On Wed, Aug 12, 2015 at 10:35:32AM +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.
>
> CC: Yang Zhang
> CC: Kevin Tian
> CC: Keir Fraser
> CC: Jan Beulich
> CC: Andrew Cooper
> Signed-off-by: Feng Wu
> Acked-by: Kevin Tian
> ---
> v5:
> - Make some function parameters const
> - Call "spin_unlock_irq(&desc->lock);" a little eariler
> - Add "ASSERT(spin_is_locked(&pcidevs_lock))"
> - -EBADSLT -> -ENODEV, EBADSLT is removed in the lasted Xen
>
> v4:
> - Don't inline setup_posted_irte()
> - const struct pi_desc *pi_desc for setup_posted_irte()
> - return -EINVAL when pirq_spin_lock_irq_desc() fails.
> - Make some variables const
> - Release irq desc lock earlier in pi_update_irte()
> - Remove the pointless do-while() loop when doing cmpxchg16b()
>
> v3:
> - Remove "adding PDA_MASK()" when updating 'pda_l' and 'pda_h' for IRTE.
> - Change the return type of pi_update_irte() to int.
> - Remove some pointless printk message in pi_update_irte().
> - Use structure assignment instead of memcpy() for irte copy.
>
> xen/drivers/passthrough/vtd/intremap.c | 112
> +
> xen/drivers/passthrough/vtd/iommu.h| 2 +
> xen/include/asm-x86/iommu.h| 2 +
> 3 files changed, 116 insertions(+)
>
> diff --git a/xen/drivers/passthrough/vtd/intremap.c
> b/xen/drivers/passthrough/vtd/intremap.c
> index e9fffa6..8ec85d3 100644
> --- a/xen/drivers/passthrough/vtd/intremap.c
> +++ b/xen/drivers/passthrough/vtd/intremap.c
> @@ -899,3 +899,115 @@ void iommu_disable_x2apic_IR(void)
> for_each_drhd_unit ( drhd )
> disable_qinval(drhd->iommu);
> }
> +
> +static void setup_posted_irte(
space before '{]'
> +struct iremap_entry *new_ire,
> +const struct pi_desc *pi_desc,
> +const uint8_t gvec)
Not sure why but your parameters are on their own line? Shouldnt at least one
be with the function name - and then the rest on the same offset?
> +{
> +new_ire->post.urg = 0;
> +new_ire->post.vector = gvec;
> +new_ire->post.pda_l = virt_to_maddr(pi_desc) >> (32 - PDA_LOW_BIT);
> +new_ire->post.pda_h = virt_to_maddr(pi_desc) >> 32;
> +
> +new_ire->post.res_1 = 0;
> +new_ire->post.res_2 = 0;
> +new_ire->post.res_3 = 0;
> +new_ire->post.res_4 = 0;
> +new_ire->post.res_5 = 0;
> +
> +new_ire->post.im = 1;
> +}
> +
> +/*
> + * This function is used to update the IRTE for posted-interrupt
> + * when guest changes MSI/MSI-X information.
> + */
> +int pi_update_irte(
> +const struct vcpu *v,
> +const struct pirq *pirq,
> +const uint8_t gvec)
Ditto - perhaps move these to be right after the function name?
> +{
> +struct irq_desc *desc;
> +const struct msi_desc *msi_desc;
> +int remap_index;
> +int rc = 0;
> +const struct pci_dev *pci_dev;
> +const 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, old_ire;
> +const struct pi_desc *pi_desc = &v->arch.hvm_vmx.pi_desc;
> +__uint128_t ret;
> +
> +desc = pirq_spin_lock_irq_desc(pirq, NULL);
> +if ( !desc )
> +return -EINVAL;
> +
> +msi_desc = desc->msi_desc;
> +if ( !msi_desc )
> +{
> +rc = -ENODEV;
> +goto unlock_out;
> +}
> +
> +pci_dev = msi_desc->dev;
> +if ( !pci_dev )
> +{
> +rc = -ENODEV;
> +goto unlock_out;
> +}
> +
> +remap_index = msi_desc->remap_index;
> +
> +spin_unlock_irq(&desc->lock);
> +
> +ASSERT(spin_is_locked(&pcidevs_lock));
> +
> +/*
> + * For performance concern, we will store the 'iommu' pointer in
> + * 'struct msi_desc' in some other place, so we don't need to waste
> + * time searching it here. I will fix this later.
> + */
> +drhd = acpi_find_matched_drhd_unit(pci_dev);
> +if ( !drhd )
> +{
> +rc = -ENODEV;
> +goto unlock_out;
But you already unlocked desc->lock (so doing unlock_out would do a second
spin unlock)? Should this be an return -ENODEV?
> +}
> +
> +iommu = drhd->iommu;
> +ir_ctrl = iommu_ir_ctrl(iommu);
> +if ( !ir_ctrl )
> +{
> +rc = -ENODEV;
> +goto unlock_out;
Ditto.
> +}
> +
> +spin_lock_irq(&ir_ctrl->iremap_lock);
> +
> +GET_IREMAP_ENTRY(ir_ctrl->iremap_maddr, remap_index, iremap_entries, p);
> +
> +old_ire = new_ire = *p;
> +
> +/* Setup/Update interrupt remapping table entry. */
> +setup_posted_irte(&new_ire, pi_desc, gvec);
> +ret = cmpxchg16b(p, &old_ire, &new_ire);
> +
> +ASSERT(ret == *(__uint128_t *)&old_ire);
> +
> +iommu_flush_cache_entry(p, sizeof(*p));
The other use sites of iommu_flush_cache_entry are sizeof(struct iremap_entry).
I think if you are doing this modification - then you should also have an
patch to modify the other code to be in sync
