KVM: MIPS/Emulate: Use lockless GVA helpers for cache emulation

Use the lockless GVA helpers to implement the reading of guest
instructions for emulation. This will allow it to handle asynchronous
TLB flushes when they are implemented.

This is a little more complicated than the other two cases (get_inst()
and dynamic translation) due to the need to emulate the appropriate
guest TLB exception when the address isn't present or isn't valid in the
guest TLB.

Since there are several protected cache ops that may need to be
performed safely, this is abstracted by kvm_mips_guest_cache_op() which
is passed a protected cache op function pointer and takes care of the
lockless operation and fault handling / retry if the op should fail,
taking advantage of the new errors which the protected cache ops can now
return. This allows the existing advance fault handling which relied on
host TLB lookups to be removed, along with the now unused
kvm_mips_host_tlb_lookup(),

Signed-off-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>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

1 files changed, 0 insertions, 35 deletions

diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index cee2e9feb942..2819eb793345 100644
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -117,41 +117,6 @@ int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
 }
 EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
 
-int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
-{
-	unsigned long old_entryhi, flags;
-	int idx;
-
-	local_irq_save(flags);
-
-	old_entryhi = read_c0_entryhi();
-
-	if (KVM_GUEST_KERNEL_MODE(vcpu))
-		write_c0_entryhi((vaddr & VPN2_MASK) |
-				 kvm_mips_get_kernel_asid(vcpu));
-	else {
-		write_c0_entryhi((vaddr & VPN2_MASK) |
-				 kvm_mips_get_user_asid(vcpu));
-	}
-
-	mtc0_tlbw_hazard();
-
-	tlb_probe();
-	tlb_probe_hazard();
-	idx = read_c0_index();
-
-	/* Restore old ASID */
-	write_c0_entryhi(old_entryhi);
-	mtc0_tlbw_hazard();
-
-	local_irq_restore(flags);
-
-	kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
-
-	return idx;
-}
-EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_lookup);
-
 static int _kvm_mips_host_tlb_inv(unsigned long entryhi)
 {
 	int idx;