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[82.30.61.225]) by smtp.gmail.com with ESMTPSA id c79sm14527579wme.43.2021.11.15.08.32.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 15 Nov 2021 08:32:41 -0800 (PST) Date: Mon, 15 Nov 2021 16:32:38 +0000 From: "Dr. David Alan Gilbert" To: Joerg Roedel Cc: Sean Christopherson , Borislav Petkov , Dave Hansen , Peter Gonda , Brijesh Singh , x86@kernel.org, linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, Thomas Gleixner , Ingo Molnar , Tom Lendacky , "H. Peter Anvin" , Ard Biesheuvel , Paolo Bonzini , Vitaly Kuznetsov , Wanpeng Li , Jim Mattson , Andy Lutomirski , Dave Hansen , Sergio Lopez , Peter Zijlstra , Srinivas Pandruvada , David Rientjes , Dov Murik , Tobin Feldman-Fitzthum , Michael Roth , Vlastimil Babka , "Kirill A . Shutemov" , Andi Kleen , tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com Subject: Re: [PATCH Part2 v5 00/45] Add AMD Secure Nested Paging (SEV-SNP) Hypervisor Support Message-ID: References: <20210820155918.7518-1-brijesh.singh@amd.com> <061ccd49-3b9f-d603-bafd-61a067c3f6fa@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/2.0.7 (2021-05-04) Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org * Joerg Roedel (jroedel@suse.de) wrote: > On Mon, Nov 15, 2021 at 03:33:03PM +0000, Dr. David Alan Gilbert wrote: > > How would you debug an unexpected access by the host kernel using a > > guests kdump? > > The host needs to log the access in some way (trace-event, pr_err) with > relevant information. Yeh OK that makes sense if the host-owner could then enable some type of debugging based on that event for the unfortunate guest owner. > And with the guest-side kdump you can rule out that it was a guest bug > which triggered the access. And you learn what the guest was trying to > do when it triggered the access. This also helps finding the issue on > the host side (if it is a host-side issue). > > (Guest and host owner need to work together for debugging, of course). Yeh. Dave > Regards, > > -- > Jörg Rödel > jroedel@suse.de > > SUSE Software Solutions Germany GmbH > Maxfeldstr. 5 > 90409 Nürnberg > Germany > > (HRB 36809, AG Nürnberg) > Geschäftsführer: Ivo Totev > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK