diff options
| author | Demi Marie Obenour <demi@invisiblethingslab.com> | 2023-01-19 14:03:57 -0500 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2023-01-22 10:14:15 +0100 |
| commit | aca1d27ac38a61d7db4b56418386992cb96b63f0 (patch) | |
| tree | de5f4428831e9caf2ff8a1cbacb3753f59d083b9 /drivers/firmware | |
| parent | ab03e91e60ce457a90e6aa2c97ca2fa139b73f55 (diff) | |
efi: xen: Implement memory descriptor lookup based on hypercall
Xen on x86 boots dom0 in EFI mode but without providing a memory map.
This means that some consistency checks we would like to perform on
configuration tables or other data structures in memory are not
currently possible. Xen does, however, expose EFI memory descriptor
info via a Xen hypercall, so let's wire that up instead. It turns out
that the returned information is not identical to what Linux's
efi_mem_desc_lookup would return: the address returned is the address
passed to the hypercall, and the size returned is the number of bytes
remaining in the configuration table. However, none of the callers of
efi_mem_desc_lookup() currently care about this. In the future, Xen may
gain a hypercall that returns the actual start address, which can be
used instead.
Co-developed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Demi Marie Obenour <demi@invisiblethingslab.com>
Tested-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'drivers/firmware')
| -rw-r--r-- | drivers/firmware/efi/efi.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index d295be116039..90142f6e588d 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -478,7 +478,7 @@ void __init efi_find_mirror(void) * and if so, populate the supplied memory descriptor with the appropriate * data. */ -int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) +int __efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) { efi_memory_desc_t *md; @@ -512,6 +512,9 @@ int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) return -ENOENT; } +extern int efi_mem_desc_lookup(u64 phys_addr, efi_memory_desc_t *out_md) + __weak __alias(__efi_mem_desc_lookup); + /* * Calculate the highest address of an efi memory descriptor. */ |