From patchwork Mon Mar 3 13:30:08 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nikita Kalyazin X-Patchwork-Id: 13998842 Received: from smtp-fw-6001.amazon.com (smtp-fw-6001.amazon.com [52.95.48.154]) (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 4DCFF213E88; Mon, 3 Mar 2025 13:30:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=52.95.48.154 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741008652; cv=none; b=txl/TsypPzv5HcxiVFi32CLVXadnHJrP6sPl/pkTw/7W7/0nY3Gb4hTc9a1hh/4NlL/mGlbGjaiCaA3d9fbL3pIwnfEedat+7OSAUdbTxaP1blj6pfI/6EWqwF5oQwsOasyDq+g1WSUNX5jSis3W+RNDKnFLlE/EBcdeJP5HB2g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741008652; c=relaxed/simple; bh=yngMXZswSSlfh1x2jJZYvt8kJxzt6cXiGjCMNtqGspo=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=V6gwBK9hRJaWdhVJoOAk4M8qV/+1veruXjaRdf+jT+S0u0nqMhkWrQyQ3+QxVWFc5BFLXXtEuu0jDJLEpPP0ROEwcCqIaKitbFfFNCtR6MRh3RaHmM1ydfEKR5pihiP54/w+zXges8H/JJ09beZLmUUzP3bbPhcKfaDCNwW5UXU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.uk; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=EE76lk97; arc=none smtp.client-ip=52.95.48.154 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="EE76lk97" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1741008651; x=1772544651; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=J7/xtyBJVACA1f5rni1kJ1y38BiqCsgl928AjTc2EPg=; b=EE76lk97+6gXjNeC/Er8mlxx2nEdBVW5+5OiBa/QmpZiSiDgLIgc5vKB SZn/pSjtjxd3ukmFeWps3qlTB4KAsqdVjNwIrui5bSTI+nOPAJ2SE7ArE yNZsmuhoJbxPNPX6nkjiMuQv2A3F0khsLgPMe2uM3VROIMMuyUF4KEFuT Y=; X-IronPort-AV: E=Sophos;i="6.13,329,1732579200"; d="scan'208";a="467377029" Received: from iad12-co-svc-p1-lb1-vlan2.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.43.8.2]) by smtp-border-fw-6001.iad6.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Mar 2025 13:30:47 +0000 Received: from EX19MTAEUA001.ant.amazon.com [10.0.43.254:58431] by smtpin.naws.eu-west-1.prod.farcaster.email.amazon.dev [10.0.2.142:2525] with esmtp (Farcaster) id 95972e55-02f1-4ae5-bb4d-b9d69caeff17; Mon, 3 Mar 2025 13:30:45 +0000 (UTC) X-Farcaster-Flow-ID: 95972e55-02f1-4ae5-bb4d-b9d69caeff17 Received: from EX19D004EUA003.ant.amazon.com (10.252.50.230) by EX19MTAEUA001.ant.amazon.com (10.252.50.50) 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 13:30:42 +0000 Received: from EX19MTAUEA001.ant.amazon.com (10.252.134.203) by EX19D004EUA003.ant.amazon.com (10.252.50.230) 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 13:30:41 +0000 Received: from email-imr-corp-prod-iad-1box-1a-9bbde7a3.us-east-1.amazon.com (10.43.8.2) by mail-relay.amazon.com (10.252.134.102) 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 13:30:41 +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-iad-1box-1a-9bbde7a3.us-east-1.amazon.com (Postfix) with ESMTPS id 3176540617; Mon, 3 Mar 2025 13:30:40 +0000 (UTC) From: Nikita Kalyazin To: , , CC: , , , , , , , , , , , , , , , , Subject: [RFC PATCH 2/5] KVM: guest_memfd: add support for uffd missing Date: Mon, 3 Mar 2025 13:30:08 +0000 Message-ID: <20250303133011.44095-3-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> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Add support for sending a pagefault event if userfaultfd is registered. Only page missing event is currently supported. Signed-off-by: Nikita Kalyazin --- virt/kvm/guest_memfd.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c index af825f7494ea..358c3776ed66 100644 --- a/virt/kvm/guest_memfd.c +++ b/virt/kvm/guest_memfd.c @@ -4,6 +4,9 @@ #include #include #include +#ifdef CONFIG_KVM_PRIVATE_MEM +#include +#endif /* CONFIG_KVM_PRIVATE_MEM */ #include "kvm_mm.h" @@ -332,9 +335,16 @@ static vm_fault_t kvm_gmem_fault(struct vm_fault *vmf) struct folio *folio; vm_fault_t ret = VM_FAULT_LOCKED; + folio = filemap_get_entry(inode->i_mapping, vmf->pgoff); + if (!folio && userfaultfd_missing(vmf->vma)) + return handle_userfault(vmf, VM_UFFD_MISSING); + if (folio) + folio_lock(folio); + filemap_invalidate_lock_shared(inode->i_mapping); - folio = kvm_gmem_get_folio(inode, vmf->pgoff); + if (!folio) + folio = kvm_gmem_get_folio(inode, vmf->pgoff); if (IS_ERR(folio)) { switch (PTR_ERR(folio)) { case -EAGAIN: