From: "Xu, Quan" <quan.xu@intel.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: "Tian, Kevin" <kevin.tian@intel.com>, Keir Fraser <keir@xen.org>,
George Dunlap <george.dunlap@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
"dario.faggioli@citrix.com" <dario.faggioli@citrix.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
"Nakajima, Jun" <jun.nakajima@intel.com>
Subject: Re: [Patch v6 02/11] IOMMU/MMU: enhance the call trees of IOMMU unmapping and mapping
Date: Thu, 2 Jun 2016 06:00:12 +0000 [thread overview]
Message-ID: <945CA011AD5F084CBEA3E851C0AB28894B8C498A@SHSMSX101.ccr.corp.intel.com> (raw)
In-Reply-To: <574ECF7602000078000F0518@prv-mh.provo.novell.com>
On June 01, 2016 6:05 PM, Jan Beulich <JBeulich@suse.com> wrote:
> >>> On 31.05.16 at 15:57, <quan.xu@intel.com> wrote:
> > --- a/xen/arch/x86/mm/p2m-pt.c
> > +++ b/xen/arch/x86/mm/p2m-pt.c
> > @@ -673,6 +673,8 @@ p2m_pt_set_entry(struct p2m_domain *p2m,
> unsigned long gfn, mfn_t mfn,
> > if ( iommu_enabled && need_iommu(p2m->domain) &&
> > (iommu_old_flags != iommu_pte_flags || old_mfn != mfn_x(mfn)) )
> > {
> > + int ret;
> > +
> > if ( iommu_use_hap_pt(p2m->domain) )
> > {
> > if ( iommu_old_flags )
> > @@ -680,11 +682,27 @@ p2m_pt_set_entry(struct p2m_domain *p2m,
> unsigned long gfn, mfn_t mfn,
> > }
> > else if ( iommu_pte_flags )
> > for ( i = 0; i < (1UL << page_order); i++ )
> > - iommu_map_page(p2m->domain, gfn + i, mfn_x(mfn) + i,
> > - iommu_pte_flags);
> > + {
> > + ret = iommu_map_page(p2m->domain, gfn + i, mfn_x(mfn) + i,
> > + iommu_pte_flags);
> > + if ( unlikely(ret) )
> > + {
> > + while ( i-- )
> > + iommu_unmap_page(p2m->domain, gfn + i);
> > +
> > + if ( !rc )
> > + rc = ret;
> > +
> > + break;
> > + }
> > + }
>
> So why do you not use the same code structure here as you do on the EPT
> side?
I try to modify these code in a slight way, but if you point out some extra issue, I am pleased to fix it.
Furthermore, I was not sure whether I made an arbitrary decision here to add the condition 'rc == 0' or not,
Even I was aware of that the 'rc' is zero when the code run here..
> I.e. do away with using "ret" altogether, moving it all into ...
>
> > else
> > for ( i = 0; i < (1UL << page_order); i++ )
> > - iommu_unmap_page(p2m->domain, gfn + i);
> > + {
> > + ret = iommu_unmap_page(p2m->domain, gfn + i);
> > + if ( !rc )
> > + rc = ret;
> > + }
>
> ... this extremely narrow scope?
>
What about this fix:
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -670,7 +670,7 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
&& (gfn + (1UL << page_order) - 1 > p2m->max_mapped_pfn) )
p2m->max_mapped_pfn = gfn + (1UL << page_order) - 1;
- if ( iommu_enabled && need_iommu(p2m->domain) &&
+ if ( rc == 0 && iommu_enabled && need_iommu(p2m->domain) &&
(iommu_old_flags != iommu_pte_flags || old_mfn != mfn_x(mfn)) )
{
if ( iommu_use_hap_pt(p2m->domain) )
@@ -678,13 +678,33 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long gfn, mfn_t mfn,
if ( iommu_old_flags )
amd_iommu_flush_pages(p2m->domain, gfn, page_order);
}
- else if ( iommu_pte_flags )
- for ( i = 0; i < (1UL << page_order); i++ )
- iommu_map_page(p2m->domain, gfn + i, mfn_x(mfn) + i,
- iommu_pte_flags);
else
- for ( i = 0; i < (1UL << page_order); i++ )
- iommu_unmap_page(p2m->domain, gfn + i);
+ {
+ if ( iommu_pte_flags )
+ for ( i = 0; i < (1UL << page_order); i++ )
+ {
+ rc = iommu_map_page(p2m->domain, gfn + i, mfn_x(mfn) + i,
+ iommu_pte_flags);
+ if ( unlikely(rc) )
+ {
+ while ( i-- )
+ iommu_unmap_page(p2m->domain, gfn + i);
+
+ break;
+ }
+ }
+ else
+ {
+ int ret;
+
+ for ( i = 0; i < (1UL << page_order); i++ )
+ {
+ ret = iommu_unmap_page(p2m->domain, gfn + i);
+ if ( !rc )
+ rc = ret;
+ }
+ }
+ }
}
Quan
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next prev parent reply other threads:[~2016-06-02 6:00 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 13:57 [Patch v6 00/11] Check VT-d Device-TLB flush error Xu, Quan
2016-05-31 13:57 ` [Patch v6 01/11] IOMMU: handle IOMMU mapping and unmapping failures Xu, Quan
2016-06-01 9:52 ` Jan Beulich
2016-05-31 13:57 ` [Patch v6 02/11] IOMMU/MMU: enhance the call trees of IOMMU unmapping and mapping Xu, Quan
2016-06-01 10:05 ` Jan Beulich
2016-06-02 6:00 ` Xu, Quan [this message]
2016-06-02 9:13 ` Jan Beulich
2016-05-31 13:57 ` [Patch v6 03/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU unmapping (top level ones) Xu, Quan
2016-05-31 13:57 ` [Patch v6 04/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU mapping " Xu, Quan
2016-06-01 10:24 ` Jan Beulich
2016-06-02 7:25 ` Xu, Quan
2016-06-02 9:21 ` Jan Beulich
2016-06-02 12:43 ` Xu, Quan
2016-06-07 7:51 ` Xu, Quan
2016-06-07 8:19 ` Jan Beulich
2016-06-07 8:40 ` Xu, Quan
2016-06-07 10:11 ` Jan Beulich
2016-05-31 13:57 ` [Patch v6 05/11] IOMMU/MMU: propagate IOMMU Device-TLB flush error up to iommu_iotlb_flush{, _all} " Xu, Quan
2016-05-31 13:57 ` [Patch v6 06/11] propagate IOMMU Device-TLB flush error up to EPT update " Xu, Quan
2016-05-31 13:57 ` [Patch v6 07/11] IOMMU: propagate IOMMU Device-TLB flush error up to IOMMU suspending " Xu, Quan
2016-06-01 10:39 ` Jan Beulich
2016-06-02 2:58 ` Xu, Quan
2016-06-02 9:22 ` Jan Beulich
2016-05-31 13:57 ` [Patch v6 08/11] IOMMU: propagate IOMMU Device-TLB flush error (leaf ones) Xu, Quan
2016-05-31 13:57 ` [Patch v6 09/11] vt-d: fix the IOMMU flush issue Xu, Quan
2016-06-01 15:36 ` Jan Beulich
2016-06-02 2:50 ` Xu, Quan
2016-05-31 13:57 ` [Patch v6 10/11] vt-d: propagate the IOMMU Device-TLB flush error up to ME phantom functions Xu, Quan
2016-05-31 13:57 ` [Patch v6 11/11] vt-d: add __must_check annotation to IOMMU flush pointers and handlers Xu, Quan
2016-06-02 10:06 ` Jan Beulich
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