KVM: PPC: PV wrteei
On BookE the preferred way to write the EE bit is the wrteei instruction. It
already encodes the EE bit in the instruction.
So in order to get BookE some speedups as well, let's also PV'nize thati
instruction.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kernel/kvm_emul.S b/arch/powerpc/kernel/kvm_emul.S
index 8cd22f4..3199f65 100644
--- a/arch/powerpc/kernel/kvm_emul.S
+++ b/arch/powerpc/kernel/kvm_emul.S
@@ -204,3 +204,44 @@
.global kvm_emulate_mtmsr_len
kvm_emulate_mtmsr_len:
.long (kvm_emulate_mtmsr_end - kvm_emulate_mtmsr) / 4
+
+
+
+.global kvm_emulate_wrteei
+kvm_emulate_wrteei:
+
+ SCRATCH_SAVE
+
+ /* Fetch old MSR in r31 */
+ LL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
+
+ /* Remove MSR_EE from old MSR */
+ li r30, 0
+ ori r30, r30, MSR_EE
+ andc r31, r31, r30
+
+ /* OR new MSR_EE onto the old MSR */
+kvm_emulate_wrteei_ee:
+ ori r31, r31, 0
+
+ /* Write new MSR value back */
+ STL64(r31, KVM_MAGIC_PAGE + KVM_MAGIC_MSR, 0)
+
+ SCRATCH_RESTORE
+
+ /* Go back to caller */
+kvm_emulate_wrteei_branch:
+ b .
+kvm_emulate_wrteei_end:
+
+.global kvm_emulate_wrteei_branch_offs
+kvm_emulate_wrteei_branch_offs:
+ .long (kvm_emulate_wrteei_branch - kvm_emulate_wrteei) / 4
+
+.global kvm_emulate_wrteei_ee_offs
+kvm_emulate_wrteei_ee_offs:
+ .long (kvm_emulate_wrteei_ee - kvm_emulate_wrteei) / 4
+
+.global kvm_emulate_wrteei_len
+kvm_emulate_wrteei_len:
+ .long (kvm_emulate_wrteei_end - kvm_emulate_wrteei) / 4