> -----Original Message-----
> From: Alex Williamson [mailto:alex.william...@redhat.com]
> Sent: Tuesday, November 11, 2014 5:57 AM
> To: Wu, Feng
> Cc: g...@kernel.org; pbonz...@redhat.com; dw...@infradead.org;
> j...@8bytes.org; t...@linutronix.de; mi...@redhat.com; h...@zytor.com;
> x...@kernel.org; k...@vger.kernel.org; io...@lists.linux-foundation.org;
> linux-kernel@vger.kernel.org
> Subject: Re: [PATCH 02/13] KVM: Initialize VT-d Posted-Interrtups Descriptor
>
> On Mon, 2014-11-10 at 14:26 +0800, Feng Wu wrote:
> > This patch initialize the VT-d Posted-interrupt Descritpor.
> >
> > Signed-off-by: Feng Wu <feng...@intel.com>
> > ---
> > arch/x86/include/asm/irq_remapping.h | 1 +
> > arch/x86/kernel/apic/apic.c | 1 +
> > arch/x86/kvm/vmx.c | 56
> ++++++++++++++++++++++++++++++++-
> > 3 files changed, 56 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/x86/include/asm/irq_remapping.h
> b/arch/x86/include/asm/irq_remapping.h
> > index b7747c4..a3cc437 100644
> > --- a/arch/x86/include/asm/irq_remapping.h
> > +++ b/arch/x86/include/asm/irq_remapping.h
> > @@ -57,6 +57,7 @@ extern bool setup_remapped_irq(int irq,
> > struct irq_chip *chip);
> >
> > void irq_remap_modify_chip_defaults(struct irq_chip *chip);
> > +extern int irq_post_enabled;
> >
> > #else /* CONFIG_IRQ_REMAP */
> >
> > diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
> > index ba6cc04..987408d 100644
> > --- a/arch/x86/kernel/apic/apic.c
> > +++ b/arch/x86/kernel/apic/apic.c
> > @@ -162,6 +162,7 @@ __setup("apicpmtimer", setup_apicpmtimer);
> > #endif
> >
> > int x2apic_mode;
> > +EXPORT_SYMBOL_GPL(x2apic_mode);
> > #ifdef CONFIG_X86_X2APIC
> > /* x2apic enabled before OS handover */
> > int x2apic_preenabled;
> > diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
> > index 3e556c6..a4670d3 100644
> > --- a/arch/x86/kvm/vmx.c
> > +++ b/arch/x86/kvm/vmx.c
> > @@ -45,6 +45,7 @@
> > #include <asm/perf_event.h>
> > #include <asm/debugreg.h>
> > #include <asm/kexec.h>
> > +#include <asm/irq_remapping.h>
> >
> > #include "trace.h"
> >
> > @@ -408,13 +409,32 @@ struct nested_vmx {
> > };
> >
> > #define POSTED_INTR_ON 0
> > +#define POSTED_INTR_SN 1
> > +
> > /* Posted-Interrupt Descriptor */
> > struct pi_desc {
> > u32 pir[8]; /* Posted interrupt requested */
> > - u32 control; /* bit 0 of control is outstanding notification bit */
> > - u32 rsvd[7];
> > + union {
> > + struct {
> > + u64 on : 1,
> > + sn : 1,
> > + rsvd_1 : 13,
> > + ndm : 1,
> > + nv : 8,
> > + rsvd_2 : 8,
> > + ndst : 32;
> > + };
> > + u64 control;
> > + };
> > + u32 rsvd[6];
> > } __aligned(64);
> >
> > +static void pi_clear_sn(struct pi_desc *pi_desc)
> > +{
> > + return clear_bit(POSTED_INTR_SN,
> > + (unsigned long *)&pi_desc->control);
> > +}
> > +
> > static bool pi_test_and_set_on(struct pi_desc *pi_desc)
> > {
> > return test_and_set_bit(POSTED_INTR_ON,
> > @@ -4396,6 +4416,33 @@ static void ept_set_mmio_spte_mask(void)
> > kvm_mmu_set_mmio_spte_mask((0x3ull << 62) | 0x6ull);
> > }
> >
> > +static bool pi_desc_init(struct vcpu_vmx *vmx)
> > +{
> > + unsigned int dest;
> > +
> > + if (irq_post_enabled == 0)
> > + return true;
> > +
> > + /*
> > + * Initialize Posted-Interrupt Descriptor
> > + */
> > +
> > + pi_clear_sn(&vmx->pi_desc);
> > + vmx->pi_desc.nv = POSTED_INTR_VECTOR;
> > +
> > + /* Physical mode for Notificaiton Event */
> > + vmx->pi_desc.ndm = 0;
> > + dest = cpu_physical_id(vmx->vcpu.cpu);
> > +
> > + if (x2apic_mode)
> > + vmx->pi_desc.ndst = dest;
> > + else
> > + vmx->pi_desc.ndst = (dest << 8) & 0xFF00;
> > +
> > + return true;
>
> Why does this bother to return anything since it can only return true?
Yes, I will make this function void. Thanks for the comments!
Thanks,
Feng
>
> > +}
> > +
> > +
> > /*
> > * Sets up the vmcs for emulated real mode.
> > */
> > @@ -4439,6 +4486,11 @@ static int vmx_vcpu_setup(struct vcpu_vmx
> *vmx)
> >
> > vmcs_write64(POSTED_INTR_NV, POSTED_INTR_VECTOR);
> > vmcs_write64(POSTED_INTR_DESC_ADDR, __pa((&vmx->pi_desc)));
> > +
> > + if (!pi_desc_init(vmx)) {
>
> And therefore this cannot happen.
>
> > + printk(KERN_ERR "Initialize PI descriptor error!\n");
> > + return 1;
>
> This is the wrong error anyway, vmx_create_vcpu() returns ERR_PTR(1)
> which fails the reverse IS_ERR()
>
> Thanks,
> Alex
>
> > + }
> > }
> >
> > if (ple_gap) {
>
>
