KVM: vmx: handle_cr ignores 32/64-bit mode (1e32c079) · Commits · 戴 / test

On 32-bit mode only bits [31:0] of the CR should be used for setting the CR value. Otherwise, the host may incorrectly assume the value is invalid if bits [63:32] are not zero. Moreover, the CR is currently being read twice when CR8 is used. Last, nested mov-cr exiting is modified to handle the CR value correctly as well. Signed-off-by:

Nadav Amit <namit@cs.technion.ac.il> Signed-off-by:

Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/vmx.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -5058,7 +5058,7 @@ static int handle_cr(struct kvm_vcpu *vcpu)
		reg = (exit_qualification >> 8) & 15;
		switch ((exit_qualification >> 4) & 3) {
		case 0: /* mov to cr */
		val = kvm_register_read(vcpu, reg);
		val = kvm_register_readl(vcpu, reg);
		trace_kvm_cr_write(cr, val);
		switch (cr) {
		case 0:
		@@ -5075,7 +5075,7 @@ static int handle_cr(struct kvm_vcpu *vcpu)
		return 1;
		case 8: {
		u8 cr8_prev = kvm_get_cr8(vcpu);
		u8 cr8 = kvm_register_read(vcpu, reg);
		u8 cr8 = (u8)val;
		err = kvm_set_cr8(vcpu, cr8);
		kvm_complete_insn_gp(vcpu, err);
		if (irqchip_in_kernel(vcpu->kvm))
		@@ -6770,7 +6770,7 @@ static bool nested_vmx_exit_handled_cr(struct kvm_vcpu *vcpu,
		unsigned long exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
		int cr = exit_qualification & 15;
		int reg = (exit_qualification >> 8) & 15;
		unsigned long val = kvm_register_read(vcpu, reg);
		unsigned long val = kvm_register_readl(vcpu, reg);

		switch ((exit_qualification >> 4) & 3) {
		case 0: /* mov to cr */

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