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authorJoerg Roedel <joerg.roedel@amd.com>2008-01-21 13:09:33 +0100
committerAvi Kivity <avi@qumranet.com>2008-01-21 19:42:00 +0200
commit67704e250e558f937c25fa44b6dd0e4fb9f12341 (patch)
tree5821ead9c3342e692595eff5df3934b4f71925ba
parent5b644f6246905396f05ebe0f570c50bd81fce850 (diff)
KVM: SVM: Fix lazy FPU switchingkvm-60rc1
If the guest writes to cr0 and leaves the TS flag at 0 while vcpu->fpu_active is also 0, the TS flag in the guest's cr0 gets lost. This leads to corrupt FPU state an causes Windows Vista 64bit to crash very soon after boot. This patch fixes this bug. Signed-off-by: Joerg Roedel <joerg.roedel@amd.com> Signed-off-by: Markus Rechberger <markus.rechberger@amd.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
-rw-r--r--arch/x86/kvm/svm.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 2da9e11d12f3..7bdbe16ca3d8 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -792,6 +792,8 @@ static void svm_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
vcpu->arch.cr0 = cr0;
cr0 |= X86_CR0_PG | X86_CR0_WP;
cr0 &= ~(X86_CR0_CD | X86_CR0_NW);
+ if (!vcpu->fpu_active)
+ cr0 |= X86_CR0_TS;
svm->vmcb->save.cr0 = cr0;
}