This patch updates the Posted-Interrupts Descriptor when vCPU is preempted.
sched out: - Set 'SN' to suppress furture non-urgent interrupts posted for the vCPU. sched in: - Clear 'SN' - Change NDST if vCPU is scheduled to a different CPU - Set 'NV' to POSTED_INTR_VECTOR Signed-off-by: Feng Wu <feng...@intel.com> --- arch/x86/kvm/vmx.c | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c index 234f720..9c87064 100644 --- a/arch/x86/kvm/vmx.c +++ b/arch/x86/kvm/vmx.c @@ -45,6 +45,7 @@ #include <asm/debugreg.h> #include <asm/kexec.h> #include <asm/apic.h> +#include <asm/irq_remapping.h> #include "trace.h" #include "pmu.h" @@ -2001,10 +2002,60 @@ static void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu) vmcs_writel(HOST_IA32_SYSENTER_ESP, sysenter_esp); /* 22.2.3 */ vmx->loaded_vmcs->cpu = cpu; } + + if (irq_remapping_cap(IRQ_POSTING_CAP)) { + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + struct pi_desc old, new; + unsigned int dest; + + do { + old.control = new.control = pi_desc->control; + + /* + * If 'nv' field is POSTED_INTR_WAKEUP_VECTOR, there + * are two possible cases: + * 1. After running 'pi_pre_block', context switch + * happened. For this case, 'sn' was set in + * vmx_vcpu_put(), so we need to clear it here. + * 2. After running 'pi_pre_block', we were blocked, + * and woken up by some other guy. For this case, + * we don't need to do anything, 'pi_post_block' + * will do everything for us. However, we cannot + * check whether it is case #1 or case #2 here + * (maybe, not needed), so we also clear sn here, + * I think it is not a big deal. + */ + if (pi_desc->nv != POSTED_INTR_WAKEUP_VECTOR) { + if (vcpu->cpu != cpu) { + dest = cpu_physical_id(cpu); + + if (x2apic_enabled()) + new.ndst = dest; + else + new.ndst = (dest << 8) & 0xFF00; + } + + /* set 'NV' to 'notification vector' */ + new.nv = POSTED_INTR_VECTOR; + } + + /* Allow posting non-urgent interrupts */ + new.sn = 0; + } while (cmpxchg(&pi_desc->control, old.control, + new.control) != old.control); + } } static void vmx_vcpu_put(struct kvm_vcpu *vcpu) { + if (irq_remapping_cap(IRQ_POSTING_CAP)) { + struct pi_desc *pi_desc = vcpu_to_pi_desc(vcpu); + + /* Set SN when the vCPU is preempted */ + if (vcpu->preempted) + pi_set_sn(pi_desc); + } + __vmx_load_host_state(to_vmx(vcpu)); if (!vmm_exclusive) { __loaded_vmcs_clear(to_vmx(vcpu)->loaded_vmcs); -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/