From 81231c698a71af6e1815df72c06685d295e1cc1d Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Sun, 24 Jan 2010 16:26:40 +0200 Subject: [PATCH] KVM: VMX: Pass cr0.mp through to the guest when the fpu is active When cr0.mp is clear, the guest doesn't expect a #NM in response to a WAIT instruction. Because we always keep cr0.mp set, it will get a #NM, and potentially be confused. Fix by keeping cr0.mp set only when the fpu is inactive, and passing it through when inactive. Reported-by: Lorenzo Martignoni Analyzed-by: Gleb Natapov Signed-off-by: Avi Kivity Signed-off-by: Marcelo Tosatti --- arch/x86/kvm/vmx.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index a680d939546f..7a56879a058c 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -66,7 +66,7 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO); #define KVM_GUEST_CR0_MASK \ (KVM_GUEST_CR0_MASK_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE) #define KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST \ - (X86_CR0_WP | X86_CR0_NE | X86_CR0_MP) + (X86_CR0_WP | X86_CR0_NE) #define KVM_VM_CR0_ALWAYS_ON \ (KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE) #define KVM_CR4_GUEST_OWNED_BITS \ @@ -791,12 +791,15 @@ static void vmx_vcpu_put(struct kvm_vcpu *vcpu) static void vmx_fpu_activate(struct kvm_vcpu *vcpu) { + ulong cr0; + if (vcpu->fpu_active) return; vcpu->fpu_active = 1; - vmcs_clear_bits(GUEST_CR0, X86_CR0_TS); - if (kvm_read_cr0_bits(vcpu, X86_CR0_TS)) - vmcs_set_bits(GUEST_CR0, X86_CR0_TS); + cr0 = vmcs_readl(GUEST_CR0); + cr0 &= ~(X86_CR0_TS | X86_CR0_MP); + cr0 |= kvm_read_cr0_bits(vcpu, X86_CR0_TS | X86_CR0_MP); + vmcs_writel(GUEST_CR0, cr0); update_exception_bitmap(vcpu); vcpu->arch.cr0_guest_owned_bits = X86_CR0_TS; vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits); @@ -807,7 +810,7 @@ static void vmx_decache_cr0_guest_bits(struct kvm_vcpu *vcpu); static void vmx_fpu_deactivate(struct kvm_vcpu *vcpu) { vmx_decache_cr0_guest_bits(vcpu); - vmcs_set_bits(GUEST_CR0, X86_CR0_TS); + vmcs_set_bits(GUEST_CR0, X86_CR0_TS | X86_CR0_MP); update_exception_bitmap(vcpu); vcpu->arch.cr0_guest_owned_bits = 0; vmcs_writel(CR0_GUEST_HOST_MASK, ~vcpu->arch.cr0_guest_owned_bits); @@ -1757,7 +1760,7 @@ static void vmx_set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0) ept_update_paging_mode_cr0(&hw_cr0, cr0, vcpu); if (!vcpu->fpu_active) - hw_cr0 |= X86_CR0_TS; + hw_cr0 |= X86_CR0_TS | X86_CR0_MP; vmcs_writel(CR0_READ_SHADOW, cr0); vmcs_writel(GUEST_CR0, hw_cr0); -- 2.20.1