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Subject: Re: [PATCH] kdump, vmcoreinfo: Export sme_me_mask value to vmcoreinfo
To:     Borislav Petkov <bp@alien8.de>
Cc:     linux-kernel@vger.kernel.org, kexec@lists.infradead.org,
        tglx@linutronix.de, mingo@redhat.com, x86@kernel.org,
        bhe@redhat.com, dyoung@redhat.com
References: <20181026093630.8520-1-lijiang@redhat.com>
 <053CC83A-9A95-4C12-9627-AABD1427DA9C@alien8.de>
 <1263471c-a27d-a698-15f0-b5947f13ea93@redhat.com>
 <20181026163554.GA26331@nazgul.tnic>
From:   lijiang <lijiang@redhat.com>
Message-ID: <e8357c26-1969-f870-d2e5-62b77a1b4fd5@redhat.com>
Date:   Sat, 27 Oct 2018 10:19:52 +0800
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在 2018年10月27日 00:35, Borislav Petkov 写道:
> On Fri, Oct 26, 2018 at 08:32:11PM +0800, lijiang wrote:
>> If SME is enabled in the first kernel, the crash kernel's page table(pgd/pud/pmd/pte)
>> contains the memory encryption mask, so i have to remove the sme mask to obtain the
>> true physical address when dump vmcore.
> 
> Sorry, I have no clue what makedumpfile does exactly so you'd have to
> be more detailed (or wait until I look at it :)). Which kernel accesses
> which kernel's pagetable?
> 
> /me goes and looks at the makedumpfile's manpage...
> 

So sorry that i should provide more detail about this.
Thanks a lot for spending time reading the manpage.

> Ok, it uses vmcoreinfo to exclude pages which would mean, it accesses
> the first kernel's pagetable and traverses it.
> 
> Am I close?
> 

Yes, your explanation is perfect.

Thanks.
Lianbo