From: George Dunlap <George.Dunlap@eu.citrix.com>
To: Quan Xu <quan.xu@intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>, Keir Fraser <keir@xen.org>,
Jun Nakajima <jun.nakajima@intel.com>,
Liu Jinsong <jinsong.liu@alibaba-inc.com>,
Dario Faggioli <dario.faggioli@citrix.com>,
"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
Jan Beulich <jbeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Feng Wu <feng.wu@intel.com>
Subject: Re: [PATCH 1/2] IOMMU/MMU: Adjust top level functions for VT-d Device-TLB flush error.
Date: Thu, 17 Mar 2016 12:30:21 +0000 [thread overview]
Message-ID: <CAFLBxZaTyOE61YX+qe_2qXU=zF32fr-409LK5OSm4QzT+z1EJw@mail.gmail.com> (raw)
In-Reply-To: <1458197676-60696-2-git-send-email-quan.xu@intel.com>
On Thu, Mar 17, 2016 at 6:54 AM, Quan Xu <quan.xu@intel.com> wrote:
> diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
> index c997b53..526548e 100644
> --- a/xen/arch/x86/mm.c
> +++ b/xen/arch/x86/mm.c
> @@ -2467,7 +2467,7 @@ static int __get_page_type(struct page_info *page, unsigned long type,
> int preemptible)
> {
> unsigned long nx, x, y = page->u.inuse.type_info;
> - int rc = 0;
> + int rc = 0, ret = 0;
>
> ASSERT(!(type & ~(PGT_type_mask | PGT_pae_xen_l2)));
>
> @@ -2578,11 +2578,11 @@ static int __get_page_type(struct page_info *page, unsigned long type,
> if ( d && is_pv_domain(d) && unlikely(need_iommu(d)) )
> {
> if ( (x & PGT_type_mask) == PGT_writable_page )
> - iommu_unmap_page(d, mfn_to_gmfn(d, page_to_mfn(page)));
> + ret = iommu_unmap_page(d, mfn_to_gmfn(d, page_to_mfn(page)));
> else if ( type == PGT_writable_page )
> - iommu_map_page(d, mfn_to_gmfn(d, page_to_mfn(page)),
> - page_to_mfn(page),
> - IOMMUF_readable|IOMMUF_writable);
> + ret = iommu_map_page(d, mfn_to_gmfn(d, page_to_mfn(page)),
> + page_to_mfn(page),
> + IOMMUF_readable|IOMMUF_writable);
> }
> }
>
> @@ -2599,6 +2599,9 @@ static int __get_page_type(struct page_info *page, unsigned long type,
> if ( (x & PGT_partial) && !(nx & PGT_partial) )
> put_page(page);
>
> + if ( !rc )
> + rc = ret;
> +
What's this about? If the iommu_[un]map_page() operation times out,
we still go through with calling alloc_page_type(); and if
alloc_page_type() fails we return its failure value, but if it
succeeds, we return the error from iommu_[un]map_page()?
> return rc;
> }
>
> diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
> index 3cb6868..f9bcce7 100644
> --- a/xen/arch/x86/mm/p2m-ept.c
> +++ b/xen/arch/x86/mm/p2m-ept.c
> @@ -830,7 +830,15 @@ out:
> {
> if ( iommu_flags )
> for ( i = 0; i < (1 << order); i++ )
> - iommu_map_page(d, gfn + i, mfn_x(mfn) + i, iommu_flags);
> + {
> + rc = iommu_map_page(d, gfn + i, mfn_x(mfn) + i, iommu_flags);
> + if ( rc )
> + {
> + while ( i-- > 0 )
> + iommu_unmap_page(d, gfn + i);
This won't unmap gfn+0 (since it will break out when i == 0 without
calling unmap).
If i were signed, we could make the conditional ">= 0"; but
unfortunately it's unsigned, so you'll have to do something more
complicated.
While we're at it, is it worth adding "unlikely()" to the if() condition here?
> + break;
> + }
> + }
> else
> for ( i = 0; i < (1 << order); i++ )
> iommu_unmap_page(d, gfn + i);
> diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
> index 3d80612..c33b753 100644
> --- a/xen/arch/x86/mm/p2m-pt.c
> +++ b/xen/arch/x86/mm/p2m-pt.c
> @@ -680,8 +680,16 @@ 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);
> + {
> + rc = iommu_map_page(p2m->domain, gfn + i, mfn_x(mfn) + i,
> + iommu_pte_flags);
> + if ( rc )
> + {
> + while ( i-- > 0 )
> + iommu_unmap_page(p2m->domain, gfn + i);
Same with gfn+0.
-George
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next prev parent reply other threads:[~2016-03-17 12:30 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-17 6:54 [PATCH 0/2] Check VT-d Device-TLB flush error Quan Xu
2016-03-17 6:54 ` [PATCH 1/2] IOMMU/MMU: Adjust top level functions for " Quan Xu
2016-03-17 7:32 ` Tian, Kevin
2016-03-17 7:58 ` Jan Beulich
2016-03-17 8:00 ` Tian, Kevin
2016-03-17 12:30 ` George Dunlap [this message]
2016-03-17 12:33 ` George Dunlap
2016-03-18 3:19 ` Xu, Quan
2016-03-18 8:09 ` Jan Beulich
2016-03-24 6:45 ` Xu, Quan
2016-03-18 7:54 ` Xu, Quan
2016-03-18 8:19 ` Jan Beulich
2016-03-18 9:09 ` Xu, Quan
2016-03-18 9:29 ` Jan Beulich
2016-03-18 9:38 ` Dario Faggioli
2016-03-18 9:48 ` Jan Beulich
2016-03-21 6:18 ` Tian, Kevin
2016-03-21 12:22 ` Jan Beulich
2016-03-24 9:02 ` Xu, Quan
2016-03-24 9:58 ` Jan Beulich
2016-03-24 14:12 ` Xu, Quan
2016-03-24 14:37 ` Jan Beulich
2016-03-17 17:14 ` Jan Beulich
2016-03-28 3:33 ` Xu, Quan
2016-03-29 7:20 ` Jan Beulich
2016-03-30 2:28 ` Xu, Quan
2016-03-30 2:35 ` Xu, Quan
2016-03-30 8:05 ` Jan Beulich
2016-03-17 6:54 ` [PATCH 2/2] IOMMU/MMU: Adjust low " Quan Xu
2016-03-17 7:37 ` Tian, Kevin
2016-03-18 2:30 ` Xu, Quan
2016-03-18 8:06 ` Jan Beulich
2016-03-21 5:01 ` Tian, Kevin
2016-03-17 15:31 ` George Dunlap
2016-03-18 6:57 ` Xu, Quan
2016-03-18 10:20 ` Jan Beulich
2016-03-25 9:27 ` Xu, Quan
2016-03-29 7:36 ` Jan Beulich
2016-04-11 3:09 ` Xu, Quan
2016-04-11 3:27 ` Xu, Quan
2016-04-11 16:34 ` Jan Beulich
2016-04-12 1:09 ` Xu, Quan
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