Messages in this thread | | | Subject | Re: [PATCH] iommu/vt-d: fix usage of force parameter in intel_ir_reconfigure_irte() | From | Jag Raman <> | Date | Wed, 4 Apr 2018 14:06:39 -0400 |
| |
On 3/6/2018 5:39 PM, Jagannathan Raman wrote: > It was noticed that the IRTE configured for guest OS kernel > was over-written while the guest was running. As a result, > vt-d Posted Interrupts configured for the guest are not being > delivered directly, and instead bounces off the host. Every > interrupt delivery takes a VM Exit. > > It was noticed that the following stack is doing the over-write: > [ 147.463177] modify_irte+0x171/0x1f0 > [ 147.463405] intel_ir_set_affinity+0x5c/0x80 > [ 147.463641] msi_domain_set_affinity+0x32/0x90 > [ 147.463881] irq_do_set_affinity+0x37/0xd0 > [ 147.464125] irq_set_affinity_locked+0x9d/0xb0 > [ 147.464374] __irq_set_affinity+0x42/0x70 > [ 147.464627] write_irq_affinity.isra.5+0xe1/0x110 > [ 147.464895] proc_reg_write+0x38/0x70 > [ 147.465150] __vfs_write+0x36/0x180 > [ 147.465408] ? handle_mm_fault+0xdf/0x200 > [ 147.465671] ? _cond_resched+0x15/0x30 > [ 147.465936] vfs_write+0xad/0x1a0 > [ 147.466204] SyS_write+0x52/0xc0 > [ 147.466472] do_syscall_64+0x74/0x1a0 > [ 147.466744] entry_SYSCALL_64_after_hwframe+0x3d/0xa2 > > reversing the sense of force check in intel_ir_reconfigure_irte() > restores proper posted interrupt functionality > > Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> > --- > Hi Thomas, > > I noticed that you added intel_ir_reconfigure_irte() with the > following commit: > d491bdff888e ("iommu/vt-d: Reevaluate vector configuration on > activate()") > > Could you please confirm the usage of "force" parameter in > intel_ir_reconfigure_irte()? > > drivers/iommu/intel_irq_remapping.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c > index 66f69af..3062a15 100644 > --- a/drivers/iommu/intel_irq_remapping.c > +++ b/drivers/iommu/intel_irq_remapping.c > @@ -1136,7 +1136,7 @@ static void intel_ir_reconfigure_irte(struct irq_data *irqd, bool force) > irte->dest_id = IRTE_DEST(cfg->dest_apicid); > > /* Update the hardware only if the interrupt is in remapped mode. */ > - if (!force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) > + if (force || ir_data->irq_2_iommu.mode == IRQ_REMAPPING) > modify_irte(&ir_data->irq_2_iommu, irte); > } > >
*ping*
| |