diff mbox

[v2,3/3] kvm: nVMX: Validate the I/O bitmaps on nested VM-entry

Message ID 20170710192904.102893-3-jmattson@google.com (mailing list archive)
State New, archived
Headers show

Commit Message

Jim Mattson July 10, 2017, 7:29 p.m. UTC 
According to the SDM, if the “use I/O bitmaps” VM-execution control is
1, bits 11:0 of each I/O-bitmap address must be 0. Neither address
should set any bits beyond the processor’s physical-address width.

Signed-off-by: Jim Mattson <jmattson@google.com>
---
 arch/x86/kvm/vmx.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
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Patch

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index eec9e0191311..7f27e7908477 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -9594,6 +9594,19 @@  static void vmx_start_preemption_timer(struct kvm_vcpu *vcpu)
 		      ns_to_ktime(preemption_timeout), HRTIMER_MODE_REL);
 }
 
+static int nested_vmx_check_io_bitmap_controls(struct kvm_vcpu *vcpu,
+					       struct vmcs12 *vmcs12)
+{
+	if (!nested_cpu_has(vmcs12, CPU_BASED_USE_IO_BITMAPS))
+		return 0;
+
+	if (!page_address_valid(vcpu, vmcs12->io_bitmap_a) ||
+	    !page_address_valid(vcpu, vmcs12->io_bitmap_b))
+		return -EINVAL;
+
+	return 0;
+}
+
 static int nested_vmx_check_msr_bitmap_controls(struct kvm_vcpu *vcpu,
 						struct vmcs12 *vmcs12)
 {
@@ -10288,6 +10301,9 @@  static int check_vmentry_prereqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12)
 	    vmcs12->guest_activity_state != GUEST_ACTIVITY_HLT)
 		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
 
+	if (nested_vmx_check_io_bitmap_controls(vcpu, vmcs12))
+		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;
+
 	if (nested_vmx_check_msr_bitmap_controls(vcpu, vmcs12))
 		return VMXERR_ENTRY_INVALID_CONTROL_FIELD;