Book3S_32 doesn't know about segment faults. It only knows about page faults.
So in order to know that we didn't map a segment, we need to fake segment
faults.
We do this by setting invalid segment registers to an invalid VSID and then
check for that VSID on normal page faults.
Signed-off-by: Alexander Graf <agraf@xxxxxxx>
---
arch/powerpc/kvm/book3s.c | 23 +++++++++++++++++++++++
1 files changed, 23 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index b917b97..178ddd4 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -774,6 +774,18 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
switch (exit_nr) {
case BOOK3S_INTERRUPT_INST_STORAGE:
vcpu->stat.pf_instruc++;
+
+#ifdef CONFIG_PPC_BOOK3S_32
+ /* We set segments as unused segments when invalidating them. So
+ * treat the respective fault as segment fault. */
+ if (to_svcpu(vcpu)->sr[kvmppc_get_pc(vcpu) >> SID_SHIFT]
+ == SR_INVALID) {
+ kvmppc_mmu_map_segment(vcpu, kvmppc_get_pc(vcpu));
+ r = RESUME_GUEST;
+ break;
+ }
+#endif
+
/* only care about PTEG not found errors, but leave NX alone */
if (to_svcpu(vcpu)->shadow_srr1 & 0x40000000) {
r = kvmppc_handle_pagefault(run, vcpu, kvmppc_get_pc(vcpu), exit_nr);
@@ -798,6 +810,17 @@ int kvmppc_handle_exit(struct kvm_run *run, struct kvm_vcpu *vcpu,
{
ulong dar = kvmppc_get_fault_dar(vcpu);
vcpu->stat.pf_storage++;
+
+#ifdef CONFIG_PPC_BOOK3S_32
+ /* We set segments as unused segments when invalidating them. So
+ * treat the respective fault as segment fault. */
+ if ((to_svcpu(vcpu)->sr[dar >> SID_SHIFT]) == SR_INVALID) {
+ kvmppc_mmu_map_segment(vcpu, dar);
+ r = RESUME_GUEST;
+ break;
+ }
+#endif
+
/* The only case we need to handle is missing shadow PTEs */
if (to_svcpu(vcpu)->fault_dsisr & DSISR_NOHPTE) {
r = kvmppc_handle_pagefault(run, vcpu, dar, exit_nr);
--
1.6.0.2
--
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