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Commit 4c38609a authored by Avi Kivity's avatar Avi Kivity Committed by Marcelo Tosatti
Browse files

KVM: VMX: Make guest cr4 mask more conservative 



Instead of specifying the bits which we want to trap on, specify the bits
which we allow the guest to change transparently.  This is safer wrt future
changes to cr4.

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent fc78f519

arch/x86/kvm/vmx.c

+6 −4
Original line number Diff line number Diff line
@@ -69,8 +69,10 @@ module_param(emulate_invalid_guest_state, bool, S_IRUGO); 
	(X86_CR0_WP | X86_CR0_NE | X86_CR0_TS | X86_CR0_MP)

#define KVM_VM_CR0_ALWAYS_ON						\

	(KVM_VM_CR0_ALWAYS_ON_UNRESTRICTED_GUEST | X86_CR0_PG | X86_CR0_PE)

#define KVM_GUEST_CR4_MASK						\

	(X86_CR4_VME | X86_CR4_PSE | X86_CR4_PAE | X86_CR4_PGE | X86_CR4_VMXE)

#define KVM_CR4_GUEST_OWNED_BITS				      \

	(X86_CR4_PVI | X86_CR4_DE | X86_CR4_PCE | X86_CR4_OSFXSR      \

	 | X86_CR4_OSXMMEXCPT)



#define KVM_PMODE_VM_CR4_ALWAYS_ON (X86_CR4_PAE | X86_CR4_VMXE)

#define KVM_RMODE_VM_CR4_ALWAYS_ON (X86_CR4_VME | X86_CR4_PAE | X86_CR4_VMXE)
@@ -2421,8 +2423,8 @@ static int vmx_vcpu_setup(struct vcpu_vmx *vmx) 
	vmcs_write32(VM_ENTRY_CONTROLS, vmcs_config.vmentry_ctrl);



	vmcs_writel(CR0_GUEST_HOST_MASK, ~0UL);

	vmcs_writel(CR4_GUEST_HOST_MASK, KVM_GUEST_CR4_MASK);

	vmx->vcpu.arch.cr4_guest_owned_bits = ~KVM_GUEST_CR4_MASK;

	vmx->vcpu.arch.cr4_guest_owned_bits = KVM_CR4_GUEST_OWNED_BITS;

	vmcs_writel(CR4_GUEST_HOST_MASK, ~vmx->vcpu.arch.cr4_guest_owned_bits);



	tsc_base = vmx->vcpu.kvm->arch.vm_init_tsc;

	rdtscll(tsc_this);