[edk2-devel] [PATCH 1/1] OvmfPkg/VirtNorFlashDxe: map flash memory as uncacheable

[Gerd Hoffmann]

Switching from the ArmPlatformPkg/NorFlashDxe driver to the
OvmfPkg/VirtNorFlashDxe driver had the side effect that flash address
space got registered as EFI_MEMORY_WC instead of EFI_MEMORY_UC.

That confuses the linux kernel's numa code, seems this makes kernel
consider the flash being node memory.  "lsmem" changes from ...

    RANGE                                 SIZE  STATE REMOVABLE BLOCK
    0x0000000040000000-0x000000013fffffff   4G online       yes  8-39

... to ...

    RANGE                                  SIZE  STATE REMOVABLE BLOCK
    0x0000000000000000-0x0000000007ffffff  128M online       yes     0
    0x0000000040000000-0x000000013fffffff    4G online       yes  8-39

... and in the kernel log got new error lines:

    NUMA: Warning: invalid memblk node 512 [mem 0x0000000004000000-0x0000000007ffffff]
    NUMA: Faking a node at [mem 0x0000000004000000-0x000000013fffffff]

Changing the attributes back to EFI_MEMORY_UC fixes this.

Fixes: b92298af8218 ("ArmVirtPkg/ArmVirtQemu: migrate to OVMF's VirtNorFlashDxe")
Signed-off-by: Gerd Hoffmann <kraxel at redhat.com>
---
 OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c b/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
index ff3121af2a40..f9a41f6aab0f 100644
--- a/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
+++ b/OvmfPkg/VirtNorFlashDxe/VirtNorFlashDxe.c
@@ -394,14 +394,14 @@ NorFlashFvbInitialize (
                   EfiGcdMemoryTypeMemoryMappedIo,
                   Instance->DeviceBaseAddress,
                   RuntimeMmioRegionSize,
-                  EFI_MEMORY_WC | EFI_MEMORY_RUNTIME
+                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
                   );
   ASSERT_EFI_ERROR (Status);
 
   Status = gDS->SetMemorySpaceAttributes (
                   Instance->DeviceBaseAddress,
                   RuntimeMmioRegionSize,
-                  EFI_MEMORY_WC | EFI_MEMORY_RUNTIME
+                  EFI_MEMORY_UC | EFI_MEMORY_RUNTIME
                   );
   ASSERT_EFI_ERROR (Status);
 
-- 
2.39.0



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