hi, I am reading through the code of writing GCMD_REG in iommu.c for VT-d on xen-unstable tip. According to the Intel VT-d spec. it looks that we have to make sure that only one bit of this register is modified at one time with one register write. But the current code doesn''t do that kind of checking, right? Thanks, Neo -- I would remember that if researchers were not ambitious probably today we haven''t the technology we are using! _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Han, Weidong
2008-Jul-14 09:10 UTC
RE: [Xen-devel] Questions about writing to GCMD_REG in iommu.c
Current code has guaranteed this. After writing GCMD_REG, there is a checking to make sure hardware completing it. Can you point out the code which misses the check? Randy (Weidong) Neo Jia wrote:> hi, > > I am reading through the code of writing GCMD_REG in iommu.c for VT-d > on xen-unstable tip. According to the Intel VT-d spec. it looks that > we have to make sure that only one bit of this register is modified at > one time with one register write. But the current code doesn''t do that > kind of checking, right? > > Thanks, > Neo_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel