On Mon, Jun 28, 2010 at 11:16:59PM -0400, Sheng Yang wrote: > Some guest device driver may leverage the "Non-Snoop" I/O, and explicitly > WBINVD or CLFLUSH to a RAM space. Since migration may occur before WBINVD or > CLFLUSH, we need to maintain data consistency either by: > 1: flushing cache (wbinvd) when the guest is scheduled out if there is no > wbinvd exit, or > 2: execute wbinvd on all dirty physical CPUs when guest wbinvd exits. Sorry for jumping in late. This code is not required on AMD platforms because the io-page-tables for the AMD IOMMU have a FC bit (force coherent) that must just be set. The current code does not set this bit but I will prepare a patch for that. This wbinvd emulation code should be avoided where possible. Joerg -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
