> From: Jacob Pan <jacob.jun....@linux.intel.com> > Sent: Saturday, February 20, 2021 1:09 AM > > Hi Kevin, > > On Fri, 19 Feb 2021 06:19:04 +0000, "Tian, Kevin" <kevin.t...@intel.com> > wrote: > > > > From: Jacob Pan <jacob.jun....@linux.intel.com> > > > Sent: Friday, February 19, 2021 5:31 AM > > > > > > Write protect bit, when set, inhibits supervisor writes to the read-only > > > pages. In guest supervisor shared virtual addressing (SVA), > > > write-protect should be honored upon guest bind supervisor PASID > > > request. > > > > > > This patch extends the VT-d portion of the IOMMU UAPI to include WP bit. > > > WPE bit of the supervisor PASID entry will be set to match CPU CR0.WP > > > bit. > > > > > > Signed-off-by: Sanjay Kumar <sanjay.k.ku...@intel.com> > > > Signed-off-by: Jacob Pan <jacob.jun....@linux.intel.com> > > > --- > > > drivers/iommu/intel/pasid.c | 5 +++++ > > > include/uapi/linux/iommu.h | 3 ++- > > > 2 files changed, 7 insertions(+), 1 deletion(-) > > > > > > diff --git a/drivers/iommu/intel/pasid.c b/drivers/iommu/intel/pasid.c > > > index 0b7e0e726ade..c7a2ec930af4 100644 > > > --- a/drivers/iommu/intel/pasid.c > > > +++ b/drivers/iommu/intel/pasid.c > > > @@ -763,6 +763,11 @@ intel_pasid_setup_bind_data(struct > intel_iommu > > > *iommu, struct pasid_entry *pte, > > > return -EINVAL; > > > } > > > pasid_set_sre(pte); > > > + /* Enable write protect WP if guest requested */ > > > + if (pasid_data->flags & IOMMU_SVA_VTD_GPASID_WPE) { > > > + if (pasid_enable_wpe(pte)) > > > + return -EINVAL; > > > > We should call pasid_set_wpe directly, as this binding is about guest > > page table and suppose the guest has done whatever check required > > (e.g. gcr0.wp) before setting this bit. pasid_enable_wpe has an > > additional check on host cr0.wp thus is logically incorrect here. > > > If the host CPU does not support WP, can guest VCPU still support WP? If > so, I agree. >
If you change 'support' to 'enable', then the answer is yes. _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu