x86/pvh: extract only 4 bytes of start address for 32 bit kernels

When loading the PVH start address from a 32 bit ELF note, extract
only the appropriate number of bytes.

Fixes: ab969087da65 ("pvh: Boot uncompressed kernel using direct boot ABI")
Signed-off-by: David Edmondson <david.edmondson@oracle.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20210302090315.3031492-3-david.edmondson@oracle.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index 6329f90ef9095e6f507f1f83ec396b61c02b02b6..7865660e2ce551d26b76edb082b43ce2b74aaa4b 100644 (file)
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -690,6 +690,8 @@ static uint64_t read_pvh_start_addr(void *arg1, void *arg2, bool is64)
         elf_note_data_addr =
             ((void *)nhdr64) + nhdr_size64 +
             QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
+
+        pvh_start_addr = *elf_note_data_addr;
     } else {
         struct elf32_note *nhdr32 = (struct elf32_note *)arg1;
         uint32_t nhdr_size32 = sizeof(struct elf32_note);
@@ -699,9 +701,9 @@ static uint64_t read_pvh_start_addr(void *arg1, void *arg2, bool is64)
         elf_note_data_addr =
             ((void *)nhdr32) + nhdr_size32 +
             QEMU_ALIGN_UP(nhdr_namesz, phdr_align);
-    }
 
-    pvh_start_addr = *elf_note_data_addr;
+        pvh_start_addr = *(uint32_t *)elf_note_data_addr;
+    }
 
     return pvh_start_addr;
 }