KVM: PPC: Convert MSR to shared page
One of the most obvious registers to share with the guest directly is the
MSR. The MSR contains the "interrupts enabled" flag which the guest has to
toggle in critical sections.
So in order to bring the overhead of interrupt en- and disabling down, let's
put msr into the shared page. Keep in mind that even though you can fully read
its contents, writing to it doesn't always update all state. There are a few
safe fields that don't require hypervisor interaction. See the documentation
for a list of MSR bits that are safe to be set from inside the guest.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/e500_tlb.c b/arch/powerpc/kvm/e500_tlb.c
index 21011e1..092a390 100644
--- a/arch/powerpc/kvm/e500_tlb.c
+++ b/arch/powerpc/kvm/e500_tlb.c
@@ -314,10 +314,10 @@
| MAS1_TID(get_tlb_tid(gtlbe)) | MAS1_TS | MAS1_VALID;
stlbe->mas2 = (gvaddr & MAS2_EPN)
| e500_shadow_mas2_attrib(gtlbe->mas2,
- vcpu_e500->vcpu.arch.msr & MSR_PR);
+ vcpu_e500->vcpu.arch.shared->msr & MSR_PR);
stlbe->mas3 = (hpaddr & MAS3_RPN)
| e500_shadow_mas3_attrib(gtlbe->mas3,
- vcpu_e500->vcpu.arch.msr & MSR_PR);
+ vcpu_e500->vcpu.arch.shared->msr & MSR_PR);
stlbe->mas7 = (hpaddr >> 32) & MAS7_RPN;
trace_kvm_stlb_write(index_of(tlbsel, esel), stlbe->mas1, stlbe->mas2,
@@ -576,28 +576,28 @@
int kvmppc_mmu_itlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
{
- unsigned int as = !!(vcpu->arch.msr & MSR_IS);
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_IS);
return kvmppc_e500_tlb_search(vcpu, eaddr, get_cur_pid(vcpu), as);
}
int kvmppc_mmu_dtlb_index(struct kvm_vcpu *vcpu, gva_t eaddr)
{
- unsigned int as = !!(vcpu->arch.msr & MSR_DS);
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_DS);
return kvmppc_e500_tlb_search(vcpu, eaddr, get_cur_pid(vcpu), as);
}
void kvmppc_mmu_itlb_miss(struct kvm_vcpu *vcpu)
{
- unsigned int as = !!(vcpu->arch.msr & MSR_IS);
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_IS);
kvmppc_e500_deliver_tlb_miss(vcpu, vcpu->arch.pc, as);
}
void kvmppc_mmu_dtlb_miss(struct kvm_vcpu *vcpu)
{
- unsigned int as = !!(vcpu->arch.msr & MSR_DS);
+ unsigned int as = !!(vcpu->arch.shared->msr & MSR_DS);
kvmppc_e500_deliver_tlb_miss(vcpu, vcpu->arch.fault_dear, as);
}