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From: Jan Beulich <jbeulich@suse.com>
To: Tamas K Lengyel <tamas.lengyel@intel.com>
Cc: "Tamas K Lengyel" <tamas@tklengyel.com>, "Wei Liu" <wl@xen.org>,
	"George Dunlap" <george.dunlap@eu.citrix.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	xen-devel@lists.xenproject.org,
	"Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH v4 13/18] x86/mem_sharing: Skip xen heap pages in memshr nominate
Date: Mon, 20 Jan 2020 17:23:58 +0100	[thread overview]
Message-ID: <03edb7c7-967a-19f4-76bd-9aa9c9af1bd3@suse.com> (raw)
In-Reply-To: <ce3871c8e9ee01523d2032990ff8acaaaf69a350.1578503483.git.tamas.lengyel@intel.com>

On 08.01.2020 18:14, Tamas K Lengyel wrote:
> Trying to share these would fail anyway, better to skip them early.
> 
> Signed-off-by: Tamas K Lengyel <tamas.lengyel@intel.com>

Reviewed-by: Jan Beulich <jbeulich@suse.com>
albeit I wonder if this couldn't be further generalized by ...

> --- a/xen/arch/x86/mm/mem_sharing.c
> +++ b/xen/arch/x86/mm/mem_sharing.c
> @@ -852,6 +852,11 @@ static int nominate_page(struct domain *d, gfn_t gfn,
>      if ( !p2m_is_sharable(p2mt) )
>          goto out;
>  
> +    /* Skip xen heap pages */
> +    page = mfn_to_page(mfn);
> +    if ( !page || is_xen_heap_page(page) )
> +        goto out;

... checking for a zero type ref count (the only means to permit
a type change) here, and maybe also ->count_info to fit what
page_make_sharable() expects.

Jan

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  reply	other threads:[~2020-01-20 16:24 UTC|newest]

Thread overview: 57+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-08 17:13 [Xen-devel] [PATCH v4 00/18] VM forking Tamas K Lengyel
2020-01-08 17:13 ` [Xen-devel] [PATCH v4 01/18] x86/hvm: introduce hvm_copy_context_and_params Tamas K Lengyel
2020-01-16 12:27   ` Jan Beulich
2020-01-16 14:06     ` Tamas K Lengyel
2020-01-08 17:13 ` [Xen-devel] [PATCH v4 02/18] xen/x86: Make hap_get_allocation accessible Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 03/18] x86/mem_sharing: make get_two_gfns take locks conditionally Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 04/18] x86/mem_sharing: drop flags from mem_sharing_unshare_page Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 05/18] x86/mem_sharing: don't try to unshare twice during page fault Tamas K Lengyel
2020-01-16 14:53   ` Jan Beulich
2020-01-16 15:59     ` Tamas K Lengyel
2020-01-16 16:03       ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 06/18] x86/mem_sharing: define mem_sharing_domain to hold some scattered variables Tamas K Lengyel
2020-01-16 15:23   ` Jan Beulich
2020-01-16 16:05     ` Tamas K Lengyel
2020-01-16 16:08       ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 07/18] x86/mem_sharing: Use INVALID_MFN and p2m_is_shared in relinquish_shared_pages Tamas K Lengyel
2020-01-16 15:40   ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 08/18] x86/mem_sharing: Make add_to_physmap static and shorten name Tamas K Lengyel
2020-01-16 15:40   ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 09/18] x86/mem_sharing: Convert MEM_SHARING_DESTROY_GFN to a bool Tamas K Lengyel
2020-01-16 15:42   ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 10/18] x86/mem_sharing: Replace MEM_SHARING_DEBUG with gdprintk Tamas K Lengyel
2020-01-16 16:01   ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 11/18] x86/mem_sharing: ASSERT that p2m_set_entry succeeds Tamas K Lengyel
2020-01-16 16:07   ` Jan Beulich
2020-01-16 16:12     ` Tamas K Lengyel
2020-01-17  9:23       ` Jan Beulich
2020-01-17 16:59         ` Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 12/18] x86/mem_sharing: Enable mem_sharing on first memop Tamas K Lengyel
2020-01-16 16:18   ` Jan Beulich
2020-01-16 16:34     ` Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 13/18] x86/mem_sharing: Skip xen heap pages in memshr nominate Tamas K Lengyel
2020-01-20 16:23   ` Jan Beulich [this message]
2020-01-20 16:32     ` Tamas K Lengyel
2020-01-20 16:38       ` Jan Beulich
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 14/18] x86/mem_sharing: check page type count earlier Tamas K Lengyel
2020-01-20 16:34   ` Jan Beulich
2020-01-20 16:46     ` Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 15/18] xen/mem_sharing: VM forking Tamas K Lengyel
2020-01-09 10:28   ` Julien Grall
2020-01-09 13:41     ` Tamas K Lengyel
2020-01-09 15:10       ` Roger Pau Monné
2020-01-09 15:34         ` Jan Beulich
2020-01-09 15:57           ` Tamas K Lengyel
2020-01-09 16:03             ` Jan Beulich
2020-01-09 16:06               ` Tamas K Lengyel
2020-01-09 15:54         ` Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 16/18] xen/mem_access: Use __get_gfn_type_access in set_mem_access Tamas K Lengyel
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 17/18] x86/mem_sharing: reset a fork Tamas K Lengyel
2020-01-09 10:30   ` Julien Grall
2020-01-08 17:14 ` [Xen-devel] [PATCH v4 18/18] xen/tools: VM forking toolstack side Tamas K Lengyel
2020-01-16 15:47 ` [Xen-devel] [PATCH v4 00/18] VM forking Jan Beulich
2020-01-16 16:24   ` Tamas K Lengyel
2020-01-17  9:12     ` Jan Beulich
2020-01-17 11:15       ` Anthony PERARD
2020-01-17 14:22         ` Tamas K Lengyel
2020-01-17 14:25       ` Tamas K Lengyel

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