[PATCH v7 15/28] 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>
---
v7: - Moved vits_access_guest_table() from vgic-v3-its.c to vgic.c
      and renamed as vgic_access_guest_memory().
    - Renamed entry paramter in vgic_access_guest_memory() to gipa
    - Introduced new header file vits.h for vITS and moved vits structures
      from gic-its.h to vits.h
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   |  123 ++++++++++++++++++++++++++++++++++++++++++
 xen/arch/arm/vgic.c          |   39 ++++++++++++++
 xen/include/asm-arm/domain.h |    2 +
 xen/include/asm-arm/vits.h   |   68 +++++++++++++++++++++++
 4 files changed, 232 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..df54ce5
--- /dev/null
+++ b/xen/arch/arm/vgic-v3-its.c
@@ -0,0 +1,123 @@
+/*
+ * 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 <asm/vits.h>
+#include <xen/log2.h>
+
+/* 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%d: 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 vgic_access_guest_memory(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%d: 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%d: vITS: ITT out of range\n", d->domain_id);
+        return -EINVAL;
+    }
+
+    vitt_entry = dt_entry.vitt_ipa + offset;
+
+    return vgic_access_guest_memory(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/arch/arm/vgic.c b/xen/arch/arm/vgic.c
index fb2a205..baa74c7 100644
--- a/xen/arch/arm/vgic.c
+++ b/xen/arch/arm/vgic.c
@@ -25,6 +25,7 @@
 #include <xen/irq.h>
 #include <xen/sched.h>
 #include <xen/perfc.h>
+#include <xen/domain_page.h>
 
 #include <asm/current.h>
 
@@ -527,6 +528,44 @@ void vgic_free_virq(struct domain *d, unsigned int virq)
     clear_bit(virq, d->arch.vgic.allocated_irqs);
 }
 
+int vgic_access_guest_memory(struct domain *d, paddr_t gipa, 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(gipa), &p2mt, P2M_ALLOC);
+    if ( !page )
+    {
+        printk(XENLOG_G_ERR "d%d: 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%d: vITS: with wrong attributes\n", d->domain_id);
+        return -EINVAL;
+    }
+
+    p = __map_domain_page(page);
+    /* Offset within the mapped page */
+    offset = gipa & ~PAGE_MASK;
+
+    if ( set )
+        memcpy(p + offset, addr, size);
+    else
+        memcpy(addr, p + offset, size);
+
+    unmap_domain_page(p);
+    put_page(page);
+
+    return 0;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 7ddaeaa..0f2aa66 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -112,6 +112,8 @@ struct arch_domain
         } rdist_regions[MAX_RDIST_COUNT];
         int nr_regions;                     /* Number of rdist regions */
         uint32_t rdist_stride;              /* Re-Distributor stride */
+        /* Virtual ITS */
+        struct vgic_its *vits;
 #endif
     } vgic;
 
diff --git a/xen/include/asm-arm/vits.h b/xen/include/asm-arm/vits.h
new file mode 100644
index 0000000..6cb5d01
--- /dev/null
+++ b/xen/include/asm-arm/vits.h
@@ -0,0 +1,68 @@
+/*
+ * 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/>.
+ */
+
+#ifndef __ASM_ARM_VITS_H__
+#define __ASM_ARM_VITS_H__
+
+/*
+ * Per domain virtual ITS structure.
+ */
+struct vgic_its
+{
+   /* vITT device table ipa */
+   paddr_t dt_ipa;
+   /* vITT device table size */
+   uint64_t dt_size;
+};
+
+/*
+ * 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;
+};
+
+int vgic_access_guest_memory(struct domain *d, paddr_t gipa, 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_VITS_H__ */
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
-- 
1.7.9.5