VMFUNC is not supported for L1 guests, and executing VMFUNC in
L1 shall generate a #UD directly. Just disable it in secondary
proc-based execution control for L1, instead of intercepting it
and inject the #UD again.
Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
---
arch/x86/kvm/vmx/nested.c | 17 +++++------------
arch/x86/kvm/vmx/vmx.c | 4 +++-
2 files changed, 8 insertions(+), 13 deletions(-)
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 0c62352dda6a..8858c6c0979f 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -5793,11 +5793,11 @@ static int handle_vmfunc(struct kvm_vcpu *vcpu)
u32 function = kvm_rax_read(vcpu);
/*
- * VMFUNC is only supported for nested guests, but we always enable the
- * secondary control for simplicity; for non-nested mode, fake that we
- * didn't by injecting #UD.
+ * VMFUNC is only supported for nested guests, instead of triggering
+ * a VM Exit, non-nested guests shall receive #UD directly.
*/
if (!is_guest_mode(vcpu)) {
+ vcpu_unimpl(vcpu, "vmx: unexpected vm exit EXIT_REASON_VMFUNC.\n");
kvm_queue_exception(vcpu, UD_VECTOR);
return 1;
}
@@ -6808,6 +6808,7 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY |
SECONDARY_EXEC_RDRAND_EXITING |
SECONDARY_EXEC_ENABLE_INVPCID |
+ SECONDARY_EXEC_ENABLE_VMFUNC |
SECONDARY_EXEC_RDSEED_EXITING |
SECONDARY_EXEC_XSAVES |
SECONDARY_EXEC_TSC_SCALING;
@@ -6839,16 +6840,8 @@ void nested_vmx_setup_ctls_msrs(struct vmcs_config *vmcs_conf, u32 ept_caps)
SECONDARY_EXEC_ENABLE_PML;
msrs->ept_caps |= VMX_EPT_AD_BIT;
}
- }
- if (cpu_has_vmx_vmfunc()) {
- msrs->secondary_ctls_high |=
- SECONDARY_EXEC_ENABLE_VMFUNC;
- /*
- * Advertise EPTP switching unconditionally
- * since we emulate it
- */
- if (enable_ept)
+ if (cpu_has_vmx_vmfunc())
msrs->vmfunc_controls =
VMX_VMFUNC_EPTP_SWITCHING;
}
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 65f092e4a81b..9e17de62eb37 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4483,6 +4483,9 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx)
SECONDARY_EXEC_VIRTUAL_INTR_DELIVERY);
exec_control &= ~SECONDARY_EXEC_VIRTUALIZE_X2APIC_MODE;
+ /* VMFUNC is not supported for L1 guest, just disable it. */
+ exec_control &= ~SECONDARY_EXEC_ENABLE_VMFUNC;
+
/* SECONDARY_EXEC_DESC is enabled/disabled on writes to CR4.UMIP,
* in vmx_set_cr4. */
exec_control &= ~SECONDARY_EXEC_DESC;
@@ -6000,7 +6003,6 @@ static int (*kvm_vmx_exit_handlers[])(struct kvm_vcpu *vcpu) = {
[EXIT_REASON_RDSEED] = kvm_handle_invalid_op,
[EXIT_REASON_PML_FULL] = handle_pml_full,
[EXIT_REASON_INVPCID] = handle_invpcid,
- [EXIT_REASON_VMFUNC] = handle_vmx_instruction,
[EXIT_REASON_PREEMPTION_TIMER] = handle_preemption_timer,
[EXIT_REASON_ENCLS] = handle_encls,
[EXIT_REASON_BUS_LOCK] = handle_bus_lock_vmexit,
--
2.17.1
