linux/arch/mips/kvm/stats.c
James Hogan 0a5604272d 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
2015-03-27 21:25:07 +00:00

82 lines
1.4 KiB
C

/*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* KVM/MIPS: COP0 access histogram
*
* Copyright (C) 2012 MIPS Technologies, Inc. All rights reserved.
* Authors: Sanjay Lal <sanjayl@kymasys.com>
*/
#include <linux/kvm_host.h>
char *kvm_mips_exit_types_str[MAX_KVM_MIPS_EXIT_TYPES] = {
"WAIT",
"CACHE",
"Signal",
"Interrupt",
"COP0/1 Unusable",
"TLB Mod",
"TLB Miss (LD)",
"TLB Miss (ST)",
"Address Err (ST)",
"Address Error (LD)",
"System Call",
"Reserved Inst",
"Break Inst",
"Trap Inst",
"D-Cache Flushes",
};
char *kvm_cop0_str[N_MIPS_COPROC_REGS] = {
"Index",
"Random",
"EntryLo0",
"EntryLo1",
"Context",
"PG Mask",
"Wired",
"HWREna",
"BadVAddr",
"Count",
"EntryHI",
"Compare",
"Status",
"Cause",
"EXC PC",
"PRID",
"Config",
"LLAddr",
"Watch Lo",
"Watch Hi",
"X Context",
"Reserved",
"Impl Dep",
"Debug",
"DEPC",
"PerfCnt",
"ErrCtl",
"CacheErr",
"TagLo",
"TagHi",
"ErrorEPC",
"DESAVE"
};
void kvm_mips_dump_stats(struct kvm_vcpu *vcpu)
{
#ifdef CONFIG_KVM_MIPS_DEBUG_COP0_COUNTERS
int i, j;
kvm_info("\nKVM VCPU[%d] COP0 Access Profile:\n", vcpu->vcpu_id);
for (i = 0; i < N_MIPS_COPROC_REGS; i++) {
for (j = 0; j < N_MIPS_COPROC_SEL; j++) {
if (vcpu->arch.cop0->stat[i][j])
kvm_info("%s[%d]: %lu\n", kvm_cop0_str[i], j,
vcpu->arch.cop0->stat[i][j]);
}
}
#endif
}