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From: "Chen, Tiejun" <tiejun.chen@intel.com>
To: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: Kevin Tian <kevin.tian@intel.com>, Keir Fraser <keir@xen.org>,
	Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Tim Deegan <tim@xen.org>,
	"xen-devel@lists.xen.org" <xen-devel@lists.xen.org>,
	Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>,
	Jan Beulich <jbeulich@suse.com>,
	Yang Zhang <yang.z.zhang@intel.com>,
	Stefano Stabellini <stefano.stabellini@citrix.com>,
	Ian Campbell <ian.campbell@citrix.com>
Subject: Re: [v7][PATCH 03/16] xen/passthrough: extend hypercall to support rdm reservation policy
Date: Mon, 13 Jul 2015 14:47:22 +0800	[thread overview]
Message-ID: <55A35EFA.9030304@intel.com> (raw)
In-Reply-To: <CAFLBxZbZkS3ZRyTC-g07MYNCDDm4Tb3rCB2oJRzx3qVHxxEvPA@mail.gmail.com>

> Thanks for this; a few more comments...
>

Thanks for your time.

>> @@ -1577,9 +1578,15 @@ int iommu_do_pci_domctl(
>>           seg = machine_sbdf >> 16;
>>           bus = PCI_BUS(machine_sbdf);
>>           devfn = PCI_DEVFN2(machine_sbdf);
>> +        flag = domctl->u.assign_device.flag;
>> +        if ( flag > XEN_DOMCTL_DEV_RDM_RELAXED )
>
> This is not a blocker, but a stylistic comment: I would have inverted
> the bitmask here, as that's conceptually what you're checking.  I
> won't make this a blocker for going in.

What about this?

diff --git a/xen/drivers/passthrough/pci.c b/xen/drivers/passthrough/pci.c
index 6e23fc6..17a4206 100644
--- a/xen/drivers/passthrough/pci.c
+++ b/xen/drivers/passthrough/pci.c
@@ -1579,7 +1579,7 @@ int iommu_do_pci_domctl(
          bus = PCI_BUS(machine_sbdf);
          devfn = PCI_DEVFN2(machine_sbdf);
          flag = domctl->u.assign_device.flag;
-        if ( flag > XEN_DOMCTL_DEV_RDM_RELAXED )
+        if ( flag & ~XEN_DOMCTL_DEV_RDM_MASK )
          {
              ret = -EINVAL;
              break;
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index bca25c9..07549a4 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -480,6 +480,7 @@ struct xen_domctl_assign_device {
      } u;
      /* IN */
  #define XEN_DOMCTL_DEV_RDM_RELAXED      1
+#define XEN_DOMCTL_DEV_RDM_MASK         0x1
      uint32_t  flag;   /* flag of assigned device */
  };
  typedef struct xen_domctl_assign_device xen_domctl_assign_device_t;

>
>> @@ -1898,7 +1899,14 @@ static int intel_iommu_add_device(u8 devfn, struct pci_dev *pdev)
>>                PCI_BUS(bdf) == pdev->bus &&
>>                PCI_DEVFN2(bdf) == devfn )
>>           {
>> -            ret = rmrr_identity_mapping(pdev->domain, 1, rmrr);
>> +            /*
>> +             * Here means we're add a device to the hardware domain
>> +             * so actually RMRR is always reserved on e820 so either
>> +             * of flag is fine for hardware domain and here we'd like
>> +             * to pass XEN_DOMCTL_DEV_RDM_RELAXED.
>> +             */
>
> Sorry I didn't give feedback on your comment before.  I don't find it
> clear enough; I'd suggest something like this:
>
> "iommu_add_device() is only called for the hardware domain (see
> xen/drivers/passthrough/pci.c:pci_add_device()).  Since RMRRs are
> always reserved in the e820 map for the hardware domain, there
> shouldn't be a conflict."

Loos good and thanks.

>
> I also said that if we went with anything other than STRICT that we'd
> need to check to make sure that the domain really was the hardware
> domain before proceeding, in case the assumption that pdev->domain ==
> hardware_domain ever changed.  (Perhaps with an ASSERT -- Jan, what do
> you think?)

Sounds reasonable.

>
> Also, passing in RELAXED in locations where the flag is completely
> ignored (such as when removing mappings) doesn't really make any
> sense.
>
> On the whole I think it would be better if you removed the RELAXED
> flag for both removals and for hardware domains.
>

Just as I said in another email I agreed your STRICT way.

Thanks
Tiejun

  parent reply	other threads:[~2015-07-13  6:47 UTC|newest]

Thread overview: 119+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-09  5:33 [v7][PATCH 00/16] Fix RMRR Tiejun Chen
2015-07-09  5:33 ` [v7][PATCH 01/16] xen: introduce XENMEM_reserved_device_memory_map Tiejun Chen
2015-07-09  5:33 ` [v7][PATCH 02/16] xen/vtd: create RMRR mapping Tiejun Chen
2015-07-09  5:33 ` [v7][PATCH 03/16] xen/passthrough: extend hypercall to support rdm reservation policy Tiejun Chen
2015-07-10 13:26   ` George Dunlap
2015-07-10 15:01     ` Jan Beulich
2015-07-10 15:07       ` George Dunlap
2015-07-13  6:37         ` Chen, Tiejun
2015-07-13  5:57       ` Chen, Tiejun
2015-07-13  6:47     ` Chen, Tiejun [this message]
2015-07-13  8:57       ` Jan Beulich
2015-07-14 10:46       ` George Dunlap
2015-07-14 10:53         ` Chen, Tiejun
2015-07-14 11:30           ` George Dunlap
2015-07-14 11:45             ` Jan Beulich
2015-07-14 13:25               ` George Dunlap
2015-07-09  5:33 ` [v7][PATCH 04/16] xen: enable XENMEM_memory_map in hvm Tiejun Chen
2015-07-09  5:33 ` [v7][PATCH 05/16] hvmloader: get guest memory map into memory_map[] Tiejun Chen
2015-07-10 13:49   ` George Dunlap
2015-07-13  7:03     ` Chen, Tiejun
2015-07-09  5:33 ` [v7][PATCH 06/16] hvmloader/pci: skip reserved ranges Tiejun Chen
2015-07-13 13:12   ` Jan Beulich
2015-07-14  6:39     ` Chen, Tiejun
2015-07-14  9:27       ` Jan Beulich
2015-07-14 10:54         ` Chen, Tiejun
2015-07-14 11:50           ` Jan Beulich
2015-07-15  0:55             ` Chen, Tiejun
2015-07-15  4:27               ` Chen, Tiejun
2015-07-15  8:34                 ` Jan Beulich
2015-07-15  8:59                   ` Chen, Tiejun
2015-07-15  9:10                     ` Chen, Tiejun
2015-07-15  9:27                     ` Jan Beulich
2015-07-15 10:34                       ` Chen, Tiejun
2015-07-15 11:25                         ` Jan Beulich
2015-07-15 11:34                           ` Chen, Tiejun
2015-07-15 13:56                             ` George Dunlap
2015-07-15 16:14                               ` George Dunlap
2015-07-16  2:05                                 ` Chen, Tiejun
2015-07-16  9:40                                   ` George Dunlap
2015-07-16 10:01                                     ` Chen, Tiejun
2015-07-15 11:05                       ` George Dunlap
2015-07-15 11:20                         ` Chen, Tiejun
2015-07-15 12:43                           ` George Dunlap
2015-07-15 13:23                             ` Chen, Tiejun
2015-07-15 11:24                         ` Jan Beulich
2015-07-15 11:38                           ` George Dunlap
2015-07-15 11:27                         ` Jan Beulich
2015-07-15 11:40                           ` Chen, Tiejun
2015-07-15  8:32               ` Jan Beulich
2015-07-15  9:04                 ` Chen, Tiejun
2015-07-15 12:57                 ` Wei Liu
2015-07-15 13:40     ` George Dunlap
2015-07-15 14:00       ` Jan Beulich
2015-07-15 15:19         ` George Dunlap
2015-07-09  5:33 ` [v7][PATCH 07/16] hvmloader/e820: construct guest e820 table Tiejun Chen
2015-07-13 13:35   ` Jan Beulich
2015-07-14  5:22     ` Chen, Tiejun
2015-07-14  9:32       ` Jan Beulich
2015-07-14 10:22         ` Chen, Tiejun
2015-07-14 10:48           ` Jan Beulich
2015-07-15 16:00   ` George Dunlap
2015-07-16  1:58     ` Chen, Tiejun
2015-07-16  9:41       ` George Dunlap
2015-07-09  5:33 ` [v7][PATCH 08/16] tools/libxc: Expose new hypercall xc_reserved_device_memory_map Tiejun Chen
2015-07-09  5:34 ` [v7][PATCH 09/16] tools: extend xc_assign_device() to support rdm reservation policy Tiejun Chen
2015-07-09  5:34 ` [v7][PATCH 10/16] tools: introduce some new parameters to set rdm policy Tiejun Chen
2015-07-09  9:20   ` Wei Liu
2015-07-09  9:44     ` Chen, Tiejun
2015-07-09 10:37       ` Ian Jackson
2015-07-09 10:53         ` Chen, Tiejun
2015-07-09 18:02   ` Ian Jackson
2015-07-10  0:46     ` Chen, Tiejun
2015-07-09  5:34 ` [v7][PATCH 11/16] tools/libxl: detect and avoid conflicts with RDM Tiejun Chen
2015-07-09  9:11   ` Wei Liu
2015-07-09  9:41     ` Chen, Tiejun
2015-07-09 18:14   ` Ian Jackson
2015-07-10  3:19     ` Chen, Tiejun
2015-07-10 10:14       ` Ian Jackson
2015-07-13  9:19         ` Chen, Tiejun
2015-07-09  5:34 ` [v7][PATCH 12/16] tools: introduce a new parameter to set a predefined rdm boundary Tiejun Chen
2015-07-09 18:14   ` Ian Jackson
2015-07-09  5:34 ` [v7][PATCH 13/16] libxl: construct e820 map with RDM information for HVM guest Tiejun Chen
2015-07-09 18:17   ` Ian Jackson
2015-07-10  5:40     ` Chen, Tiejun
2015-07-10  9:18       ` Ian Campbell
2015-07-13  9:47         ` Chen, Tiejun
2015-07-13 10:15           ` Ian Campbell
2015-07-14  5:44             ` Chen, Tiejun
2015-07-14  7:42               ` Ian Campbell
2015-07-14  8:03                 ` Chen, Tiejun
2015-07-10 10:15       ` Ian Jackson
2015-07-09  5:34 ` [v7][PATCH 14/16] xen/vtd: enable USB device assignment Tiejun Chen
2015-07-09  5:34 ` [v7][PATCH 15/16] xen/vtd: prevent from assign the device with shared rmrr Tiejun Chen
2015-07-13 13:41   ` Jan Beulich
2015-07-14  1:42     ` Chen, Tiejun
2015-07-14  9:19       ` Jan Beulich
2015-07-09  5:34 ` [v7][PATCH 16/16] tools: parse to enable new rdm policy parameters Tiejun Chen
2015-07-09 18:23   ` Ian Jackson
2015-07-10  6:05     ` Chen, Tiejun
2015-07-10 10:23       ` Ian Jackson
2015-07-13  9:31         ` Chen, Tiejun
2015-07-13  9:40           ` Ian Campbell
2015-07-13  9:55             ` Chen, Tiejun
2015-07-13 10:17               ` Ian Campbell
2015-07-13 17:08                 ` Ian Jackson
2015-07-14  1:29                   ` Chen, Tiejun
2015-07-10 14:50 ` [v7][PATCH 00/16] Fix RMRR George Dunlap
2015-07-10 14:56   ` Jan Beulich
2015-07-16  7:55   ` Jan Beulich
2015-07-16  8:03     ` Chen, Tiejun
2015-07-16  8:08       ` Jan Beulich
2015-07-16  8:13         ` Chen, Tiejun
2015-07-16  8:26           ` Jan Beulich
2015-07-16  9:27             ` George Dunlap
2015-07-16  9:44               ` Jan Beulich
2015-07-16  9:59                 ` George Dunlap
2015-07-16  8:30         ` Ian Campbell
2015-07-16  8:46           ` Wei Liu
2015-07-16  9:45           ` Lars Kurth

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