[PATCH 2/5] KVM: e500: use shadow TLB entry as witness for writability
From: Paolo Bonzini <pbonzini@redhat.com>
Date: 2025-01-12 09:55:41
Also in:
kvm, lkml, regressions
Subsystem:
kernel virtual machine for powerpc (kvm/powerpc), linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
kvmppc_e500_ref_setup is returning whether the guest TLB entry is writable, which is than passed to kvm_release_faultin_page. This makes little sense for two reasons: first, because the function sets up the private data for the page and the return value feels like it has been bolted on the side; second, because what really matters is whether the _shadow_ TLB entry is writable. If it is not writable, the page can be released as non-dirty. Shift from using tlbe_is_writable(gtlbe) to doing the same check on the shadow TLB entry. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- arch/powerpc/kvm/e500_mmu_host.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c
index 6824e8139801..c266c02f120f 100644
--- a/arch/powerpc/kvm/e500_mmu_host.c
+++ b/arch/powerpc/kvm/e500_mmu_host.c@@ -242,7 +242,7 @@ static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe) return tlbe->mas7_3 & (MAS3_SW|MAS3_UW); } -static inline bool kvmppc_e500_ref_setup(struct tlbe_ref *ref, +static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref, struct kvm_book3e_206_tlb_entry *gtlbe, kvm_pfn_t pfn, unsigned int wimg) {
@@ -251,8 +251,6 @@ static inline bool kvmppc_e500_ref_setup(struct tlbe_ref *ref, /* Use guest supplied MAS2_G and MAS2_E */ ref->flags |= (gtlbe->mas2 & MAS2_ATTRIB_MASK) | wimg; - - return tlbe_is_writable(gtlbe); } static inline void kvmppc_e500_ref_release(struct tlbe_ref *ref)
@@ -489,9 +487,10 @@ static inline int kvmppc_e500_shadow_map(struct kvmppc_vcpu_e500 *vcpu_e500, } local_irq_restore(flags); - writable = kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg); + kvmppc_e500_ref_setup(ref, gtlbe, pfn, wimg); kvmppc_e500_setup_stlbe(&vcpu_e500->vcpu, gtlbe, tsize, ref, gvaddr, stlbe); + writable = tlbe_is_writable(stlbe); /* Clear i-cache for new pages */ kvmppc_mmu_flush_icache(pfn);
--
2.47.1