[kvm-unit-tests PATCH v2 15/18] arm64: efi: Don't map reserved regions

Andrew Jones
2024-02-27T19:22:18Z

We shouldn't need to map all the regions that the EFI memory map
contains. Just map EFI_LOADER_CODE and EFI_LOADER_DATA, since
those are for the loaded unit test, and any region types which
could be used by the unit test for its own memory allocations. We
still map EFI_BOOT_SERVICES_DATA since the primary stack is on a
region of that type. In a later patch we'll switch to a stack we
allocate ourselves to drop that one too.

Signed-off-by: Andrew Jones <andrew.jones@linux.dev>
---
lib/arm/mmu.c | 6 +-----
lib/arm/setup.c | 4 ++--
lib/memregions.c | 8 ++++++++
3 files changed, 11 insertions(+), 7 deletions(-)

diff --git a/lib/arm/mmu.c b/lib/arm/mmu.c
index eb5e82a95f06..9dce7da85709 100644
--- a/lib/arm/mmu.c
+++ b/lib/arm/mmu.c
@@ -221,12 +221,8 @@ void *setup_mmu(phys_addr_t phys_end, void *unused)
mmu_idmap = alloc_page();

for (r = mem_regions; r->end; ++r) {
- if (r->flags & MR_F_IO) {
+ if (r->flags & (MR_F_IO | MR_F_RESERVED)) {
continue;
- } else if (r->flags & MR_F_RESERVED) {
- /* Reserved pages need to be writable for whatever reserved them */
- mmu_set_range_ptes(mmu_idmap, r->start, r->start, r->end,
- __pgprot(PTE_WBWA));
} else if (r->flags & MR_F_CODE) {
/* armv8 requires code shared between EL1 and EL0 to be read-only */
mmu_set_range_ptes(mmu_idmap, r->start, r->start, r->end,
diff --git a/lib/arm/setup.c b/lib/arm/setup.c
index 521928186fb0..08658b9a222b 100644
--- a/lib/arm/setup.c
+++ b/lib/arm/setup.c
@@ -309,8 +309,8 @@ static efi_status_t efi_mem_init(efi_bootinfo_t *efi_bootinfo)
data->flags &= ~MR_F_CODE;

for (struct mem_region *m = mem_regions; m->end; ++m) {
- if (m != code && (m->flags & MR_F_CODE))
- m->flags = MR_F_RESERVED;
+ if (m != code)
+ assert(!(m->flags & MR_F_CODE));

if (!(m->flags & MR_F_IO)) {
if (m->start < __phys_offset)
diff --git a/lib/memregions.c b/lib/memregions.c
index 9cdbb639ab62..3c6f751eb4f2 100644
--- a/lib/memregions.c
+++ b/lib/memregions.c
@@ -112,6 +112,14 @@ void memregions_efi_init(struct efi_boot_memmap *mem_map,
case EFI_LOADER_CODE:
r.flags = MR_F_CODE;
break;
+ case EFI_LOADER_DATA:
+ break;
+ case EFI_BOOT_SERVICES_DATA:
+ /*
+ * FIXME: This would ideally be MR_F_RESERVED, but the
+ * primary stack is in a region of this EFI type.
+ */
+ break;
case EFI_PERSISTENT_MEMORY:
r.flags = MR_F_PERSISTENT;
break;
--
2.43.0