mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
KVM: x86: fix apic_accept_events vs check_nested_events
vmx_apic_init_signal_blocked is buggy in that it returns true even in VMX non-root mode. In non-root mode, however, INITs are not latched, they just cause a vmexit. Previously, KVM was waiting for them to be processed when kvm_apic_accept_events and in the meanwhile it ate the SIPIs that the processor received. However, in order to implement the wait-for-SIPI activity state, KVM will have to process KVM_APIC_SIPI in vmx_check_nested_events, and it will not be possible anymore to disregard SIPIs in non-root mode as the code is currently doing. By calling kvm_x86_ops.nested_ops->check_events, we can force a vmexit (with the side-effect of latching INITs) before incorrectly injecting an INIT or SIPI in a guest, and therefore vmx_apic_init_signal_blocked can do the right thing. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
parent
7a873e4555
commit
1c96dcceae
|
@ -2843,14 +2843,35 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
|
|||
{
|
||||
struct kvm_lapic *apic = vcpu->arch.apic;
|
||||
u8 sipi_vector;
|
||||
int r;
|
||||
unsigned long pe;
|
||||
|
||||
if (!lapic_in_kernel(vcpu) || !apic->pending_events)
|
||||
if (!lapic_in_kernel(vcpu))
|
||||
return;
|
||||
|
||||
/*
|
||||
* Read pending events before calling the check_events
|
||||
* callback.
|
||||
*/
|
||||
pe = smp_load_acquire(&apic->pending_events);
|
||||
if (!pe)
|
||||
return;
|
||||
|
||||
if (is_guest_mode(vcpu)) {
|
||||
r = kvm_x86_ops.nested_ops->check_events(vcpu);
|
||||
if (r < 0)
|
||||
return;
|
||||
/*
|
||||
* If an event has happened and caused a vmexit,
|
||||
* we know INITs are latched and therefore
|
||||
* we will not incorrectly deliver an APIC
|
||||
* event instead of a vmexit.
|
||||
*/
|
||||
}
|
||||
|
||||
/*
|
||||
* INITs are latched while CPU is in specific states
|
||||
* (SMM, VMX non-root mode, SVM with GIF=0).
|
||||
* (SMM, VMX root mode, SVM with GIF=0).
|
||||
* Because a CPU cannot be in these states immediately
|
||||
* after it has processed an INIT signal (and thus in
|
||||
* KVM_MP_STATE_INIT_RECEIVED state), just eat SIPIs
|
||||
|
@ -2858,13 +2879,13 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
|
|||
*/
|
||||
if (kvm_vcpu_latch_init(vcpu)) {
|
||||
WARN_ON_ONCE(vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED);
|
||||
if (test_bit(KVM_APIC_SIPI, &apic->pending_events))
|
||||
if (test_bit(KVM_APIC_SIPI, &pe))
|
||||
clear_bit(KVM_APIC_SIPI, &apic->pending_events);
|
||||
return;
|
||||
}
|
||||
|
||||
pe = xchg(&apic->pending_events, 0);
|
||||
if (test_bit(KVM_APIC_INIT, &pe)) {
|
||||
clear_bit(KVM_APIC_INIT, &apic->pending_events);
|
||||
kvm_vcpu_reset(vcpu, true);
|
||||
if (kvm_vcpu_is_bsp(apic->vcpu))
|
||||
vcpu->arch.mp_state = KVM_MP_STATE_RUNNABLE;
|
||||
|
@ -2873,6 +2894,7 @@ void kvm_apic_accept_events(struct kvm_vcpu *vcpu)
|
|||
}
|
||||
if (test_bit(KVM_APIC_SIPI, &pe) &&
|
||||
vcpu->arch.mp_state == KVM_MP_STATE_INIT_RECEIVED) {
|
||||
clear_bit(KVM_APIC_SIPI, &apic->pending_events);
|
||||
/* evaluate pending_events before reading the vector */
|
||||
smp_rmb();
|
||||
sipi_vector = apic->sipi_vector;
|
||||
|
|
|
@ -7558,7 +7558,7 @@ static void enable_smi_window(struct kvm_vcpu *vcpu)
|
|||
|
||||
static bool vmx_apic_init_signal_blocked(struct kvm_vcpu *vcpu)
|
||||
{
|
||||
return to_vmx(vcpu)->nested.vmxon;
|
||||
return to_vmx(vcpu)->nested.vmxon && !is_guest_mode(vcpu);
|
||||
}
|
||||
|
||||
static void vmx_migrate_timers(struct kvm_vcpu *vcpu)
|
||||
|
|
Loading…
Reference in a new issue