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From: "Jan Beulich" <JBeulich@suse.com>
To: "Andrew Cooper" <andrew.cooper3@citrix.com>,
	"Stefano Stabellini" <sstabellini@kernel.org>
Cc: xen-devel <xen-devel@lists.xenproject.org>,
	Julien Grall <julien.grall@arm.com>,
	Stefano Stabellini <stefanos@xilinx.com>
Subject: Re: [Xen-devel] [PATCH v2 03/10] xen: extend XEN_DOMCTL_memory_mapping to handle memory policy
Date: Wed, 19 Jun 2019 00:53:13 -0600
Message-ID: <5D09DBD9020000780023981A@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <alpine.DEB.2.21.1906181612230.2072@sstabellini-ThinkPad-T480s>

>>> On 19.06.19 at 01:15, <sstabellini@kernel.org> wrote:
> On Tue, 18 Jun 2019, Stefano Stabellini wrote:
>> On Tue, 18 Jun 2019, Jan Beulich wrote:
>> > >>> On 17.06.19 at 23:28, <sstabellini@kernel.org> wrote:
>> > > On Thu, 2 May 2019, Jan Beulich wrote:
>> > >> >>> On 30.04.19 at 23:02, <sstabellini@kernel.org> wrote:
>> > >> > --- a/xen/include/public/domctl.h
>> > >> > +++ b/xen/include/public/domctl.h
>> > >> > @@ -571,12 +571,24 @@ struct xen_domctl_bind_pt_irq {
>> > >> >  */
>> > >> >  #define DPCI_ADD_MAPPING         1
>> > >> >  #define DPCI_REMOVE_MAPPING      0
>> > >> > +/*
>> > >> > + * Default memory policy. Corresponds to:
>> > >> > + * Arm: MEMORY_POLICY_ARM_DEV_nGRE
>> > >> > + * x86: MEMORY_POLICY_X86_UC
>> > >> > + */
>> > >> > +#define MEMORY_POLICY_DEFAULT    0
>> > >> > +/* x86 only. Memory type UNCACHABLE */
>> > >> > +#define MEMORY_POLICY_X86_UC     0
>> > >> 
>> > >> I'm afraid this may end up misleading, as on NPT and in
>> > >> shadow mode we use UC- instead of UC afaics. Andrew,
>> > >> do you have an opinion either way what exactly should
>> > >> be stated here?
>> > > 
>> > > Ping?
>> > 
>> > To me? I've stated my opinion.
>> 
>> I cannot name the macro "MEMORY_POLICY_X86_UC-" because it cannot end
>> with a "-". Instead, I can name it MEMORY_POLICY_X86_UC_MINUS that seems
>> to be what Linux does. I'll rename the optional xl parameter too from
>> "x86_uc" to "x86_uc_minus".
> 
> I chatted with Andrew on IRC and he suggested to get rid of the option
> entirely -- there is just one on x86 and doesn't necessarily need to be
> explicitly visible. We could only have MEMORY_POLICY_DEFAULT, and also
> remove the x86_uc setting from libxl/xl.
> 
> I am OK with this. However, given that I have already made all the
> changes to have MEMORY_POLICY_X86_UC_MINUS and x86_uc_minus everywhere,
> I'll send an update of the series with them.

Aren't we back to the question them whether to make this an Arm-
only interface? I'm having trouble seeing the value of an interface
which allows one to only "switch" from default to default.

Jan



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Thread overview: 86+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-30 21:02 [PATCH v2 0/10] iomem " Stefano Stabellini
2019-04-30 21:02 ` [Xen-devel] " Stefano Stabellini
2019-04-30 21:02 ` [PATCH v2 01/10] xen: add a p2mt parameter to map_mmio_regions Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-02 14:59   ` Jan Beulich
2019-05-02 14:59     ` [Xen-devel] " Jan Beulich
2019-05-02 18:49     ` Stefano Stabellini
2019-05-02 18:49       ` [Xen-devel] " Stefano Stabellini
2019-05-15 13:39   ` Oleksandr
2019-05-15 13:39     ` [Xen-devel] " Oleksandr
2019-04-30 21:02 ` [PATCH v2 02/10] xen: rename un/map_mmio_regions to un/map_regions Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-01  9:22   ` Julien Grall
2019-05-01  9:22     ` [Xen-devel] " Julien Grall
2019-06-17 21:24     ` Stefano Stabellini
2019-06-18 11:05       ` Julien Grall
2019-06-18 20:19         ` Stefano Stabellini
2019-05-02 15:03   ` Jan Beulich
2019-05-02 15:03     ` [Xen-devel] " Jan Beulich
2019-05-02 18:55     ` Stefano Stabellini
2019-05-02 18:55       ` [Xen-devel] " Stefano Stabellini
2019-04-30 21:02 ` [PATCH v2 03/10] xen: extend XEN_DOMCTL_memory_mapping to handle memory policy Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-02 15:12   ` Jan Beulich
2019-05-02 15:12     ` [Xen-devel] " Jan Beulich
2019-06-17 21:28     ` Stefano Stabellini
2019-06-18  8:59       ` Jan Beulich
2019-06-18 20:32         ` Stefano Stabellini
2019-06-18 23:15           ` Stefano Stabellini
2019-06-19  6:53             ` Jan Beulich [this message]
2019-05-07 16:41   ` Julien Grall
2019-05-07 16:41     ` [Xen-devel] " Julien Grall
2019-06-17 22:43     ` Stefano Stabellini
2019-06-18 11:13       ` Julien Grall
2019-05-15 14:40   ` Oleksandr
2019-05-15 14:40     ` [Xen-devel] " Oleksandr
2019-04-30 21:02 ` [PATCH v2 04/10] libxc: introduce xc_domain_mem_map_policy Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-04-30 21:02 ` [PATCH v2 05/10] libxl/xl: add memory policy option to iomem Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-01  9:42   ` Julien Grall
2019-05-01  9:42     ` [Xen-devel] " Julien Grall
2019-06-17 22:32     ` Stefano Stabellini
2019-06-18 11:09       ` Julien Grall
2019-06-18 11:15   ` Julien Grall
2019-06-18 22:07     ` Stefano Stabellini
2019-06-18 22:20       ` Julien Grall
2019-06-18 22:46         ` Stefano Stabellini
2019-04-30 21:02 ` [PATCH v2 06/10] xen/arm: extend device_tree_for_each_node Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-07 17:12   ` Julien Grall
2019-05-07 17:12     ` [Xen-devel] " Julien Grall
2019-04-30 21:02 ` [PATCH v2 07/10] xen/arm: make process_memory_node a device_tree_node_func Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-01  9:47   ` Julien Grall
2019-05-01  9:47     ` [Xen-devel] " Julien Grall
2019-04-30 21:02 ` [PATCH v2 08/10] xen/arm: keep track of reserved-memory regions Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-01 10:03   ` Julien Grall
2019-05-01 10:03     ` [Xen-devel] " Julien Grall
2019-06-21 23:47     ` Stefano Stabellini
2019-05-07 17:21   ` Julien Grall
2019-05-07 17:21     ` [Xen-devel] " Julien Grall
2019-04-30 21:02 ` [PATCH v2 09/10] xen/arm: map reserved-memory regions as normal memory in dom0 Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-07 19:52   ` Julien Grall
2019-05-07 19:52     ` [Xen-devel] " Julien Grall
2019-04-30 21:02 ` [PATCH v2 10/10] xen/arm: add reserved-memory regions to the dom0 memory node Stefano Stabellini
2019-04-30 21:02   ` [Xen-devel] " Stefano Stabellini
2019-05-07 20:15   ` Julien Grall
2019-05-07 20:15     ` [Xen-devel] " Julien Grall
2019-05-10 20:51     ` Stefano Stabellini
2019-05-10 20:51       ` [Xen-devel] " Stefano Stabellini
2019-05-10 21:43       ` Julien Grall
2019-05-10 21:43         ` [Xen-devel] " Julien Grall
2019-05-11 12:40         ` Julien Grall
2019-05-11 12:40           ` [Xen-devel] " Julien Grall
2019-05-20 21:26           ` Stefano Stabellini
2019-05-20 21:26             ` [Xen-devel] " Stefano Stabellini
2019-05-20 22:38             ` Julien Grall
2019-05-20 22:38               ` [Xen-devel] " Julien Grall
2019-06-05 16:30               ` Julien Grall
2019-06-21 23:47                 ` Stefano Stabellini
2019-05-16 16:52 ` [PATCH v2 0/10] iomem memory policy Oleksandr
2019-05-16 16:52   ` [Xen-devel] " Oleksandr
2019-06-21 23:48   ` Stefano Stabellini

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