[PATCH 02/21] libxc: add ARM support to xc_dom (PV domain building)

[Ian Campbell <ian.campbell@citrix.com>]

Includes ARM zImage support.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 tools/libxc/Makefile                 |    1 +
 tools/libxc/xc_dom.h                 |   20 ++++-
 tools/libxc/xc_dom_arm.c             |  140 ++++++++++++++++++++++++++-
 tools/libxc/xc_dom_armzimageloader.c |  174 ++++++++++++++++++++++++++++++++++
 tools/libxc/xc_dom_core.c            |   10 +-
 tools/libxc/xg_private.h             |    4 +
 6 files changed, 339 insertions(+), 10 deletions(-)
 create mode 100644 tools/libxc/xc_dom_armzimageloader.c

diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index 441ba4d..d44abf9 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -58,6 +58,7 @@ GUEST_SRCS-y += libelf-dominfo.c libelf-relocate.c
 GUEST_SRCS-y                 += xc_dom_core.c xc_dom_boot.c
 GUEST_SRCS-y                 += xc_dom_elfloader.c
 GUEST_SRCS-$(CONFIG_X86)     += xc_dom_bzimageloader.c
+GUEST_SRCS-$(CONFIG_ARM)     += xc_dom_armzimageloader.c
 GUEST_SRCS-y                 += xc_dom_binloader.c
 GUEST_SRCS-y                 += xc_dom_compat_linux.c
 
diff --git a/tools/libxc/xc_dom.h b/tools/libxc/xc_dom.h
index 2aef64a..3cd6dae 100644
--- a/tools/libxc/xc_dom.h
+++ b/tools/libxc/xc_dom.h
@@ -89,10 +89,24 @@ struct xc_dom_image {
 
     /* other state info */
     uint32_t f_active[XENFEAT_NR_SUBMAPS];
+    /*
+     * p2m_host maps guest physical addresses an offset from
+     * rambase_pfn (see below) into gfns.
+     *
+     * For a pure PV guest this means that it maps GPFNs into MFNs for
+     * a hybrid guest this means that it maps GPFNs to GPFNS.
+     *
+     * Note that the input is offset by rambase.
+     */
     xen_pfn_t *p2m_host;
     void *p2m_guest;
 
-    /* physical memory */
+    /* physical memory
+     *
+     * A PV guest has a single contiguous block of physical RAM,
+     * consisting of total_pages starting at rambase_pfn.
+     */
+    xen_pfn_t rambase_pfn;
     xen_pfn_t total_pages;
     struct xc_dom_phys *phys_pages;
     int realmodearea_log;
@@ -286,7 +300,7 @@ static inline xen_pfn_t xc_dom_p2m_host(struct xc_dom_image *dom, xen_pfn_t pfn)
 {
     if (dom->shadow_enabled)
         return pfn;
-    return dom->p2m_host[pfn];
+    return dom->p2m_host[pfn - dom->rambase_pfn];
 }
 
 static inline xen_pfn_t xc_dom_p2m_guest(struct xc_dom_image *dom,
@@ -294,7 +308,7 @@ static inline xen_pfn_t xc_dom_p2m_guest(struct xc_dom_image *dom,
 {
     if (xc_dom_feature_translated(dom))
         return pfn;
-    return dom->p2m_host[pfn];
+    return dom->p2m_host[pfn - dom->rambase_pfn];
 }
 
 /* --- arch bits --------------------------------------------------- */
diff --git a/tools/libxc/xc_dom_arm.c b/tools/libxc/xc_dom_arm.c
index 122d0e8..3eef0d0 100644
--- a/tools/libxc/xc_dom_arm.c
+++ b/tools/libxc/xc_dom_arm.c
@@ -18,14 +18,143 @@
  * Copyright (c) 2011, Citrix Systems
  */
 #include <inttypes.h>
+
 #include <xen/xen.h>
+#include <xen/io/protocols.h>
+
 #include "xg_private.h"
 #include "xc_dom.h"
 
+/* ------------------------------------------------------------------------ */
+/*
+ * arm guests are hybrid and start off with paging disabled, therefore no
+ * pagetables and nothing to do here.
+ */
+static int count_pgtables_arm(struct xc_dom_image *dom)
+{
+    DOMPRINTF_CALLED(dom->xch);
+    return 0;
+}
+
+static int setup_pgtables_arm(struct xc_dom_image *dom)
+{
+    DOMPRINTF_CALLED(dom->xch);
+    return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int alloc_magic_pages(struct xc_dom_image *dom)
+{
+    DOMPRINTF_CALLED(dom->xch);
+    /* XXX
+     *   dom->p2m_guest
+     *   dom->start_info_pfn
+     *   dom->xenstore_pfn
+     *   dom->console_pfn
+     */
+    return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int start_info_arm(struct xc_dom_image *dom)
+{
+    DOMPRINTF_CALLED(dom->xch);
+    return 0;
+}
+
+static int shared_info_arm(struct xc_dom_image *dom, void *ptr)
+{
+    DOMPRINTF_CALLED(dom->xch);
+    return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static int vcpu_arm(struct xc_dom_image *dom, void *ptr)
+{
+    vcpu_guest_context_t *ctxt = ptr;
+
+    DOMPRINTF_CALLED(dom->xch);
+
+    /* clear everything */
+    memset(ctxt, 0, sizeof(*ctxt));
+
+    ctxt->user_regs.pc = dom->parms.virt_entry;
+
+    /* Linux boot protocol. See linux.Documentation/arm/Booting. */
+    ctxt->user_regs.r0 = 0; /* SBZ */
+    /* Machine ID: We use DTB therefore no machine id */
+    ctxt->user_regs.r1 = 0xffffffff;
+    /* ATAGS/DTB: We currently require that the guest kernel to be
+     * using CONFIG_ARM_APPENDED_DTB. Ensure that r2 does not look
+     * like a valid pointer to a set of ATAGS or a DTB.
+     */
+    ctxt->user_regs.r2 = 0xffffffff;
+
+    ctxt->sctlr = /* #define SCTLR_BASE */0x00c50078;
+
+    ctxt->ttbr0 = 0;
+    ctxt->ttbr1 = 0;
+    ctxt->ttbcr = 0; /* Defined Reset Value */
+
+    ctxt->user_regs.cpsr = PSR_ABT_MASK|PSR_FIQ_MASK|PSR_IRQ_MASK|PSR_MODE_SVC;
+
+    DOMPRINTF("Initial state CPSR %#"PRIx32" PC %#"PRIx32,
+           ctxt->user_regs.cpsr, ctxt->user_regs.pc);
+
+    return 0;
+}
+
+/* ------------------------------------------------------------------------ */
+
+static struct xc_dom_arch xc_dom_32 = {
+    .guest_type = "xen-3.0-armv7l",
+    .native_protocol = XEN_IO_PROTO_ABI_ARM,
+    .page_shift = PAGE_SHIFT_ARM,
+    .sizeof_pfn = 8,
+    .alloc_magic_pages = alloc_magic_pages,
+    .count_pgtables = count_pgtables_arm,
+    .setup_pgtables = setup_pgtables_arm,
+    .start_info = start_info_arm,
+    .shared_info = shared_info_arm,
+    .vcpu = vcpu_arm,
+};
+
+static void __init register_arch_hooks(void)
+{
+    xc_dom_register_arch_hooks(&xc_dom_32);
+}
+
 int arch_setup_meminit(struct xc_dom_image *dom)
 {
-    errno = ENOSYS;
-    return -1;
+    int rc;
+    xen_pfn_t pfn, allocsz, i;
+
+    dom->shadow_enabled = 1;
+
+    dom->p2m_host = xc_dom_malloc(dom, sizeof(xen_pfn_t) * dom->total_pages);
+
+    /* setup initial p2m */
+    for ( pfn = 0; pfn < dom->total_pages; pfn++ )
+        dom->p2m_host[pfn] = pfn + dom->rambase_pfn;
+
+    /* allocate guest memory */
+    for ( i = rc = allocsz = 0;
+          (i < dom->total_pages) && !rc;
+          i += allocsz )
+    {
+        allocsz = dom->total_pages - i;
+        if ( allocsz > 1024*1024 )
+            allocsz = 1024*1024;
+
+        rc = xc_domain_populate_physmap_exact(
+            dom->xch, dom->guest_domid, allocsz,
+            0, 0, &dom->p2m_host[i]);
+    }
+
+    return 0;
 }
 
 int arch_setup_bootearly(struct xc_dom_image *dom)
@@ -36,9 +165,14 @@ int arch_setup_bootearly(struct xc_dom_image *dom)
 
 int arch_setup_bootlate(struct xc_dom_image *dom)
 {
-    DOMPRINTF("%s: doing nothing", __FUNCTION__);
+    /* XXX
+     *   map shared info
+     *   map grant tables
+     *   setup shared info
+     */
     return 0;
 }
+
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxc/xc_dom_armzimageloader.c b/tools/libxc/xc_dom_armzimageloader.c
new file mode 100644
index 0000000..f316e87
--- /dev/null
+++ b/tools/libxc/xc_dom_armzimageloader.c
@@ -0,0 +1,174 @@
+/*
+ * Xen domain builder -- ARM zImage bits
+ *
+ * Parse and load ARM zImage kernel images.
+ *
+ * Copyright (C) 2012, Citrix Systems.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <inttypes.h>
+
+#include "xg_private.h"
+#include "xc_dom.h"
+
+#include <arpa/inet.h> /* XXX ntohl is not the right function... */
+
+/*
+ * Guest virtual RAM starts here. This must be consistent with the DTB
+ * appended to the guest kernel.
+ */
+#define GUEST_RAM_BASE 0x80000000
+
+#define ZIMAGE_MAGIC_OFFSET 0x24
+#define ZIMAGE_START_OFFSET 0x28
+#define ZIMAGE_END_OFFSET   0x2c
+
+#define ZIMAGE_MAGIC 0x016f2818
+
+struct minimal_dtb_header {
+    uint32_t magic;
+    uint32_t total_size;
+    /* There are other fields but we don't use them yet. */
+};
+
+#define DTB_MAGIC 0xd00dfeed
+
+static int xc_dom_probe_zimage_kernel(struct xc_dom_image *dom)
+{
+    uint32_t *zimage;
+    uint32_t end;
+
+    if ( dom->kernel_blob == NULL )
+    {
+        xc_dom_panic(dom->xch, XC_INTERNAL_ERROR,
+                     "%s: no kernel image loaded", __FUNCTION__);
+        return -EINVAL;
+    }
+
+    if ( dom->kernel_size < 0x30 /*sizeof(struct setup_header)*/ )
+    {
+        xc_dom_printf(dom->xch, "%s: kernel image too small", __FUNCTION__);
+        return -EINVAL;
+    }
+
+    zimage = (uint32_t *)dom->kernel_blob;
+    if ( zimage[ZIMAGE_MAGIC_OFFSET/4] != ZIMAGE_MAGIC )
+    {
+        xc_dom_printf(dom->xch, "%s: kernel is not a bzImage", __FUNCTION__);
+        return -EINVAL;
+    }
+
+    end = zimage[ZIMAGE_END_OFFSET/4];
+
+    /*
+     * Check for an appended DTB.
+     */
+    if ( end + sizeof(struct minimal_dtb_header) < dom->kernel_size ) {
+        struct minimal_dtb_header *dtb_hdr;
+        dtb_hdr = (struct minimal_dtb_header *)(dom->kernel_blob + end);
+        if (ntohl/*be32_to_cpu*/(dtb_hdr->magic) == DTB_MAGIC) {
+            xc_dom_printf(dom->xch, "%s: found an appended DTB", __FUNCTION__);
+            end += ntohl/*be32_to_cpu*/(dtb_hdr->total_size);
+        }
+    }
+
+    dom->kernel_size = end;
+
+    return 0;
+}
+
+static int xc_dom_parse_zimage_kernel(struct xc_dom_image *dom)
+{
+    uint32_t *zimage;
+    uint32_t start, entry_addr;
+    uint64_t v_start, v_end;
+    uint64_t rambase = GUEST_RAM_BASE;
+
+    DOMPRINTF_CALLED(dom->xch);
+
+    zimage = (uint32_t *)dom->kernel_blob;
+
+    dom->rambase_pfn = rambase >> XC_PAGE_SHIFT;
+
+    /* Do not load kernel at the very first RAM address */
+    v_start = rambase + 0x8000;
+    v_end = v_start + dom->kernel_size;
+
+    start = zimage[ZIMAGE_START_OFFSET/4];
+
+    if (start == 0)
+        entry_addr = v_start;
+    else
+        entry_addr = start;
+
+    /* find kernel segment */
+    dom->kernel_seg.vstart = v_start;
+    dom->kernel_seg.vend   = v_end;
+
+    dom->parms.virt_entry = entry_addr;
+
+    dom->guest_type = "xen-3.0-armv7l";
+    DOMPRINTF("%s: %s: RAM starts at %"PRI_xen_pfn,
+              __FUNCTION__, dom->guest_type, dom->rambase_pfn);
+    DOMPRINTF("%s: %s: 0x%" PRIx64 " -> 0x%" PRIx64 "",
+              __FUNCTION__, dom->guest_type,
+              dom->kernel_seg.vstart, dom->kernel_seg.vend);
+    return 0;
+}
+
+static int xc_dom_load_zimage_kernel(struct xc_dom_image *dom)
+{
+    void *dst;
+
+    DOMPRINTF_CALLED(dom->xch);
+
+    dst = xc_dom_seg_to_ptr(dom, &dom->kernel_seg);
+
+    DOMPRINTF("%s: kernel sed %#"PRIx64"-%#"PRIx64,
+              __func__, dom->kernel_seg.vstart, dom->kernel_seg.vend);
+    DOMPRINTF("%s: copy %zd bytes from blob %p to dst %p",
+              __func__, dom->kernel_size, dom->kernel_blob, dst);
+
+    memcpy(dst, dom->kernel_blob, dom->kernel_size);
+
+    return 0;
+}
+
+static struct xc_dom_loader zimage_loader = {
+    .name = "Linux zImage (ARM)",
+    .probe = xc_dom_probe_zimage_kernel,
+    .parser = xc_dom_parse_zimage_kernel,
+    .loader = xc_dom_load_zimage_kernel,
+};
+
+static void __init register_loader(void)
+{
+    xc_dom_register_loader(&zimage_loader);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-set-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/tools/libxc/xc_dom_core.c b/tools/libxc/xc_dom_core.c
index fea9de5..5244b04 100644
--- a/tools/libxc/xc_dom_core.c
+++ b/tools/libxc/xc_dom_core.c
@@ -307,15 +307,17 @@ void *xc_dom_pfn_to_ptr(struct xc_dom_image *dom, xen_pfn_t pfn,
                         xen_pfn_t count)
 {
     struct xc_dom_phys *phys;
+    xen_pfn_t offset;
     unsigned int page_shift = XC_DOM_PAGE_SHIFT(dom);
     char *mode = "unset";
 
-    if ( pfn > dom->total_pages ||    /* multiple checks to avoid overflows */
+    offset = pfn - dom->rambase_pfn;
+    if ( offset > dom->total_pages || /* multiple checks to avoid overflows */
          count > dom->total_pages ||
-         pfn > dom->total_pages - count )
+         offset > dom->total_pages - count )
     {
-        DOMPRINTF("%s: pfn out of range (0x%" PRIpfn " > 0x%" PRIpfn ")",
-                  __FUNCTION__, pfn, dom->total_pages);
+        DOMPRINTF("%s: pfn %"PRI_xen_pfn" out of range (0x%" PRIpfn " > 0x%" PRIpfn ")",
+                  __FUNCTION__, pfn, offset, dom->total_pages);
         return NULL;
     }
 
diff --git a/tools/libxc/xg_private.h b/tools/libxc/xg_private.h
index a29fa26..a271942 100644
--- a/tools/libxc/xg_private.h
+++ b/tools/libxc/xg_private.h
@@ -148,6 +148,10 @@ typedef l4_pgentry_64_t l4_pgentry_t;
 #define l4_table_offset(_a) l4_table_offset_x86_64(_a)
 #endif
 
+#define PAGE_SHIFT_ARM          12
+#define PAGE_SIZE_ARM           (1UL << PAGE_SHIFT_ARM)
+#define PAGE_MASK_ARM           (~(PAGE_SIZE_ARM-1))
+
 #define PAGE_SHIFT_X86          12
 #define PAGE_SIZE_X86           (1UL << PAGE_SHIFT_X86)
 #define PAGE_MASK_X86           (~(PAGE_SIZE_X86-1))
-- 
1.7.9.1