When KVM emulates the RDHWR instruction, decode the instruction more
strictly. The rs field (bits 25:21) should be zero, as should bits 10:9.
Bits 8:6 is the register select field in MIPSr6, so we aren't strict
about those bits (no other operations should use that encoding space).
Signed-off-by: James Hogan <james.hogan@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim Krčmář <rkrcmar@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
---
arch/mips/kvm/emulate.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/mips/kvm/emulate.c b/arch/mips/kvm/emulate.c
index 62e6a7b313ae..be18dfe9ecaa 100644
--- a/arch/mips/kvm/emulate.c
+++ b/arch/mips/kvm/emulate.c
@@ -2357,7 +2357,9 @@ enum emulation_result kvm_mips_handle_ri(u32 cause, u32 *opc,
}
if (inst.r_format.opcode == spec3_op &&
- inst.r_format.func == rdhwr_op) {
+ inst.r_format.func == rdhwr_op &&
+ inst.r_format.rs == 0 &&
+ (inst.r_format.re >> 3) == 0) {
int usermode = !KVM_GUEST_KERNEL_MODE(vcpu);
int rd = inst.r_format.rd;
int rt = inst.r_format.rt;
--
2.4.10
