From: Jan Beulich <jbeulich@suse.com>
To: Paul Durrant <paul@xen.org>
Cc: "Kevin Tian" <kevin.tian@intel.com>, "Wei Liu" <wl@xen.org>,
"Andrew Cooper" <andrew.cooper3@citrix.com>,
"Paul Durrant" <pdurrant@amazon.com>,
"George Dunlap" <george.dunlap@citrix.com>,
xen-devel@lists.xenproject.org,
"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [PATCH v4 10/14] iommu: remove the share_p2m operation
Date: Thu, 6 Aug 2020 14:18:58 +0200 [thread overview]
Message-ID: <d19fe76d-2972-2e8d-86a1-08741dca0f9d@suse.com> (raw)
In-Reply-To: <20200804134209.8717-11-paul@xen.org>
On 04.08.2020 15:42, Paul Durrant wrote:
> --- a/xen/drivers/passthrough/vtd/iommu.c
> +++ b/xen/drivers/passthrough/vtd/iommu.c
> @@ -318,6 +318,48 @@ static u64 addr_to_dma_page_maddr(struct domain *domain, u64 addr, int alloc)
> return pte_maddr;
> }
>
> +static uint64_t domain_pgd_maddr(struct domain *d, struct vtd_iommu *iommu)
The 2nd param can be const, and I wonder whether it wouldn't better be
named e.g. "vtd". Then again all you're after is iommu->nr_pt_levels,
so maybe the caller would better pass in that value (removing the
appearance of there being some further dependency about the specific
IOMMU's properties)?
> +{
> + struct domain_iommu *hd = dom_iommu(d);
> + uint64_t pgd_maddr;
> + unsigned int agaw;
> +
> + ASSERT(spin_is_locked(&hd->arch.mapping_lock));
> +
> + if ( iommu_use_hap_pt(d) )
> + {
> + mfn_t pgd_mfn =
> + pagetable_get_mfn(p2m_get_pagetable(p2m_get_hostp2m(d)));
> +
> + return pagetable_get_paddr(pagetable_from_mfn(pgd_mfn));
Why the pagetable -> MFN -> pagetable -> paddr transformation? I.e. just
return pagetable_get_paddr(p2m_get_pagetable(p2m_get_hostp2m(d)));
? Oh, I've now realized that's how the old code was written.
> + }
> +
> + if ( !hd->arch.vtd.pgd_maddr )
> + {
> + addr_to_dma_page_maddr(d, 0, 1);
> +
> + if ( !hd->arch.vtd.pgd_maddr )
> + return 0;
> + }
> +
> + pgd_maddr = hd->arch.vtd.pgd_maddr;
> +
> + /* Skip top levels of page tables for 2- and 3-level DRHDs. */
> + for ( agaw = level_to_agaw(4);
> + agaw != level_to_agaw(iommu->nr_pt_levels);
> + agaw-- )
> + {
> + struct dma_pte *p = map_vtd_domain_page(pgd_maddr);
const?
> +
> + pgd_maddr = dma_pte_addr(*p);
> + unmap_vtd_domain_page(p);
> + if ( !pgd_maddr )
> + return 0;
> + }
> +
> + return pgd_maddr;
> +}
Jan
next prev parent reply other threads:[~2020-08-06 12:19 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-04 13:41 [PATCH v4 00/14] IOMMU cleanup Paul Durrant
2020-08-04 13:41 ` [PATCH v4 01/14] x86/iommu: re-arrange arch_iommu to separate common fields Paul Durrant
2020-08-14 6:14 ` Tian, Kevin
2020-08-04 13:41 ` [PATCH v4 02/14] x86/iommu: add common page-table allocator Paul Durrant
2020-08-05 15:39 ` Jan Beulich
2020-08-04 13:41 ` [PATCH v4 03/14] x86/iommu: convert VT-d code to use new page table allocator Paul Durrant
2020-08-14 6:41 ` Tian, Kevin
2020-08-14 7:16 ` Durrant, Paul
2020-08-04 13:41 ` [PATCH v4 04/14] x86/iommu: convert AMD IOMMU " Paul Durrant
2020-08-04 13:42 ` [PATCH v4 05/14] iommu: remove unused iommu_ops method and tasklet Paul Durrant
2020-08-04 13:42 ` [PATCH v4 06/14] iommu: flush I/O TLB if iommu_map() or iommu_unmap() fail Paul Durrant
2020-08-05 16:06 ` Jan Beulich
2020-08-05 16:18 ` Paul Durrant
2020-08-06 11:41 ` Jan Beulich
2020-08-14 6:53 ` Tian, Kevin
2020-08-14 7:19 ` Durrant, Paul
2020-08-04 13:42 ` [PATCH v4 07/14] iommu: make map, unmap and flush all take both an order and a count Paul Durrant
2020-08-06 9:57 ` Jan Beulich
2020-08-11 11:00 ` Durrant, Paul
2020-08-14 6:57 ` Tian, Kevin
2020-08-04 13:42 ` [PATCH v4 08/14] remove remaining uses of iommu_legacy_map/unmap Paul Durrant
2020-08-06 10:28 ` Jan Beulich
2020-08-12 9:36 ` [EXTERNAL] " Paul Durrant
2020-08-04 13:42 ` [PATCH v4 09/14] common/grant_table: batch flush I/O TLB Paul Durrant
2020-08-06 11:49 ` Jan Beulich
2020-08-04 13:42 ` [PATCH v4 10/14] iommu: remove the share_p2m operation Paul Durrant
2020-08-06 12:18 ` Jan Beulich [this message]
2020-08-14 7:04 ` Tian, Kevin
2020-08-04 13:42 ` [PATCH v4 11/14] iommu: stop calling IOMMU page tables 'p2m tables' Paul Durrant
2020-08-06 12:23 ` Jan Beulich
2020-08-14 7:12 ` Tian, Kevin
2020-08-04 13:42 ` [PATCH v4 12/14] vtd: use a bit field for root_entry Paul Durrant
2020-08-06 12:34 ` Jan Beulich
2020-08-12 13:13 ` Durrant, Paul
2020-08-18 8:27 ` Jan Beulich
2020-08-14 7:17 ` Tian, Kevin
2020-08-04 13:42 ` [PATCH v4 13/14] vtd: use a bit field for context_entry Paul Durrant
2020-08-06 12:46 ` Jan Beulich
2020-08-12 13:47 ` Paul Durrant
2020-08-14 7:19 ` Tian, Kevin
2020-08-04 13:42 ` [PATCH v4 14/14] vtd: use a bit field for dma_pte Paul Durrant
2020-08-06 12:53 ` Jan Beulich
2020-08-12 13:49 ` Paul Durrant
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