Messages in this thread | | | Date | Thu, 19 Jul 2018 15:18:03 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCHv5 08/19] x86/mm: Introduce variables to store number, shift and mask of KeyIDs |
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On Thu, 19 Jul 2018, Kirill A. Shutemov wrote: > On Thu, Jul 19, 2018 at 02:37:35PM +0200, Thomas Gleixner wrote: > > On Thu, 19 Jul 2018, Kirill A. Shutemov wrote: > > > On Wed, Jul 18, 2018 at 04:19:10PM -0700, Dave Hansen wrote: > > > > > } else { > > > > > /* > > > > > * Reset __PHYSICAL_MASK. > > > > > @@ -591,6 +592,9 @@ static void detect_tme(struct cpuinfo_x86 *c) > > > > > * between CPUs. > > > > > */ > > > > > physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1; > > > > > + mktme_keyid_mask = 0; > > > > > + mktme_keyid_shift = 0; > > > > > + mktme_nr_keyids = 0; > > > > > } > > > > > > > > Should be unnecessary. These are zeroed by the compiler. > > > > > > No. detect_tme() called for each CPU in the system. > > > > And then the variables are cleared out while other CPUs can access them? > > How is that supposed to work? > > This code path only matter in patalogical case: when MKTME configuation is > inconsitent between CPUs. Basically if BIOS screwed things up we disable > MKTME.
I still don't see how that's supposed to work.
When the inconsistent CPU is brought up _AFTER_ MKTME is enabled, then how does clearing the variables help? It does not magically make all the other stuff go away.
Thanks,
tglx
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