Use AMD SEV C-bit in inital page tables setup by locore0.

Similar to the NX-bit apply the C-bit to the PTEs built by locore0.
Right now, pg_crypt is initialized to 0, so nothing will change.

from hshoexer@; OK mlarkin@

diff --git a/sys/arch/amd64/amd64/locore0.S b/sys/arch/amd64/amd64/locore0.S
index b0f4f55..bbfed3a 100644 (file)
--- a/sys/arch/amd64/amd64/locore0.S
+++ b/sys/arch/amd64/amd64/locore0.S
@@ -1,4 +1,4 @@
-/*     $OpenBSD: locore0.S,v 1.23 2024/05/12 16:49:38 guenther Exp $   */
+/*     $OpenBSD: locore0.S,v 1.24 2024/07/10 12:36:13 bluhm Exp $      */
 /*     $NetBSD: locore.S,v 1.13 2004/03/25 18:33:17 drochner Exp $     */
 
 /*
@@ -314,17 +314,21 @@ cont:
        NDML3_ENTRIES + NDML2_ENTRIES + 3) * NBPG)
 
 #define fillkpt \
-1:     movl    %eax,(%ebx)     ;       /* store phys addr */ \
-       movl    $0,4(%ebx)      ;       /* upper 32 bits 0 */ \
-       addl    $8,%ebx         ;       /* next pte/pde */ \
-       addl    $NBPG,%eax      ;       /* next phys page */ \
-       loop    1b              ;       /* till finished */
+       pushl   %ebp                            ;       /* save */ \
+       movl    RELOC((pg_crypt + 4)), %ebp     ;       /* C bit? */ \
+1:     movl    %eax,(%ebx)                     ;       /* store phys addr */ \
+       movl    %ebp,4(%ebx)                    ;       /* upper 32 bits */ \
+       addl    $8,%ebx                         ;       /* next pte/pde */ \
+       addl    $NBPG,%eax                      ;       /* next phys page */ \
+       loop    1b                              ;       /* till finished */ \
+       popl    %ebp                            ;       /* restore */
 
 
 #define fillkpt_nx \
        pushl   %ebp                            ;       /* save */ \
-1:     movl    %eax,(%ebx)                     ;       /* store phys addr */ \
        movl    RELOC((pg_nx + 4)), %ebp        ;       /* NX bit? */ \
+       orl     RELOC((pg_crypt + 4)), %ebp     ;       /* C bit? */ \
+1:     movl    %eax,(%ebx)                     ;       /* store phys addr */ \
        movl    %ebp,4(%ebx)                    ;       /* upper 32 bits */ \
        addl    $8,%ebx                         ;       /* next pte/pde */ \
        addl    $NBPG,%eax                      ;       /* next phys page */ \
@@ -510,6 +514,7 @@ store_pte:
        movl    %eax, (%ebx)
        pushl   %ebp
        movl    RELOC((pg_nx + 4)), %ebp
+       orl     RELOC((pg_crypt + 4)), %ebp
        movl    %ebp, 4(%ebx)
        popl    %ebp
        addl    $8, %ebx
@@ -535,6 +540,7 @@ store_pte:
        movl    %eax,(%ebx)
        pushl   %ebp
        movl    RELOC((pg_nx + 4)), %ebp
+       orl     RELOC((pg_crypt + 4)), %ebp
        movl    %ebp, 4(%ebx)
        popl    %ebp