Commit 7c1bd80c authored by Nicholas Piggin's avatar Nicholas Piggin Committed by Paul Mackerras

KVM: PPC: Book3S HV: Send kvmppc_bad_interrupt NMIs to Linux handlers

It's possible to take a SRESET or MCE in these paths due to a bug
in the host code or a NMI IPI, etc. A recent bug attempting to load
a virtual address from real mode gave th complete but cryptic error,
abridged:

      Oops: Bad interrupt in KVM entry/exit code, sig: 6 [#1]
      LE SMP NR_CPUS=2048 NUMA PowerNV
      CPU: 53 PID: 6582 Comm: qemu-system-ppc Not tainted
      NIP:  c0000000000155ac LR: c0000000000c2430 CTR: c000000000015580
      REGS: c000000fff76dd80 TRAP: 0200   Not tainted
      MSR:  9000000000201003 <SF,HV,ME,RI,LE>  CR: 48082222  XER: 00000000
      CFAR: 0000000102900ef0 DAR: d00017fffd941a28 DSISR: 00000040 SOFTE: 3
      NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
      LR [c0000000000c2430] do_tlbies+0x230/0x2f0

Sending the NMIs through the Linux handlers gives a nicer output:

      Severe Machine check interrupt [Not recovered]
        NIP [c0000000000155ac]: perf_trace_tlbie+0x2c/0x1a0
        Initiator: CPU
        Error type: Real address [Load (bad)]
          Effective address: d00017fffcc01a28
      opal: Machine check interrupt unrecoverable: MSR(RI=0)
      opal: Hardware platform error: Unrecoverable Machine Check exception
      CPU: 0 PID: 6700 Comm: qemu-system-ppc Tainted: G   M
      NIP:  c0000000000155ac LR: c0000000000c23c0 CTR: c000000000015580
      REGS: c000000fff9e9d80 TRAP: 0200   Tainted: G   M
      MSR:  9000000000201001 <SF,HV,ME,LE>  CR: 48082222  XER: 00000000
      CFAR: 000000010cbc1a30 DAR: d00017fffcc01a28 DSISR: 00000040 SOFTE: 3
      NIP [c0000000000155ac] perf_trace_tlbie+0x2c/0x1a0
      LR [c0000000000c23c0] do_tlbies+0x1c0/0x280
Signed-off-by: default avatarNicholas Piggin <npiggin@gmail.com>
Signed-off-by: default avatarPaul Mackerras <paulus@ozlabs.org>
parent eadce3b4
......@@ -18,6 +18,7 @@
#include <linux/cma.h>
#include <linux/bitops.h>
#include <asm/asm-prototypes.h>
#include <asm/cputable.h>
#include <asm/kvm_ppc.h>
#include <asm/kvm_book3s.h>
......@@ -633,7 +634,19 @@ int kvmppc_rm_h_eoi(struct kvm_vcpu *vcpu, unsigned long xirr)
void kvmppc_bad_interrupt(struct pt_regs *regs)
{
die("Bad interrupt in KVM entry/exit code", regs, SIGABRT);
/*
* 100 could happen at any time, 200 can happen due to invalid real
* address access for example (or any time due to a hardware problem).
*/
if (TRAP(regs) == 0x100) {
get_paca()->in_nmi++;
system_reset_exception(regs);
get_paca()->in_nmi--;
} else if (TRAP(regs) == 0x200) {
machine_check_exception(regs);
} else {
die("Bad interrupt in KVM entry/exit code", regs, SIGABRT);
}
panic("Bad KVM trap");
}
......
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