On 25/08/2015 10:50, Feng Wu wrote:
> 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.wu@xxxxxxxxx>
> ---
> 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);
>
Please make this separate functions vmx_vcpu_pi_load and vmx_vcpu_pi_put.
Paolo
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