>-----Original Message----- >From: Michael S. Tsirkin <m...@redhat.com> >Sent: Wednesday, May 10, 2023 2:29 PM >To: Duan, Zhenzhong <zhenzhong.d...@intel.com> >Cc: qemu-devel@nongnu.org; pet...@redhat.com; jasow...@redhat.com; >pbonz...@redhat.com; richard.hender...@linaro.org; edua...@habkost.net; >marcel.apfelb...@gmail.com >Subject: Re: [PATCH] intel-iommu: Set status bit after operation completed > >On Thu, Mar 09, 2023 at 05:23:19PM +0800, Zhenzhong Duan wrote: >> According to SDM 11.4.4.2 Global Status Register: >> "This field is cleared by hardware when software sets the SRTP field >> in the Global Command register. This field is set by hardware when >> hardware completes the ‘Set Root Table Pointer’ operation using the >> value provided in the Root Table Address register" >> >> Follow above spec to clear then set RTPS after finish all works, this >> way helps avoiding potential race with guest kernel. Though linux >> kernel is single threaded in writing GCMD_REG and checking GSTS_REG. >> >> Same reasion for GSTS_REG.TES >> >> Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com> > > >So I am dropping this?
Yes, please. As Peter point out, there is no such race as BQL serialize that. Thanks Zhenzhong
