From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E112B149E14; Wed, 3 Apr 2024 15:37:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712158662; cv=none; b=XlUdXbaAAmmu+8lOjMCPNH5r2bRtkFZGaH3rbs76MKq3YY2r7TZGQ/qLWmnDBVO7Qku+QgGLvFHhduEuxTMuqPKSjfWTlRGmYkn6JDJg9OYiUauIZaxWUJR1ZzyZDkCFbNZEHfxVFR2U9m+XQWN7en/RLTXxWJ4PkIz/VAg1wvs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712158662; c=relaxed/simple; bh=QJChaVAp28BDDX83PqbBHFkbmbYUNuu15HZqdJSXkew=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=Yq+ouACWrd9a+RGUo2tgQN4iuxguQskAXobLtP1F5hoTV4bCjOD245qUwUyCgc96CRB8uuoRl7uuYEmW4VKSMuXptFKddGzsPFWQQZawGYnO15LXGyGU1ROYOGzwJb/fQ4fNske1nSsZYkM317KtPqRw+A2kz+g6NNp4GTFo76M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Ie2IcwL4; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Ie2IcwL4" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1712158661; x=1743694661; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=QJChaVAp28BDDX83PqbBHFkbmbYUNuu15HZqdJSXkew=; b=Ie2IcwL4Q7B8mbHEdOUHjfU5XEkJY4D9o82CDnKqJXJlHNX85xbZuZIP HYPbaGjZ0SL/U0juSHptSQN+aC3gbFnojAZ2KQvCYK+5ag9iFbjOrseaK cNDe25mf0o/Jn7po8OEslU0kdKbUA0AygEnLmQW7+KTLvpphDVRbBKOJa nYlK/43Ye28L1BOsl2vXBuivCVN/0vexCfSPyo0uEksXaFBENaRZwvBhI 9Tpm1RQxZo+UVMVUimVYHAIfslJmy1Vvbal+VGVaomTcvuKx3ASBuIlaz /anQR21aEr9eFH2/QLO6aOHR9Q9ZqFJo3FZbePgoiGODkE48aq/08b2mQ Q==; X-CSE-ConnectionGUID: zCWnttiTQKuBUbaTiDKWKg== X-CSE-MsgGUID: Dwvx7rT+R2WHlCOQbFq50w== X-IronPort-AV: E=McAfee;i="6600,9927,11033"; a="7978851" X-IronPort-AV: E=Sophos;i="6.07,177,1708416000"; d="scan'208";a="7978851" Received: from orviesa003.jf.intel.com ([10.64.159.143]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2024 08:37:40 -0700 X-CSE-ConnectionGUID: C9r8JNIGTH6X/XyVwhZi2g== X-CSE-MsgGUID: 1aG80udaTneHuT7+mWUbTQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,177,1708416000"; d="scan'208";a="23177428" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by ORVIESA003-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Apr 2024 08:37:39 -0700 Date: Wed, 3 Apr 2024 08:37:38 -0700 From: Isaku Yamahata To: Paolo Bonzini Cc: Isaku Yamahata , Michael Roth , kvm@vger.kernel.org, linux-coco@lists.linux.dev, linux-mm@kvack.org, linux-crypto@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, seanjc@google.com, vkuznets@redhat.com, jmattson@google.com, luto@kernel.org, dave.hansen@linux.intel.com, slp@redhat.com, pgonda@google.com, peterz@infradead.org, srinivas.pandruvada@linux.intel.com, rientjes@google.com, dovmurik@linux.ibm.com, tobin@ibm.com, bp@alien8.de, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com, pankaj.gupta@amd.com, liam.merwick@oracle.com, Brijesh Singh , Xu Yilun , Binbin Wu , Xiaoyao Li , isaku.yamahata@linux.intel.com Subject: Re: [PATCH v12 11/29] KVM: SEV: Add KVM_SEV_SNP_LAUNCH_UPDATE command Message-ID: <20240403153738.GC2444378@ls.amr.corp.intel.com> References: <20240329225835.400662-1-michael.roth@amd.com> <20240329225835.400662-12-michael.roth@amd.com> <8c3685a6-833c-4b3c-83f4-c0bd78bba36e@redhat.com> <20240401222229.qpnpozdsr6b2sntk@amd.com> <20240402225840.GB2444378@ls.amr.corp.intel.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: On Wed, Apr 03, 2024 at 02:51:59PM +0200, Paolo Bonzini wrote: > On Wed, Apr 3, 2024 at 12:58 AM Isaku Yamahata wrote: > > I think TDX can use it with slight change. Pass vcpu instead of KVM, page pin > > down and mmu_lock. TDX requires non-leaf Secure page tables to be populated > > before adding a leaf. Maybe with the assumption that vcpu doesn't run, GFN->PFN > > relation is stable so that mmu_lock isn't needed? What about punch hole? > > > > The flow would be something like as follows. > > > > - lock slots_lock > > > > - kvm_gmem_populate(vcpu) > > - pin down source page instead of do_memcopy. > > Both pinning the source page and the memcpy can be done in the > callback. I think the right thing to do is: > > 1) eliminate do_memcpy, letting AMD code taking care of > copy_from_user. > > 2) pass to the callback only gfn/pfn/src, where src is computed as > > args->src ? args->src + i * PAGE_SIZE : NULL > > If another architecture/vendor needs do_memcpy, they can add > something like kvm_gmem_populate_copy. > > > - get pfn with __kvm_gmem_get_pfn() > > - read lock mmu_lock > > - in the post_populate callback > > - lookup tdp mmu page table to check if the table is populated. > > lookup only version of kvm_tdp_mmu_map(). > > We need vcpu instead of kvm. > > Passing vcpu can be done using the opaque callback argument to > kvm_gmem_populate. > > Likewise, the mmu_lock can be taken by the TDX post_populate > callback. Yes, it should work. Let me give it a try. -- Isaku Yamahata