git: 3d0399c718b2 - main - [PowerPC64] Clear low-order bits of ARPN

[Leandro Lupori]

The branch main has been updated by luporl:

URL: https://cgit.FreeBSD.org/src/commit/?id=3d0399c718b260da087d28825069f26d4f670065

commit 3d0399c718b260da087d28825069f26d4f670065
Author:     Leandro Lupori <luporl at FreeBSD.org>
AuthorDate: 2021-03-25 16:30:56 +0000
Commit:     Leandro Lupori <luporl at FreeBSD.org>
CommitDate: 2021-03-25 17:01:57 +0000

    [PowerPC64] Clear low-order bits of ARPN
    
    PowerISA 2.07B says that the low-order p-12 bits of the real page number
    contained in ARPN and LP fields of a PTE must be 0s and are ignored
    by the hardware (Book III-S, 5.7.7.1), where 2^p is the actual page size
    in bytes, but we were clearing only the LP field.
    
    This worked on bare metal and QEMU with KVM, that ignore these bits,
    but caused a kernel panic on QEMU with TCG, that expects them to be
    cleared.
    
    This fixes running FreeBSD with HPT superpages enabled on QEMU
    with TCG.
    
    MFC after:      2 weeks
    Sponsored by:   Eldorado Research Institute (eldorado.org.br)
---
 sys/powerpc/aim/mmu_oea64.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sys/powerpc/aim/mmu_oea64.c b/sys/powerpc/aim/mmu_oea64.c
index 14fea6f29a52..1aa05501bd1b 100644
--- a/sys/powerpc/aim/mmu_oea64.c
+++ b/sys/powerpc/aim/mmu_oea64.c
@@ -3717,7 +3717,7 @@ moea64_sp_enter(pmap_t pmap, vm_offset_t va, vm_page_t m,
 		pvo = pvos[i];
 
 		pvo->pvo_pte.prot = prot;
-		pvo->pvo_pte.pa = (pa & ~LPTE_LP_MASK) | LPTE_LP_4K_16M |
+		pvo->pvo_pte.pa = (pa & ~HPT_SP_MASK) | LPTE_LP_4K_16M |
 		    moea64_calc_wimg(pa, pmap_page_get_memattr(m));
 
 		if ((flags & PMAP_ENTER_WIRED) != 0)
@@ -3874,7 +3874,7 @@ moea64_sp_promote(pmap_t pmap, vm_offset_t va, vm_page_t m)
 	for (pvo = first, va_end = PVO_VADDR(pvo) + HPT_SP_SIZE;
 	    pvo != NULL && PVO_VADDR(pvo) < va_end;
 	    pvo = RB_NEXT(pvo_tree, &pmap->pmap_pvo, pvo)) {
-		pvo->pvo_pte.pa &= ~LPTE_LP_MASK;
+		pvo->pvo_pte.pa &= ADDR_POFF | ~HPT_SP_MASK;
 		pvo->pvo_pte.pa |= LPTE_LP_4K_16M;
 		pvo->pvo_vaddr |= PVO_LARGE;
 	}