inject: Warn the user on a not set valid bit in MCA_STATUS | From | "Koralahalli Channabasappa, Smita" <> | Date | Tue, 26 Oct 2021 11:58:58 -0500 |
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Hi Boris,
On 10/26/21 5:02 AM, Borislav Petkov wrote:
> On Tue, Oct 19, 2021 at 06:36:38PM -0500, Smita Koralahalli wrote: >> MCA handlers check the valid bit in each status register (MCA_STATUS[Val]) >> and will likely ignore signatures if the valid bit is not set. >> >> Warn the user if the valid bit is not set before doing error injection. >> >> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com> >> --- >> v2: >> Added a warning statement instead of setting the valid bit. >> --- >> arch/x86/kernel/cpu/mce/inject.c | 3 +++ >> 1 file changed, 3 insertions(+) >> >> diff --git a/arch/x86/kernel/cpu/mce/inject.c b/arch/x86/kernel/cpu/mce/inject.c >> index 601efd104bb4..a993dc3d0333 100644 >> --- a/arch/x86/kernel/cpu/mce/inject.c >> +++ b/arch/x86/kernel/cpu/mce/inject.c >> @@ -487,6 +487,9 @@ static void do_inject(void) >> >> i_mce.tsc = rdtsc_ordered(); >> >> + if (!(i_mce.status & MCI_STATUS_VAL)) >> + pr_warn("Handlers might ignore signatures with Val=0 in MCA_STATUS\n"); >> + >> if (i_mce.misc) >> i_mce.status |= MCI_STATUS_MISCV; >> >> -- > So what's the real reason for this? > > You've injected and you didn't get any feedback and were wondering why? > > If handlers ignore !VAL MCEs, why don't you simply set it > unconditionally on entry to do_inject()?
Like how it was done here? https://lkml.kernel.org/r/20210915232739.6367-3-Smita.KoralahalliChannabasappa@amd.com
Thanks,
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