From patchwork Mon Mar 3 13:30:10 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikita Kalyazin X-Patchwork-Id: 13998853 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 DF33DC282D1 for ; Mon, 3 Mar 2025 13:31:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7494F6B0099; Mon, 3 Mar 2025 08:31:24 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 6F9166B009A; Mon, 3 Mar 2025 08:31:24 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5C1086B009B; Mon, 3 Mar 2025 08:31:24 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 3CD766B0099 for ; Mon, 3 Mar 2025 08:31:24 -0500 (EST) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay02.hostedemail.com (Postfix) with ESMTP id B63BE12098E for ; Mon, 3 Mar 2025 13:31:23 +0000 (UTC) X-FDA: 83180326446.04.415C174 Received: from smtp-fw-80008.amazon.com (smtp-fw-80008.amazon.com [99.78.197.219]) by imf25.hostedemail.com (Postfix) with ESMTP id 46AEEA0020 for ; Mon, 3 Mar 2025 13:31:21 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=amazon.com header.s=amazon201209 header.b=s2W5wGeI; dmarc=pass (policy=quarantine) header.from=amazon.com; spf=pass (imf25.hostedemail.com: domain of "prvs=150a0b0d2=kalyazin@amazon.co.uk" designates 99.78.197.219 as permitted sender) smtp.mailfrom="prvs=150a0b0d2=kalyazin@amazon.co.uk" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741008681; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=JIXEK8fZmfp3pTHcHhhnyrOSlMvjIkeSF6WjbQ+OQL4=; b=bmCgRwWud5QR4/iSQvD37cD7b4N6qRaIZbJaK3ELVCLkV6F8rTKdxoEAgSLwj415MB2fXI CDFChfiDIRHWO6INGkQ1Kdl6FePogbztFk/k2w9MR99ZZbek4z58/MQvrZoTE6zpqGmx6d sXOtCmCNHMWzZJkHaHFbe/XYIfgKAn0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741008681; a=rsa-sha256; cv=none; b=kAxyCTqMMS5tV9OubXQUk2D6HZ0YGIIGprwGTladKXpWHr1diZXovCiMsi6ljGoVRJ7k0g jcfkeBa61aNASeL/4qBTifCKQiQ0f/syae4pqCCNI+oOcLuzZbPDvC4jZtZpCw+1GFoMYD rbnMxoIZTJIuVBSU541geolZI2rhrCI= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=amazon.com header.s=amazon201209 header.b=s2W5wGeI; dmarc=pass (policy=quarantine) header.from=amazon.com; spf=pass (imf25.hostedemail.com: domain of "prvs=150a0b0d2=kalyazin@amazon.co.uk" designates 99.78.197.219 as permitted sender) smtp.mailfrom="prvs=150a0b0d2=kalyazin@amazon.co.uk" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1741008681; x=1772544681; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=JIXEK8fZmfp3pTHcHhhnyrOSlMvjIkeSF6WjbQ+OQL4=; b=s2W5wGeISK7yaueIJ+ZGrClco8ruRCd4Zm+jUiREvyygUaoNVUWP8Jgg wnNWjeDtZ8UQPE6TWR9wRo2W9gvx/h1MoixTUR/uRPEz/KaWv93ebFqvb 2JtUkQCZToqMQEyRjWh+VN2vALxw2jhZOgFAD2e9xmpL/QvQgZdDVy9lI E=; X-IronPort-AV: E=Sophos;i="6.13,329,1732579200"; d="scan'208";a="174959912" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-east-1.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-80008.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2025 13:31:17 +0000 Received: from EX19MTAUWA001.ant.amazon.com [10.0.7.35:29532] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.9.61:2525] with esmtp (Farcaster) id 1338de01-a28d-410f-a789-9dc43131ae5f; Mon, 3 Mar 2025 13:31:16 +0000 (UTC) X-Farcaster-Flow-ID: 1338de01-a28d-410f-a789-9dc43131ae5f Received: from EX19D003UWB004.ant.amazon.com (10.13.138.24) by EX19MTAUWA001.ant.amazon.com (10.250.64.204) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Mon, 3 Mar 2025 13:31:08 +0000 Received: from EX19MTAUWC002.ant.amazon.com (10.250.64.143) by EX19D003UWB004.ant.amazon.com (10.13.138.24) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14; Mon, 3 Mar 2025 13:31:07 +0000 Received: from email-imr-corp-prod-pdx-all-2c-785684ef.us-west-2.amazon.com (10.25.36.210) by mail-relay.amazon.com (10.250.64.149) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA) id 15.2.1544.14 via Frontend Transport; Mon, 3 Mar 2025 13:31:07 +0000 Received: from dev-dsk-kalyazin-1a-a12e27e2.eu-west-1.amazon.com (dev-dsk-kalyazin-1a-a12e27e2.eu-west-1.amazon.com [172.19.103.116]) by email-imr-corp-prod-pdx-all-2c-785684ef.us-west-2.amazon.com (Postfix) with ESMTPS id 27701A1025; Mon, 3 Mar 2025 13:31:05 +0000 (UTC) From: Nikita Kalyazin To: , , CC: , , , , , , , , , , , , , , , , Subject: [RFC PATCH 4/5] mm: userfaultfd: support continue for guest_memfd Date: Mon, 3 Mar 2025 13:30:10 +0000 Message-ID: <20250303133011.44095-5-kalyazin@amazon.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250303133011.44095-1-kalyazin@amazon.com> References: <20250303133011.44095-1-kalyazin@amazon.com> MIME-Version: 1.0 X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 46AEEA0020 X-Stat-Signature: ezagbd7d13uxgpd76o3hu35mgz668xj4 X-HE-Tag: 1741008681-945509 X-HE-Meta: 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 KBPg4cCF 01+/HFFgXgjToVFX/VYbgCbvQJ04mY39nXdBTeyo4e7t+BOCGcgSlgVJMYyNjiPe3lVVnHtx1ZmSVlYlm7A7zqRjkrBo5z+6/YMWnTmlDq89JL7qTVtYzxybFgmrlsXRL+75Ta/ivMxSBkRIottBKkKUSwi9t1frg0h1FmjiNdGFOr5gablcsWxpQzZUM6ko98XT8Aa60tK7gu5hlkvpnyEWpiHGhXU7trBsiuPT8jnlTv2araedvDVuY2WH66oA+Qf9GPy1uFH+Ibuf42Ha+SRxqk4DIBeYYtUxO61qK8VyzY7hB5hdt2PyqYuaYzCPuOpCW74EPo5VRiNSHFN7dMrHhuICZKAzNlXu5vS9j3GdcpvCOnfDFD4ieYJlLe3DOZGR/zK+k1kJe19ke3KPlTgH1VoJoSPr07S2mUdKpHBFOwwx76Ql4b7N7cvBSOwcNGoXsXZIu/pn6T0H4HpSW2T7SxaVSngKabC+SCS5aLUMNLgdwDwA3svGaogalesVt6bOYeyR9cmI19ncy1teZLkx8SmsEYkGLHHhkzoDYhsbx5W0= 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: List-Subscribe: List-Unsubscribe: When userspace receives a page missing event, it is supposed to populate the missing page in guest_memfd pagecache via the write syscall and unblock the faulting process via UFFDIO_CONTINUE. Signed-off-by: Nikita Kalyazin --- mm/userfaultfd.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c index af3dfc3633db..aaff66a7f15b 100644 --- a/mm/userfaultfd.c +++ b/mm/userfaultfd.c @@ -19,6 +19,10 @@ #include #include "internal.h" +#ifdef CONFIG_KVM_PRIVATE_MEM +bool kvm_gmem_vma_is_gmem(struct vm_area_struct *vma); +#endif + static __always_inline bool validate_dst_vma(struct vm_area_struct *dst_vma, unsigned long dst_end) { @@ -391,6 +395,16 @@ static int mfill_atomic_pte_continue(pmd_t *dst_pmd, struct page *page; int ret; +#ifdef CONFIG_KVM_PRIVATE_MEM + if (kvm_gmem_vma_is_gmem(dst_vma)) { + ret = 0; + folio = filemap_get_entry(inode->i_mapping, pgoff); + if (IS_ERR(folio)) + ret = PTR_ERR(folio); + else + folio_lock(folio); + } else +#endif ret = shmem_get_folio(inode, pgoff, 0, &folio, SGP_NOALLOC); /* Our caller expects us to return -EFAULT if we failed to find folio */ if (ret == -ENOENT) @@ -769,9 +783,16 @@ static __always_inline ssize_t mfill_atomic(struct userfaultfd_ctx *ctx, return mfill_atomic_hugetlb(ctx, dst_vma, dst_start, src_start, len, flags); - if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma)) + if (!vma_is_anonymous(dst_vma) && !vma_is_shmem(dst_vma) +#ifdef CONFIG_KVM_PRIVATE_MEM + && !kvm_gmem_vma_is_gmem(dst_vma) +#endif + ) goto out_unlock; if (!vma_is_shmem(dst_vma) && +#ifdef CONFIG_KVM_PRIVATE_MEM + !kvm_gmem_vma_is_gmem(dst_vma) && +#endif uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE)) goto out_unlock;