[PATCH 6.6 106/166] KVM: nVMX: Fold requested virtual interrupt check into has_nested_events()

Greg Kroah-Hartman
2026-04-24T13:38:03Z

From: Sean Christopherson <seanjc@google.com>

[ Upstream commit 321ef62b0c5f6f57bb8500a2ca5986052675abbf ]

Check for a Requested Virtual Interrupt, i.e. a virtual interrupt that is
pending delivery, in vmx_has_nested_events() and drop the one-off
kvm_x86_ops.guest_apic_has_interrupt() hook.

In addition to dropping a superfluous hook, this fixes a bug where KVM
would incorrectly treat virtual interrupts _for L2_ as always enabled due
to kvm_arch_interrupt_allowed(), by way of vmx_interrupt_blocked(),
treating IRQs as enabled if L2 is active and vmcs12 is configured to exit
on IRQs, i.e. KVM would treat a virtual interrupt for L2 as a valid wake
event based on L1's IRQ blocking status.

Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240607172609.3205077-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Cc: Taeyang Lee <0wn@theori.io>
[sean: deal with lack of vmx/main.c and vmx/x86_ops.h]
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/x86/include/asm/kvm-x86-ops.h | 1 -
arch/x86/include/asm/kvm_host.h | 1 -
arch/x86/kvm/vmx/nested.c | 4 ++++
arch/x86/kvm/vmx/vmx.c | 21 ---------------------
arch/x86/kvm/x86.c | 10 +---------
5 files changed, 5 insertions(+), 32 deletions(-)

diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h
index a0a4fc684e63b..3d00c2444a757 100644
--- a/arch/x86/include/asm/kvm-x86-ops.h
+++ b/arch/x86/include/asm/kvm-x86-ops.h
@@ -83,7 +83,6 @@ KVM_X86_OP_OPTIONAL(update_cr8_intercept)
KVM_X86_OP(refresh_apicv_exec_ctrl)
KVM_X86_OP_OPTIONAL(hwapic_irr_update)
KVM_X86_OP_OPTIONAL(hwapic_isr_update)
-KVM_X86_OP_OPTIONAL_RET0(guest_apic_has_interrupt)
KVM_X86_OP_OPTIONAL(load_eoi_exitmap)
KVM_X86_OP_OPTIONAL(set_virtual_apic_mode)
KVM_X86_OP_OPTIONAL(set_apic_access_page_addr)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index df950c184c597..d79b8f7a39913 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1671,7 +1671,6 @@ struct kvm_x86_ops {
void (*refresh_apicv_exec_ctrl)(struct kvm_vcpu *vcpu);
void (*hwapic_irr_update)(struct kvm_vcpu *vcpu, int max_irr);
void (*hwapic_isr_update)(struct kvm_vcpu *vcpu, int isr);
- bool (*guest_apic_has_interrupt)(struct kvm_vcpu *vcpu);
void (*load_eoi_exitmap)(struct kvm_vcpu *vcpu, u64 *eoi_exit_bitmap);
void (*set_virtual_apic_mode)(struct kvm_vcpu *vcpu);
void (*set_apic_access_page_addr)(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index fb274bae41e2c..377b30212c191 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -4007,6 +4007,10 @@ static bool vmx_has_nested_events(struct kvm_vcpu *vcpu, bool for_injection)

vppr = *((u32 *)(vapic + APIC_PROCPRI));

+ max_irr = vmx_get_rvi();
+ if ((max_irr & 0xf0) > (vppr & 0xf0))
+ return true;
+
if (vmx->nested.pi_pending && vmx->nested.pi_desc &&
pi_test_on(vmx->nested.pi_desc)) {
max_irr = pi_find_highest_vector(vmx->nested.pi_desc);
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index b68fb5329a13e..4a45e86c5e2fc 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4127,26 +4127,6 @@ void pt_update_intercept_for_msr(struct kvm_vcpu *vcpu)
}
}

-static bool vmx_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
-{
- struct vcpu_vmx *vmx = to_vmx(vcpu);
- void *vapic_page;
- u32 vppr;
- int rvi;
-
- if (WARN_ON_ONCE(!is_guest_mode(vcpu)) ||
- !nested_cpu_has_vid(get_vmcs12(vcpu)) ||
- WARN_ON_ONCE(!vmx->nested.virtual_apic_map.gfn))
- return false;
-
- rvi = vmx_get_rvi();
-
- vapic_page = vmx->nested.virtual_apic_map.hva;
- vppr = *((u32 *)(vapic_page + APIC_PROCPRI));
-
- return ((rvi & 0xf0) > (vppr & 0xf0));
-}
-
static void vmx_msr_filter_changed(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -8390,7 +8370,6 @@ static struct kvm_x86_ops vmx_x86_ops __initdata = {
.required_apicv_inhibits = VMX_REQUIRED_APICV_INHIBITS,
.hwapic_irr_update = vmx_hwapic_irr_update,
.hwapic_isr_update = vmx_hwapic_isr_update,
- .guest_apic_has_interrupt = vmx_guest_apic_has_interrupt,
.sync_pir_to_irr = vmx_sync_pir_to_irr,
.deliver_interrupt = vmx_deliver_interrupt,
.dy_apicv_has_pending_interrupt = pi_has_pending_interrupt,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ac0b458582c38..485c1820e65a9 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -12906,12 +12906,6 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
kvm_arch_free_memslot(kvm, old);
}

-static inline bool kvm_guest_apic_has_interrupt(struct kvm_vcpu *vcpu)
-{
- return (is_guest_mode(vcpu) &&
- static_call(kvm_x86_guest_apic_has_interrupt)(vcpu));
-}
-
static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
{
if (!list_empty_careful(&vcpu->async_pf.done))
@@ -12942,9 +12936,7 @@ static inline bool kvm_vcpu_has_events(struct kvm_vcpu *vcpu)
if (kvm_test_request(KVM_REQ_PMI, vcpu))
return true;

- if (kvm_arch_interrupt_allowed(vcpu) &&
- (kvm_cpu_has_interrupt(vcpu) ||
- kvm_guest_apic_has_interrupt(vcpu)))
+ if (kvm_arch_interrupt_allowed(vcpu) && kvm_cpu_has_interrupt(vcpu))
return true;

if (kvm_hv_has_stimer_pending(vcpu))
--
2.53.0