On 25/03/15 12:31, Feng Wu wrote:
The basic idea here is: 1. When vCPU's state is RUNSTATE_running, - set 'NV' to 'Notification Vector'. - Clear 'SN' to accpet PI. - set 'NDST' to the right pCPU. 2. When vCPU's state is RUNSTATE_blocked, - set 'NV' to 'Wake-up Vector', so we can wake up the related vCPU when posted-interrupt happens for it. - Clear 'SN' to accpet PI. 3. When vCPU's state is RUNSTATE_runnable/RUNSTATE_offline, - Set 'SN' to suppress non-urgent interrupts. (Current, we only support non-urgent interrupts) - Set 'NV' back to 'Notification Vector' if needed.Signed-off-by: Feng Wu <feng...@intel.com> --- xen/arch/x86/hvm/vmx/vmx.c | 108 +++++++++++++++++++++++++++++++++++++++++++++ xen/common/schedule.c | 3 ++ 2 files changed, 111 insertions(+) diff --git a/xen/arch/x86/hvm/vmx/vmx.c b/xen/arch/x86/hvm/vmx/vmx.c index b30392c..6323bd6 100644 --- a/xen/arch/x86/hvm/vmx/vmx.c +++ b/xen/arch/x86/hvm/vmx/vmx.c @@ -1710,6 +1710,113 @@ static void vmx_handle_eoi(u8 vector) __vmwrite(GUEST_INTR_STATUS, status); }+static void vmx_pi_desc_update(struct vcpu *v, int new_state)+{ + struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc; + struct pi_desc old, new; + int old_state = v->runstate.state; + unsigned long flags; + + if ( !iommu_intpost ) + return; + + switch ( new_state ) + { + case RUNSTATE_runnable: + case RUNSTATE_offline: + /* + * We don't need to send notification event to a non-running + * vcpu, the interrupt information will be delivered to it before + * VM-ENTRY when the vcpu is scheduled to run next time. + */ + pi_set_sn(pi_desc); + + /* + * If the state is transferred from RUNSTATE_blocked, + * we should set 'NV' feild back to posted_intr_vector, + * so the Posted-Interrupts can be delivered to the vCPU + * by VT-d HW after it is scheduled to run. + */ + if ( old_state == RUNSTATE_blocked ) + { + do + { + old.control = new.control = pi_desc->control; + new.nv = posted_intr_vector; + } + while ( cmpxchg(&pi_desc->control, old.control, new.control) + != old.control ); + + /* + * Delete the vCPU from the related wakeup queue + * if we are resuming from blocked state + */ + spin_lock_irqsave(&per_cpu(blocked_vcpu_on_cpu_lock, + v->processor), flags); + list_del(&v->blocked_vcpu_list);
The scheduler is perfectly able to change v->processor behind your back, so your spinlocks are not protecting access to v->blocked_vcpu_list.
~Andrew
+ spin_unlock_irqrestore(&per_cpu(blocked_vcpu_on_cpu_lock, + v->processor), flags); + } + break; + + case RUNSTATE_blocked: + /* + * The vCPU is blocked on the wait queue. + * Store the blocked vCPU on the list of the + * vcpu->wakeup_cpu, which is the destination + * of the wake-up notification event. + */ + spin_lock_irqsave(&per_cpu(blocked_vcpu_on_cpu_lock, + v->processor), flags); + list_add_tail(&v->blocked_vcpu_list, + &per_cpu(blocked_vcpu_on_cpu, v->processor)); + spin_unlock_irqrestore(&per_cpu(blocked_vcpu_on_cpu_lock, + v->processor), flags); + + do + { + old.control = new.control = pi_desc->control; + + /* + * We should not block the vCPU if + * an interrupt is posted for it. + */ + + if ( pi_test_on(&old) == 1 ) + { + tasklet_schedule(&v->vcpu_wakeup_tasklet); + return; + } + + pi_clear_sn(&new); + new.nv = pi_wakeup_vector; + } + while ( cmpxchg(&pi_desc->control, old.control, new.control) + != old.control ); + break; + + case RUNSTATE_running: + ASSERT( pi_test_sn(pi_desc) == 1 ); + + do + { + old.control = new.control = pi_desc->control; + if ( x2apic_enabled ) + new.ndst = cpu_physical_id(v->processor); + else + new.ndst = (cpu_physical_id(v->processor) << 8) & 0xFF00; + + pi_clear_sn(&new); + } + while ( cmpxchg(&pi_desc->control, old.control, new.control) + != old.control ); + break; + + default: + break; + } +} + void vmx_hypervisor_cpuid_leaf(uint32_t sub_idx, uint32_t *eax, uint32_t *ebx, uint32_t *ecx, uint32_t *edx) @@ -1795,6 +1902,7 @@ static struct hvm_function_table __initdata vmx_function_table = { .process_isr = vmx_process_isr, .deliver_posted_intr = vmx_deliver_posted_intr, .sync_pir_to_irr = vmx_sync_pir_to_irr, + .pi_desc_update = vmx_pi_desc_update, .handle_eoi = vmx_handle_eoi, .nhvm_hap_walk_L1_p2m = nvmx_hap_walk_L1_p2m, .hypervisor_cpuid_leaf = vmx_hypervisor_cpuid_leaf, diff --git a/xen/common/schedule.c b/xen/common/schedule.c index ef79847..acf3186 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -157,6 +157,9 @@ static inline void vcpu_runstate_change( v->runstate.state_entry_time = new_entry_time; }+ if ( is_hvm_vcpu(v) && hvm_funcs.pi_desc_update )+ hvm_funcs.pi_desc_update(v, new_state); + v->runstate.state = new_state; }
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