[PATCH 1/5] efi: Don't issue error message when booted under xen

[Matt Fleming]

From: Juergen Gross <jgross@xxxxxxxx>

When booted as Xen dom0 there won't be an EFI memmap allocated. Avoid
issuing an error message in this case:

[    0.144079] efi: Failed to allocate new EFI memmap

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.9+
Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
---
 arch/x86/platform/efi/quirks.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 26615991d69c..e0cf95a83f3f 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -360,6 +360,9 @@ void __init efi_free_boot_services(void)
 		free_bootmem_late(start, size);
 	}
 
+	if (!num_entries)
+		return;
+
 	new_size = efi.memmap.desc_size * num_entries;
 	new_phys = efi_memmap_alloc(num_entries);
 	if (!new_phys) {
-- 
2.12.2