From: James Hogan Date: Fri, 16 Sep 2016 12:14:09 +0000 (+0100) Subject: KVM: MIPS: Drop dubious EntryHi optimisation X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=bf18db4e7bd99f3a65bcc43225790b16af733321;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git KVM: MIPS: Drop dubious EntryHi optimisation There exists a slightly dubious optimisation in the implementation of the MIPS KVM EntryHi emulation which skips TLB invalidation if the EntryHi points to an address in the guest KSeg0 region, intended to catch guest TLB invalidations where the ASID is almost immediately restored to the previous value. Now that we perform lazy host ASID regeneration for guest user mode when the guest ASID changes we should be able to drop the optimisation without a significant impact (only the extra TLB refills for the small amount of code while the TLB is being invalidated). Signed-off-by: James Hogan Cc: Paolo Bonzini Cc: "Radim Krčmář" Cc: Ralf Baechle Cc: linux-mips@linux-mips.org Cc: kvm@vger.kernel.org --- diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c index 8dc9e64346e6..4db4c0370859 100644 --- a/arch/mips/kvm/emulate.c +++ b/arch/mips/kvm/emulate.c @@ -1162,8 +1162,7 @@ enum emulation_result kvm_mips_emulate_CP0(union mips_instruction inst, } else if (rd == MIPS_CP0_TLB_HI && sel == 0) { u32 nasid = vcpu->arch.gprs[rt] & KVM_ENTRYHI_ASID; - if ((KSEGX(vcpu->arch.gprs[rt]) != CKSEG0) && - ((kvm_read_c0_guest_entryhi(cop0) & + if (((kvm_read_c0_guest_entryhi(cop0) & KVM_ENTRYHI_ASID) != nasid)) { trace_kvm_asid_change(vcpu, kvm_read_c0_guest_entryhi(cop0)