According to section "TLB Flush" in APM vol 2,
"Support for TLB_CONTROL commands other than the first two, is
optional and is indicated by CPUID Fn8000_000A_EDX[FlushByAsid].
All encodings of TLB_CONTROL not defined in the APM are reserved."
Signed-off-by: Krish Sadhukhan <krish.sadhukhan@xxxxxxxxxx>
---
arch/x86/kvm/svm/nested.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c
index 5e13357da21e..028cc2a1f028 100644
--- a/arch/x86/kvm/svm/nested.c
+++ b/arch/x86/kvm/svm/nested.c
@@ -235,6 +235,22 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)
kvm_vcpu_is_legal_gpa(vcpu, addr + size - 1);
}
+static bool nested_svm_check_tlb_ctl(struct kvm_vcpu *vcpu, u8 tlb_ctl)
+{
+ switch(tlb_ctl) {
+ case TLB_CONTROL_DO_NOTHING:
+ case TLB_CONTROL_FLUSH_ALL_ASID:
+ return true;
+ case TLB_CONTROL_FLUSH_ASID:
+ case TLB_CONTROL_FLUSH_ASID_LOCAL:
+ if (guest_cpuid_has(vcpu, X86_FEATURE_FLUSHBYASID))
+ return true;
+ fallthrough;
+ default:
+ return false;
+ }
+}
+
static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
struct vmcb_control_area *control)
{
@@ -254,6 +270,9 @@ static bool nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
IOPM_SIZE)))
return false;
+ if (CC(!nested_svm_check_tlb_ctl(vcpu, control->tlb_ctl)))
+ return false;
+
return true;
}
--
2.27.0
