Messages in this thread | | | Subject | Re: [PATCH 07/11] treewide: Replace the use of mem_encrypt_active() with prot_guest_has() | From | "Kuppuswamy, Sathyanarayanan" <> | Date | Tue, 10 Aug 2021 13:09:02 -0700 |
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On 8/10/21 12:48 PM, Tom Lendacky wrote: > On 8/10/21 1:45 PM, Kuppuswamy, Sathyanarayanan wrote: >> >> >> On 7/27/21 3:26 PM, Tom Lendacky wrote: >>> diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c >>> index de01903c3735..cafed6456d45 100644 >>> --- a/arch/x86/kernel/head64.c >>> +++ b/arch/x86/kernel/head64.c >>> @@ -19,7 +19,7 @@ >>> #include <linux/start_kernel.h> >>> #include <linux/io.h> >>> #include <linux/memblock.h> >>> -#include <linux/mem_encrypt.h> >>> +#include <linux/protected_guest.h> >>> #include <linux/pgtable.h> >>> #include <asm/processor.h> >>> @@ -285,7 +285,7 @@ unsigned long __head __startup_64(unsigned long >>> physaddr, >>> * there is no need to zero it after changing the memory encryption >>> * attribute. >>> */ >>> - if (mem_encrypt_active()) { >>> + if (prot_guest_has(PATTR_MEM_ENCRYPT)) { >>> vaddr = (unsigned long)__start_bss_decrypted; >>> vaddr_end = (unsigned long)__end_bss_decrypted; >> >> >> Since this change is specific to AMD, can you replace PATTR_MEM_ENCRYPT with >> prot_guest_has(PATTR_SME) || prot_guest_has(PATTR_SEV). It is not used in >> TDX. > > This is a direct replacement for now. I think the change you're requesting > should be done as part of the TDX support patches so it's clear why it is > being changed.
Ok. I will include it part of TDX changes.
> > But, wouldn't TDX still need to do something with this shared/unencrypted > area, though? Or since it is shared, there's actually nothing you need to > do (the bss decrpyted section exists even if CONFIG_AMD_MEM_ENCRYPT is not > configured)?
Kirill had a requirement to turn on CONFIG_AMD_MEM_ENCRYPT for adding lazy accept support in TDX guest kernel. Kirill, can you add details here?
> > Thanks, > Tom > >>
-- Sathyanarayanan Kuppuswamy Linux Kernel Developer
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