Now that x86 always uses eager fpu switching on the host, there's no
need for KVM to manipulate the host's CR0.TS.
This should be both simpler and faster.
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/kvm/vmx.c | 12 ++++--------
arch/x86/kvm/x86.c | 5 -----
2 files changed, 4 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index cf1b16dbc98a..531c44633190 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2144,12 +2144,6 @@ static void __vmx_load_host_state(struct vcpu_vmx *vmx)
#endif
if (vmx->host_state.msr_host_bndcfgs)
wrmsrl(MSR_IA32_BNDCFGS, vmx->host_state.msr_host_bndcfgs);
- /*
- * If the FPU is not active (through the host task or
- * the guest vcpu), then restore the cr0.TS bit.
- */
- if (!fpregs_active() && !vmx->vcpu.guest_fpu_loaded)
- stts();
load_gdt(this_cpu_ptr(&host_gdt));
}
@@ -4871,9 +4865,11 @@ static void vmx_set_constant_host_state(struct vcpu_vmx *vmx)
u32 low32, high32;
unsigned long tmpl;
struct desc_ptr dt;
- unsigned long cr4;
+ unsigned long cr0, cr4;
- vmcs_writel(HOST_CR0, read_cr0() & ~X86_CR0_TS); /* 22.2.3 */
+ cr0 = read_cr0();
+ WARN_ON(cr0 & X86_CR0_TS);
+ vmcs_writel(HOST_CR0, cr0); /* 22.2.3 */
vmcs_writel(HOST_CR3, read_cr3()); /* 22.2.3 FIXME: shadow tables */
/* Save the most likely value for this task's CR4 in the VMCS. */
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d5700263dad2..123d428d319a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5060,11 +5060,6 @@ static void emulator_get_fpu(struct x86_emulate_ctxt *ctxt)
{
preempt_disable();
kvm_load_guest_fpu(emul_to_vcpu(ctxt));
- /*
- * CR0.TS may reference the host fpu state, not the guest fpu state,
- * so it may be clear at this point.
- */
- clts();
}
static void emulator_put_fpu(struct x86_emulate_ctxt *ctxt)
--
2.7.4
--
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