[PATCH v6 15/31] xen/arm: ITS: Add virtual ITS driver

[vijay.kilari@gmail.com]

From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>

This patch introduces virtual ITS driver with following
functionality
 - Introduces helper functions to manage device table and
   ITT table in guest memory
 - Helper function to handle virtual ITS devices assigned
   to domain

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
---
v6: - Exported vits_access_guest_memory() api
v5: - Removed RB tree that manages vitual ITS devices
v4: - Rename functions {find,remove,insert}_vits_* to
      vits_{find,remove,insert}.
    - Add common helper function to map and read/write dt
      or vitt table entry.
    - Removed unused code
---
 xen/arch/arm/vgic-v3-its.c    |  162 +++++++++++++++++++++++++++++++++++++++++
 xen/include/asm-arm/domain.h  |    2 +
 xen/include/asm-arm/gic-its.h |   38 ++++++++++
 3 files changed, 202 insertions(+)

diff --git a/xen/arch/arm/vgic-v3-its.c b/xen/arch/arm/vgic-v3-its.c
new file mode 100644
index 0000000..14c38b3
--- /dev/null
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -0,0 +1,162 @@
+/*
+ * Copyright (C) 2015 Cavium Inc.
+ * Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/bitops.h>
+#include <xen/config.h>
+#include <xen/init.h>
+#include <xen/irq.h>
+#include <xen/list.h>
+#include <xen/sched.h>
+#include <xen/sizes.h>
+#include <xen/domain_page.h>
+#include <asm/device.h>
+#include <asm/mmio.h>
+#include <asm/io.h>
+#include <asm/gic_v3_defs.h>
+#include <asm/gic.h>
+#include <asm/vgic.h>
+#include <asm/gic-its.h>
+#include <xen/log2.h>
+
+int vits_access_guest_table(struct domain *d, paddr_t entry, void *addr,
+                            uint32_t size, bool_t set)
+{
+    struct page_info *page;
+    uint64_t offset;
+    p2m_type_t p2mt;
+    void *p;
+
+    page = get_page_from_gfn(d, paddr_to_pfn(entry), &p2mt, P2M_ALLOC);
+    if ( !page )
+    {
+        printk(XENLOG_G_ERR "d%"PRIu16": vITS: Failed to get table entry\n",
+               d->domain_id);
+        return -EINVAL;
+    }
+
+    if ( !p2m_is_ram(p2mt) )
+    {
+        put_page(page);
+        printk(XENLOG_G_ERR "d%"PRIu16": vITS: with wrong attributes\n",
+               d->domain_id);
+        return -EINVAL;
+    }
+
+    p = __map_domain_page(page);
+    /* Offset within the mapped page */
+    offset = entry & ~PAGE_MASK;
+
+    if ( set )
+        memcpy(p + offset, addr, size);
+    else
+        memcpy(addr, p + offset, size);
+
+    unmap_domain_page(p);
+    put_page(page);
+
+    return 0;
+}
+
+/* ITS device table helper functions */
+static int vits_vdevice_entry(struct domain *d, uint32_t dev_id,
+                              struct vdevice_table *entry, bool_t set)
+{
+    uint64_t offset;
+    paddr_t dt_entry;
+    const struct vgic_its *vits = d->arch.vgic.vits;
+
+    BUILD_BUG_ON(sizeof(struct vdevice_table) != 16);
+
+    offset = dev_id * sizeof(struct vdevice_table);
+    if ( offset > vits->dt_size )
+    {
+        printk(XENLOG_G_ERR
+               "d%"PRIu16":vITS:Out of range off 0x%"PRIx64" id 0x%"PRIx32"\n",
+               d->domain_id, offset, dev_id);
+        return -EINVAL;
+    }
+
+    dt_entry = vits->dt_ipa + offset;
+
+    return vits_access_guest_table(d, dt_entry, entry,
+                                   sizeof(struct vdevice_table), set);
+}
+
+static int vits_set_vdevice_entry(struct domain *d, uint32_t devid,
+                                  struct vdevice_table *entry)
+{
+    return vits_vdevice_entry(d, devid, entry, 1);
+}
+
+int vits_get_vdevice_entry(struct domain *d, uint32_t devid,
+                           struct vdevice_table *entry)
+{
+    return vits_vdevice_entry(d, devid, entry, 0);
+}
+
+static int vits_vitt_entry(struct domain *d, uint32_t devid,
+                           uint32_t event, struct vitt *entry, bool_t set)
+{
+    struct vdevice_table dt_entry;
+    paddr_t vitt_entry;
+    uint64_t offset;
+
+    BUILD_BUG_ON(sizeof(struct vitt) != 8);
+
+    if ( vits_get_vdevice_entry(d, devid, &dt_entry) )
+    {
+        printk(XENLOG_G_ERR
+               "d%"PRIu16": vITS: Fail to get vdevice for vdevid 0x%"PRIx32"\n",
+               d->domain_id, devid);
+        return -EINVAL;
+    }
+
+    /* dt_entry has been validated in vits_get_vdevice_entry */
+    offset = event * sizeof(struct vitt);
+    if ( offset > dt_entry.vitt_size )
+    {
+        printk(XENLOG_G_ERR "d%"PRIu16": vITS: ITT out of range\n",
+               d->domain_id);
+        return -EINVAL;
+    }
+
+    vitt_entry = dt_entry.vitt_ipa + offset;
+
+    return vits_access_guest_table(d, vitt_entry, entry,
+                                   sizeof(struct vitt), set);
+}
+
+static int vits_set_vitt_entry(struct domain *d, uint32_t devid,
+                               uint32_t event, struct vitt *entry)
+{
+    return vits_vitt_entry(d, devid, event, entry, 1);
+}
+
+int vits_get_vitt_entry(struct domain *d, uint32_t devid,
+                        uint32_t event, struct vitt *entry)
+{
+    return vits_vitt_entry(d, devid, event, entry, 0);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 56aa208..986a4d6 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -104,6 +104,8 @@ struct arch_domain
         paddr_t dbase; /* Distributor base address */
         paddr_t cbase; /* CPU base address */
 #ifdef HAS_GICV3
+        /* Virtual ITS */
+        struct vgic_its *vits;
         /* GIC V3 addressing */
         /* List of contiguous occupied by the redistributors */
         struct vgic_rdist_region {
diff --git a/xen/include/asm-arm/gic-its.h b/xen/include/asm-arm/gic-its.h
index 7a46e21..42f6551 100644
--- a/xen/include/asm-arm/gic-its.h
+++ b/xen/include/asm-arm/gic-its.h
@@ -116,6 +116,17 @@ struct its_collection {
     u16 col_id;
 };
 
+/*
+ * Per domain virtual ITS structure.
+ */
+struct vgic_its
+{
+   /* vITT device table ipa */
+   paddr_t dt_ipa;
+   /* vITT device table size */
+   uint64_t dt_size;
+};
+
 /* ITS command structure */
 typedef union {
     u64 bits[4];
@@ -275,6 +286,27 @@ struct its_device {
     struct rb_node          node;
 };
 
+/*
+ * struct vdevice_table and struct vitt are typically stored in memory
+ * which has been provided by the guest out of its own address space
+ * and which remains accessible to the guest.
+ *
+ * Therefore great care _must_ be taken when accessing an entry in
+ * either table to validate the sanity of any values which are used.
+ */
+struct vdevice_table {
+    uint64_t vitt_ipa;
+    uint32_t vitt_size;
+    uint32_t padding;
+};
+
+struct vitt {
+    uint16_t valid:1;
+    uint16_t pad:15;
+    uint16_t vcollection;
+    uint32_t vlpi;
+};
+
 void irqdesc_set_lpi_event(struct irq_desc *desc, unsigned id);
 unsigned int irqdesc_get_lpi_event(struct irq_desc *desc);
 struct its_device *irqdesc_get_its_device(struct irq_desc *desc);
@@ -284,6 +316,12 @@ int its_init(struct rdist_prop *rdists);
 int its_cpu_init(void);
 int its_add_device(u32 devid, u32 nr_ites, struct dt_device_node *dt_its);
 int its_assign_device(struct domain *d, u32 vdevid, u32 pdevid);
+int vits_access_guest_table(struct domain *d, paddr_t entry, void *addr,
+                            uint32_t size, bool_t set);
+int vits_get_vitt_entry(struct domain *d, uint32_t devid,
+                        uint32_t event, struct vitt *entry);
+int vits_get_vdevice_entry(struct domain *d, uint32_t devid,
+                           struct vdevice_table *entry);
 
 #endif /* __ASM_ARM_GIC_ITS_H__ */
 /*
-- 
1.7.9.5