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authorJoerg Roedel <joerg.roedel@amd.com>2008-01-21 13:09:33 +0100
committerAvi Kivity <avi@qumranet.com>2008-03-03 11:18:18 +0200
commit334df50a866ff7e234c9566960997ca5b9d0a382 (patch)
treeb5fb897acca9ab85ba879f98d5dfafbc69560819 /arch/x86/kvm/svm.c
parent038f2f725503b55ab76cfd2645915a85594710fe (diff)
KVM: SVM: Fix lazy FPU switching
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>
Diffstat (limited to 'arch/x86/kvm/svm.c')
-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 de755cb1431..511628916c4 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;
}