From 1c0cd66adbac8aa339b9521eceb18b00d1b0699e Mon Sep 17 00:00:00 2001
From: James Hogan <james.hogan@imgtec.com>
Date: Fri, 6 Feb 2015 10:56:27 +0000
Subject: MIPS: KVM: Add FP exception handling
Add guest exception handling for floating point exceptions and
coprocessor 1 unusable exceptions.
Floating point exceptions from the guest need passing to the guest
kernel, so for these a guest FPE is emulated.
Also, coprocessor 1 unusable exceptions are normally passed straight
through to the guest (because no guest FPU was supported), but the
hypervisor can now handle them if the guest has its FPU enabled by
restoring the guest FPU context and enabling the FPU.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: linux-mips@linux-mips.org
Cc: kvm@vger.kernel.org
---
arch/mips/kvm/mips.c | 7 +++++++
1 file changed, 7 insertions(+)
(limited to 'arch/mips/kvm/mips.c')
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index b26a48d81467..dd0833833bea 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -50,6 +50,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "resvd_inst", VCPU_STAT(resvd_inst_exits), KVM_STAT_VCPU },
{ "break_inst", VCPU_STAT(break_inst_exits), KVM_STAT_VCPU },
{ "trap_inst", VCPU_STAT(trap_inst_exits), KVM_STAT_VCPU },
+ { "fpe", VCPU_STAT(fpe_exits), KVM_STAT_VCPU },
{ "flush_dcache", VCPU_STAT(flush_dcache_exits), KVM_STAT_VCPU },
{ "halt_successful_poll", VCPU_STAT(halt_successful_poll), KVM_STAT_VCPU },
{ "halt_wakeup", VCPU_STAT(halt_wakeup), KVM_STAT_VCPU },
@@ -1148,6 +1149,12 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
ret = kvm_mips_callbacks->handle_trap(vcpu);
break;
+ case T_FPE:
+ ++vcpu->stat.fpe_exits;
+ trace_kvm_exit(vcpu, FPE_EXITS);
+ ret = kvm_mips_callbacks->handle_fpe(vcpu);
+ break;
+
case T_MSADIS:
ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
break;
--
cgit