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 lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6B862CAC592 for ; Fri, 19 Sep 2025 07:08:13 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1uzVD4-0000Kq-7h; Fri, 19 Sep 2025 03:07:10 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uzVD2-0000Kg-MK for qemu-devel@nongnu.org; Fri, 19 Sep 2025 03:07:08 -0400 Received: from mgamail.intel.com ([198.175.65.20]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1uzVD0-0004Ny-Dj for qemu-devel@nongnu.org; Fri, 19 Sep 2025 03:07:08 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1758265626; x=1789801626; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=mqnx10V3WIST4DpcoDl54PQvxPbncVWp5MGYDqUo2mQ=; b=N6eephgdBJLnzyP87IVzov3ziqLBlb2JFNd+i422oX3DLJI6M1uqx8bD WfocaR4PUdAq9Ql4ZcqTYbhkiGW6P2KC377aRxWyDpSXWdItqLMwWuq2g K5CKCLceTens7YdRcyO96eFNE2rkusWm3uTC7C2IiW8K2RWl3WiS5d2WX i4ogpl3iiCE/E7jghJoGAjRUo1Fjok7PmJwIeM7qMabgmaMzVfggH1jZh zWeF/fhc0DAetqqNFcWjxyMbNqxABRoUzpeB8yGKwT1W8d92BuFIUx3k3 m/uqPnSKLzh0WJpeVOeXwWG3ok8nJKi4gplpisFWZ08XKMgHmOz59IFJ+ Q==; X-CSE-ConnectionGUID: UU+ZBo3EQqSwzPN3ukyLVg== X-CSE-MsgGUID: 20qLdBjZQc2ynL7sap6B4A== X-IronPort-AV: E=McAfee;i="6800,10657,11557"; a="60304413" X-IronPort-AV: E=Sophos;i="6.18,277,1751266800"; d="scan'208";a="60304413" Received: from orviesa007.jf.intel.com ([10.64.159.147]) by orvoesa112.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Sep 2025 00:07:03 -0700 X-CSE-ConnectionGUID: Up86aWRsSuOUIPjUQoNP3w== X-CSE-MsgGUID: WQqhTtc2S7aLJTkSqWwJjw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.18,277,1751266800"; d="scan'208";a="175584374" Received: from unknown (HELO gnr-sp-2s-612.sh.intel.com) ([10.112.230.229]) by orviesa007-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Sep 2025 00:07:00 -0700 From: Zhenzhong Duan To: qemu-devel@nongnu.org Cc: alex.williamson@redhat.com, clg@redhat.com, eric.auger@redhat.com, mst@redhat.com, jasowang@redhat.com, peterx@redhat.com, yi.l.liu@intel.com, clement.mathieu--drif@eviden.com, Zhenzhong Duan Subject: [PATCH 2/2] intel_iommu: Simplify caching mode check with VFIO device Date: Fri, 19 Sep 2025 03:06:38 -0400 Message-ID: <20250919070638.983549-3-zhenzhong.duan@intel.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250919070638.983549-1-zhenzhong.duan@intel.com> References: <20250919070638.983549-1-zhenzhong.duan@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=198.175.65.20; envelope-from=zhenzhong.duan@intel.com; helo=mgamail.intel.com X-Spam_score_int: -43 X-Spam_score: -4.4 X-Spam_bar: ---- X-Spam_report: (-4.4 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.005, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_MED=-2.3, RCVD_IN_VALIDITY_CERTIFIED_BLOCKED=0.001, RCVD_IN_VALIDITY_RPBL_BLOCKED=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org In early days, we have different tricks to ensure caching-mode=on with VFIO device: 28cf553afe ("intel_iommu: Sanity check vfio-pci config on machine init done") c6cbc29d36 ("pc/q35: Disallow vfio-pci hotplug without VT-d caching mode") b8d78277c0 ("intel-iommu: fail MAP notifier without caching mode") Because without caching mode, MAP notifier won't work correctly since guest won't send IOTLB update event when it establishes new mappings in the I/O page tables. Now with host IOMMU device interface between VFIO and vIOMMU, we can simplify it with a small check in set_iommu_device(). This also works for future VDPA implementation which may also need caching mode on. For coldplug VFIO device: qemu-system-x86_64: -device vfio-pci,host=0000:3b:00.0,id=hostdev3,bus=root0,iommufd=iommufd0: vfio 0000:3b:00.0: Failed to set vIOMMU: Device assignment is not allowed without enabling caching-mode=on for Intel IOMMU. For hotplug VFIO device: Error: vfio 0000:3b:00.0: Failed to set vIOMMU: Device assignment is not allowed without enabling caching-mode=on for Intel IOMMU. Signed-off-by: Zhenzhong Duan --- hw/i386/intel_iommu.c | 47 ++++++------------------------------------- hw/i386/pc.c | 20 ------------------ 2 files changed, 6 insertions(+), 61 deletions(-) diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c index f04300022e..5c67b42dde 100644 --- a/hw/i386/intel_iommu.c +++ b/hw/i386/intel_iommu.c @@ -85,13 +85,6 @@ struct vtd_iotlb_key { static void vtd_address_space_refresh_all(IntelIOMMUState *s); static void vtd_address_space_unmap(VTDAddressSpace *as, IOMMUNotifier *n); -static void vtd_panic_require_caching_mode(void) -{ - error_report("We need to set caching-mode=on for intel-iommu to enable " - "device assignment with IOMMU protection."); - exit(1); -} - static void vtd_define_quad(IntelIOMMUState *s, hwaddr addr, uint64_t val, uint64_t wmask, uint64_t w1cmask) { @@ -3731,13 +3724,6 @@ static int vtd_iommu_notify_flag_changed(IOMMUMemoryRegion *iommu, "Snoop Control with vhost or VFIO is not supported"); return -ENOTSUP; } - if (!s->caching_mode && (new & IOMMU_NOTIFIER_MAP)) { - error_setg_errno(errp, ENOTSUP, - "device %02x.%02x.%x requires caching mode", - pci_bus_num(vtd_as->bus), PCI_SLOT(vtd_as->devfn), - PCI_FUNC(vtd_as->devfn)); - return -ENOTSUP; - } if (!x86_iommu->dt_supported && (new & IOMMU_NOTIFIER_DEVIOTLB_UNMAP)) { error_setg_errno(errp, ENOTSUP, "device %02x.%02x.%x requires device IOTLB mode", @@ -4378,6 +4364,12 @@ static bool vtd_dev_set_iommu_device(PCIBus *bus, void *opaque, int devfn, assert(hiod); + if (!s->caching_mode) { + error_setg(errp, "Device assignment is not allowed without enabling " + "caching-mode=on for Intel IOMMU."); + return false; + } + vtd_iommu_lock(s); if (g_hash_table_lookup(s->vtd_host_iommu_dev, &key)) { @@ -4910,32 +4902,6 @@ static bool vtd_decide_config(IntelIOMMUState *s, Error **errp) return true; } -static int vtd_machine_done_notify_one(Object *child, void *unused) -{ - IntelIOMMUState *iommu = INTEL_IOMMU_DEVICE(x86_iommu_get_default()); - - /* - * We hard-coded here because vfio-pci is the only special case - * here. Let's be more elegant in the future when we can, but so - * far there seems to be no better way. - */ - if (object_dynamic_cast(child, "vfio-pci") && !iommu->caching_mode) { - vtd_panic_require_caching_mode(); - } - - return 0; -} - -static void vtd_machine_done_hook(Notifier *notifier, void *unused) -{ - object_child_foreach_recursive(object_get_root(), - vtd_machine_done_notify_one, NULL); -} - -static Notifier vtd_machine_done_notify = { - .notify = vtd_machine_done_hook, -}; - static void vtd_realize(DeviceState *dev, Error **errp) { MachineState *ms = MACHINE(qdev_get_machine()); @@ -4990,7 +4956,6 @@ static void vtd_realize(DeviceState *dev, Error **errp) pci_setup_iommu(bus, &vtd_iommu_ops, dev); /* Pseudo address space under root PCI bus. */ x86ms->ioapic_as = vtd_host_dma_iommu(bus, s, Q35_PSEUDO_DEVFN_IOAPIC); - qemu_add_machine_init_done_notifier(&vtd_machine_done_notify); } static void vtd_class_init(ObjectClass *klass, const void *data) diff --git a/hw/i386/pc.c b/hw/i386/pc.c index bc048a6d13..01cd9a67db 100644 --- a/hw/i386/pc.c +++ b/hw/i386/pc.c @@ -1720,25 +1720,6 @@ static void pc_machine_wakeup(MachineState *machine) cpu_synchronize_all_post_reset(); } -static bool pc_hotplug_allowed(MachineState *ms, DeviceState *dev, Error **errp) -{ - X86IOMMUState *iommu = x86_iommu_get_default(); - IntelIOMMUState *intel_iommu; - - if (iommu && - object_dynamic_cast((Object *)iommu, TYPE_INTEL_IOMMU_DEVICE) && - object_dynamic_cast((Object *)dev, "vfio-pci")) { - intel_iommu = INTEL_IOMMU_DEVICE(iommu); - if (!intel_iommu->caching_mode) { - error_setg(errp, "Device assignment is not allowed without " - "enabling caching-mode=on for Intel IOMMU."); - return false; - } - } - - return true; -} - static void pc_machine_class_init(ObjectClass *oc, const void *data) { MachineClass *mc = MACHINE_CLASS(oc); @@ -1758,7 +1739,6 @@ static void pc_machine_class_init(ObjectClass *oc, const void *data) x86mc->apic_xrupt_override = true; assert(!mc->get_hotplug_handler); mc->get_hotplug_handler = pc_get_hotplug_handler; - mc->hotplug_allowed = pc_hotplug_allowed; mc->auto_enable_numa_with_memhp = true; mc->auto_enable_numa_with_memdev = true; mc->has_hotpluggable_cpus = true; -- 2.47.1