From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 56C77184 for ; Tue, 6 Sep 2022 10:33:53 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 74FCCC433D6; Tue, 6 Sep 2022 10:33:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1662460433; bh=BEJTgw4/cLVo9r6M19N464M5+kcpcrF4AMd4GiRbV/c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XPswdJgwvV05BMK6oF8t3uLF7VdIDhGrQrsKJJMjF64jMPPiij8laSTbRLgqIiIG0 8JwHxhZJKbLSseRW+gA8aBCZxVh5+OY4MlS8dBE8++1qDg2Wdd1C/Gba4p4d38KxTb AzLYNqwIQNDXYIP+hD0CCHg5zEC9FHK+8mUws+r4hV4YT4aY4Yk9d4VnNY9l9AuVO7 AI0Ad+uVDitGcCAXjMU+FlC437rP+ds4rKBlXCVjnPP5uRKFxqJBixvnb9PCoOa+sW FnVvegFB93d5PF6ldKrHYjfzccHyaL4fTmx8moc5rYWwXg3ugRNp0UYTYGX1p0pS8v oaZXCrDylcdzQ== Date: Tue, 6 Sep 2022 13:33:49 +0300 From: Jarkko Sakkinen To: Borislav Petkov Cc: Ashish Kalra , 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, tglx@linutronix.de, mingo@redhat.com, jroedel@suse.de, thomas.lendacky@amd.com, hpa@zytor.com, ardb@kernel.org, pbonzini@redhat.com, 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, michael.roth@amd.com, vbabka@suse.cz, kirill@shutemov.name, ak@linux.intel.com, tony.luck@intel.com, marcorr@google.com, sathyanarayanan.kuppuswamy@linux.intel.com, alpergun@google.com, dgilbert@redhat.com Subject: Re: [PATCH Part2 v6 09/49] x86/fault: Add support to handle the RMP fault for user address Message-ID: References: <0ecb0a4781be933fcadeb56a85070818ef3566e7.1655761627.git.ashish.kalra@amd.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Sep 06, 2022 at 01:25:10PM +0300, Jarkko Sakkinen wrote: > On Tue, Aug 09, 2022 at 06:55:43PM +0200, Borislav Petkov wrote: > > On Mon, Jun 20, 2022 at 11:03:43PM +0000, Ashish Kalra wrote: > > > + pfn = pte_pfn(*pte); > > > + > > > + /* If its large page then calculte the fault pfn */ > > > + if (level > PG_LEVEL_4K) { > > > + unsigned long mask; > > > + > > > + mask = pages_per_hpage(level) - pages_per_hpage(level - 1); > > > + pfn |= (address >> PAGE_SHIFT) & mask; > > > > Oh boy, this is unnecessarily complicated. Isn't this > > > > pfn |= pud_index(address); > > > > or > > pfn |= pmd_index(address); > > I played with this a bit and ended up with > > pfn = pte_pfn(*pte) | PFN_DOWN(address & page_level_mask(level - 1)); > > Unless I got something terribly wrong, this should do the > same (see the attached patch) as the existing calculations. IMHO a better name for this function would be do_user_rmp_addr_fault() as it is more consistent with the existing function names. BR, Jarkko