From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
To: David Hildenbrand <david@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>,
Borislav Petkov <bp@alien8.de>,
Andrew Morton <akpm@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Vlastimil Babka <vbabka@suse.cz>,
Mike Rapoport <rppt@linux.ibm.com>,
Lorenzo Stoakes <lstoakes@gmail.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
Baoquan He <bhe@redhat.com>, Vivek Goyal <vgoyal@redhat.com>,
Dave Young <dyoung@redhat.com>,
linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org, linux-coco@lists.linux.dev,
linux-efi@vger.kernel.org, kexec@lists.infradead.org
Subject: Re: [PATCH 1/3] proc/vmcore: Do not map unaccepted memory
Date: Mon, 11 Sep 2023 11:41:48 +0300 [thread overview]
Message-ID: <20230911084148.l6han7jxob42rdvm@box.shutemov.name> (raw)
In-Reply-To: <ef97f466-b27a-a883-7131-c2051480dd87@redhat.com>
On Mon, Sep 11, 2023 at 10:03:36AM +0200, David Hildenbrand wrote:
> On 06.09.23 09:39, Adrian Hunter wrote:
> > Support for unaccepted memory was added recently, refer commit
> > dcdfdd40fa82 ("mm: Add support for unaccepted memory"), whereby
> > a virtual machine may need to accept memory before it can be used.
> >
> > Do not map unaccepted memory because it can cause the guest to fail.
> >
> > For /proc/vmcore, which is read-only, this means a read or mmap of
> > unaccepted memory will return zeros.
>
> Does a second (kdump) kernel that exposes /proc/vmcore reliably get access
> to the information whether memory of the first kernel is unaccepted (IOW,
> not its memory, but the memory of the first kernel it is supposed to expose
> via /proc/vmcore)?
There are few patches in my queue to few related issue, but generally,
yes, the information is available to the target kernel via EFI
configuration table.
--
Kiryl Shutsemau / Kirill A. Shutemov
next prev parent reply other threads:[~2023-09-11 20:56 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-06 7:38 [PATCH 0/3] Do not map unaccepted memory Adrian Hunter
2023-09-06 7:39 ` [PATCH 1/3] proc/vmcore: " Adrian Hunter
2023-09-07 15:39 ` Dave Hansen
2023-09-07 15:44 ` Adrian Hunter
2023-09-07 15:51 ` Dave Hansen
2023-09-11 8:03 ` David Hildenbrand
2023-09-11 8:41 ` Kirill A. Shutemov [this message]
2023-09-11 8:42 ` David Hildenbrand
2023-09-11 9:27 ` Kirill A. Shutemov
2023-09-11 9:50 ` David Hildenbrand
2023-09-11 10:05 ` Kirill A. Shutemov
2023-09-11 14:33 ` David Hildenbrand
2023-09-06 7:39 ` [PATCH 2/3] proc/kcore: " Adrian Hunter
2023-09-07 15:36 ` Dave Hansen
2023-09-07 15:43 ` Dave Hansen
2023-09-06 7:39 ` [PATCH 3/3] /dev/mem: " Adrian Hunter
2023-09-07 10:06 ` Kirill A. Shutemov
2023-09-07 14:15 ` Dave Hansen
2023-09-07 14:25 ` Kirill A. Shutemov
2023-09-07 14:46 ` Dave Hansen
2023-09-07 15:04 ` Dave Hansen
2023-09-11 8:09 ` David Hildenbrand
2023-09-11 14:32 ` Dave Hansen
2023-09-07 10:07 ` [PATCH 0/3] " Kirill A. Shutemov
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