[PATCH v7 2/5] x86/mm: Enhance sme_populate_pgd() to update page flags

From: Brijesh Singh
Date: Mon Sep 10 2018 - 17:49:37 EST


Enhance sme_populate_pgd() to update page flags if the PMD/PTE entry
already exists.

Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Reviewed-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Fixes: 6ebcb060713f ("x86/mm: Add support to encrypt the kernel in-place")
Cc: Tom Lendacky <thomas.lendacky@xxxxxxx>
Cc: kvm@xxxxxxxxxxxxxxx
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Cc: "Radim KrÄmÃÅ" <rkrcmar@xxxxxxxxxx>
---
arch/x86/mm/mem_encrypt_identity.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/x86/mm/mem_encrypt_identity.c b/arch/x86/mm/mem_encrypt_identity.c
index f488d46..2b245af 100644
--- a/arch/x86/mm/mem_encrypt_identity.c
+++ b/arch/x86/mm/mem_encrypt_identity.c
@@ -155,9 +155,6 @@ static void __init sme_populate_pgd_large(struct sme_populate_pgd_data *ppd)
return;

pmd = pmd_offset(pud, ppd->vaddr);
- if (pmd_large(*pmd))
- return;
-
set_pmd(pmd, __pmd(ppd->paddr | ppd->pmd_flags));
}

@@ -183,8 +180,7 @@ static void __init sme_populate_pgd(struct sme_populate_pgd_data *ppd)
return;

pte = pte_offset_map(pmd, ppd->vaddr);
- if (pte_none(*pte))
- set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
+ set_pte(pte, __pte(ppd->paddr | ppd->pte_flags));
}

static void __init __sme_map_range_pmd(struct sme_populate_pgd_data *ppd)
--
2.7.4