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 X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3DB6DC433E0 for ; Tue, 29 Dec 2020 10:10:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB6F5207BC for ; Tue, 29 Dec 2020 10:10:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726008AbgL2KIo (ORCPT ); Tue, 29 Dec 2020 05:08:44 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46456 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725964AbgL2KIn (ORCPT ); Tue, 29 Dec 2020 05:08:43 -0500 Received: from mail-lf1-x133.google.com (mail-lf1-x133.google.com [IPv6:2a00:1450:4864:20::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D92A3C0613D6 for ; Tue, 29 Dec 2020 02:08:02 -0800 (PST) Received: by mail-lf1-x133.google.com with SMTP id l11so29766044lfg.0 for ; Tue, 29 Dec 2020 02:08:02 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ykn+or7byzvb1tXcbynmiwse3+d2HHncW3KrbdADuCk=; b=IG39YNphU6ylEtHCuLOrXWO3wVMBVmSUjCiBbPD1MMC2S5z9H/LowHVfwrBo4CM8yO CsfxACQOWkQ72n82LDBPMrkZfDHu01PB/PDKEZ8hRvqTctUz3LYDK93upoLpFSzVlAcR SOaMZTeC7hnacw8W66X/wLoszQ3WgeHBRrQdm183ko3ZYtPbFPJnEBU85TLCpyqJUaax xAIvzNBr7th9rm+fEFFIFicxsZWXOP4UTM2YU+laT1D8L/PDll51e+P688gBpPXLsNVr poLiY1cT+BMEDagqza7m1D2gM0e7zGuNW1OW6jkmguFD+d75LWxGNOi3X6QwNXkPt+Kn 64Xw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=ykn+or7byzvb1tXcbynmiwse3+d2HHncW3KrbdADuCk=; b=sSKDuk2gKjGpWUwHWk5ZxxSZCttRc4KAVX7eu2aRntveHW3otjPUyt2YS2KDWWc7Bu I55rzqQOeE1XIyuFuMDYBHUptAA9fLNE8Yh4+TKjidbk00Ed4uDX0eFDDYg0PcRsVhOn G4SyHnVQ6NojivVBc8ZiiWT2j81/BJuumGORWaWaIAs2rwtQswePWCNwCG3raH1r9gO4 mY+h1a7Ri5WCyupfkXh+XlPGeabtKy6+2Nlnut8Ot7+wOcY4EoIUKwNB4cz5YhC2D2v4 +eTAcJN+6O9c+qerF6Muolz1xfYc9HtNusv9i82NGcJ5Gd+/HPMPisYSD82UNhJXkY8V nGQg== X-Gm-Message-State: AOAM533SJqWDbFeyT493I4LUAYb2G5nHYmBsTckQ3Jr1NYeRFSRVpIQW q+rOMlZO/dRGhMQf4zFzSqIll2Rt4LFK6Spb X-Google-Smtp-Source: ABdhPJxbKVxnopvA7bSaVz2VWxj7jByJOWI02FaHFMo/fI7D/I7wzCg+GmoJJxrZWfoi8MoLp5gixA== X-Received: by 2002:a19:b50:: with SMTP id 77mr22076149lfl.446.1609236480995; Tue, 29 Dec 2020 02:08:00 -0800 (PST) Received: from localhost.localdomain (37-145-186-126.broadband.corbina.ru. [37.145.186.126]) by smtp.gmail.com with ESMTPSA id y13sm5612901lfg.189.2020.12.29.02.07.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Dec 2020 02:08:00 -0800 (PST) From: Elena Afanasova To: kvm@vger.kernel.org Cc: stefanha@redhat.com, jag.raman@oracle.com, elena.ufimtseva@oracle.com, Elena Afanasova Subject: [RFC 0/2] Introduce MMIO/PIO dispatch file descriptors (ioregionfd) Date: Tue, 29 Dec 2020 13:02:42 +0300 Message-Id: X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org This patchset introduces a KVM dispatch mechanism which can be used for handling MMIO/PIO accesses over file descriptors without returning from ioctl(KVM_RUN). This allows device emulation to run in another task separate from the vCPU task. This is achieved through KVM vm ioctl for registering MMIO/PIO regions and a wire protocol that KVM uses to communicate with a task handling an MMIO/PIO access. ioregionfd relies on kmemcg in order to limit the amount of kernel memory that userspace can consume. Can NR_IOBUS_DEVS hardcoded limit be enforced only in case kmemcg is disabled? Elena Afanasova (2): KVM: add initial support for KVM_SET_IOREGION KVM: add initial support for ioregionfd blocking read/write operations arch/x86/kvm/Kconfig | 1 + arch/x86/kvm/Makefile | 1 + arch/x86/kvm/x86.c | 1 + include/linux/kvm_host.h | 17 ++ include/uapi/linux/kvm.h | 23 +++ virt/kvm/Kconfig | 3 + virt/kvm/eventfd.c | 25 +++ virt/kvm/eventfd.h | 14 ++ virt/kvm/ioregion.c | 390 +++++++++++++++++++++++++++++++++++++++ virt/kvm/ioregion.h | 15 ++ virt/kvm/kvm_main.c | 20 +- 11 files changed, 507 insertions(+), 3 deletions(-) create mode 100644 virt/kvm/eventfd.h create mode 100644 virt/kvm/ioregion.c create mode 100644 virt/kvm/ioregion.h -- 2.25.1