lkml.org 
[lkml]   [2021]   [Dec]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH v8 09/40] x86/compressed: Add helper for validating pages in the decompression stage
    On Fri, Dec 10, 2021 at 09:43:01AM -0600, Brijesh Singh wrote:
    > diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c
    > index f7213d0943b8..ef77453cc629 100644
    > --- a/arch/x86/boot/compressed/ident_map_64.c
    > +++ b/arch/x86/boot/compressed/ident_map_64.c
    > @@ -275,15 +275,31 @@ static int set_clr_page_flags(struct x86_mapping_info *info,
    > * Changing encryption attributes of a page requires to flush it from
    > * the caches.
    > */
    > - if ((set | clr) & _PAGE_ENC)
    > + if ((set | clr) & _PAGE_ENC) {
    > clflush_page(address);
    >
    > + /*
    > + * If the encryption attribute is being cleared, then change
    > + * the page state to shared in the RMP table.
    > + */
    > + if (clr)
    > + snp_set_page_shared(pte_pfn(*ptep) << PAGE_SHIFT);

    You forgot to change that one.

    > + }
    > +
    > /* Update PTE */
    > pte = *ptep;
    > pte = pte_set_flags(pte, set);
    > pte = pte_clear_flags(pte, clr);
    > set_pte(ptep, pte);
    >
    > + /*
    > + * If the encryption attribute is being set, then change the page state to
    > + * private in the RMP entry. The page state must be done after the PTE
    ^
    change

    Geez, tell me, why should I be even bothering to review stuff if I have
    to go look at the previous review I did and find that you haven't really
    addressed it?!

    > diff --git a/arch/x86/include/asm/sev-common.h b/arch/x86/include/asm/sev-common.h
    > index 7ac5842e32b6..a2f956cfafba 100644
    > --- a/arch/x86/include/asm/sev-common.h
    > +++ b/arch/x86/include/asm/sev-common.h
    > @@ -57,6 +57,32 @@
    > #define GHCB_MSR_AP_RESET_HOLD_REQ 0x006
    > #define GHCB_MSR_AP_RESET_HOLD_RESP 0x007
    >
    > +/*
    > + * SNP Page State Change Operation
    > + *
    > + * GHCBData[55:52] - Page operation:
    > + * 0x0001 – Page assignment, Private
    > + * 0x0002 – Page assignment, Shared

    I wonder how you've achieved that:

    massage_diff: Warning: Unicode char [–] (0x2013) in line: + * 0x0001 – Page assignment, Private
    massage_diff: Warning: Unicode char [–] (0x2013) in line: + * 0x0002 – Page assignment, Shared

    See https://trojansource.codes/ for some background.

    --
    Regards/Gruss,
    Boris.

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

    \
     
     \ /
      Last update: 2021-12-21 14:02    [W:2.272 / U:2.244 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site