Patch "[PATCH v2 for-4.9 26/40] vfio/spapr: Add a helper to create default DMA window" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    [PATCH v2 for-4.9 26/40] vfio/spapr: Add a helper to create default DMA window

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     vfio-spapr-add-a-helper-to-create-default-dma-window.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Mar 20 11:41:01 CET 2017
From: alexander.levin@verizon.com
Date: Fri, 17 Mar 2017 00:48:28 +0000
Subject: [PATCH v2 for-4.9 26/40] vfio/spapr: Add a helper to create default DMA window
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>
Message-ID: <20170317004812.26960-26-alexander.levin@verizon.com>

From: Alexey Kardashevskiy <aik@ozlabs.ru>

[ Upstream commit 6f01cc692a16405235d5c34056455b182682123c ]

There is already a helper to create a DMA window which does allocate
a table and programs it to the IOMMU group. However
tce_iommu_take_ownership_ddw() did not use it and did these 2 calls
itself to simplify error path.

Since we are going to delay the default window creation till
the default window is accessed/removed or new window is added,
we need a helper to create a default window from all these cases.

This adds tce_iommu_create_default_window(). Since it relies on
a VFIO container to have at least one IOMMU group (for future use),
this changes tce_iommu_attach_group() to add a group to the container
first and then call the new helper.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Acked-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/vfio/vfio_iommu_spapr_tce.c |   87 +++++++++++++++++-------------------
 1 file changed, 42 insertions(+), 45 deletions(-)

--- a/drivers/vfio/vfio_iommu_spapr_tce.c
+++ b/drivers/vfio/vfio_iommu_spapr_tce.c
@@ -784,6 +784,29 @@ static long tce_iommu_remove_window(stru
 	return 0;
 }
 
+static long tce_iommu_create_default_window(struct tce_container *container)
+{
+	long ret;
+	__u64 start_addr = 0;
+	struct tce_iommu_group *tcegrp;
+	struct iommu_table_group *table_group;
+
+	if (!tce_groups_attached(container))
+		return -ENODEV;
+
+	tcegrp = list_first_entry(&container->group_list,
+			struct tce_iommu_group, next);
+	table_group = iommu_group_get_iommudata(tcegrp->grp);
+	if (!table_group)
+		return -ENODEV;
+
+	ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
+			table_group->tce32_size, 1, &start_addr);
+	WARN_ON_ONCE(!ret && start_addr);
+
+	return ret;
+}
+
 static long tce_iommu_ioctl(void *iommu_data,
 				 unsigned int cmd, unsigned long arg)
 {
@@ -1199,9 +1222,6 @@ static void tce_iommu_release_ownership_
 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
 		struct iommu_table_group *table_group)
 {
-	long i, ret = 0;
-	struct iommu_table *tbl = NULL;
-
 	if (!table_group->ops->create_table || !table_group->ops->set_window ||
 			!table_group->ops->release_ownership) {
 		WARN_ON_ONCE(1);
@@ -1210,47 +1230,7 @@ static long tce_iommu_take_ownership_ddw
 
 	table_group->ops->take_ownership(table_group);
 
-	/*
-	 * If it the first group attached, check if there is
-	 * a default DMA window and create one if none as
-	 * the userspace expects it to exist.
-	 */
-	if (!tce_groups_attached(container) && !container->tables[0]) {
-		ret = tce_iommu_create_table(container,
-				table_group,
-				0, /* window number */
-				IOMMU_PAGE_SHIFT_4K,
-				table_group->tce32_size,
-				1, /* default levels */
-				&tbl);
-		if (ret)
-			goto release_exit;
-		else
-			container->tables[0] = tbl;
-	}
-
-	/* Set all windows to the new group */
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
-		tbl = container->tables[i];
-
-		if (!tbl)
-			continue;
-
-		/* Set the default window to a new group */
-		ret = table_group->ops->set_window(table_group, i, tbl);
-		if (ret)
-			goto release_exit;
-	}
-
 	return 0;
-
-release_exit:
-	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
-		table_group->ops->unset_window(table_group, i);
-
-	table_group->ops->release_ownership(table_group);
-
-	return ret;
 }
 
 static int tce_iommu_attach_group(void *iommu_data,
@@ -1260,6 +1240,7 @@ static int tce_iommu_attach_group(void *
 	struct tce_container *container = iommu_data;
 	struct iommu_table_group *table_group;
 	struct tce_iommu_group *tcegrp = NULL;
+	bool create_default_window = false;
 
 	mutex_lock(&container->lock);
 
@@ -1302,14 +1283,30 @@ static int tce_iommu_attach_group(void *
 	}
 
 	if (!table_group->ops || !table_group->ops->take_ownership ||
-			!table_group->ops->release_ownership)
+			!table_group->ops->release_ownership) {
 		ret = tce_iommu_take_ownership(container, table_group);
-	else
+	} else {
 		ret = tce_iommu_take_ownership_ddw(container, table_group);
+		if (!tce_groups_attached(container) && !container->tables[0])
+			create_default_window = true;
+	}
 
 	if (!ret) {
 		tcegrp->grp = iommu_group;
 		list_add(&tcegrp->next, &container->group_list);
+		/*
+		 * If it the first group attached, check if there is
+		 * a default DMA window and create one if none as
+		 * the userspace expects it to exist.
+		 */
+		if (create_default_window) {
+			ret = tce_iommu_create_default_window(container);
+			if (ret) {
+				list_del(&tcegrp->next);
+				tce_iommu_release_ownership_ddw(container,
+						table_group);
+			}
+		}
 	}
 
 unlock_exit:


Patches currently in stable-queue which might be from gregkh@linuxfoundation.org are

queue-4.9/pci-add-comments-about-rom-bar-updating.patch
queue-4.9/acpi-blacklist-make-dell-latitude-3350-ethernet-work.patch
queue-4.9/s390-zcrypt-introduce-cex6-toleration.patch
queue-4.9/dccp-tcp-fix-routing-redirect-race.patch
queue-4.9/vrf-fix-use-after-free-in-vrf_xmit.patch
queue-4.9/tcp-fix-various-issues-for-sockets-morphing-to-listen-state.patch
queue-4.9/block-allow-write_same-commands-with-the-sg_io-ioctl.patch
queue-4.9/strparser-destroy-workqueue-on-module-exit.patch
queue-4.9/powerpc-mm-fix-build-break-when-cma-n-spapr_tce_iommu-y.patch
queue-4.9/vfio-spapr-postpone-default-window-creation.patch
queue-4.9/vfio-spapr-add-a-helper-to-create-default-dma-window.patch
queue-4.9/pci-do-any-vf-bar-updates-before-enabling-the-bars.patch
queue-4.9/usb-gadget-udc-atmel-remove-memory-leak.patch
queue-4.9/x86-hyperv-handle-unknown-nmis-on-one-cpu-when-unknown_nmi_panic.patch
queue-4.9/net-tunnel-set-inner-protocol-in-network-gro-hooks.patch
queue-4.9/serial-8250_pci-detach-low-level-driver-during-pci-error-recovery.patch
queue-4.9/powerpc-iommu-stop-using-current-in-mm_iommu_xxx.patch
queue-4.9/tun-fix-premature-pollout-notification-on-tun-devices.patch
queue-4.9/vxlan-correctly-validate-vxlan-id-against-vxlan_n_vid.patch
queue-4.9/bpf-fix-regression-on-verifier-pruning-wrt-map-lookups.patch
queue-4.9/tcp-dccp-block-bh-for-syn-processing.patch
queue-4.9/net-sched-act_skbmod-remove-unneeded-rcu_read_unlock-in-tcf_skbmod_dump.patch
queue-4.9/dccp-fix-memory-leak-during-tear-down-of-unsuccessful-connection-request.patch
queue-4.9/xen-do-not-re-use-pirq-number-cached-in-pci-device-msi-msg-data.patch
queue-4.9/vxlan-lock-rcu-on-tx-path.patch
queue-4.9/mlxsw-spectrum_router-avoid-potential-packets-loss.patch
queue-4.9/mpls-do-not-decrement-alive-counter-for-unregister-events.patch
queue-4.9/net-phy-avoid-deadlock-during-phy_error.patch
queue-4.9/uapi-fix-linux-packet_diag.h-userspace-compilation-error.patch
queue-4.9/pci-separate-vf-bar-updates-from-standard-bar-updates.patch
queue-4.9/pci-ignore-bar-updates-on-virtual-functions.patch
queue-4.9/geneve-lock-rcu-on-tx-path.patch
queue-4.9/dccp-fix-use-after-free-in-dccp_feat_activate_values.patch
queue-4.9/l2tp-avoid-use-after-free-caused-by-l2tp_ip_backlog_recv.patch
queue-4.9/powerpc-mm-iommu-vfio-spapr-put-pages-on-vfio-container-shutdown.patch
queue-4.9/bpf-fix-state-equivalence.patch
queue-4.9/scsi-ibmvscsis-clean-up-properly-if-target_submit_cmd-tmr-fails.patch
queue-4.9/drm-nouveau-disp-gp102-fix-cursor-overlay-immediate-channel-indices.patch
queue-4.9/pci-update-bars-using-property-bits-appropriate-for-type.patch
queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-remove-time.patch
queue-4.9/vfio-spapr-postpone-allocation-of-userspace-version-of-tce-table.patch
queue-4.9/ibmveth-calculate-gso_segs-for-large-packets.patch
queue-4.9/net-mlx5e-do-not-reduce-lro-wqe-size-when-not-using-build_skb.patch
queue-4.9/net-sched-actions-decrement-module-reference-count-after-table-flush.patch
queue-4.9/pci-don-t-update-vf-bars-while-vf-memory-space-is-enabled.patch
queue-4.9/ipv4-mask-tos-for-input-route.patch
queue-4.9/net-fix-socket-refcounting-in-skb_complete_tx_timestamp.patch
queue-4.9/net-bridge-allow-ipv6-when-multicast-flood-is-disabled.patch
queue-4.9/net-mlx5e-fix-wrong-cqe-decompression.patch
queue-4.9/net-net_enable_timestamp-can-be-called-from-irq-contexts.patch
queue-4.9/igb-workaround-for-igb-i210-firmware-issue.patch
queue-4.9/drivers-hv-ring_buffer-count-on-wrap-around-mappings-in-get_next_pkt_raw-v2.patch
queue-4.9/drm-nouveau-disp-nv50-specify-ctrl-user-separately-when-constructing-classes.patch
queue-4.9/ipv6-make-ecmp-route-replacement-less-greedy.patch
queue-4.9/ipv6-avoid-write-to-a-possibly-cloned-skb.patch
queue-4.9/pci-remove-pci_resource_bar-and-pci_iov_resource_bar.patch
queue-4.9/mpls-send-route-delete-notifications-when-router-module-is-unloaded.patch
queue-4.9/dmaengine-iota-ioat_alloc_chan_resources-should-not-perform-sleeping-allocations.patch
queue-4.9/scsi-ibmvscsis-return-correct-partition-name-to-client.patch
queue-4.9/vti6-return-gre_key-for-vti6.patch
queue-4.9/vfio-spapr-reference-mm-in-tce_container.patch
queue-4.9/scsi-ibmvscsis-rearrange-functions-for-future-patches.patch
queue-4.9/dccp-unlock-sock-before-calling-sk_free.patch
queue-4.9/bpf-fix-mark_reg_unknown_value-for-spilled-regs-on-map-value-marking.patch
queue-4.9/powerpc-iommu-pass-mm_struct-to-init-cleanup-helpers.patch
queue-4.9/slub-move-synchronize_sched-out-of-slab_mutex-on-shrink.patch
queue-4.9/net-mlx5e-register-unregister-vport-representors-on-interface-attach-detach.patch
queue-4.9/pci-decouple-ioresource_rom_enable-and-pci_rom_address_enable.patch
queue-4.9/net-don-t-call-strlen-on-the-user-buffer-in-packet_bind_spkt.patch
queue-4.9/bpf-detect-identical-ptr_to_map_value_or_null-registers.patch
queue-4.9/scsi-ibmvscsis-issues-from-dan-carpenter-smatch.patch
queue-4.9/vxlan-don-t-allow-overwrite-of-config-src-addr.patch
queue-4.9/acpi-blacklist-add-_rev-quirks-for-dell-precision-5520-and-3520.patch
queue-4.9/bridge-drop-netfilter-fake-rtable-unconditionally.patch
queue-4.9/igb-add-i211-to-i210-phy-workaround.patch
queue-4.9/drm-nouveau-disp-nv50-split-chid-into-chid.ctrl-and-chid.user.patch
queue-4.9/net-fix-socket-refcounting-in-skb_complete_wifi_ack.patch
queue-4.9/scsi-ibmvscsis-synchronize-cmds-at-tpg_enable_store-time.patch
queue-4.9/ipv6-orphan-skbs-in-reassembly-unit.patch
queue-4.9/act_connmark-avoid-crashing-on-malformed-nlattrs-with-null-parms.patch
queue-4.9/uvcvideo-uvc_scan_fallback-for-webcams-with-broken-chain.patch