Messages in this thread | | | From | "Luck, Tony" <> | Subject | Re: [PATCH] x86/mm: Don't try to change poison pages to uncacheable in a guest | Date | Sun, 17 May 2020 01:52:25 +0000 |
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But the guest isn’t likely to do the right thing with a page fault. The guest just accessed a page that it knows is poisoned (VMM just told it once that it was poisoned). There is no reason that the VMM should let the guest actually touch the poison a second time. But if the guest does, then the guest should get the expected response. I.e. another machine check.
Sent from my iPhone
> On May 16, 2020, at 08:03, Borislav Petkov <bp@alien8.de> wrote: > > On Sat, May 16, 2020 at 02:47:42PM +0000, Luck, Tony wrote: >> There is only one actual machine check. But the VMM simulates a second >> machine check to the guest when the guest tries to access the poisoned >> page. > > If the VMM unmaps the bad page, why doesn't the guest get a #PF instead > injected by the VMM instead of latter injecting a second #MCE? > > If the guest tries to access an unmapped page, it should get a #PF, I'd > expect. > > -- > Regards/Gruss, > Boris. > > https://people.kernel.org/tglx/notes-about-netiquette
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