KVM: SVM: Truncate GPR value for DR and CR accesses in !64-bit mode

commit 0884335a2e653b8a045083aa1d57ce74269ac81d upstream.

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: 7ff76d58a9 ("KVM: SVM: enhance MOV CR intercept handler")
Fixes: cae3797a46 ("KVM: SVM: enhance mov DR intercept handler")
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20210422022128.3464144-4-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Sean Christopherson 2021-04-21 19:21:22 -07:00 committed by Greg Kroah-Hartman
parent fe910d20e2
commit b3ee3f50ab

View File

@ -2362,7 +2362,7 @@ 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:
@ -2408,7 +2408,7 @@ 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);
@ -2439,13 +2439,13 @@ static int dr_interception(struct vcpu_svm *svm)
if (dr >= 16) { /* mov to DRn */
if (!kvm_require_dr(&svm->vcpu, dr - 16))
return 1;
val = kvm_register_read(&svm->vcpu, reg);
val = kvm_register_readl(&svm->vcpu, reg);
kvm_set_dr(&svm->vcpu, dr - 16, val);
} else {
if (!kvm_require_dr(&svm->vcpu, dr))
return 1;
kvm_get_dr(&svm->vcpu, dr, &val);
kvm_register_write(&svm->vcpu, reg, val);
kvm_register_writel(&svm->vcpu, reg, val);
}
return kvm_skip_emulated_instruction(&svm->vcpu);