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[v2,8/9] KVM: PPC: Book3S HV: radix refine IO region partition scope attributes

Message ID 20180509022022.21226-9-npiggin@gmail.com
State Superseded
Headers show
Series assorted radix fixes and improvemets for page fault and invalidation | expand

Commit Message

Nicholas Piggin May 9, 2018, 2:20 a.m. UTC 
When the radix fault handler has no page from the process address
space (e.g., for IO memory), it looks up the process pte and sets
partition table pte using that to get attributes like CI and guarded.
If the process table entry is to be writable, set _PAGE_DIRTY as well
to avoid an RC update. If not, then ensure _PAGE_DIRTY does not come
across. Set _PAGE_ACCESSED as well to avoid RC update.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
 arch/powerpc/kvm/book3s_64_mmu_radix.c | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)
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Patch

diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c
index aff82fd3a4d3..cfd206370086 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_radix.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c
@@ -662,9 +662,13 @@  int kvmppc_book3s_radix_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			unsigned long mask = (1ul << shift) - PAGE_SIZE;
 			pte = __pte(pte_val(pte) | (hva & mask));
 		}
-		if (!(writing || upgrade_write))
-			pte = __pte(pte_val(pte) & ~ _PAGE_WRITE);
-		pte = __pte(pte_val(pte) | _PAGE_EXEC);
+		pte = __pte(pte_val(pte) | _PAGE_EXEC | _PAGE_ACCESSED);
+		if (writing || upgrade_write) {
+			if (pte_val(pte) & _PAGE_WRITE)
+				pte = __pte(pte_val(pte) | _PAGE_DIRTY);
+		} else {
+			pte = __pte(pte_val(pte) & ~(_PAGE_WRITE | _PAGE_DIRTY));
+		}
 	}
 
 	/* Allocate space in the tree and write the PTE */