Re: [Xen-devel] [RFC v1 07/15] vt-d: Add API to update IRTE when VT-d PI is used

["Wu, Feng" <feng.wu@xxxxxxxxx>]

> -----Original Message-----
> From: Konrad Rzeszutek Wilk [mailto:konrad.wilk@xxxxxxxxxx]
> Sent: Friday, March 27, 2015 3:36 AM
> To: Wu, Feng
> Cc: xen-devel@xxxxxxxxxxxxx; Zhang, Yang Z; Tian, Kevin; keir@xxxxxxx;
> JBeulich@xxxxxxxx
> Subject: Re: [Xen-devel] [RFC v1 07/15] vt-d: Add API to update IRTE when VT-d
> PI is used
> 
> On Wed, Mar 25, 2015 at 08:31:49PM +0800, Feng Wu wrote:
> > This patch adds an API which is used to update the IRTE
> > for posted-interrupt when guest changes MSI/MSI-X information.
> >
> > Signed-off-by: Feng Wu <feng.wu@xxxxxxxxx>
> > ---
> >  xen/drivers/passthrough/vtd/intremap.c | 83
> ++++++++++++++++++++++++++++++++++
> >  xen/drivers/passthrough/vtd/iommu.h    |  3 ++
> >  xen/include/asm-x86/iommu.h            |  2 +
> >  3 files changed, 88 insertions(+)
> >
> > diff --git a/xen/drivers/passthrough/vtd/intremap.c
> b/xen/drivers/passthrough/vtd/intremap.c
> > index 0333686..f44e74d 100644
> > --- a/xen/drivers/passthrough/vtd/intremap.c
> > +++ b/xen/drivers/passthrough/vtd/intremap.c
> > @@ -898,3 +898,86 @@ void iommu_disable_x2apic_IR(void)
> >      for_each_drhd_unit ( drhd )
> >          disable_qinval(drhd->iommu);
> >  }
> > +
> > +/*
> > + * This function is used to update the IRTE for posted-interrupt
> > + * when guest changes MSI/MSI-X information
> 
> Missing period at the end.
> 
> > + */
> > +int pi_update_irte(struct vcpu *v, struct pirq *pirq, uint32_t gvec )
> 
> There is an extra space at the end?
> > +{
> > +    struct irq_desc *desc;
> > +    struct msi_desc *msi_desc;
> > +    int remap_index, rc = -1;
> > +    struct pci_dev *pci_dev;
> > +    struct acpi_drhd_unit *drhd;
> > +    struct iommu *iommu;
> > +    struct ir_ctrl *ir_ctrl;
> > +    struct iremap_entry *iremap_entries = NULL, *p = NULL;
> > +    struct iremap_entry new_ire;
> > +    struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc;
> > +    unsigned long flags;
> > +
> > +    desc = pirq_spin_lock_irq_desc(pirq, NULL);
> > +    if ( !desc )
> > +        return -1;
> > +
> > +    msi_desc = desc->msi_desc;
> > +    if ( !msi_desc )
> > +        goto unlock_out;
> > +
> > +    remap_index = msi_desc->remap_index;
> 
> Could you move this right below the 'goto' check? No point
> of doing this if pci_dev is NULL.
> 
> > +    pci_dev = msi_desc->dev;
> > +    if ( !pci_dev )
> > +        goto unlock_out;
> > +
> > +    drhd = acpi_find_matched_drhd_unit(pci_dev);
> > +    if (!drhd)
> 
> Missing spaces around !drhd.
> 
> > +    {
> > +        dprintk(XENLOG_INFO VTDPREFIX, "failed to get drhd!\n");
> 
> Perhaps a bit more data. Can you include the pci_dev BDF as well?
> 
> > +        goto unlock_out;
> > +    }
> > +
> > +    iommu = drhd->iommu;
> > +    ir_ctrl = iommu_ir_ctrl(iommu);
> > +    if ( !ir_ctrl )
> > +    {
> > +        dprintk(XENLOG_INFO VTDPREFIX, "failed to get ir_ctrl!\n");
> 
> .. for IOMMU (with some data that can help diagnose the issue when one
> boots with 'iommu=verbose') please.
> 
> > +        goto unlock_out;
> > +    }
> > +
> > +    spin_lock_irqsave(&ir_ctrl->iremap_lock, flags);
> > +
> > +    GET_IREMAP_ENTRY(ir_ctrl->iremap_maddr, remap_index,
> iremap_entries, p);
> > +
> > +    memcpy(&new_ire, p, sizeof(struct iremap_entry));
> > +
> > +    /* Setup/Update interrupt remapping table entry */
> 
> Missing period at the end.
> > +    new_ire.lo_intpost.urg = 0;
> > +    new_ire.lo_intpost.vector = gvec;
> > +    new_ire.lo_intpost.pda_l = (((u64)virt_to_maddr(pi_desc)) >>
> > +                                (32 - PDA_LOW_BIT)) & ~(-1UL <<
> PDA_LOW_BIT);
> > +    new_ire.hi_intpost.pda_h = (((u64)virt_to_maddr(pi_desc)) >>  32) &
> 
> You have an extra space after >>
> > +                                ~(-1UL << PDA_HIGH_BIT);
> 
> You can make ~(-1UL << PDA_XX_BIT) and macro here..

Thanks for all the comments!

Thanks,
Feng

> 
> > +
> > +    new_ire.lo_intpost.res_1 = 0;
> > +    new_ire.lo_intpost.res_2 = 0;
> > +    new_ire.lo_intpost.res_3 = 0;
> > +    new_ire.hi_intpost.res_1 = 0;
> > +
> > +    new_ire.lo_intpost.im = 1;
> > +
> > +    memcpy(p, &new_ire, sizeof(struct iremap_entry));
> > +    iommu_flush_cache_entry(p, sizeof(struct iremap_entry));
> > +    iommu_flush_iec_index(iommu, 0, remap_index);
> > +
> > +    if ( iremap_entries )
> > +        unmap_vtd_domain_page(iremap_entries);
> > +
> > +    spin_unlock_irqrestore(&ir_ctrl->iremap_lock, flags);
> > +
> > +    rc = 0;
> > + unlock_out:
> > +    spin_unlock_irq(&desc->lock);
> > +
> > +    return rc;
> > +}
> > diff --git a/xen/drivers/passthrough/vtd/iommu.h
> b/xen/drivers/passthrough/vtd/iommu.h
> > index cd61e12..ffa72c8 100644
> > --- a/xen/drivers/passthrough/vtd/iommu.h
> > +++ b/xen/drivers/passthrough/vtd/iommu.h
> > @@ -334,6 +334,9 @@ struct iremap_entry {
> >    };
> >  };
> >
> > +#define PDA_LOW_BIT    26
> > +#define PDA_HIGH_BIT   32
> > +
> >  /* Max intr remapping table page order is 8, as max number of IRTEs is 64K
> */
> >  #define IREMAP_PAGE_ORDER  8
> >
> > diff --git a/xen/include/asm-x86/iommu.h b/xen/include/asm-x86/iommu.h
> > index e7a65da..d233621 100644
> > --- a/xen/include/asm-x86/iommu.h
> > +++ b/xen/include/asm-x86/iommu.h
> > @@ -32,6 +32,8 @@ int iommu_supports_eim(void);
> >  int iommu_enable_x2apic_IR(void);
> >  void iommu_disable_x2apic_IR(void);
> >
> > +int pi_update_irte(struct vcpu *v, struct pirq *pirq, uint32_t gvec);
> > +
> >  #endif /* !__ARCH_X86_IOMMU_H__ */
> >  /*
> >   * Local variables:
> > --
> > 2.1.0
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxx
> > http://lists.xen.org/xen-devel

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