[PATCH v5 04/28] libxc: introduce a domain loader for HVM guest firmware

[Roger Pau Monne <roger.pau@citrix.com>]

Introduce a very simple (and dummy) domain loader to be used to load the
firmware (hvmloader) into HVM guests. Since hmvloader is just a 32bit elf
executable the loader is fairly simple.

Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
---
Changes since v3:
 - s/__FUNCTION__/__func__/g
 - Fix style errors in xc_dom_hvmloader.c.
 - Add Andrew Cooper Reviewed-by.
 - Add Wei Acked-by.
---
 tools/libxc/Makefile           |   1 +
 tools/libxc/include/xc_dom.h   |   8 ++
 tools/libxc/xc_dom_hvmloader.c | 313 +++++++++++++++++++++++++++++++++++++++++
 xen/include/xen/libelf.h       |   1 +
 4 files changed, 323 insertions(+)
 create mode 100644 tools/libxc/xc_dom_hvmloader.c

diff --git a/tools/libxc/Makefile b/tools/libxc/Makefile
index a0f899b..baaadd6 100644
--- a/tools/libxc/Makefile
+++ b/tools/libxc/Makefile
@@ -84,6 +84,7 @@ 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_X86)     += xc_dom_decompress_lz4.c
+GUEST_SRCS-$(CONFIG_X86)     += xc_dom_hvmloader.c
 GUEST_SRCS-$(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/include/xc_dom.h b/tools/libxc/include/xc_dom.h
index bc55ec9..02d9d5c 100644
--- a/tools/libxc/include/xc_dom.h
+++ b/tools/libxc/include/xc_dom.h
@@ -14,6 +14,7 @@
  */
 
 #include <xen/libelf/libelf.h>
+#include <xenguest.h>
 
 #define INVALID_P2M_ENTRY   ((xen_pfn_t)-1)
 
@@ -185,6 +186,13 @@ struct xc_dom_image {
         XC_DOM_PV_CONTAINER,
         XC_DOM_HVM_CONTAINER,
     } container_type;
+
+    /* HVM specific fields. */
+    /* Extra ACPI tables passed to HVMLOADER */
+    struct xc_hvm_firmware_module acpi_module;
+
+    /* Extra SMBIOS structures passed to HVMLOADER */
+    struct xc_hvm_firmware_module smbios_module;
 };
 
 /* --- pluggable kernel loader ------------------------------------- */
diff --git a/tools/libxc/xc_dom_hvmloader.c b/tools/libxc/xc_dom_hvmloader.c
new file mode 100644
index 0000000..79a3b99
--- /dev/null
+++ b/tools/libxc/xc_dom_hvmloader.c
@@ -0,0 +1,313 @@
+/*
+ * Xen domain builder -- HVM specific bits.
+ *
+ * Parse and load ELF firmware images for HVM domains.
+ *
+ * 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 <stdarg.h>
+#include <inttypes.h>
+#include <assert.h>
+
+#include "xg_private.h"
+#include "xc_dom.h"
+#include "xc_bitops.h"
+
+/* ------------------------------------------------------------------------ */
+/* parse elf binary                                                         */
+
+static elf_negerrnoval check_elf_kernel(struct xc_dom_image *dom, bool verbose)
+{
+    if ( dom->kernel_blob == NULL )
+    {
+        if ( verbose )
+            xc_dom_panic(dom->xch, XC_INTERNAL_ERROR,
+                         "%s: no kernel image loaded", __func__);
+        return -EINVAL;
+    }
+
+    if ( !elf_is_elfbinary(dom->kernel_blob, dom->kernel_size) )
+    {
+        if ( verbose )
+            xc_dom_panic(dom->xch, XC_INVALID_KERNEL,
+                         "%s: kernel is not an ELF image", __func__);
+        return -EINVAL;
+    }
+    return 0;
+}
+
+static elf_negerrnoval xc_dom_probe_hvm_kernel(struct xc_dom_image *dom)
+{
+    struct elf_binary elf;
+    int rc;
+
+    /* This loader is designed for HVM guest firmware. */
+    if ( dom->container_type != XC_DOM_HVM_CONTAINER )
+        return -EINVAL;
+
+    rc = check_elf_kernel(dom, 0);
+    if ( rc != 0 )
+        return rc;
+
+    rc = elf_init(&elf, dom->kernel_blob, dom->kernel_size);
+    if ( rc != 0 )
+        return rc;
+
+    /*
+     * We need to check that there are no Xen ELFNOTES, or
+     * else we might be trying to load a PV kernel.
+     */
+    elf_parse_binary(&elf);
+    rc = elf_xen_parse(&elf, &dom->parms);
+    if ( rc == 0 )
+        return -EINVAL;
+
+    return 0;
+}
+
+static elf_errorstatus xc_dom_parse_hvm_kernel(struct xc_dom_image *dom)
+    /*
+     * This function sometimes returns -1 for error and sometimes
+     * an errno value.  ?!?!
+     */
+{
+    struct elf_binary *elf;
+    elf_errorstatus rc;
+
+    rc = check_elf_kernel(dom, 1);
+    if ( rc != 0 )
+        return rc;
+
+    elf = xc_dom_malloc(dom, sizeof(*elf));
+    if ( elf == NULL )
+        return -1;
+    dom->private_loader = elf;
+    rc = elf_init(elf, dom->kernel_blob, dom->kernel_size);
+    xc_elf_set_logfile(dom->xch, elf, 1);
+    if ( rc != 0 )
+    {
+        xc_dom_panic(dom->xch, XC_INVALID_KERNEL, "%s: corrupted ELF image",
+                     __func__);
+        return rc;
+    }
+
+    if ( !elf_32bit(elf) )
+    {
+        xc_dom_panic(dom->xch, XC_INVALID_KERNEL, "%s: ELF image is not 32bit",
+                     __func__);
+        return -EINVAL;
+    }
+
+    /* parse binary and get xen meta info */
+    elf_parse_binary(elf);
+
+    /* find kernel segment */
+    dom->kernel_seg.vstart = elf->pstart;
+    dom->kernel_seg.vend   = elf->pend;
+
+    dom->guest_type = "hvm-3.0-x86_32";
+
+    if ( elf_check_broken(elf) )
+        DOMPRINTF("%s: ELF broken: %s", __func__, elf_check_broken(elf));
+
+    return rc;
+}
+
+static int modules_init(struct xc_dom_image *dom,
+                        uint64_t vend, struct elf_binary *elf,
+                        uint64_t *mstart_out, uint64_t *mend_out)
+{
+#define MODULE_ALIGN 1UL << 7
+#define MB_ALIGN     1UL << 20
+#define MKALIGN(x, a) (((uint64_t)(x) + (a) - 1) & ~(uint64_t)((a) - 1))
+    uint64_t total_len = 0, offset1 = 0;
+
+    if ( dom->acpi_module.length == 0 && dom->smbios_module.length == 0 )
+        return 0;
+
+    /* Find the total length for the firmware modules with a reasonable large
+     * alignment size to align each the modules.
+     */
+    total_len = MKALIGN(dom->acpi_module.length, MODULE_ALIGN);
+    offset1 = total_len;
+    total_len += MKALIGN(dom->smbios_module.length, MODULE_ALIGN);
+
+    /* Want to place the modules 1Mb+change behind the loader image. */
+    *mstart_out = MKALIGN(elf->pend, MB_ALIGN) + (MB_ALIGN);
+    *mend_out = *mstart_out + total_len;
+
+    if ( *mend_out > vend )
+        return -1;
+
+    if ( dom->acpi_module.length != 0 )
+        dom->acpi_module.guest_addr_out = *mstart_out;
+    if ( dom->smbios_module.length != 0 )
+        dom->smbios_module.guest_addr_out = *mstart_out + offset1;
+
+    return 0;
+}
+
+static int loadmodules(struct xc_dom_image *dom,
+                       uint64_t mstart, uint64_t mend,
+                       uint32_t domid)
+{
+    privcmd_mmap_entry_t *entries = NULL;
+    unsigned long pfn_start;
+    unsigned long pfn_end;
+    size_t pages;
+    uint32_t i;
+    uint8_t *dest;
+    int rc = -1;
+    xc_interface *xch = dom->xch;
+
+    if ( mstart == 0 || mend == 0 )
+        return 0;
+
+    pfn_start = (unsigned long)(mstart >> PAGE_SHIFT);
+    pfn_end = (unsigned long)((mend + PAGE_SIZE - 1) >> PAGE_SHIFT);
+    pages = pfn_end - pfn_start;
+
+    /* Map address space for module list. */
+    entries = calloc(pages, sizeof(privcmd_mmap_entry_t));
+    if ( entries == NULL )
+        goto error_out;
+
+    for ( i = 0; i < pages; i++ )
+        entries[i].mfn = (mstart >> PAGE_SHIFT) + i;
+
+    dest = xc_map_foreign_ranges(
+        xch, domid, pages << PAGE_SHIFT, PROT_READ | PROT_WRITE, 1 << PAGE_SHIFT,
+        entries, pages);
+    if ( dest == NULL )
+        goto error_out;
+
+    /* Zero the range so padding is clear between modules */
+    memset(dest, 0, pages << PAGE_SHIFT);
+
+    /* Load modules into range */
+    if ( dom->acpi_module.length != 0 )
+    {
+        memcpy(dest,
+               dom->acpi_module.data,
+               dom->acpi_module.length);
+    }
+    if ( dom->smbios_module.length != 0 )
+    {
+        memcpy(dest + (dom->smbios_module.guest_addr_out - mstart),
+               dom->smbios_module.data,
+               dom->smbios_module.length);
+    }
+
+    munmap(dest, pages << PAGE_SHIFT);
+    rc = 0;
+
+ error_out:
+    free(entries);
+
+    return rc;
+}
+
+static elf_errorstatus xc_dom_load_hvm_kernel(struct xc_dom_image *dom)
+{
+    struct elf_binary *elf = dom->private_loader;
+    privcmd_mmap_entry_t *entries = NULL;
+    size_t pages = (elf->pend - elf->pstart + PAGE_SIZE - 1) >> PAGE_SHIFT;
+    elf_errorstatus rc;
+    uint64_t m_start = 0, m_end = 0;
+    int i;
+
+    /* Map address space for initial elf image. */
+    entries = calloc(pages, sizeof(privcmd_mmap_entry_t));
+    if ( entries == NULL )
+        return -ENOMEM;
+
+    for ( i = 0; i < pages; i++ )
+        entries[i].mfn = (elf->pstart >> PAGE_SHIFT) + i;
+
+    elf->dest_base = xc_map_foreign_ranges(
+        dom->xch, dom->guest_domid, pages << PAGE_SHIFT,
+        PROT_READ | PROT_WRITE, 1 << PAGE_SHIFT,
+        entries, pages);
+    if ( elf->dest_base == NULL )
+    {
+        DOMPRINTF("%s: unable to map guest memory space", __func__);
+        rc = -EFAULT;
+        goto error;
+    }
+
+    elf->dest_size = pages * XC_DOM_PAGE_SIZE(dom);
+
+    rc = elf_load_binary(elf);
+    if ( rc < 0 )
+    {
+        DOMPRINTF("%s: failed to load elf binary", __func__);
+        return rc;
+    }
+
+    munmap(elf->dest_base, elf->dest_size);
+
+    rc = modules_init(dom, dom->total_pages << PAGE_SHIFT, elf, &m_start,
+                      &m_end);
+    if ( rc != 0 )
+    {
+        DOMPRINTF("%s: insufficient space to load modules.", __func__);
+        return rc;
+    }
+
+    rc = loadmodules(dom, m_start, m_end, dom->guest_domid);
+    if ( rc != 0 )
+    {
+        DOMPRINTF("%s: unable to load modules.", __func__);
+        return rc;
+    }
+
+    dom->parms.phys_entry = elf_uval(elf, elf->ehdr, e_entry);
+
+    free(entries);
+    return 0;
+
+ error:
+    assert(rc != 0);
+    free(entries);
+    return rc;
+}
+
+/* ------------------------------------------------------------------------ */
+
+struct xc_dom_loader hvm_loader = {
+    .name = "HVM-generic",
+    .probe = xc_dom_probe_hvm_kernel,
+    .parser = xc_dom_parse_hvm_kernel,
+    .loader = xc_dom_load_hvm_kernel,
+};
+
+static void __init register_loader(void)
+{
+    xc_dom_register_loader(&hvm_loader);
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/include/xen/libelf.h b/xen/include/xen/libelf.h
index 6393040..03d449e 100644
--- a/xen/include/xen/libelf.h
+++ b/xen/include/xen/libelf.h
@@ -424,6 +424,7 @@ struct elf_dom_parms {
     uint64_t elf_paddr_offset;
     uint32_t f_supported[XENFEAT_NR_SUBMAPS];
     uint32_t f_required[XENFEAT_NR_SUBMAPS];
+    uint32_t phys_entry;
 
     /* calculated */
     uint64_t virt_offset;
-- 
1.9.5 (Apple Git-50.3)


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