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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v7 5/7] xen/x86: parse Dom0 kernel for PVHv2
Introduce a helper to parse the Dom0 kernel.
A new helper is also introduced to libelf, that's used to store the destination
vcpu of the domain. This parameter is needed when loading the kernel on a HVM
domain (PVHv2), since hvm_copy_to_guest_phys requires passing the destination
vcpu.
While there also fix image_base and image_start to be of type "void *", and do
the necessary fixup of related functions.
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
Changes since v5:
- s/hvm_copy_to_guest_phys_vcpu/hvm_copy_to_guest_phys/.
- Use void * for image_base and image_start, make the necessary changes.
- Introduce elf_set_vcpu in order to store the destination vcpu in
elf_binary, and use it in elf_load_image. This avoids having to override
current.
- Style fixes.
- Round up the position of the modlist/start_info to an aligned address
depending on the kernel bitness.
Changes since v4:
- s/hvm/pvh.
- Use hvm_copy_to_guest_phys_vcpu.
Changes since v3:
- Change one error message.
- Indent "out" label by one space.
- Introduce hvm_copy_to_phys and slightly simplify the code in hvm_load_kernel.
Changes since v2:
- Remove debug messages.
- Don't hardcode the number of modules to 1.
---
xen/arch/x86/domain_build.c | 133 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 133 insertions(+)
diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index d2a1105..a47b8d2 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -39,6 +39,7 @@
#include <public/version.h>
#include <public/hvm/hvm_info_table.h>
+#include <public/arch-x86/hvm/start_info.h>
static long __initdata dom0_nrpages;
static long __initdata dom0_min_nrpages;
@@ -2022,12 +2023,136 @@ static int __init pvh_setup_p2m(struct domain *d)
#undef MB1_PAGES
}
+static int __init pvh_load_kernel(struct domain *d, const module_t *image,
+ unsigned long image_headroom,
+ module_t *initrd, void *image_base,
+ char *cmdline, paddr_t *entry,
+ paddr_t *start_info_addr)
+{
+ void *image_start = image_base + image_headroom;
+ unsigned long image_len = image->mod_end;
+ struct elf_binary elf;
+ struct elf_dom_parms parms;
+ paddr_t last_addr;
+ struct hvm_start_info start_info = { 0 };
+ struct hvm_modlist_entry mod = { 0 };
+ struct vcpu *v = d->vcpu[0];
+ int rc;
+
+ if ( (rc = bzimage_parse(image_base, &image_start, &image_len)) != 0 )
+ {
+ printk("Error trying to detect bz compressed kernel\n");
+ return rc;
+ }
+
+ if ( (rc = elf_init(&elf, image_start, image_len)) != 0 )
+ {
+ printk("Unable to init ELF\n");
+ return rc;
+ }
+#ifdef VERBOSE
+ elf_set_verbose(&elf);
+#endif
+ elf_parse_binary(&elf);
+ if ( (rc = elf_xen_parse(&elf, &parms)) != 0 )
+ {
+ printk("Unable to parse kernel for ELFNOTES\n");
+ return rc;
+ }
+
+ if ( parms.phys_entry == UNSET_ADDR32 )
+ {
+ printk("Unable to find XEN_ELFNOTE_PHYS32_ENTRY address\n");
+ return -EINVAL;
+ }
+
+ printk("OS: %s version: %s loader: %s bitness: %s\n", parms.guest_os,
+ parms.guest_ver, parms.loader,
+ elf_64bit(&elf) ? "64-bit" : "32-bit");
+
+ /* Copy the OS image and free temporary buffer. */
+ elf.dest_base = (void *)(parms.virt_kstart - parms.virt_base);
+ elf.dest_size = parms.virt_kend - parms.virt_kstart;
+
+ elf_set_vcpu(&elf, v);
+ rc = elf_load_binary(&elf);
+ if ( rc < 0 )
+ {
+ printk("Failed to load kernel: %d\n", rc);
+ printk("Xen dom0 kernel broken ELF: %s\n", elf_check_broken(&elf));
+ return rc;
+ }
+
+ last_addr = ROUNDUP(parms.virt_kend - parms.virt_base, PAGE_SIZE);
+
+ if ( initrd != NULL )
+ {
+ rc = hvm_copy_to_guest_phys(last_addr, mfn_to_virt(initrd->mod_start),
+ initrd->mod_end, v);
+ if ( rc )
+ {
+ printk("Unable to copy initrd to guest\n");
+ return rc;
+ }
+
+ mod.paddr = last_addr;
+ mod.size = initrd->mod_end;
+ last_addr += ROUNDUP(initrd->mod_end, PAGE_SIZE);
+ }
+
+ /* Free temporary buffers. */
+ discard_initial_images();
+
+ if ( cmdline != NULL )
+ {
+ rc = hvm_copy_to_guest_phys(last_addr, cmdline, strlen(cmdline) + 1,
v);
+ if ( rc )
+ {
+ printk("Unable to copy guest command line\n");
+ return rc;
+ }
+ start_info.cmdline_paddr = last_addr;
+ /*
+ * Round up to 32/64 bits (depending on the guest kernel bitness) so
+ * the modlist/start_info is aligned.
+ */
+ last_addr += ROUNDUP(strlen(cmdline) + 1, elf_64bit(&elf) ? 8 : 4);
+ }
+ if ( initrd != NULL )
+ {
+ rc = hvm_copy_to_guest_phys(last_addr, &mod, sizeof(mod), v);
+ if ( rc )
+ {
+ printk("Unable to copy guest modules\n");
+ return rc;
+ }
+ start_info.modlist_paddr = last_addr;
+ start_info.nr_modules = 1;
+ last_addr += sizeof(mod);
+ }
+
+ start_info.magic = XEN_HVM_START_MAGIC_VALUE;
+ start_info.flags = SIF_PRIVILEGED | SIF_INITDOMAIN;
+ rc = hvm_copy_to_guest_phys(last_addr, &start_info, sizeof(start_info), v);
+ if ( rc )
+ {
+ printk("Unable to copy start info to guest\n");
+ return rc;
+ }
+
+ *entry = parms.phys_entry;
+ *start_info_addr = last_addr;
+
+ return 0;
+}
+
static int __init construct_dom0_pvh(struct domain *d, const module_t *image,
unsigned long image_headroom,
module_t *initrd,
void *(*bootstrap_map)(const module_t *),
char *cmdline)
{
+ paddr_t entry, start_info;
int rc;
printk("** Building a PVH Dom0 **\n");
@@ -2041,6 +2166,14 @@ static int __init construct_dom0_pvh(struct domain *d,
const module_t *image,
return rc;
}
+ rc = pvh_load_kernel(d, image, image_headroom, initrd,
bootstrap_map(image),
+ cmdline, &entry, &start_info);
+ if ( rc )
+ {
+ printk("Failed to load Dom0 kernel\n");
+ return rc;
+ }
+
panic("Building a PVHv2 Dom0 is not yet supported.");
return 0;
}
--
2.10.1 (Apple Git-78)
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