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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5DDF2FF887E for ; Tue, 28 Apr 2026 23:29:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C69E96B00CF; Tue, 28 Apr 2026 19:29:16 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id C3F496B00D1; Tue, 28 Apr 2026 19:29:16 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id B30C26B00D2; Tue, 28 Apr 2026 19:29:16 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id A178F6B00CF for ; Tue, 28 Apr 2026 19:29:16 -0400 (EDT) Received: from smtpin30.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 5087941461 for ; Tue, 28 Apr 2026 23:25:22 +0000 (UTC) X-FDA: 84709548084.30.A5EF1BD Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf11.hostedemail.com (Postfix) with ESMTP id 2F89240008 for ; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ILyLZIk7; spf=pass (imf11.hostedemail.com: domain of devnull+ackerleytng.google.com@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=devnull+ackerleytng.google.com@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1777418720; h=from:from:sender:reply-to: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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=7uGinULIohf7X1Axd8UKaE/ALxODLs/dwvxMVf3Q5YA=; b=UTVdRdsET5+0pEVN/13/kH9+5eGZjUlr/0B2CZPQC3w83hqccRt5IG3bq4Q6g5btgcJtL8 07Mw+LaMzhbKuzWo76umFjJB/RWwSdnRkyLwe1WtIyZsl3Qrtb8FUaJXZIBrczzfmYhEJi dW/jbGZol4JDdckqI0QAshe+JpBoNEA= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=ILyLZIk7; spf=pass (imf11.hostedemail.com: domain of devnull+ackerleytng.google.com@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=devnull+ackerleytng.google.com@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1777418720; a=rsa-sha256; cv=none; b=B/32Nznj64FrNnZu8NAp5m8E2I99wBfEOeHjeWcRNVtkEUzgThoYHIZisAMVB2r6p9c7/u KBjeJvi9C0wUu9nlbSHF5WEjZXaQCBR6deYwVjsejcqtYESlUGh2ysResW+tr1rJ/khM+K wy5JOeYG1A0F/PGOoIIU4MCN7qOZ6Wo= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 8BB3360583; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id 2F9F9C2BCB3; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777418719; bh=O5EusdRtRRcBsbLXs41Iht6PiU+kaHavayRHgykcm70=; h=From:Date:Subject:References:In-Reply-To:To:Cc:Reply-To:From; b=ILyLZIk7mLcRdFizYiNm5+SQt8Rlc0tM/h5WbkdME+trzC0BLp+ecwawGTzp7X8II DyOCuQHsDjEiKr3ElyRdA9StEXtC2u0lcl+vBpq3qruQkTKF7ILo2PWH1qrxFuEUqR labSI41SqA0y78nZAvZwTa4v1OSrnwqtTBEQ5gDvBOaMyjPGtUXHfk6RW10uLHEtdv hMw93TrV2EjkWkIO0aa0v41/BfUU4ut4DUNRHwSOdUvcdlh6VBc1teBRCTY2afGGDV UI0k7eDX5mu96a/iXr8rn5vo49LfAMB3Z+Q4qdLdrFaN6X+UpYGIFuVd0u2ubwumMc WxYFtlz+uRxhA== Received: from aws-us-west-2-korg-lkml-1.web.codeaurora.org (localhost.localdomain [127.0.0.1]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23281FF887B; Tue, 28 Apr 2026 23:25:19 +0000 (UTC) From: Ackerley Tng via B4 Relay Date: Tue, 28 Apr 2026 16:25:18 -0700 Subject: [PATCH RFC v5 23/53] KVM: x86: Support SW_PROTECTED_VM in applying content modes MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260428-gmem-inplace-conversion-v5-23-d8608ccfca22@google.com> References: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> In-Reply-To: <20260428-gmem-inplace-conversion-v5-0-d8608ccfca22@google.com> To: aik@amd.com, andrew.jones@linux.dev, binbin.wu@linux.intel.com, brauner@kernel.org, chao.p.peng@linux.intel.com, david@kernel.org, ira.weiny@intel.com, jmattson@google.com, jthoughton@google.com, michael.roth@amd.com, oupton@kernel.org, pankaj.gupta@amd.com, qperret@google.com, rick.p.edgecombe@intel.com, rientjes@google.com, shivankg@amd.com, steven.price@arm.com, tabba@google.com, willy@infradead.org, wyihan@google.com, yan.y.zhao@intel.com, forkloop@google.com, pratyush@kernel.org, suzuki.poulose@arm.com, aneesh.kumar@kernel.org, Paolo Bonzini , Sean Christopherson , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Jonathan Corbet , Shuah Khan , Shuah Khan , Vishal Annapurve , Andrew Morton , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Youngjun Park , Qi Zheng , Shakeel Butt , Kiryl Shutsemau , Jason Gunthorpe , Vlastimil Babka Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, linux-coco@lists.linux.dev, Ackerley Tng X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=ed25519-sha256; t=1777418714; l=3447; i=ackerleytng@google.com; s=20260225; h=from:subject:message-id; bh=9ksW1lIO9ZmZXIT5xvo0JGaOScZO9eFAx8q/FWxGah8=; b=Cy4xUfQRFEwNJDgZS17EsIHexFRRfCGZCJzHnrfM2HPN/NoecocgbvmuMuwK8/LWmqP1BNxCk G0AVsZtj4TUBD2z0PWLopI3VJCmZQUh+/Miluf8cH7GpfDGSe8Qxxx0 X-Developer-Key: i=ackerleytng@google.com; a=ed25519; pk=sAZDYXdm6Iz8FHitpHeFlCMXwabodTm7p8/3/8xUxuU= X-Endpoint-Received: by B4 Relay for ackerleytng@google.com/20260225 with auth_id=649 X-Original-From: Ackerley Tng Reply-To: ackerleytng@google.com X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 2F89240008 X-Rspam-User: X-Stat-Signature: mbydhpzaoh3g9djpu34pjz1hghsgsb6j X-HE-Tag: 1777418719-916618 X-HE-Meta: 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 TxjqNLIu Gwt5FBA7tHB9CUHO4tzUIdlqIx7kAh3GV0elP9sSkEe2NSwjz9v6K+5gefwReWeg4yZDuq8UNUj6C4q80c1gZdH/Yy7yz7JriTaM9HOXAk2rxCipH8UrzxoJYxWTV1ll/8ayMzZCqKlKL5DfXWPB9rmgGB4Exeqq5aa8KeuGCB7IGnEDZhCIOl/lHE4UzpFrIE0ecUwVtWJLksjgOOVJ4k3CCBH59XN4UryhnKCGHXXyOSuV+O3Pcm6Ysh1T8iqpPTQrnMTKIeNAcF9/MAaJ8Mtdlz/tizvgPkwT/rP2KO7najH7Pui9n98KdnHb96i8MUzCVexqmsPzfGx/DCRuEFAUP8pmVN8i7BezeYdaXfBsCQlsGu2UnFhyoDySpNN6Go4fyXE1YUFSJxNUIwsmNkEaN+5KEg3wd2K+NTIHjmZqsKwnrq4RAsF+FZa0TL1z43WRvc18+uriN+6Q= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: From: Ackerley Tng Override the architecture-specific guest_memfd content mode functions for x86 to provide support for KVM_X86_SW_PROTECTED_VM. For software-protected VMs, specify KVM_SET_MEMORY_ATTRIBUTES2_ZERO and KVM_SET_MEMORY_ATTRIBUTES2_PRESERVE as supported content modes. Implement the logic for these modes as follows: + ZERO: Zero out the memory using the generic guest_memfd helper. + PRESERVE: Maintain the existing memory content without modification. + UNSPECIFIED: KVM_X86_SW_PROTECTED_VM is guest_memfd's testing vehicle. Scramble the memory range by filling it with random bytes so test behavior will differ from that of PRESERVE. Signed-off-by: Ackerley Tng --- arch/x86/kvm/x86.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6609957ecfea3..e8abff71001eb 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -14194,6 +14194,99 @@ void kvm_arch_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end) kvm_x86_call(gmem_invalidate)(start, end); } #endif + +u64 kvm_arch_gmem_supported_content_modes(struct kvm *kvm, bool to_private) +{ + if (!kvm) { + return KVM_SET_MEMORY_ATTRIBUTES2_ZERO | + KVM_SET_MEMORY_ATTRIBUTES2_PRESERVE; + } + + switch (kvm->arch.vm_type) { + case KVM_X86_SW_PROTECTED_VM: + return KVM_SET_MEMORY_ATTRIBUTES2_ZERO | + KVM_SET_MEMORY_ATTRIBUTES2_PRESERVE; + default: + return 0; + } +} + +int kvm_arch_gmem_apply_content_mode_zero(struct kvm *kvm, struct inode *inode, + pgoff_t start, pgoff_t end) +{ + switch (kvm->arch.vm_type) { + case KVM_X86_SW_PROTECTED_VM: + return kvm_gmem_apply_content_mode_zero(inode, start, end); + default: + return 0; + } +} + +int kvm_arch_gmem_apply_content_mode_preserve(struct kvm *kvm, + struct inode *inode, + pgoff_t start, pgoff_t end) +{ + switch (kvm->arch.vm_type) { + case KVM_X86_SW_PROTECTED_VM: + /* Do nothing to preserve content. */ + return 0; + default: + /* Not a valid content mode for other types, so do nothing. */ + return 0; + } +} + +static int __scramble_range(struct inode *inode, pgoff_t start, pgoff_t end) +{ + struct address_space *mapping = inode->i_mapping; + struct folio_batch fbatch; + struct folio *f; + char *kaddr; + int ret = 0; + int i; + + folio_batch_init(&fbatch); + while (!ret && filemap_get_folios(mapping, &start, end - 1, &fbatch)) { + for (i = 0; !ret && i < folio_batch_count(&fbatch); ++i) { + f = fbatch.folios[i]; + + folio_lock(f); + + if (folio_test_hwpoison(f)) { + ret = -EHWPOISON; + } else { + /* + * Hard-coding range to scramble since + * guest_memfd only supports PAGE_SIZE + * folios now. + */ + kaddr = kmap_local_folio(f, 0); + get_random_bytes(kaddr, PAGE_SIZE); + kunmap_local(kaddr); + } + + folio_unlock(f); + } + + folio_batch_release(&fbatch); + cond_resched(); + } + + return ret; +} + +int kvm_arch_gmem_apply_content_mode_unspecified(struct kvm *kvm, + struct inode *inode, + pgoff_t start, pgoff_t end) +{ + switch (kvm->arch.vm_type) { + case KVM_X86_SW_PROTECTED_VM: + return __scramble_range(inode, start, end); + default: + return 0; + } +} + #endif int kvm_spec_ctrl_test_value(u64 value) -- 2.54.0.545.g6539524ca2-goog