[Xen-devel] [PATCH 0/2] MSI-X mask bit acceleration

[Qing He <qing.he@xxxxxxxxx>]

This patch set adds a new MMIO intercept handler in Xen to
efficiently handle mask/unmask operation of guest passthrough
MSI-X interrupts.

It is known that certain guests, like 2.6.18 will do mask/unmask
for each MSI-X interrupt received, which impacts the performance
considerably at high interrupt rate. Handling mask/unmask in the
hypervisor avoids extensive exiting to QEmu thus improves response
time and reduces overall load.

In order to do this, the patch adds a new MMIO intercept handler,
and lock its content with rcu lock to get better mask/unmask
performance. It also adds a new hypercall parameter to bind_pt_irq
to inform Xen the guest physical address of MSI-X table so
the handler can check MMIO access against it. On guest PCI BAR
rebalancing, it will rebind the irq, allowing the handler to use
new gpa of MSI-X table

Thanks,
Qing

---

 [PATCH 1/2] hvm: passthrough MSI-X mask bit acceleration
 [PATCH 2/2] ioemu: passthrough: MSI-X mask bit acceleration

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel