From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from list by lists.gnu.org with archive (Exim 4.71) id 1aXqVQ-0003M1-Ni for mharc-grub-devel@gnu.org; Mon, 22 Feb 2016 08:26:28 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57574) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXqVO-0003La-4d for grub-devel@gnu.org; Mon, 22 Feb 2016 08:26:27 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aXqVK-00073a-Uu for grub-devel@gnu.org; Mon, 22 Feb 2016 08:26:26 -0500 Received: from mx2.suse.de ([195.135.220.15]:38711) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aXqVK-00073W-Jf for grub-devel@gnu.org; Mon, 22 Feb 2016 08:26:22 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 860B8AB9D; Mon, 22 Feb 2016 13:26:21 +0000 (UTC) Subject: Re: [PATCH v4 09/11] xen: add capability to load initrd outside of initial mapping To: Daniel Kiper References: <1456120999-5639-1-git-send-email-jgross@suse.com> <1456120999-5639-10-git-send-email-jgross@suse.com> <20160222084209.GN3482@olila.local.net-space.pl> <56CAD26E.9090205@suse.com> <20160222122411.GR3482@olila.local.net-space.pl> From: Juergen Gross X-Enigmail-Draft-Status: N1110 Message-ID: <56CB0C7D.1050909@suse.com> Date: Mon, 22 Feb 2016 14:26:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160222122411.GR3482@olila.local.net-space.pl> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x (no timestamps) [generic] X-Received-From: 195.135.220.15 Cc: grub-devel@gnu.org, phcoder@gmail.com, mchang@suse.com, xen-devel@lists.xen.org X-BeenThere: grub-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list Reply-To: The development of GNU GRUB List-Id: The development of GNU GRUB List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 22 Feb 2016 13:26:27 -0000 On 22/02/16 13:24, Daniel Kiper wrote: > On Mon, Feb 22, 2016 at 10:18:38AM +0100, Juergen Gross wrote: >> On 22/02/16 09:42, Daniel Kiper wrote: >>> On Mon, Feb 22, 2016 at 07:03:17AM +0100, Juergen Gross wrote: >>>> Modern pvops linux kernels support an initrd not covered by the initial >>>> mapping. This capability is flagged by an elf-note. >>>> >>>> In case the elf-note is set by the kernel don't place the initrd into >>>> the initial mapping. This will allow to load larger initrds and/or >>>> support domains with larger memory, as the initial mapping is limited >>>> to 2GB and it is containing the p2m list. >>>> >>>> Signed-off-by: Juergen Gross >>>> Reviewed-by: Daniel Kiper >>>> --- >>>> V4: rename grub_xen_alloc_end() to grub_xen_alloc_final() >>>> --- >>>> grub-core/loader/i386/xen.c | 61 ++++++++++++++++++++++++++++++-------- >>>> grub-core/loader/i386/xen_fileXX.c | 3 ++ >>>> include/grub/xen_file.h | 1 + >>>> 3 files changed, 52 insertions(+), 13 deletions(-) >>>> >>>> diff --git a/grub-core/loader/i386/xen.c b/grub-core/loader/i386/xen.c >>>> index 2e12763..22a94ae 100644 >>>> --- a/grub-core/loader/i386/xen.c >>>> +++ b/grub-core/loader/i386/xen.c >>>> @@ -58,6 +58,7 @@ struct xen_loader_state { >>>> grub_uint64_t modules_target_start; >>>> grub_size_t n_modules; >>>> int loaded; >>>> + int alloc_end_called; >>> >>> alloc_end_called -> alloc_final_called >>> >>>> }; >>>> >>>> static struct xen_loader_state xen_state; >>>> @@ -320,6 +321,28 @@ grub_xen_pt_alloc (void) >>>> } >>>> >>>> static grub_err_t >>>> +grub_xen_alloc_final (void) >>>> +{ >>>> + grub_err_t err; >>>> + >>>> + if (xen_state.alloc_end_called) >>>> + return GRUB_ERR_NONE; >>>> + xen_state.alloc_end_called = 1; >>> >>> This is not nice. What happens if grub_xen_p2m_alloc() allocate what >>> is needed and grub_xen_special_alloc() fails? >> >> Then grub_xen_alloc_final will fail resulting in boot failure of the >> new kernel. The memory allocated by the single functions will be freed >> in case a new boot is attempted (patch 1 and 2). >> >>> Maybe grub_xen_p2m_alloc(), grub_xen_special_alloc() and grub_xen_pt_alloc() >>> should check itself that required regions are allocated properly >>> (if (something != NULL)) and do nothing if yes. >> >> Hmm, with grub_xen_reset() doing appropriate cleanups this would be an >> option. I think I'll change it as you are suggesting. > > It looks that we can completely avoid that stuff. I think that > grub_xen_alloc_final() should be called conditionally in both > places/cases. That is all. Hmm. I think this is less clear, especially taking patch 11 into account. And I wouldn't like to tie e.g. page table allocation to something like "if (!xen_state.virt_start_info)" which would result from that change, now that I've removed xen_state.alloc_end_called as you suggested. Juergen