From 0cb30030b483d1ecc70a78494dbcb19df4b3e23f Mon Sep 17 00:00:00 2001 From: Hou Wenlong Date: Sat, 10 Jan 2026 12:00:08 +0800 Subject: [PATCH] x86/xen/pvh: Enable PAE mode for 32-bit guest only when CONFIG_X86_PAE is set [ Upstream commit db9aded979b491a24871e1621cd4e8822dbca859 ] 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 Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross Message-ID: Signed-off-by: Sasha Levin --- 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 ce4fd8d33da4..2774cf74fa94 100644 --- a/arch/x86/platform/pvh/head.S +++ b/arch/x86/platform/pvh/head.S @@ -91,10 +91,12 @@ SYM_CODE_START_LOCAL(pvh_start_xen) leal rva(early_stack_end)(%ebp), %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. */