From: Bharat Bhushan Date: Fri, 15 Nov 2013 05:31:13 +0000 (+0530) Subject: kvm: booke: clear host tlb reference flag on guest tlb invalidation X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=30a91fe24b7a6475d22d22fb0f772318ed435a1d;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git kvm: booke: clear host tlb reference flag on guest tlb invalidation On booke, "struct tlbe_ref" contains host tlb mapping information (pfn: for guest-pfn to pfn, flags: attribute associated with this mapping) for a guest tlb entry. So when a guest creates a TLB entry then "struct tlbe_ref" is set to point to valid "pfn" and set attributes in "flags" field of the above said structure. When a guest TLB entry is invalidated then flags field of corresponding "struct tlbe_ref" is updated to point that this is no more valid, also we selectively clear some other attribute bits, example: if E500_TLB_BITMAP was set then we clear E500_TLB_BITMAP, if E500_TLB_TLB0 is set then we clear this. Ideally we should clear complete "flags" as this entry is invalid and does not have anything to re-used. The other part of the problem is that when we use the same entry again then also we do not clear (started doing or-ing etc). So far it was working because the selectively clearing mentioned above actually clears "flags" what was set during TLB mapping. But the problem starts coming when we add more attributes to this then we need to selectively clear them and which is not needed. Signed-off-by: Bharat Bhushan Reviewed-by: Scott Wood Signed-off-by: Alexander Graf --- diff --git a/arch/powerpc/kvm/e500_mmu_host.c b/arch/powerpc/kvm/e500_mmu_host.c index ecf2247b13be..a45e25cd78fc 100644 --- a/arch/powerpc/kvm/e500_mmu_host.c +++ b/arch/powerpc/kvm/e500_mmu_host.c @@ -231,15 +231,15 @@ void inval_gtlbe_on_host(struct kvmppc_vcpu_e500 *vcpu_e500, int tlbsel, ref->flags &= ~(E500_TLB_TLB0 | E500_TLB_VALID); } - /* Already invalidated in between */ - if (!(ref->flags & E500_TLB_VALID)) - return; - - /* Guest tlbe is backed by at most one host tlbe per shadow pid. */ - kvmppc_e500_tlbil_one(vcpu_e500, gtlbe); + /* + * If TLB entry is still valid then it's a TLB0 entry, and thus + * backed by at most one host tlbe per shadow pid + */ + if (ref->flags & E500_TLB_VALID) + kvmppc_e500_tlbil_one(vcpu_e500, gtlbe); /* Mark the TLB as not backed by the host anymore */ - ref->flags &= ~E500_TLB_VALID; + ref->flags = 0; } static inline int tlbe_is_writable(struct kvm_book3e_206_tlb_entry *tlbe) @@ -252,7 +252,7 @@ static inline void kvmppc_e500_ref_setup(struct tlbe_ref *ref, pfn_t pfn) { ref->pfn = pfn; - ref->flags |= E500_TLB_VALID; + ref->flags = E500_TLB_VALID; /* Mark the page accessed */ kvm_set_pfn_accessed(pfn);