From: Tim Deegan <tim@xen.org>
To: Andres Lagar-Cavilla <andres@lagarcavilla.org>
Cc: olaf@aepfle.de, xen-devel@lists.xensource.com, keir@xen.org,
Tim Deegan <Tim.Deegan@citrix.com>,
andres@gridcentric.ca, wei.wang2@amd.com, hongkaixing@huawei.com,
adin@gridcentric.ca
Subject: Re: [PATCH 2 of 3] x86/mm: Teach paging to page table-based p2m
Date: Thu, 15 Mar 2012 17:21:45 +0000 [thread overview]
Message-ID: <20120315172145.GE12366@ocelot.phlegethon.org> (raw)
In-Reply-To: <b1d25298994ad7b3b8a750237a73c677.squirrel@webmail.lagarcavilla.org>
At 08:46 -0700 on 15 Mar (1331801170), Andres Lagar-Cavilla wrote:
> > Righto. In that case, I'd be happy with just clipping MFNs and not
> > trying to unpack them. But I think it should happen in the main
> > pte-building macros, not scattered around the p2m code. It should just
> > be a matter of using PADDR_MASK in the right place.
>
> Something along these lines? (RFC, not tested yet)
> Andres
>
> /* Construct a pte from a pfn and access flags. */
> #define l1e_from_pfn(pfn, flags) \
> - ((l1_pgentry_t) { ((intpte_t)(pfn) << PAGE_SHIFT) | put_pte_flags(flags) })
> + ((l1_pgentry_t) { ((intpte_t)((pfn) & (PADDR_MASK >> PAGE_SHIFT)) << \
> + PAGE_SHIFT) | put_pte_flags(flags) })
Yes, that's the idea. I think
> + ((l1_pgentry_t) { (((intpte_t)(pfn) << PAGE_SHIFT) & PADDR_MASK) \
> + | put_pte_flags(flags) })
is a little neater, maybe?
In any case, I'd like Keir's ack on this, since it will affect all the
PV pagetable code too (hopefully in a trivial and correct way).
Tim.
next prev parent reply other threads:[~2012-03-15 17:21 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-01 3:15 [PATCH 0 of 3] RFC Paging support for AMD NPT V2 Andres Lagar-Cavilla
2012-03-01 3:15 ` [PATCH 1 of 3] IOMMU: Add command line param to disable sharing of IOMMU and hap tables Andres Lagar-Cavilla
2012-03-01 3:15 ` [PATCH 2 of 3] x86/mm: Teach paging to page table-based p2m Andres Lagar-Cavilla
2012-03-08 14:15 ` Tim Deegan
2012-03-14 19:12 ` Andres Lagar-Cavilla
2012-03-15 10:52 ` Tim Deegan
2012-03-15 15:46 ` Andres Lagar-Cavilla
2012-03-15 17:21 ` Tim Deegan [this message]
2012-03-15 17:34 ` Keir Fraser
2012-03-01 3:15 ` [PATCH 3 of 3] x86/mm: Enable paging and sharing in AMD NPT mode Andres Lagar-Cavilla
2012-03-08 13:30 ` Tim Deegan
2012-03-01 7:55 ` [PATCH 0 of 3] RFC Paging support for AMD NPT V2 Hongkaixing
2012-03-01 16:34 ` Andres Lagar-Cavilla
2012-03-02 9:35 ` Hongkaixing
2012-03-02 15:55 ` Andres Lagar-Cavilla
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