From c2453693d41f31dae1b4d39b2d59d9a9c6dcb837 Mon Sep 17 00:00:00 2001 From: Alexander Graf Date: Wed, 24 Mar 2010 21:48:22 +0100 Subject: [PATCH] KVM: PPC: Don't reload FPU with invalid values When the guest activates the FPU, we load it up. That's fine when it wasn't activated before on the host, but if it was we end up reloading FPU values from last time the FPU was deactivated on the host without writing the proper values back to the vcpu struct. This patch checks if the FPU is enabled already and if so just doesn't bother activating it, making FPU operations survive guest context switches. Signed-off-by: Alexander Graf Signed-off-by: Avi Kivity --- arch/powerpc/kvm/book3s.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c index 358d5f78311a..6f409c98205c 100644 --- a/arch/powerpc/kvm/book3s.c +++ b/arch/powerpc/kvm/book3s.c @@ -702,6 +702,11 @@ static int kvmppc_handle_ext(struct kvm_vcpu *vcpu, unsigned int exit_nr, return RESUME_GUEST; } + /* We already own the ext */ + if (vcpu->arch.guest_owned_ext & msr) { + return RESUME_GUEST; + } + #ifdef DEBUG_EXT printk(KERN_INFO "Loading up ext 0x%lx\n", msr); #endif -- 2.34.1