From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A230FC0015E for ; Wed, 9 Aug 2023 12:46:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 0D0688E0002; Wed, 9 Aug 2023 08:46:35 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 059CA8E0001; Wed, 9 Aug 2023 08:46:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E3CE98E0002; Wed, 9 Aug 2023 08:46:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id D1E018E0001 for ; Wed, 9 Aug 2023 08:46:34 -0400 (EDT) Received: from smtpin23.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 914F380E5D for ; Wed, 9 Aug 2023 12:46:34 +0000 (UTC) X-FDA: 81104539908.23.366401F Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by imf29.hostedemail.com (Postfix) with ESMTP id AA2EB120029 for ; Wed, 9 Aug 2023 12:46:32 +0000 (UTC) Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux.microsoft.com header.s=default header.b=JvqfUwlr; dmarc=pass (policy=none) header.from=linux.microsoft.com; spf=pass (imf29.hostedemail.com: domain of jpiotrowski@linux.microsoft.com designates 13.77.154.182 as permitted sender) smtp.mailfrom=jpiotrowski@linux.microsoft.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1691585192; a=rsa-sha256; cv=none; b=Tvgqlm/uacqYIw3K5jOfERyTPoygsAZXZQmOkY1ekM3XoigejyTxNDV60vs45GMpPfgp31 5Jk7Zz/rDVAZSIJrZcRuKsz3iYYarnImdeLEQHbwbejtCoYpYgKs5osuUDcV3aDy5GhAl4 fk89EhzJECzfIZB5UdK9lpu6WrOXrhQ= ARC-Authentication-Results: i=1; imf29.hostedemail.com; dkim=pass header.d=linux.microsoft.com header.s=default header.b=JvqfUwlr; dmarc=pass (policy=none) header.from=linux.microsoft.com; spf=pass (imf29.hostedemail.com: domain of jpiotrowski@linux.microsoft.com designates 13.77.154.182 as permitted sender) smtp.mailfrom=jpiotrowski@linux.microsoft.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1691585192; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=G0gxRN5QnxTLEOIdIvEe864KwskWfmwxWJZYwvjDSlo=; b=i1v24nk/88WgSXDLV70GD5Y4sNG9sqTCnzp/AYQBOPCiYY6DXT3J8nuzQq9LP05FJ7HVy8 lyQCbnNadk5bIvL1hzL3jp15jqdz72tv8CTDRMLcZEXIuEMRn1Oi1s/a70M7jI1JjzCYpz xTysOF8N2a3434ur21YMie1ljeFtTz0= Received: by linux.microsoft.com (Postfix, from userid 1112) id D6FD120FC3FE; Wed, 9 Aug 2023 05:46:30 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com D6FD120FC3FE DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1691585190; bh=G0gxRN5QnxTLEOIdIvEe864KwskWfmwxWJZYwvjDSlo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=JvqfUwlrN8SFoQZfvoGT5ol8Tmiz9HmGGUsXNPJy28y9tdBKDtRIpIkaO0RTgvnGy me82/2JlMkKOJ8nouwy+b6PR8sxGfLnSMkNPCxFctzUFbnJb3MMLT5naT+6xEjxA9q sQa3F9+OJGboaWVu/aYlKhbXeWKFEEG9axlkdoYo= Date: Wed, 9 Aug 2023 05:46:30 -0700 From: Jeremi Piotrowski To: Michael Roth Cc: 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, 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, bp@alien8.de, 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, jarkko@kernel.org, ashish.kalra@amd.com, nikunj.dadhania@amd.com, liam.merwick@oracle.com, zhi.a.wang@intel.com Subject: Re: [PATCH RFC v9 19/51] x86/sev: Introduce snp leaked pages list Message-ID: <20230809124630.GA11150@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> References: <20230612042559.375660-1-michael.roth@amd.com> <20230612042559.375660-20-michael.roth@amd.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230612042559.375660-20-michael.roth@amd.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-Rspam-User: X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: AA2EB120029 X-Stat-Signature: zxguoqo6ub6y85prb5dokhxitq6yuc4q X-HE-Tag: 1691585192-210057 X-HE-Meta: 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 6nArcjiK inT15poYWN1v5qd0mrWV2C8c9nHpvJV+VIWuWRa25dJIT6CGRO+vNi8jgiva0mPIZiVRDbCC8qBL8CLlaTq0VVu7LaWveDq1AQK96Asm2uoh5SE5eWVad0ropDNCH/8xoWSBl5RV8eISWodmtUFdXbP1UvLSV1qQzREVY 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 Sun, Jun 11, 2023 at 11:25:27PM -0500, Michael Roth wrote: > From: Ashish Kalra > > Pages are unsafe to be released back to the page-allocator, if they > have been transitioned to firmware/guest state and can't be reclaimed > or transitioned back to hypervisor/shared state. In this case add > them to an internal leaked pages list to ensure that they are not freed > or touched/accessed to cause fatal page faults. > > Signed-off-by: Ashish Kalra > [mdr: relocate to arch/x86/coco/sev/host.c] > Signed-off-by: Michael Roth > --- > arch/x86/coco/sev/host.c | 28 ++++++++++++++++++++++++++++ > arch/x86/include/asm/sev-host.h | 3 +++ > 2 files changed, 31 insertions(+) > > diff --git a/arch/x86/coco/sev/host.c b/arch/x86/coco/sev/host.c > index cd3b4c6a25bc..373e91f5a337 100644 > --- a/arch/x86/coco/sev/host.c > +++ b/arch/x86/coco/sev/host.c > @@ -64,6 +64,12 @@ struct rmpentry { > static unsigned long rmptable_start __ro_after_init; > static unsigned long rmptable_end __ro_after_init; > > +/* list of pages which are leaked and cannot be reclaimed */ > +static LIST_HEAD(snp_leaked_pages_list); > +static DEFINE_SPINLOCK(snp_leaked_pages_list_lock); > + > +static atomic_long_t snp_nr_leaked_pages = ATOMIC_LONG_INIT(0); > + > #undef pr_fmt > #define pr_fmt(fmt) "SEV-SNP: " fmt > > @@ -494,3 +500,25 @@ int rmp_make_shared(u64 pfn, enum pg_level level) > return rmpupdate(pfn, &val); > } > EXPORT_SYMBOL_GPL(rmp_make_shared); > + > +void snp_leak_pages(unsigned long pfn, unsigned int npages) > +{ > + struct page *page = pfn_to_page(pfn); > + > + WARN(1, "psc failed, pfn 0x%lx pages %d (marked offline)\n", pfn, npages); > + > + spin_lock(&snp_leaked_pages_list_lock); > + while (npages--) { > + /* > + * Reuse the page's buddy list for chaining into the leaked > + * pages list. This page should not be on a free list currently > + * and is also unsafe to be added to a free list. > + */ > + list_add_tail(&page->buddy_list, &snp_leaked_pages_list); > + sev_dump_rmpentry(pfn); > + pfn++; > + } > + spin_unlock(&snp_leaked_pages_list_lock); > + atomic_long_inc(&snp_nr_leaked_pages); > +} > +EXPORT_SYMBOL_GPL(snp_leak_pages); > diff --git a/arch/x86/include/asm/sev-host.h b/arch/x86/include/asm/sev-host.h > index 753e80d16433..bab3b226777a 100644 > --- a/arch/x86/include/asm/sev-host.h > +++ b/arch/x86/include/asm/sev-host.h > @@ -19,6 +19,8 @@ void sev_dump_rmpentry(u64 pfn); > int psmash(u64 pfn); > int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, int asid, bool immutable); > int rmp_make_shared(u64 pfn, enum pg_level level); > +void snp_leak_pages(unsigned long pfn, unsigned int npages); > + > #else > static inline int snp_lookup_rmpentry(u64 pfn, bool *assigned, int *level) { return 0; } > static inline void sev_dump_rmpentry(u64 pfn) {} > @@ -29,6 +31,7 @@ static inline int rmp_make_private(u64 pfn, u64 gpa, enum pg_level level, int as > return -ENODEV; > } > static inline int rmp_make_shared(u64 pfn, enum pg_level level) { return -ENODEV; } > +void snp_leak_pages(unsigned long pfn, unsigned int npages) {} This needs to be 'static inline' or the build fails with multiple definition errors. I'm building a guest kernel with CONFIG_KVM_AMD_SEV disabled. Jeremi > #endif > > #endif > -- > 2.25.1 >