> -----Original Message----- > From: Wei Liu [mailto:wei.l...@citrix.com] > Sent: 09 October 2018 11:42 > To: xen-devel@lists.xenproject.org > Cc: Jan Beulich <jbeul...@suse.com>; Roger Pau Monne > <roger....@citrix.com>; Paul Durrant <paul.durr...@citrix.com>; Wei Liu > <wei.l...@citrix.com>; Kevin Tian <kevin.t...@intel.com> > Subject: [PATCH] x86/vtd: fix IOMMU share PT destruction path > > Commit 2916951c1 ("mm / iommu: include need_iommu() test in > iommu_use_hap_pt()") included need_iommu() in iommu_use_hap_pt and > 91d4eca7add (" mm / iommu: split need_iommu() into has_iommu_pt() and > need_iommu_pt_sync()") made things finer grain by spliting need_iommu > into three states. > > The destruction path can't use iommu_use_hap_pt because at the point > platform op is called, IOMMU is already switched to disabled state and > the shared PT test would always be false. >
This is VT-d specific and the issue could affect AMD too. Can't you just switch round the call to teardown and setting IOMMU_status_disabled in xen/drivers/passthrough/iommu.c:iommu_teardown()? Paul > Signed-off-by: Wei Liu <wei.l...@citrix.com> > --- > xen/drivers/passthrough/vtd/iommu.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/xen/drivers/passthrough/vtd/iommu.c > b/xen/drivers/passthrough/vtd/iommu.c > index f94b522c73..d66d9e8ad0 100644 > --- a/xen/drivers/passthrough/vtd/iommu.c > +++ b/xen/drivers/passthrough/vtd/iommu.c > @@ -1752,7 +1752,13 @@ static void iommu_domain_teardown(struct domain *d) > xfree(mrmrr); > } > > - if ( iommu_use_hap_pt(d) ) > + ASSERT(hap_enabled(d)); > + > + /* > + * We can't use iommu_use_hap_pt here because the IOMMU state is > already > + * changed to IOMMU_STATUS_disabled at this point. > + */ > + if ( iommu_hap_pt_share ) > return; > > spin_lock(&hd->arch.mapping_lock); > -- > 2.11.0 _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
