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Commit 1e32c079 authored by Nadav Amit's avatar Nadav Amit Committed by Paolo Bonzini
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KVM: vmx: handle_cr ignores 32/64-bit mode 



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: default avatarNadav Amit <namit@cs.technion.ac.il>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent a449c7aa

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 */