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@xxxxxxx>
---
arch/powerpc/include/asm/kvm_book3s.h | 3 ++
arch/powerpc/kvm/book3s_64_exports.c | 7 ++++++
arch/powerpc/kvm/book3s_64_rmhandlers.S | 34 +++++++++++++++++++++++++++++++
3 files changed, 44 insertions(+), 0 deletions(-)
diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h
index c7db69f..e1b441c 100644
--- a/arch/powerpc/include/asm/kvm_book3s.h
+++ b/arch/powerpc/include/asm/kvm_book3s.h
@@ -124,6 +124,9 @@ extern void kvmppc_set_bat(struct kvm_vcpu *vcpu, struct kvmppc_bat *bat,
extern u32 kvmppc_trampoline_lowmem;
extern u32 kvmppc_trampoline_enter;
extern void kvmppc_rmcall(ulong srr0, ulong srr1);
+extern void kvmppc_load_up_fpu(void);
+extern void kvmppc_load_up_altivec(void);
+extern void kvmppc_load_up_vsx(void);
static inline struct kvmppc_vcpu_book3s *to_book3s(struct kvm_vcpu *vcpu)
{
diff --git a/arch/powerpc/kvm/book3s_64_exports.c b/arch/powerpc/kvm/book3s_64_exports.c
index 99b0712..1dd5a1d 100644
--- a/arch/powerpc/kvm/book3s_64_exports.c
+++ b/arch/powerpc/kvm/book3s_64_exports.c
@@ -23,3 +23,10 @@
EXPORT_SYMBOL_GPL(kvmppc_trampoline_enter);
EXPORT_SYMBOL_GPL(kvmppc_trampoline_lowmem);
EXPORT_SYMBOL_GPL(kvmppc_rmcall);
+EXPORT_SYMBOL_GPL(kvmppc_load_up_fpu);
+#ifdef CONFIG_ALTIVEC
+EXPORT_SYMBOL_GPL(kvmppc_load_up_altivec);
+#endif
+#ifdef CONFIG_VSX
+EXPORT_SYMBOL_GPL(kvmppc_load_up_vsx);
+#endif
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 @@ _GLOBAL(kvmppc_rmcall)
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
--
1.6.0.2
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