[PATCH v4 2/3] KVM: nVMX: Validate the IA32_BNDCFGS on nested VM-entry

From: Wanpeng Li
Date: Thu Nov 02 2017 - 20:35:43 EST


From: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>

According to the SDM, if the "load IA32_BNDCFGS" VM-entry controls is 1, the
following checks are performed on the field for the IA32_BNDCFGS MSR:
- Bits reserved in the IA32_BNDCFGS MSR must be 0.
- The linear address in bits 63:12 must be canonical.

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
Cc: Jim Mattson <jmattson@xxxxxxxxxx>
Signed-off-by: Wanpeng Li <wanpeng.li@xxxxxxxxxxx>
---
v3 -> v4:
* simply condition
* use && instead of nested "if"s

arch/x86/kvm/vmx.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index e6c8ffa..6cf3972 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -10805,6 +10805,11 @@ static int check_vmentry_postreqs(struct kvm_vcpu *vcpu, struct vmcs12 *vmcs12,
return 1;
}

+ if (kvm_mpx_supported() &&
+ (is_noncanonical_address(vmcs12->guest_bndcfgs & PAGE_MASK, vcpu) ||
+ (vmcs12->guest_bndcfgs & MSR_IA32_BNDCFGS_RSVD)))
+ return 1;
+
return 0;
}

--
2.7.4