Re: [PATCH Part1 RFC v4 24/36] x86/compressed/acpi: move EFI config table access to common code
From: Borislav Petkov <bp@alien8.de>
Date: 2021-08-19 10:47:31
Also in:
kvm, linux-coco, linux-crypto, linux-efi, lkml, platform-driver-x86
On Wed, Jul 07, 2021 at 01:14:54PM -0500, Brijesh Singh wrote:
From: Michael Roth <redacted> Future patches for SEV-SNP-validated CPUID will also require early parsing of the EFI configuration. Move the related code into a set of helpers that can be re-used for that purpose. Signed-off-by: Michael Roth <redacted> Signed-off-by: Brijesh Singh <redacted> --- arch/x86/boot/compressed/Makefile | 1 + arch/x86/boot/compressed/acpi.c | 124 +++++--------- arch/x86/boot/compressed/efi-config-table.c | 180 ++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 50 ++++++ 4 files changed, 272 insertions(+), 83 deletions(-) create mode 100644 arch/x86/boot/compressed/efi-config-table.c
arch/x86/boot/compressed/efi.c should be good enough. And in general, this patch is hard to review because it does a bunch of things at the same time. You should split it: - the first patch sould carve out only the functionality into helpers without adding or changing the existing functionality. - later ones should add the new functionality, in single logical steps. Some preliminary comments below as far as I can:
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 431bf7f846c3..b41aecfda49c 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile@@ -100,6 +100,7 @@ endif vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o +vmlinux-objs-$(CONFIG_EFI) += $(obj)/efi-config-table.o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a $(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCEdiff --git a/arch/x86/boot/compressed/acpi.c b/arch/x86/boot/compressed/acpi.c index 8bcbcee54aa1..e087dcaf43b3 100644 --- a/arch/x86/boot/compressed/acpi.c +++ b/arch/x86/boot/compressed/acpi.c@@ -24,42 +24,36 @@ struct mem_vector immovable_mem[MAX_NUMNODES*2]; * Search EFI system tables for RSDP. If both ACPI_20_TABLE_GUID and * ACPI_TABLE_GUID are found, take the former, which has more features. */ +#ifdef CONFIG_EFI +static bool +rsdp_find_fn(efi_guid_t guid, unsigned long vendor_table, bool efi_64, + void *opaque) +{ + acpi_physical_address *rsdp_addr = opaque; + + if (!(efi_guidcmp(guid, ACPI_TABLE_GUID))) { + *rsdp_addr = vendor_table; + } else if (!(efi_guidcmp(guid, ACPI_20_TABLE_GUID))) { + *rsdp_addr = vendor_table; + return false;
No "return false" in the ACPI_TABLE_GUID branch above? Maybe this has to do with the preference to ACPI_20_TABLE_GUID. In any case, this looks silly. Please do the iteration simple and stupid without the function pointer and get rid of that efi_foreach_conf_entry() thing - this is not firmware.
quoted hunk ↗ jump to hunk
diff --git a/arch/x86/boot/compressed/efi-config-table.c b/arch/x86/boot/compressed/efi-config-table.c new file mode 100644 index 000000000000..d1a34aa7cefd --- /dev/null +++ b/arch/x86/boot/compressed/efi-config-table.c
...
+/*
If you're going to add proper comments, make them kernel-doc. I.e., it should start with /** and then use ./scripts/kernel-doc -none arch/x86/boot/compressed/efi-config-table.c to check them all they're proper.
+ * Given boot_params, retrieve the physical address of EFI system table. + * + * @boot_params: pointer to boot_params + * @sys_table_pa: location to store physical address of system table + * @is_efi_64: location to store whether using 64-bit EFI or not + * + * Returns 0 on success. On error, return params are left unchanged. + */ +int +efi_bp_get_system_table(struct boot_params *boot_params,
There's no need for the "_bp_" - just efi_get_system_table(). Ditto for
the other naming.
I'll review the rest properly after you've split it.
Thx.
--
Regards/Gruss,
Boris.
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