[3/9] KVM: SVM: Truncate GPR value for DR and CR accesses in !64-bit mode

Commit Message

Sean Christopherson Feb. 13, 2021, 1:05 a.m. UTC

Drop bits 63:32 on loads/stores to/from DRs and CRs when the vCPU is not
in 64-bit mode.  The APM states bits 63:32 are dropped for both DRs and
CRs:

  In 64-bit mode, the operand size is fixed at 64 bits without the need
  for a REX prefix. In non-64-bit mode, the operand size is fixed at 32
  bits and the upper 32 bits of the destination are forced to 0.

Fixes: 7ff76d58a9dc ("KVM: SVM: enhance MOV CR intercept handler")
Fixes: cae3797a4639 ("KVM: SVM: enhance mov DR intercept handler")
Cc: [e-mail]
Signed-off-by: Sean Christopherson <[e-mail]>
---
 arch/x86/kvm/svm/svm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Patch

diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 42d4710074a6..d077584d45ec 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -2526,7 +2526,7 @@  static int cr_interception(struct vcpu_svm *svm)
 	err = 0;
 	if (cr >= 16) { /* mov to cr */
 		cr -= 16;
-		val = kvm_register_read(&svm->vcpu, reg);
+		val = kvm_register_readl(&svm->vcpu, reg);
 		trace_kvm_cr_write(cr, val);
 		switch (cr) {
 		case 0:
@@ -2572,7 +2572,7 @@  static int cr_interception(struct vcpu_svm *svm)
 			kvm_queue_exception(&svm->vcpu, UD_VECTOR);
 			return 1;
 		}
-		kvm_register_write(&svm->vcpu, reg, val);
+		kvm_register_writel(&svm->vcpu, reg, val);
 		trace_kvm_cr_read(cr, val);
 	}
 	return kvm_complete_insn_gp(&svm->vcpu, err);
@@ -2637,11 +2637,11 @@  static int dr_interception(struct vcpu_svm *svm)
 	dr = svm->vmcb->control.exit_code - SVM_EXIT_READ_DR0;
 	if (dr >= 16) { /* mov to DRn  */
 		dr -= 16;
-		val = kvm_register_read(&svm->vcpu, reg);
+		val = kvm_register_readl(&svm->vcpu, reg);
 		err = kvm_set_dr(&svm->vcpu, dr, val);
 	} else {
 		kvm_get_dr(&svm->vcpu, dr, &val);
-		kvm_register_write(&svm->vcpu, reg, val);
+		kvm_register_writel(&svm->vcpu, reg, val);
 	}
 
 	return kvm_complete_insn_gp(&svm->vcpu, err);