From: "Chen, Tiejun" <tiejun.chen@intel.com>
To: Jan Beulich <JBeulich@suse.com>
Cc: Wei Liu <wei.liu2@citrix.com>,
Ian Campbell <ian.campbell@citrix.com>,
Stefano Stabellini <stefano.stabellini@eu.citrix.com>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Ian Jackson <ian.jackson@eu.citrix.com>,
xen-devel@lists.xen.org, Keir Fraser <keir@xen.org>
Subject: Re: [v7][PATCH 07/16] hvmloader/e820: construct guest e820 table
Date: Tue, 14 Jul 2015 13:22:16 +0800 [thread overview]
Message-ID: <55A49C88.2060803@intel.com> (raw)
In-Reply-To: <55A3DADC0200007800090355@mail.emea.novell.com>
>> Now we can use that memory map to build our final
>> e820 table but it may need to reorder all e820
>> entries.
>
> "it" being what? I'm afraid I can't really make sense of the second
> half of the sentence...
I hope the following can work for you,
...
but finally we should sort them into an increasing order since
we shouldn't assume the original order is always good.
>
>> --- a/tools/firmware/hvmloader/e820.c
>> +++ b/tools/firmware/hvmloader/e820.c
>> @@ -108,7 +108,9 @@ int build_e820_table(struct e820entry *e820,
>> unsigned int lowmem_reserved_base,
>> unsigned int bios_image_base)
[snip]
>
>> + */
>> + for ( i = 0; i < memory_map.nr_map; i++ )
>> + {
>> + uint64_t end = e820[i].addr + e820[i].size;
>
> Either loop index/boundary or used array are wrong here: In the
> earlier loop you copied memory_map[0...nr_map-1] to
> e820[n...n+nr_map-1], but here you're looping looking at
> e820[0...nr_map-1]
You're right. I should lookup all e820[] like this,
for ( i = 0; i < nr; i++ )
>
>> + if ( e820[i].type == E820_RAM &&
>> + low_mem_end > e820[i].addr && low_mem_end < end )
>
> Assuming you mean to look at the RDM e820[] entries here, this
> is not a correct check: You don't care about partly or fully
> contained, all you care about is whether low_mem_end extends
> beyond the start of the region.
Here I'm looking at the e820 entry indicating low memory. Because
low_mem_end = hvm_info->low_mem_pgend << PAGE_SHIFT;
and when we allocate MMIO in pci.c, its possible to populate RAM so
hvm_info->low_mem_pgend would be changed over there. So we need to
compensate this loss with high memory. Here memory_map[] also records
the original low/high memory, so if low_mem_end is less-than the
original we need this compensation.
So here we have two steps to address this issue,
#1. Calculate the loss
>
>> + {
>> + add_high_mem = end - low_mem_end;
>> + e820[i].size = low_mem_end - e820[i].addr;
>> + }
>> + }
>> +
>> + /*
>> + * And then we also need to adjust highmem.
>> + */
>
> A single line comment should use the respective comment style.
>
#2. Compensate the loss
>> + if ( add_high_mem )
>> + {
>> + for ( i = 0; i < memory_map.nr_map; i++ )
s/memory_map.nr_map/nr
>> + {
>> + if ( e820[i].type == E820_RAM &&
>> + e820[i].addr > (1ull << 32))
>> + e820[i].size += add_high_mem;
>> + }
>> + }
>
> But looking at the code I think the comment should be extended to
> state that we currently expect there to be exactly one such RAM
> region.
>
I can add this at the beginning of #1 loop,
Its possible to relocate RAM to allocate sufficient MMIO previously so
low_mem_pgend would be changed over there. And here memory_map[] records
the original low/high memory, so if low_mem_end is less than the
original we need to revise low/high memory range in e820.
Thanks
Tiejun
next prev parent reply other threads:[~2015-07-14 5:22 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
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 [this message]
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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