KVM: x86: Rework INIT and SIPI handling
A VCPU sending INIT or SIPI to some other VCPU races for setting the
remote VCPU's mp_state. When we were unlucky, KVM_MP_STATE_INIT_RECEIVED
was overwritten by kvm_emulate_halt and, thus, got lost.
This introduces APIC events for those two signals, keeping them in
kvm_apic until kvm_apic_accept_events is run over the target vcpu
context. kvm_apic_has_events reports to kvm_arch_vcpu_runnable if there
are pending events, thus if vcpu blocking should end.
The patch comes with the side effect of effectively obsoleting
KVM_MP_STATE_SIPI_RECEIVED. We still accept it from user space, but
immediately translate it to KVM_MP_STATE_INIT_RECEIVED + KVM_APIC_SIPI.
The vcpu itself will no longer enter the KVM_MP_STATE_SIPI_RECEIVED
state. That also means we no longer exit to user space after receiving a
SIPI event.
Furthermore, we already reset the VCPU on INIT, only fixing up the code
segment later on when SIPI arrives. Moreover, we fix INIT handling for
the BSP: it never enter wait-for-SIPI but directly starts over on INIT.
Tested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
diff --git a/arch/x86/kvm/lapic.h b/arch/x86/kvm/lapic.h
index 1676d34..2c721b9 100644
--- a/arch/x86/kvm/lapic.h
+++ b/arch/x86/kvm/lapic.h
@@ -5,6 +5,9 @@
#include <linux/kvm_host.h>
+#define KVM_APIC_INIT 0
+#define KVM_APIC_SIPI 1
+
struct kvm_timer {
struct hrtimer timer;
s64 period; /* unit: ns */
@@ -32,6 +35,8 @@
void *regs;
gpa_t vapic_addr;
struct page *vapic_page;
+ unsigned long pending_events;
+ unsigned int sipi_vector;
};
int kvm_create_lapic(struct kvm_vcpu *vcpu);
void kvm_free_lapic(struct kvm_vcpu *vcpu);
@@ -39,6 +44,7 @@
int kvm_apic_has_interrupt(struct kvm_vcpu *vcpu);
int kvm_apic_accept_pic_intr(struct kvm_vcpu *vcpu);
int kvm_get_apic_interrupt(struct kvm_vcpu *vcpu);
+void kvm_apic_accept_events(struct kvm_vcpu *vcpu);
void kvm_lapic_reset(struct kvm_vcpu *vcpu);
u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu);
void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8);
@@ -158,4 +164,9 @@
struct kvm_lapic_irq *irq,
u64 *eoi_bitmap);
+static inline bool kvm_apic_has_events(struct kvm_vcpu *vcpu)
+{
+ return vcpu->arch.apic->pending_events;
+}
+
#endif