In order to transfer the early mapping state into KVM's MMIO
guard infrastucture, provide a small helper that will retrieve
the associated PTE.
Signed-off-by: Marc Zyngier <m...@kernel.org>
---
arch/arm64/include/asm/fixmap.h | 2 ++
arch/arm64/mm/mmu.c | 15 +++++++++++++++
2 files changed, 17 insertions(+)
diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h
index 4335800201c9..1aae625b944f 100644
--- a/arch/arm64/include/asm/fixmap.h
+++ b/arch/arm64/include/asm/fixmap.h
@@ -105,6 +105,8 @@ void __init early_fixmap_init(void);
extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t
prot);
+extern pte_t *__get_fixmap_pte(enum fixed_addresses idx);
+
#include <asm-generic/fixmap.h>
#endif /* !__ASSEMBLY__ */
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index d74586508448..f1b7abd04025 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -1286,6 +1286,21 @@ void __set_fixmap(enum fixed_addresses idx,
}
}
+pte_t *__get_fixmap_pte(enum fixed_addresses idx)
+{
+ unsigned long addr = __fix_to_virt(idx);
+ pte_t *ptep;
+
+ BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
+
+ ptep = fixmap_pte(addr);
+
+ if (!pte_valid(*ptep))
+ return NULL;
+
+ return ptep;
+}
+
void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot)
{
const u64 dt_virt_base = __fix_to_virt(FIX_FDT);
--
2.30.2
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