KVM: TDX: Disable PI wakeup for IPIv

Disable PI wakeup for IPI virtualization (IPIv) case for TDX.

When a vCPU is being scheduled out, notification vector is switched and
pi_wakeup_handler() is enabled when the vCPU has interrupt enabled and
posted interrupt is used to wake up the vCPU.

For VMX, a blocked vCPU can be the target of posted interrupts when using
IPIv or VT-d PI.  TDX doesn't support IPIv, disable PI wakeup for IPIv.
Also, since the guest status of TD vCPU is protected, assume interrupt is
always enabled for TD. (PV HLT hypercall is not support yet, TDX guest
tells VMM whether HLT is called with interrupt disabled or not.)

Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
[binbin: split into new patch]
Signed-off-by: Binbin Wu <binbin.wu@linux.intel.com>
Message-ID: <20250222014757.897978-3-binbin.wu@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/vmx/posted_intr.c b/arch/x86/kvm/vmx/posted_intr.c
index 5696e0f9f924f678612102b69c5da8a9d1bbcd0a..25f8a19e28317df623b66495a3e64d3ea7c36e33 100644 (file)
--- a/arch/x86/kvm/vmx/posted_intr.c
+++ b/arch/x86/kvm/vmx/posted_intr.c
@@ -11,6 +11,7 @@
 #include "posted_intr.h"
 #include "trace.h"
 #include "vmx.h"
+#include "tdx.h"
 
 /*
  * Maintain a per-CPU list of vCPUs that need to be awakened by wakeup_handler()
@@ -190,7 +191,8 @@ static bool vmx_needs_pi_wakeup(struct kvm_vcpu *vcpu)
         * notification vector is switched to the one that calls
         * back to the pi_wakeup_handler() function.
         */
-       return vmx_can_use_ipiv(vcpu) || vmx_can_use_vtd_pi(vcpu->kvm);
+       return (vmx_can_use_ipiv(vcpu) && !is_td_vcpu(vcpu)) ||
+               vmx_can_use_vtd_pi(vcpu->kvm);
 }
 
 void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu)
@@ -200,7 +202,8 @@ void vmx_vcpu_pi_put(struct kvm_vcpu *vcpu)
        if (!vmx_needs_pi_wakeup(vcpu))
                return;
 
-       if (kvm_vcpu_is_blocking(vcpu) && !vmx_interrupt_blocked(vcpu))
+       if (kvm_vcpu_is_blocking(vcpu) &&
+           (is_td_vcpu(vcpu) || !vmx_interrupt_blocked(vcpu)))
                pi_enable_wakeup_handler(vcpu);
 
        /*

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 70d1783fc2d8bd8766ea17f76ed253a89a5ec3ca..895184fc0c66138c77baf9e009091421aec86d2a 100644 (file)
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -650,6 +650,7 @@ int tdx_vcpu_create(struct kvm_vcpu *vcpu)
 
        fpstate_set_confidential(&vcpu->arch.guest_fpu);
        vcpu->arch.apic->guest_apic_protected = true;
+       INIT_LIST_HEAD(&tdx->vt.pi_wakeup_list);
 
        vcpu->arch.efer = EFER_SCE | EFER_LME | EFER_LMA | EFER_NX;