Re: [PATCH v2 01/12] x86/ioremap: Selectively build arch override encryption functions

2021-08-16 Thread Borislav Petkov
On Fri, Aug 13, 2021 at 11:59:20AM -0500, Tom Lendacky wrote:
> In prep for other uses of the prot_guest_has() function besides AMD's
> memory encryption support, selectively build the AMD memory encryption
> architecture override functions only when CONFIG_AMD_MEM_ENCRYPT=y. These
> functions are:
> - early_memremap_pgprot_adjust()
> - arch_memremap_can_ram_remap()
> 
> Additionally, routines that are only invoked by these architecture
> override functions can also be conditionally built. These functions are:
> - memremap_should_map_decrypted()
> - memremap_is_efi_data()
> - memremap_is_setup_data()
> - early_memremap_is_setup_data()
> 
> And finally, phys_mem_access_encrypted() is conditionally built as well,
> but requires a static inline version of it when CONFIG_AMD_MEM_ENCRYPT is
> not set.
> 
> Cc: Thomas Gleixner 
> Cc: Ingo Molnar 
> Cc: Borislav Petkov 
> Cc: Dave Hansen 
> Cc: Andy Lutomirski 
> Cc: Peter Zijlstra 
> Signed-off-by: Tom Lendacky 
> ---
>  arch/x86/include/asm/io.h | 8 
>  arch/x86/mm/ioremap.c | 2 +-
>  2 files changed, 9 insertions(+), 1 deletion(-)

LGTM.

-- 
Regards/Gruss,
Boris.

https://people.kernel.org/tglx/notes-about-netiquette


[PATCH v2 01/12] x86/ioremap: Selectively build arch override encryption functions

2021-08-13 Thread Tom Lendacky
In prep for other uses of the prot_guest_has() function besides AMD's
memory encryption support, selectively build the AMD memory encryption
architecture override functions only when CONFIG_AMD_MEM_ENCRYPT=y. These
functions are:
- early_memremap_pgprot_adjust()
- arch_memremap_can_ram_remap()

Additionally, routines that are only invoked by these architecture
override functions can also be conditionally built. These functions are:
- memremap_should_map_decrypted()
- memremap_is_efi_data()
- memremap_is_setup_data()
- early_memremap_is_setup_data()

And finally, phys_mem_access_encrypted() is conditionally built as well,
but requires a static inline version of it when CONFIG_AMD_MEM_ENCRYPT is
not set.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: Dave Hansen 
Cc: Andy Lutomirski 
Cc: Peter Zijlstra 
Signed-off-by: Tom Lendacky 
---
 arch/x86/include/asm/io.h | 8 
 arch/x86/mm/ioremap.c | 2 +-
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h
index 841a5d104afa..5c6a4af0b911 100644
--- a/arch/x86/include/asm/io.h
+++ b/arch/x86/include/asm/io.h
@@ -391,6 +391,7 @@ extern void arch_io_free_memtype_wc(resource_size_t start, 
resource_size_t size)
 #define arch_io_reserve_memtype_wc arch_io_reserve_memtype_wc
 #endif
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
 extern bool arch_memremap_can_ram_remap(resource_size_t offset,
unsigned long size,
unsigned long flags);
@@ -398,6 +399,13 @@ extern bool arch_memremap_can_ram_remap(resource_size_t 
offset,
 
 extern bool phys_mem_access_encrypted(unsigned long phys_addr,
  unsigned long size);
+#else
+static inline bool phys_mem_access_encrypted(unsigned long phys_addr,
+unsigned long size)
+{
+   return true;
+}
+#endif
 
 /**
  * iosubmit_cmds512 - copy data to single MMIO location, in 512-bit units
diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c
index 60ade7dd71bd..ccff76cedd8f 100644
--- a/arch/x86/mm/ioremap.c
+++ b/arch/x86/mm/ioremap.c
@@ -508,6 +508,7 @@ void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
memunmap((void *)((unsigned long)addr & PAGE_MASK));
 }
 
+#ifdef CONFIG_AMD_MEM_ENCRYPT
 /*
  * Examine the physical address to determine if it is an area of memory
  * that should be mapped decrypted.  If the memory is not part of the
@@ -746,7 +747,6 @@ bool phys_mem_access_encrypted(unsigned long phys_addr, 
unsigned long size)
return arch_memremap_can_ram_remap(phys_addr, size, 0);
 }
 
-#ifdef CONFIG_AMD_MEM_ENCRYPT
 /* Remap memory with encryption */
 void __init *early_memremap_encrypted(resource_size_t phys_addr,
  unsigned long size)
-- 
2.32.0