x86/EFI: simplify PCI option ROM retrieval

While putting together the kernel side of this I realized that c/s
26397:d9c7b82aa7b1 went a little too far in requiring a buffer for the
option ROM contents - all that is really needed is handing Dom0
physical address and size of the data block.

Signed-off-by: Jan Beulich <jbeulich@suse.com>

1 files changed, 2 insertions, 9 deletions

diff --git a/xen/arch/x86/efi/runtime.c b/xen/arch/x86/efi/runtime.c
index c5b03bfe2c..73aa15eb9a 100644
--- a/xen/arch/x86/efi/runtime.c
+++ b/xen/arch/x86/efi/runtime.c
@@ -189,16 +189,9 @@ int efi_get_info(uint32_t idx, union xenpf_efi_info *info)
                  info->pci_rom.vendor == ent->vendor &&
                  info->pci_rom.devid == ent->devid )
             {
-                int rc = 0;
-
-                if ( info->pci_rom.size < ent->size )
-                    rc = -ENOSPC;
-                else if ( copy_to_guest(info->pci_rom.data,
-                                        ent->data, ent->size) )
-                    rc = -EFAULT;
+                info->pci_rom.address = __pa(ent->data);
                 info->pci_rom.size = ent->size;
-
-                return rc;
+                return 0;
             }
         return -ESRCH;
     }