[kvm-unit-tests PATCH] x86: on 32-bit do not initialize memory above 2GB
From: Nadav Amit <hidden>
Date: 2021-03-13 07:35:56
Subsystem:
library code, the rest · Maintainers:
Andrew Morton, Linus Torvalds
From: Nadav Amit <redacted> taskswitch2 test fails on certain configurations with more than 2GB of memory. The reason is that on i386, setup_mmu() creates a hole above 2GB and does not map that area. Do not initialize the memory above 2GB on i386. Signed-off-by: Nadav Amit <redacted> --- lib/x86/setup.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/lib/x86/setup.c b/lib/x86/setup.c
index 7befe09..001853c 100644
--- a/lib/x86/setup.c
+++ b/lib/x86/setup.c@@ -107,6 +107,15 @@ void setup_multiboot(struct mbi_bootinfo *bi) u64 best_start = (uintptr_t) &edata; u64 best_end = bootinfo->mem_upper * 1024ull; + +#ifndef __x86_64__ + /* + * On i386, setup_mmu() creates a hole above 2GB, so do not initialize + * the memory above 2GB. + */ + if (best_end > 2ul << 30) + best_end = 2ul << 30; +#endif phys_alloc_init(best_start, best_end - best_start); if (bootinfo->mods_count != 1)
--
2.25.1