> -----Original Message----- > From: Borislav Petkov [mailto:b...@alien8.de] > Sent: Wednesday, April 05, 2017 2:22 PM > To: Ghannam, Yazen <yazen.ghan...@amd.com> > Cc: linux-e...@vger.kernel.org; Tony Luck <tony.l...@intel.com>; > x...@kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH v2 1/2] x86/mce/AMD: Redo use of SMCA > MCA_DE{STAT,ADDR} registers > > > > How does log_error() know if we can't use the normal MSRs? > > MCI_STATUS_VAL. > > > We check for MCI_STATUS_VAL in log_error(). > > Yes. > > > We also need to check for MCI_STATUS_DEFERRED but only if we're coming > > from the deferred error handler. > > Why? We *are* coming from the #DF handler so are you expecting a > different type of error in the MSRs? >
Yes, there could be depending on how MCA_CONFIG[LogDeferredInMcaStat] is set among other things. If it's set, then I expect a Deferred error in MCA_STATUS since any Correctable Errors will be overwritten. Multiple bank types can generate Deferred errors so there may also be cases where for some types a valid Uncorrectable error happens and overwrites the Deferred error before we can handle it. In which case we lose the Deferred error if we don't check MCA_DESTAT. If it's not set, then it's possible to have a valid Correctable error in MCA_STATUS while the valid Deferred error is in MCA_DESTAT. Right now MCA_CONFIG[LogDeferredInMcaStat] is set but this may change for future SMCA implementations. Thanks, Yazen
