diff options
| -rw-r--r-- | OvmfPkg/Library/PlatformInitLib/MemDetect.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/OvmfPkg/Library/PlatformInitLib/MemDetect.c b/OvmfPkg/Library/PlatformInitLib/MemDetect.c index 1102b00ecb..662e7e85bb 100644 --- a/OvmfPkg/Library/PlatformInitLib/MemDetect.c +++ b/OvmfPkg/Library/PlatformInitLib/MemDetect.c @@ -646,16 +646,19 @@ PlatformAddressWidthFromCpuid ( ));
if (Valid) {
- if (PhysBits > 47) {
+ if (PhysBits > 46) {
/*
* Avoid 5-level paging altogether for now, which limits
* PhysBits to 48. Also avoid using address bit 48, due to sign
* extension we can't identity-map these addresses (and lots of
* places in edk2 assume we have everything identity-mapped).
* So the actual limit is 47.
+ *
+ * Also some older linux kernels apparently have problems handling
+ * phys-bits > 46 correctly, so use that as limit.
*/
- DEBUG ((DEBUG_INFO, "%a: limit PhysBits to 47 (avoid 5-level paging)\n", __func__));
- PhysBits = 47;
+ DEBUG ((DEBUG_INFO, "%a: limit PhysBits to 46 (avoid 5-level paging)\n", __func__));
+ PhysBits = 46;
}
if (!Page1GSupport && (PhysBits > 40)) {
|