[RFC,3/3] libelf: PVH: only allow elf_paddr_offset of 0

Commit Message

Jason Andryuk May 14, 2021, 3:17 p.m. UTC

Modern Linux and FreeBSD hardcode it to 0.  Just drop its use for PVH.

Signed-off-by: Jason Andryuk <[e-mail]>
---
 xen/arch/x86/hvm/dom0_build.c      | 2 +-
 xen/common/libelf/libelf-dominfo.c | 6 ++++++
 2 files changed, 7 insertions(+), 1 deletion(-)

Patch

diff --git a/xen/arch/x86/hvm/dom0_build.c b/xen/arch/x86/hvm/dom0_build.c
index 552448ce5d..335321ed3e 100644
--- a/xen/arch/x86/hvm/dom0_build.c
+++ b/xen/arch/x86/hvm/dom0_build.c
@@ -574,7 +574,7 @@  static int __init pvh_load_kernel(struct domain *d, const module_t *image,
     }
 
     /* Copy the OS image and free temporary buffer. */
-    elf.dest_base = (void *)parms.phys_kstart - parms.elf_paddr_offset;
+    elf.dest_base = (void *)parms.phys_kstart;
     elf.dest_size = parms.phys_kend - parms.phys_kstart;
 
     elf_set_vcpu(&elf, v);
diff --git a/xen/common/libelf/libelf-dominfo.c b/xen/common/libelf/libelf-dominfo.c
index 13eb39ec52..12feb8755e 100644
--- a/xen/common/libelf/libelf-dominfo.c
+++ b/xen/common/libelf/libelf-dominfo.c
@@ -433,6 +433,12 @@  static elf_errorstatus elf_xen_addr_calc_check_pvh(struct elf_binary *elf,
             parms->phys_kend = elf->bsd_symtab_pend;
     }
 
+    if ( parms->elf_paddr_offset != 0 ) {
+        elf_err(elf, "ERROR: ELF elf_paddr_offset (0x" PRIx64 ") is non-zero\n",
+                parms->elf_paddr_offset);
+        return -1;
+    }
+
     elf_msg(elf, "ELF: addresses:\n");
     elf_msg(elf, "    phys_kstart      = 0x%" PRIx64 "\n", parms->phys_kstart);
     elf_msg(elf, "    phys_kend        = 0x%" PRIx64 "\n", parms->phys_kend);