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

[Sean Christopherson]

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: sta...@vger.kernel.org
Signed-off-by: Sean Christopherson <sea...@google.com>
---
 arch/x86/kvm/svm/svm.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

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);
-- 
2.30.0.478.g8a0d178c01-goog