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Shutemov" , Andi Kleen , tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, Marc Zyngier , Will Deacon , Quentin Perret 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 In-Reply-To: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 199265092EE8 X-Stat-Signature: xisqg679unwuiuhbory3h8nhjf47w8r3 Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=rymaTROe; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=hhlqvIWu; dmarc=pass (policy=none) header.from=suse.de; spf=pass (imf01.hostedemail.com: domain of jroedel@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=jroedel@suse.de X-HE-Tag: 1637073999-339295 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Nov 15, 2021 at 07:15:07PM +0000, Sean Christopherson wrote: > It creates a new attack surface, e.g. if the guest mishandles the #VC a= nd does > PVALIDATE on memory that it previously accepted, then userspace can att= ack the > guest by accessing guest private memory to coerce the guest into consum= ing corrupted > data. If a guest can be tricked into a double PVALIDATE or otherwise misbehaves on a #VC exception, then it is a guest bug and needs to be fixed there. It is a core requirement to the #VC handler that it can not be tricked that way. Regards, --=20 J=F6rg R=F6del jroedel@suse.de SUSE Software Solutions Germany GmbH Maxfeldstr. 5 90409 N=FCrnberg Germany =20 (HRB 36809, AG N=FCrnberg) Gesch=E4ftsf=FChrer: Ivo Totev