KVM: MIPS/VZ: Emulate hit CACHE ops for Octeon III

Octeon III doesn't implement the optional GuestCtl0.CG bit to allow
guest mode to execute virtual address based CACHE instructions, so
implement emulation of a few important ones specifically for Octeon III
in response to a GPSI exception.

Currently the main reason to perform these operations is for icache
synchronisation, so they are implemented as a simple icache flush with
local_flush_icache_range().

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

diff --git a/arch/mips/kvm/vz.c b/arch/mips/kvm/vz.c
index 21f4495feb152c7c0e9f33551126047329e23692..5c495277bf4401a270cc43f93313f28385680838 100644 (file)
--- a/arch/mips/kvm/vz.c
+++ b/arch/mips/kvm/vz.c
@@ -1105,6 +1105,17 @@ static enum emulation_result kvm_vz_gpsi_cache(union mips_instruction inst,
        case Index_Writeback_Inv_D:
                flush_dcache_line_indexed(va);
                return EMULATE_DONE;
+       case Hit_Invalidate_I:
+       case Hit_Invalidate_D:
+       case Hit_Writeback_Inv_D:
+               if (boot_cpu_type() == CPU_CAVIUM_OCTEON3) {
+                       /* We can just flush entire icache */
+                       local_flush_icache_range(0, 0);
+                       return EMULATE_DONE;
+               }
+
+               /* So far, other platforms support guest hit cache ops */
+               break;
        default:
                break;
        };