Revert KVM: MIPS: Drop other CPU ASIDs on guest MMU changes

This reverts commit d450527ad04ad180636679aeb3161ec58079f1ba which was
commit 91e4f1b6073dd680d86cdb7e42d7cccca9db39d8 upstream as it was
incorrect.  A fixed version will be forthcoming.

Reported-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Radim Krčmář" <rkrcmar@redhat.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index bbe5687..ef4fbeb 100644 (file)
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -807,47 +807,6 @@ enum emulation_result kvm_mips_emul_tlbr(struct kvm_vcpu *vcpu)
        return EMULATE_FAIL;
 }
 
-/**
- * kvm_mips_invalidate_guest_tlb() - Indicates a change in guest MMU map.
- * @vcpu:      VCPU with changed mappings.
- * @tlb:       TLB entry being removed.
- *
- * This is called to indicate a single change in guest MMU mappings, so that we
- * can arrange TLB flushes on this and other CPUs.
- */
-static void kvm_mips_invalidate_guest_tlb(struct kvm_vcpu *vcpu,
-                                         struct kvm_mips_tlb *tlb)
-{
-       int cpu, i;
-       bool user;
-
-       /* No need to flush for entries which are already invalid */
-       if (!((tlb->tlb_lo[0] | tlb->tlb_lo[1]) & ENTRYLO_V))
-               return;
-       /* User address space doesn't need flushing for KSeg2/3 changes */
-       user = tlb->tlb_hi < KVM_GUEST_KSEG0;
-
-       preempt_disable();
-
-       /*
-        * Probe the shadow host TLB for the entry being overwritten, if one
-        * matches, invalidate it
-        */
-       kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
-
-       /* Invalidate the whole ASID on other CPUs */
-       cpu = smp_processor_id();
-       for_each_possible_cpu(i) {
-               if (i == cpu)
-                       continue;
-               if (user)
-                       vcpu->arch.guest_user_asid[i] = 0;
-               vcpu->arch.guest_kernel_asid[i] = 0;
-       }
-
-       preempt_enable();
-}
-
 /* Write Guest TLB Entry @ Index */
 enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
 {
@@ -867,8 +826,11 @@ enum emulation_result kvm_mips_emul_tlbwi(struct kvm_vcpu *vcpu)
        }
 
        tlb = &vcpu->arch.guest_tlb[index];
-
-       kvm_mips_invalidate_guest_tlb(vcpu, tlb);
+       /*
+        * Probe the shadow host TLB for the entry being overwritten, if one
+        * matches, invalidate it
+        */
+       kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 
        tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
        tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
@@ -897,7 +859,11 @@ enum emulation_result kvm_mips_emul_tlbwr(struct kvm_vcpu *vcpu)
 
        tlb = &vcpu->arch.guest_tlb[index];
 
-       kvm_mips_invalidate_guest_tlb(vcpu, tlb);
+       /*
+        * Probe the shadow host TLB for the entry being overwritten, if one
+        * matches, invalidate it
+        */
+       kvm_mips_host_tlb_inv(vcpu, tlb->tlb_hi);
 
        tlb->tlb_mask = kvm_read_c0_guest_pagemask(cop0);
        tlb->tlb_hi = kvm_read_c0_guest_entryhi(cop0);
@@ -1016,7 +982,6 @@ enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
        int32_t rt, rd, copz, sel, co_bit, op;
        uint32_t pc = vcpu->arch.pc;
        unsigned long curr_pc;
-       int cpu, i;
 
        /*
         * Update PC and hold onto current PC in case there is
@@ -1124,16 +1089,8 @@ enum emulation_result kvm_mips_emulate_CP0(uint32_t inst, uint32_t *opc,
                                                vcpu->arch.gprs[rt]
                                                & ASID_MASK);
 
-                                       preempt_disable();
                                        /* Blow away the shadow host TLBs */
                                        kvm_mips_flush_host_tlb(1);
-                                       cpu = smp_processor_id();
-                                       for_each_possible_cpu(i)
-                                               if (i != cpu) {
-                                                       vcpu->arch.guest_user_asid[i] = 0;
-                                                       vcpu->arch.guest_kernel_asid[i] = 0;
-                                               }
-                                       preempt_enable();
                                }
                                kvm_write_c0_guest_entryhi(cop0,
                                                           vcpu->arch.gprs[rt]);