Re: [PATCH 22/31] vhost: Add VhostIOVATree
在 2022/2/2 上午1:27, Eugenio Perez Martin 写道:
On Sun, Jan 30, 2022 at 6:21 AM Jason Wang wrote:
在 2022/1/22 上午4:27, Eugenio Pérez 写道:
This tree is able to look for a translated address from an IOVA address.
At first glance it is similar to util/iova-tree. However, SVQ working on
devices with limited IOVA space need more capabilities,
So did the IOVA tree (e.g l2 vtd can only work in the range of GAW and
without RMRRs).
like allocating
IOVA chunks or performing reverse translations (qemu addresses to iova).
This looks like a general request as well. So I wonder if we can simply
extend iova tree instead.
While both are true, I don't see code that performs allocations or
qemu vaddr to iova translations. But if the changes can be integrated
into iova-tree that would be great for sure.
The main drawback I see is the need to maintain two trees instead of
one for users of iova-tree. While complexity does not grow, it needs
to double the amount of work needed.
If you care about the performance, we can disable the reverse mapping
during the allocation. For vIOMMU users it won't notice any performance
penalty.
Thanks
Thanks!
Thanks
The allocation capability, as "assign a free IOVA address to this chunk
of memory in qemu's address space" allows shadow virtqueue to create a
new address space that is not restricted by guest's addressable one, so
we can allocate shadow vqs vrings outside of it.
It duplicates the tree so it can search efficiently both directions,
and it will signal overlap if iova or the translated address is
present in any tree.
Signed-off-by: Eugenio Pérez
---
hw/virtio/vhost-iova-tree.h | 27 +++
hw/virtio/vhost-iova-tree.c | 157
hw/virtio/meson.build | 2 +-
3 files changed, 185 insertions(+), 1 deletion(-)
create mode 100644 hw/virtio/vhost-iova-tree.h
create mode 100644 hw/virtio/vhost-iova-tree.c
diff --git a/hw/virtio/vhost-iova-tree.h b/hw/virtio/vhost-iova-tree.h
new file mode 100644
index 00..610394eaf1
--- /dev/null
+++ b/hw/virtio/vhost-iova-tree.h
@@ -0,0 +1,27 @@
+/*
+ * vhost software live migration ring
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_VIRTIO_VHOST_IOVA_TREE_H
+#define HW_VIRTIO_VHOST_IOVA_TREE_H
+
+#include "qemu/iova-tree.h"
+#include "exec/memory.h"
+
+typedef struct VhostIOVATree VhostIOVATree;
+
+VhostIOVATree *vhost_iova_tree_new(uint64_t iova_first, uint64_t iova_last);
+void vhost_iova_tree_delete(VhostIOVATree *iova_tree);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostIOVATree, vhost_iova_tree_delete);
+
+const DMAMap *vhost_iova_tree_find_iova(const VhostIOVATree *iova_tree,
+const DMAMap *map);
+int vhost_iova_tree_map_alloc(VhostIOVATree *iova_tree, DMAMap *map);
+void vhost_iova_tree_remove(VhostIOVATree *iova_tree, const DMAMap *map);
+
+#endif
diff --git a/hw/virtio/vhost-iova-tree.c b/hw/virtio/vhost-iova-tree.c
new file mode 100644
index 00..0021dbaf54
--- /dev/null
+++ b/hw/virtio/vhost-iova-tree.c
@@ -0,0 +1,157 @@
+/*
+ * vhost software live migration ring
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/iova-tree.h"
+#include "vhost-iova-tree.h"
+
+#define iova_min_addr qemu_real_host_page_size
+
+/**
+ * VhostIOVATree, able to:
+ * - Translate iova address
+ * - Reverse translate iova address (from translated to iova)
+ * - Allocate IOVA regions for translated range (potentially slow operation)
+ *
+ * Note that it cannot remove nodes.
+ */
+struct VhostIOVATree {
+/* First addresable iova address in the device */
+uint64_t iova_first;
+
+/* Last addressable iova address in the device */
+uint64_t iova_last;
+
+/* IOVA address to qemu memory maps. */
+IOVATree *iova_taddr_map;
+
+/* QEMU virtual memory address to iova maps */
+GTree *taddr_iova_map;
+};
+
+static gint vhost_iova_tree_cmp_taddr(gconstpointer a, gconstpointer b,
+ gpointer data)
+{
+const DMAMap *m1 = a, *m2 = b;
+
+if (m1->translated_addr > m2->translated_addr + m2->size) {
+return 1;
+}
+
+if (m1->translated_addr + m1->size < m2->translated_addr) {
+return -1;
+}
+
+/* Overlapped */
+return 0;
+}
+
+/**
+ * Create a new IOVA tree
+ *
+ * Returns the new IOVA tree
+ */
+VhostIOVATree *vhost_iova_tree_new(hwaddr iova_first, hwaddr iova_last)
+{
+VhostIOVATree *tree = g_new(VhostIOVATree, 1);
+
+/* Some devices does not like 0 addresses */
+tree->iova_first = MAX(iova_first, iova_min_addr);
+tree->iova_last = iova_last;
+
+tree->iova_taddr_map = iova_tree_new();
+tree->taddr_iova_map = g_tree_new_full(vhost_iova_tree_cmp_taddr, NULL,
+
Re: [PATCH 22/31] vhost: Add VhostIOVATree
在 2022/1/22 上午4:27, Eugenio Pérez 写道:
This tree is able to look for a translated address from an IOVA address.
At first glance it is similar to util/iova-tree. However, SVQ working on
devices with limited IOVA space need more capabilities,
So did the IOVA tree (e.g l2 vtd can only work in the range of GAW and
without RMRRs).
like allocating
IOVA chunks or performing reverse translations (qemu addresses to iova).
This looks like a general request as well. So I wonder if we can simply
extend iova tree instead.
Thanks
The allocation capability, as "assign a free IOVA address to this chunk
of memory in qemu's address space" allows shadow virtqueue to create a
new address space that is not restricted by guest's addressable one, so
we can allocate shadow vqs vrings outside of it.
It duplicates the tree so it can search efficiently both directions,
and it will signal overlap if iova or the translated address is
present in any tree.
Signed-off-by: Eugenio Pérez
---
hw/virtio/vhost-iova-tree.h | 27 +++
hw/virtio/vhost-iova-tree.c | 157
hw/virtio/meson.build | 2 +-
3 files changed, 185 insertions(+), 1 deletion(-)
create mode 100644 hw/virtio/vhost-iova-tree.h
create mode 100644 hw/virtio/vhost-iova-tree.c
diff --git a/hw/virtio/vhost-iova-tree.h b/hw/virtio/vhost-iova-tree.h
new file mode 100644
index 00..610394eaf1
--- /dev/null
+++ b/hw/virtio/vhost-iova-tree.h
@@ -0,0 +1,27 @@
+/*
+ * vhost software live migration ring
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef HW_VIRTIO_VHOST_IOVA_TREE_H
+#define HW_VIRTIO_VHOST_IOVA_TREE_H
+
+#include "qemu/iova-tree.h"
+#include "exec/memory.h"
+
+typedef struct VhostIOVATree VhostIOVATree;
+
+VhostIOVATree *vhost_iova_tree_new(uint64_t iova_first, uint64_t iova_last);
+void vhost_iova_tree_delete(VhostIOVATree *iova_tree);
+G_DEFINE_AUTOPTR_CLEANUP_FUNC(VhostIOVATree, vhost_iova_tree_delete);
+
+const DMAMap *vhost_iova_tree_find_iova(const VhostIOVATree *iova_tree,
+const DMAMap *map);
+int vhost_iova_tree_map_alloc(VhostIOVATree *iova_tree, DMAMap *map);
+void vhost_iova_tree_remove(VhostIOVATree *iova_tree, const DMAMap *map);
+
+#endif
diff --git a/hw/virtio/vhost-iova-tree.c b/hw/virtio/vhost-iova-tree.c
new file mode 100644
index 00..0021dbaf54
--- /dev/null
+++ b/hw/virtio/vhost-iova-tree.c
@@ -0,0 +1,157 @@
+/*
+ * vhost software live migration ring
+ *
+ * SPDX-FileCopyrightText: Red Hat, Inc. 2021
+ * SPDX-FileContributor: Author: Eugenio Pérez
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/iova-tree.h"
+#include "vhost-iova-tree.h"
+
+#define iova_min_addr qemu_real_host_page_size
+
+/**
+ * VhostIOVATree, able to:
+ * - Translate iova address
+ * - Reverse translate iova address (from translated to iova)
+ * - Allocate IOVA regions for translated range (potentially slow operation)
+ *
+ * Note that it cannot remove nodes.
+ */
+struct VhostIOVATree {
+/* First addresable iova address in the device */
+uint64_t iova_first;
+
+/* Last addressable iova address in the device */
+uint64_t iova_last;
+
+/* IOVA address to qemu memory maps. */
+IOVATree *iova_taddr_map;
+
+/* QEMU virtual memory address to iova maps */
+GTree *taddr_iova_map;
+};
+
+static gint vhost_iova_tree_cmp_taddr(gconstpointer a, gconstpointer b,
+ gpointer data)
+{
+const DMAMap *m1 = a, *m2 = b;
+
+if (m1->translated_addr > m2->translated_addr + m2->size) {
+return 1;
+}
+
+if (m1->translated_addr + m1->size < m2->translated_addr) {
+return -1;
+}
+
+/* Overlapped */
+return 0;
+}
+
+/**
+ * Create a new IOVA tree
+ *
+ * Returns the new IOVA tree
+ */
+VhostIOVATree *vhost_iova_tree_new(hwaddr iova_first, hwaddr iova_last)
+{
+VhostIOVATree *tree = g_new(VhostIOVATree, 1);
+
+/* Some devices does not like 0 addresses */
+tree->iova_first = MAX(iova_first, iova_min_addr);
+tree->iova_last = iova_last;
+
+tree->iova_taddr_map = iova_tree_new();
+tree->taddr_iova_map = g_tree_new_full(vhost_iova_tree_cmp_taddr, NULL,
+ NULL, g_free);
+return tree;
+}
+
+/**
+ * Delete an iova tree
+ */
+void vhost_iova_tree_delete(VhostIOVATree *iova_tree)
+{
+iova_tree_destroy(iova_tree->iova_taddr_map);
+g_tree_unref(iova_tree->taddr_iova_map);
+g_free(iova_tree);
+}
+
+/**
+ * Find the IOVA address stored from a memory address
+ *
+ * @tree The iova tree
+ * @map The map with the memory address
+ *
+ * Return the stored mapping, or NULL if not found.
+ */
+const DMAMap *vhost_iova_tree_find_iova(const VhostIOVATree *tree,
+const DMAMap *map)
+{
+return
