summaryrefslogtreecommitdiffstats
path: root/arch/mips/kvm/mips.c
diff options
context:
space:
mode:
authorJames Hogan2015-02-06 17:03:57 +0100
committerJames Hogan2015-03-27 22:25:07 +0100
commit0a5604272d80c985f87de959f0bb7e36fd53d3c7 (patch)
tree391bbee989a6ab6ab22d7b4b32a0b7850602d5be /arch/mips/kvm/mips.c
parentMIPS: Clear [MSA]FPE CSR.Cause after notify_die() (diff)
downloadkernel-qcow2-linux-0a5604272d80c985f87de959f0bb7e36fd53d3c7.tar.gz
kernel-qcow2-linux-0a5604272d80c985f87de959f0bb7e36fd53d3c7.tar.xz
kernel-qcow2-linux-0a5604272d80c985f87de959f0bb7e36fd53d3c7.zip
MIPS: KVM: Handle TRAP exceptions from guest kernel
Trap instructions are used by Linux to implement BUG_ON(), however KVM doesn't pass trap exceptions on to the guest if they occur in guest kernel mode, instead triggering an internal error "Exception Code: 13, not yet handled". The guest kernel then doesn't get a chance to print the usual BUG message and stack trace. Implement handling of the trap exception so that it gets passed to the guest and the user is left with a more useful log message. Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Gleb Natapov <gleb@kernel.org> Cc: kvm@vger.kernel.org Cc: linux-mips@linux-mips.org
Diffstat (limited to 'arch/mips/kvm/mips.c')
-rw-r--r--arch/mips/kvm/mips.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index f5e7ddab02f7..399b5517ecb8 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -48,6 +48,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
{ "syscall", VCPU_STAT(syscall_exits), KVM_STAT_VCPU },
{ "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 },
{ "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 },
@@ -1119,6 +1120,12 @@ int kvm_mips_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu)
ret = kvm_mips_callbacks->handle_break(vcpu);
break;
+ case T_TRAP:
+ ++vcpu->stat.trap_inst_exits;
+ trace_kvm_exit(vcpu, TRAP_INST_EXITS);
+ ret = kvm_mips_callbacks->handle_trap(vcpu);
+ break;
+
case T_MSADIS:
ret = kvm_mips_callbacks->handle_msa_disabled(vcpu);
break;