KVM: PPC: Add helper functions to call real mode loaders
Linux contains quite some bits of code to load FPU, Altivec and VSX lazily for
a task. It calls those bits in real mode, coming from an interrupt handler.
For KVM we better reuse those, so let's wrap a bit of trampoline magic around
them and then we can call them from normal module code.
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/powerpc/kvm/book3s_64_rmhandlers.S b/arch/powerpc/kvm/book3s_64_rmhandlers.S
index e7091c9..c83c60a 100644
--- a/arch/powerpc/kvm/book3s_64_rmhandlers.S
+++ b/arch/powerpc/kvm/book3s_64_rmhandlers.S
@@ -158,6 +158,40 @@
mtsrr1 r4
RFI
+/*
+ * Activate current's external feature (FPU/Altivec/VSX)
+ */
+#define define_load_up(what) \
+ \
+_GLOBAL(kvmppc_load_up_ ## what); \
+ subi r1, r1, INT_FRAME_SIZE; \
+ mflr r3; \
+ std r3, _LINK(r1); \
+ mfmsr r4; \
+ std r31, GPR3(r1); \
+ mr r31, r4; \
+ li r5, MSR_DR; \
+ oris r5, r5, MSR_EE@h; \
+ andc r4, r4, r5; \
+ mtmsr r4; \
+ \
+ bl .load_up_ ## what; \
+ \
+ mtmsr r31; \
+ ld r3, _LINK(r1); \
+ ld r31, GPR3(r1); \
+ addi r1, r1, INT_FRAME_SIZE; \
+ mtlr r3; \
+ blr
+
+define_load_up(fpu)
+#ifdef CONFIG_ALTIVEC
+define_load_up(altivec)
+#endif
+#ifdef CONFIG_VSX
+define_load_up(vsx)
+#endif
+
.global kvmppc_trampoline_lowmem
kvmppc_trampoline_lowmem:
.long kvmppc_handler_lowmem_trampoline - _stext