MIPS: KVM: remove shadow_tlb code

The kvm_mips_init_shadow_tlb() function is called from
kvm_arch_vcpu_init() and initialises entries 0 to
current_cpu_data.tlbsize-1 of the virtual cpu's shadow_tlb[64] array.

However newer cores with FTLBs can have a tlbsize > 64, for example the
ProAptiv I'm testing on has a total tlbsize of 576. This causes
kvm_mips_init_shadow_tlb() to overflow the shadow_tlb[64] array and
overwrite the comparecount_timer among other things, causing a lock up
when starting a KVM guest.

Aside from kvm_mips_init_shadow_tlb() which only initialises it, the
shadow_tlb[64] array is only actually used by the following functions:
 - kvm_shadow_tlb_put() & kvm_shadow_tlb_load()
     These are never called. The only call sites are #if 0'd out.
 - kvm_mips_dump_shadow_tlbs()
     This is never called.

It was originally added for trap & emulate, but turned out to be
unnecessary so it was disabled.

So instead of fixing the shadow_tlb initialisation code, lets just
remove the shadow_tlb[64] array and the above functions entirely. The
only functional change here is the removal of broken shadow_tlb
initialisation. The rest just deletes dead code.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: linux-mips@linux-mips.org
Cc: Gleb Natapov <gleb@redhat.com>
Cc: kvm@vger.kernel.org
Cc: Sanjay Lal <sanjayl@kymasys.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/6384/

1 files changed, 0 insertions, 7 deletions

diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 32966969f2f..a995fce8779 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -391,9 +391,6 @@ struct kvm_vcpu_arch {
 	uint32_t guest_kernel_asid[NR_CPUS];
 	struct mm_struct guest_kernel_mm, guest_user_mm;
 
-	struct kvm_mips_tlb shadow_tlb[NR_CPUS][KVM_MIPS_GUEST_TLB_SIZE];
-
-
 	struct hrtimer comparecount_timer;
 
 	int last_sched_cpu;
@@ -529,7 +526,6 @@ extern enum emulation_result kvm_mips_handle_tlbmod(unsigned long cause,
 
 extern void kvm_mips_dump_host_tlbs(void);
 extern void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu);
-extern void kvm_mips_dump_shadow_tlbs(struct kvm_vcpu *vcpu);
 extern void kvm_mips_flush_host_tlb(int skip_kseg0);
 extern int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long entryhi);
 extern int kvm_mips_host_tlb_inv_index(struct kvm_vcpu *vcpu, int index);
@@ -541,10 +537,7 @@ extern unsigned long kvm_mips_translate_guest_kseg0_to_hpa(struct kvm_vcpu *vcpu
 						   unsigned long gva);
 extern void kvm_get_new_mmu_context(struct mm_struct *mm, unsigned long cpu,
 				    struct kvm_vcpu *vcpu);
-extern void kvm_shadow_tlb_put(struct kvm_vcpu *vcpu);
-extern void kvm_shadow_tlb_load(struct kvm_vcpu *vcpu);
 extern void kvm_local_flush_tlb_all(void);
-extern void kvm_mips_init_shadow_tlb(struct kvm_vcpu *vcpu);
 extern void kvm_mips_alloc_new_mmu_context(struct kvm_vcpu *vcpu);
 extern void kvm_mips_vcpu_load(struct kvm_vcpu *vcpu, int cpu);
 extern void kvm_mips_vcpu_put(struct kvm_vcpu *vcpu);