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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v5 6/9] xen/x86: parse Dom0 kernel for PVHv2
Introduce a helper to parse the Dom0 kernel.
Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
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 | 143 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 143 insertions(+)
diff --git a/xen/arch/x86/domain_build.c b/xen/arch/x86/domain_build.c
index fbce1c2..4f5f712 100644
--- a/xen/arch/x86/domain_build.c
+++ b/xen/arch/x86/domain_build.c
@@ -39,6 +39,7 @@
#include <asm/hpet.h>
#include <public/version.h>
+#include <public/arch-x86/hvm/start_info.h>
static long __initdata dom0_nrpages;
static long __initdata dom0_min_nrpages;
@@ -1959,12 +1960,146 @@ 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, char *image_base,
+ char *cmdline, paddr_t *entry,
+ paddr_t *start_info_addr)
+{
+ char *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;
+ struct hvm_modlist_entry mod = { 0 };
+ struct vcpu *saved_current, *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;
+
+ /*
+ * NB: we need to set vCPU 0 of Dom0 as the current vCPU (instead of the
+ * idle one) because elf_load_binary calls raw_{copy_to/clear}_guest, and
+ * the target domain is not passed anywhere. This is very similar to what
+ * is done during classic PV Dom0 creation, where Xen switches to the Dom0
+ * page tables. We also cannot pass a struct domain or vcpu to
+ * elf_load_binary, since the interface is shared with the toolstack, and
+ * it doesn't have any notion of a domain or vcpu struct.
+ */
+ saved_current = current;
+ set_current(v);
+ rc = elf_load_binary(&elf);
+ set_current(saved_current);
+ 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_vcpu(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();
+
+ memset(&start_info, 0, sizeof(start_info));
+ if ( cmdline != NULL )
+ {
+ rc = hvm_copy_to_guest_phys_vcpu(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;
+ last_addr += ROUNDUP(strlen(cmdline) + 1, 8);
+ }
+ if ( initrd != NULL )
+ {
+ rc = hvm_copy_to_guest_phys_vcpu(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_vcpu(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");
@@ -1978,6 +2113,14 @@ 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;
+ }
+
return 0;
}
--
2.10.1 (Apple Git-78)
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