From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Jan Beulich" Subject: Re: [RFC][PATCH 13/13] hvmloader/e820: construct guest e820 table Date: Fri, 15 May 2015 09:54:49 +0100 Message-ID: <5555D079020000780007A745@mail.emea.novell.com> References: <1428657724-3498-1-git-send-email-tiejun.chen@intel.com> <1428657724-3498-14-git-send-email-tiejun.chen@intel.com> <553529850200007800073DB7@mail.emea.novell.com> <55558E20.6020305@intel.com> <5555AD8B020000780007A5AE@mail.emea.novell.com> <555594AA.4040905@intel.com> <5555B4D7020000780007A620@mail.emea.novell.com> <55559C07.6000601@intel.com> <5555BDAF020000780007A679@mail.emea.novell.com> <5555A7A1.9020006@intel.com> <5555C671020000780007A6DD@mail.emea.novell.com> <5555B2B4.2060609@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5555B2B4.2060609@intel.com> Content-Disposition: inline List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Tiejun Chen Cc: tim@xen.org, kevin.tian@intel.com, wei.liu2@citrix.com, ian.campbell@citrix.com, andrew.cooper3@citrix.com, Ian.Jackson@eu.citrix.com, xen-devel@lists.xen.org, stefano.stabellini@citrix.com, yang.z.zhang@intel.com List-Id: xen-devel@lists.xenproject.org >>> On 15.05.15 at 10:47, wrote: > On 2015/5/15 16:12, Jan Beulich wrote: >>>>> On 15.05.15 at 10:00, wrote: >>> On 2015/5/15 15:34, Jan Beulich wrote: >>>>>>> On 15.05.15 at 09:11, wrote: >>>>> On 2015/5/15 14:56, Jan Beulich wrote: >>>>>>>>> On 15.05.15 at 08:39, wrote: >>>>>>> On 2015/5/15 14:25, Jan Beulich wrote: >>>>>>>>>>> On 15.05.15 at 08:11, wrote: >>>>>>>>> Even we may separate the >>>>>>>>> low memory to construct memory_map.map[]... >>>>>>>> >>>>>>>> ??? >>>>>>> >>>>>>> Sorry I just mean that the low memory is not represented with only one >>>>>>> memory_map.map[] in some cases. >>>>>> >>>>>> That's correct. >>>>>> >>>>> >>>>> So just lets keep that original BUG_ON()? >>>> >>>> In your previous reply you seemed to agree that the BUG_ON() is >>>> becoming meaningless. Why do you now suggest to keep it then? >>>> >>> >>> Sorry just let me clear this. >>> >>> We still need to check this, >>> >>> (hvm_info->low_mem_pgend << PAGE_SHIFT) < (2u << 20) >>> >>> Right? I agree the original is really less relevant as you said. >> >> And I didn't ask you to drop it. All I asked it to amend it with another >> BUG_ON() checking what the one above won't cover anymore. >> > > Another point hits me in this case while we're discussing MMIO in > another email. > > We may populate RAM to get enough MMIO in pci_setup() so this means > hvm_info->low_mem_pgend would be changed. Furthermore, low_mem_pgend > isn't going to keep recording our original lowmem while building domain. > So I think this original BUG_ON() is still good to cover this case. But > obviously, we need to adjust its associated memory_map.map[x] right now. > > So what about this? I don't think I have enough context anymore of all the other changes that you have pending to be able to reasonably judge on such code fragments. This will need looking at in the context of the next patch series revision. Jan