From: Ashish Kalra <ashish.ka...@amd.com>

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 memboot & then subsequently cause random
EFI memmap corruption once memblock is freed/teared-down.

Signed-off-by: Ashish Kalra <ashish.ka...@amd.com>
---
 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 memboot & 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


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