KVM: PPC: Book3S PR: Refactor program interrupt related code into separate function

The function kvmppc_handle_exit_pr() is quite huge and thus hard to read,
and even contains a "spaghetti-code"-like goto between the different case
labels of the big switch statement. This can be made much more readable
by moving the code related to injecting program interrupts / instruction
emulation into a separate function instead.

Signed-off-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
This commit is contained in:
Thomas Huth 2017-01-25 13:27:22 +01:00 committed by Paul Mackerras
parent 8464c8842d
commit fcd4f3c6d1

View file

@ -902,6 +902,69 @@ static void kvmppc_clear_debug(struct kvm_vcpu *vcpu)
}
}
static int kvmppc_exit_pr_progint(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
enum emulation_result er;
ulong flags;
u32 last_inst;
int emul, r;
/*
* shadow_srr1 only contains valid flags if we came here via a program
* exception. The other exceptions (emulation assist, FP unavailable,
* etc.) do not provide flags in SRR1, so use an illegal-instruction
* exception when injecting a program interrupt into the guest.
*/
if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
else
flags = SRR1_PROGILL;
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul != EMULATE_DONE)
return RESUME_GUEST;
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
kvmppc_get_pc(vcpu), last_inst);
#endif
if ((last_inst & 0xff0007ff) != (INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
return RESUME_GUEST;
}
}
vcpu->stat.emulated_inst_exits++;
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
r = RESUME_GUEST_NV;
break;
case EMULATE_AGAIN:
r = RESUME_GUEST;
break;
case EMULATE_FAIL:
pr_crit("%s: emulation at %lx failed (%08x)\n",
__func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
r = RESUME_HOST_NV;
break;
case EMULATE_EXIT_USER:
r = RESUME_HOST_NV;
break;
default:
BUG();
}
return r;
}
int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
unsigned int exit_nr)
{
@ -1044,71 +1107,8 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
break;
case BOOK3S_INTERRUPT_PROGRAM:
case BOOK3S_INTERRUPT_H_EMUL_ASSIST:
{
enum emulation_result er;
ulong flags;
u32 last_inst;
int emul;
program_interrupt:
/*
* shadow_srr1 only contains valid flags if we came here via
* a program exception. The other exceptions (emulation assist,
* FP unavailable, etc.) do not provide flags in SRR1, so use
* an illegal-instruction exception when injecting a program
* interrupt into the guest.
*/
if (exit_nr == BOOK3S_INTERRUPT_PROGRAM)
flags = vcpu->arch.shadow_srr1 & 0x1f0000ull;
else
flags = SRR1_PROGILL;
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC, &last_inst);
if (emul != EMULATE_DONE) {
r = RESUME_GUEST;
break;
}
if (kvmppc_get_msr(vcpu) & MSR_PR) {
#ifdef EXIT_DEBUG
pr_info("Userspace triggered 0x700 exception at\n 0x%lx (0x%x)\n",
kvmppc_get_pc(vcpu), last_inst);
#endif
if ((last_inst & 0xff0007ff) !=
(INS_DCBZ & 0xfffffff7)) {
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
}
}
vcpu->stat.emulated_inst_exits++;
er = kvmppc_emulate_instruction(run, vcpu);
switch (er) {
case EMULATE_DONE:
r = RESUME_GUEST_NV;
break;
case EMULATE_AGAIN:
r = RESUME_GUEST;
break;
case EMULATE_FAIL:
printk(KERN_CRIT "%s: emulation at %lx failed (%08x)\n",
__func__, kvmppc_get_pc(vcpu), last_inst);
kvmppc_core_queue_program(vcpu, flags);
r = RESUME_GUEST;
break;
case EMULATE_DO_MMIO:
run->exit_reason = KVM_EXIT_MMIO;
r = RESUME_HOST_NV;
break;
case EMULATE_EXIT_USER:
r = RESUME_HOST_NV;
break;
default:
BUG();
}
r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);
break;
}
case BOOK3S_INTERRUPT_SYSCALL:
{
u32 last_sc;
@ -1185,7 +1185,7 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu,
emul = kvmppc_get_last_inst(vcpu, INST_GENERIC,
&last_inst);
if (emul == EMULATE_DONE)
goto program_interrupt;
r = kvmppc_exit_pr_progint(run, vcpu, exit_nr);
else
r = RESUME_GUEST;