KVM: x86: Recompute PID.ON when clearing PID.SN

Some Posted-Interrupts from passthrough devices may be lost or
overwritten when the vCPU is in runnable state.

The SN (Suppress Notification) of PID (Posted Interrupt Descriptor) will
be set when the vCPU is preempted (vCPU in KVM_MP_STATE_RUNNABLE state but
not running on physical CPU). If a posted interrupt comes at this time,
the irq remapping facility will set the bit of PIR (Posted Interrupt
Requests) but not ON (Outstanding Notification).  Then, the interrupt
will not be seen by KVM, which always expects PID.ON=1 if PID.PIR=1
as documented in the Intel processor SDM but not in the VT-d specification.
To fix this, restore the invariant after PID.SN is cleared.

Signed-off-by: Luwei Kang <luwei.kang@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Luwei Kang
2019-02-14 10:48:07 +08:00
zatwierdzone przez Paolo Bonzini
rodzic 08e16754ca
commit c112b5f502
3 zmienionych plików z 18 dodań i 22 usunięć

Wyświetl plik

@@ -337,18 +337,18 @@ static inline int pi_test_and_set_pir(int vector, struct pi_desc *pi_desc)
return test_and_set_bit(vector, (unsigned long *)pi_desc->pir);
}
static inline void pi_clear_sn(struct pi_desc *pi_desc)
{
return clear_bit(POSTED_INTR_SN,
(unsigned long *)&pi_desc->control);
}
static inline void pi_set_sn(struct pi_desc *pi_desc)
{
return set_bit(POSTED_INTR_SN,
(unsigned long *)&pi_desc->control);
}
static inline void pi_set_on(struct pi_desc *pi_desc)
{
set_bit(POSTED_INTR_ON,
(unsigned long *)&pi_desc->control);
}
static inline void pi_clear_on(struct pi_desc *pi_desc)
{
clear_bit(POSTED_INTR_ON,