KVM: MIPS/TLB: Handle virtually tagged icaches

When TLB entries are invalidated in the presence of a virtually tagged
icache, such as that found on Octeon CPUs, flush the icache so that we
don't get a reserved instruction exception even though the TLB mapping
is removed.

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: David Daney <david.daney@cavium.com>
Cc: Andreas Herrmann <andreas.herrmann@caviumnetworks.com>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org

1 files changed, 14 insertions, 0 deletions

diff --git a/arch/mips/kvm/tlb.c b/arch/mips/kvm/tlb.c
index c215470fdcb0..fbab2f747721 100644
--- a/arch/mips/kvm/tlb.c
+++ b/arch/mips/kvm/tlb.c
@@ -185,6 +185,13 @@ int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va,
 
         local_irq_restore(flags);
 
+        /*
+         * We don't want to get reserved instruction exceptions for missing tlb
+         * entries.
+         */
+        if (cpu_has_vtag_icache)
+                flush_icache_all();
+
         if (user && idx_user >= 0)
                 kvm_debug("%s: Invalidated guest user entryhi %#lx @ idx %d\n",
                           __func__, (va & VPN2_MASK) |
@@ -260,6 +267,13 @@ int kvm_vz_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
         htw_start();
         local_irq_restore(flags);
 
+        /*
+         * We don't want to get reserved instruction exceptions for missing tlb
+         * entries.
+         */
+        if (cpu_has_vtag_icache)
+                flush_icache_all();
+
         if (idx > 0)
                 kvm_debug("%s: Invalidated root entryhi %#lx @ idx %d\n",
                           __func__, (va & VPN2_MASK) |