KVM: MIPS/MMU: Convert commpage fault handling to page tables

Now that we have GVA page tables and an optimised TLB refill handler in
place, convert the handling of commpage faults from the guest kernel to
fill the GVA page table and invalidate the TLB entry, rather than
filling the wired TLB entry directly.

For simplicity we no longer use a wired entry for the commpage (refill
should be much cheaper with the fast-path handler anyway). Since we
don't need to manipulate the TLB directly any longer, move the function
from tlb.c to mmu.c. This puts it closer to the similar functions
handling KSeg0 and TLB mapped page faults from the guest.

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, 1 insertions, 33 deletions

diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index c369fdd19fbc..c4fc52e39f34 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -92,28 +92,10 @@ void kvm_arch_check_processor_compat(void *rtn)
 	*(int *)rtn = 0;
 }
 
-static void kvm_mips_init_tlbs(struct kvm *kvm)
-{
-	unsigned long wired;
-
-	/*
-	 * Add a wired entry to the TLB, it is used to map the commpage to
-	 * the Guest kernel
-	 */
-	wired = read_c0_wired();
-	write_c0_wired(wired + 1);
-	mtc0_tlbw_hazard();
-	kvm->arch.commpage_tlb = wired;
-
-	kvm_debug("[%d] commpage TLB: %d\n", smp_processor_id(),
-		  kvm->arch.commpage_tlb);
-}
-
 static void kvm_mips_init_vm_percpu(void *arg)
 {
 	struct kvm *kvm = (struct kvm *)arg;
 
-	kvm_mips_init_tlbs(kvm);
 	kvm_mips_callbacks->vm_init(kvm);
 
 }
@@ -165,25 +147,11 @@ void kvm_mips_free_vcpus(struct kvm *kvm)
 	mutex_unlock(&kvm->lock);
 }
 
-static void kvm_mips_uninit_tlbs(void *arg)
-{
-	/* Restore wired count */
-	write_c0_wired(0);
-	mtc0_tlbw_hazard();
-	/* Clear out all the TLBs */
-	kvm_local_flush_tlb_all();
-}
-
 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
 	kvm_mips_free_vcpus(kvm);
 
-	/* If this is the last instance, restore wired count */
-	if (atomic_dec_return(&kvm_mips_instance) == 0) {
-		kvm_debug("%s: last KVM instance, restoring TLB parameters\n",
-			  __func__);
-		on_each_cpu(kvm_mips_uninit_tlbs, NULL, 1);
-	}
+	atomic_dec(&kvm_mips_instance);
 }
 
 long kvm_arch_dev_ioctl(struct file *filp, unsigned int ioctl,