From eab176722f4628b2d9cf76221a43dd3a0e37e632 Mon Sep 17 00:00:00 2001
From: Scott Wood <scottwood@freescale.com>
Date: Wed, 27 Apr 2011 17:24:10 -0500
Subject: [PATCH] KVM: PPC: booke: save/restore VRSAVE (a.k.a. USPRG0)
Linux doesn't use USPRG0 (now renamed VRSAVE in the architecture, even
when Altivec isn't involved), but a guest might.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
arch/powerpc/include/asm/kvm_host.h | 1 +
arch/powerpc/kernel/asm-offsets.c | 1 +
arch/powerpc/kvm/booke_interrupts.S | 1 -
arch/powerpc/kvm/powerpc.c | 13 +++++++++++++
4 files changed, 15 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index 890897cee050..a16804399165 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -223,6 +223,7 @@ struct kvm_vcpu_arch {
ulong hflags;
ulong guest_owned_ext;
#endif
+ u32 vrsave; /* also USPRG0 */
u32 mmucr;
ulong sprg4;
ulong sprg5;
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 23e6a93145ab..cf0d82278951 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -395,6 +395,7 @@ int main(void)
DEFINE(VCPU_HOST_STACK, offsetof(struct kvm_vcpu, arch.host_stack));
DEFINE(VCPU_HOST_PID, offsetof(struct kvm_vcpu, arch.host_pid));
DEFINE(VCPU_GPRS, offsetof(struct kvm_vcpu, arch.gpr));
+ DEFINE(VCPU_VRSAVE, offsetof(struct kvm_vcpu, arch.vrsave));
DEFINE(VCPU_SPRG4, offsetof(struct kvm_vcpu, arch.sprg4));
DEFINE(VCPU_SPRG5, offsetof(struct kvm_vcpu, arch.sprg5));
DEFINE(VCPU_SPRG6, offsetof(struct kvm_vcpu, arch.sprg6));
diff --git a/arch/powerpc/kvm/booke_interrupts.S b/arch/powerpc/kvm/booke_interrupts.S
index 1cc471faac2d..b58ccae95904 100644
--- a/arch/powerpc/kvm/booke_interrupts.S
+++ b/arch/powerpc/kvm/booke_interrupts.S
@@ -380,7 +380,6 @@ lightweight_exit:
* because host interrupt handlers would get confused. */
lwz r1, VCPU_GPR(r1)(r4)
- /* XXX handle USPRG0 */
/* Host interrupt handlers may have clobbered these guest-readable
* SPRGs, so we need to reload them here with the guest's values. */
lwz r3, VCPU_SPRG4(r4)
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index ec3d2e75c0a8..9e6aa8bfd160 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -298,12 +298,25 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
+#ifdef CONFIG_BOOKE
+ /*
+ * vrsave (formerly usprg0) isn't used by Linux, but may
+ * be used by the guest.
+ *
+ * On non-booke this is associated with Altivec and
+ * is handled by code in book3s.c.
+ */
+ mtspr(SPRN_VRSAVE, vcpu->arch.vrsave);
+#endif
kvmppc_core_vcpu_load(vcpu, cpu);
}
void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu)
{
kvmppc_core_vcpu_put(vcpu);
+#ifdef CONFIG_BOOKE
+ vcpu->arch.vrsave = mfspr(SPRN_VRSAVE);
+#endif
}
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
--
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