From: Ashish Kalra <[email protected]>
For kexec use case, need to use and stick to the EFI memmap passed
from the first kernel via boot-params/setup data, hence,
skip efi_arch_mem_reserve() during kexec.
Additionally during SNP guest kexec testing discovered that EFI memmap
is corrupted during chained kexec. kexec_enter_virtual_mode() during
late init will remap the efi_memmap physical pages allocated in
efi_arch_mem_reserve() via memblock & then subsequently cause random
EFI memmap corruption once memblock is freed/teared-down.
Signed-off-by: Ashish Kalra <[email protected]>
---
arch/x86/platform/efi/quirks.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index f0cc00032751..d4562d074371 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -258,6 +258,16 @@ void __init efi_arch_mem_reserve(phys_addr_t addr, u64 size)
int num_entries;
void *new;
+ /*
+ * For kexec use case, need to use the EFI memmap passed from the first
+ * kernel via boot-params/setup data and need to skip this.
+ * Additionally kexec_enter_virtual_mode() during late init will remap
+ * the efi_memmap physical pages allocated here via memblock & then
+ * subsequently cause random EFI memmap corruption once memblock is freed.
+ */
+ if (efi_setup)
+ return;
+
if (efi_mem_desc_lookup(addr, &md) ||
md.type != EFI_BOOT_SERVICES_DATA) {
pr_err("Failed to lookup EFI memory descriptor for %pa\n", &addr);
--
2.34.1