[PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set

["Hou Wenlong" <houwenlong.hwl@xxxxxxxxxxxx>]

The PVH entry is available for 32-bit KVM guests, and 32-bit KVM guests
do not depend on CONFIG_X86_PAE. However, mk_early_pgtbl_32() builds
different pagetables depending on whether CONFIG_X86_PAE is set.
Therefore, enabling PAE mode for 32-bit KVM guests without
CONFIG_X86_PAE being set would result in a boot failure during CR3
loading.

Signed-off-by: Hou Wenlong <houwenlong.hwl@xxxxxxxxxxxx>
---
 arch/x86/platform/pvh/head.S | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index c4365a05ab83..085adb1b2313 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -70,10 +70,12 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
 
        mov $_pa(early_stack_end), %esp
 
+#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)
        /* Enable PAE mode. */
        mov %cr4, %eax
        orl $X86_CR4_PAE, %eax
        mov %eax, %cr4
+#endif
 
 #ifdef CONFIG_X86_64
        /* Enable Long mode. */
-- 
2.31.1