From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?windows-1252?Q?Roger_Pau_Monn=E9?= Subject: Re: [PATCH v4 25/31] xen: allow HVM guests to use XENMEM_memory_map Date: Fri, 7 Aug 2015 17:44:22 +0200 Message-ID: <55C4D256.90301@citrix.com> References: <1438942688-7610-1-git-send-email-roger.pau@citrix.com> <1438942688-7610-26-git-send-email-roger.pau@citrix.com> <20150807122241.GN6005@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZNjp2-000775-Dk for xen-devel@lists.xenproject.org; Fri, 07 Aug 2015 15:44:40 +0000 In-Reply-To: <20150807122241.GN6005@zion.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu Cc: Ian Campbell , Stefano Stabellini , Andrew Cooper , Ian Jackson , Jan Beulich , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org El 07/08/15 a les 14.22, Wei Liu ha escrit: > On Fri, Aug 07, 2015 at 12:18:02PM +0200, Roger Pau Monne wrote: >> Enable this hypercall for HVM guests in order to fetch the e820 memory >> map in the absence of an emulated BIOS. The memory map is populated and >> notified to Xen in arch_setup_meminit_hvm. >> >> Signed-off-by: Roger Pau Monn=E9 >> Cc: Ian Jackson >> Cc: Stefano Stabellini >> Cc: Ian Campbell >> Cc: Wei Liu >> Cc: Jan Beulich >> Cc: Andrew Cooper >> --- >> tools/libxc/xc_dom_x86.c | 29 ++++++++++++++++++++++++++++- >> 1 file changed, 28 insertions(+), 1 deletion(-) >> >> diff --git a/tools/libxc/xc_dom_x86.c b/tools/libxc/xc_dom_x86.c >> index b587b12..87bce6e 100644 >> --- a/tools/libxc/xc_dom_x86.c >> +++ b/tools/libxc/xc_dom_x86.c >> @@ -1205,6 +1205,7 @@ static int check_mmio_hole(uint64_t start, uint64_= t memsize, >> return 1; >> } >> = >> +#define MAX_E820_ENTRIES 128 >> static int meminit_hvm(struct xc_dom_image *dom) >> { >> unsigned long i, vmemid, nr_pages =3D dom->total_pages; >> @@ -1225,6 +1226,8 @@ static int meminit_hvm(struct xc_dom_image *dom) >> unsigned int nr_vmemranges, nr_vnodes; >> xc_interface *xch =3D dom->xch; >> uint32_t domid =3D dom->guest_domid; >> + struct e820entry entries[MAX_E820_ENTRIES]; >> + int e820_index =3D 0; >> = >> if ( nr_pages > target_pages ) >> memflags |=3D XENMEMF_populate_on_demand; >> @@ -1275,6 +1278,13 @@ static int meminit_hvm(struct xc_dom_image *dom) >> vnode_to_pnode =3D dom->vnode_to_pnode; >> } >> = >> + /* Add one additional memory range to account for the VGA hole */ >> + if ( (nr_vmemranges + (dom->emulation ? 1 : 0)) > MAX_E820_ENTRIES ) >> + { >> + DOMPRINTF("Too many memory ranges"); >> + goto error_out; >> + } >> + >> total_pages =3D 0; >> p2m_size =3D 0; >> for ( i =3D 0; i < nr_vmemranges; i++ ) >> @@ -1363,9 +1373,13 @@ static int meminit_hvm(struct xc_dom_image *dom) >> * Under 2MB mode, we allocate pages in batches of no more than 8MB= to = >> * ensure that we can be preempted and hence dom0 remains responsiv= e. >> */ >> - if ( dom->emulation ) >> + if ( dom->emulation ) { >> rc =3D xc_domain_populate_physmap_exact( >> xch, domid, 0xa0, 0, memflags, &dom->p2m_host[0x00]); >> + entries[e820_index].addr =3D 0; >> + entries[e820_index].size =3D 0xa0 << PAGE_SHIFT; >> + entries[e820_index++].type =3D E820_RAM; >> + } >> = >> stat_normal_pages =3D 0; >> for ( vmemid =3D 0; vmemid < nr_vmemranges; vmemid++ ) >> @@ -1392,6 +1406,12 @@ static int meminit_hvm(struct xc_dom_image *dom) >> else >> cur_pages =3D vmemranges[vmemid].start >> PAGE_SHIFT; >> = >> + /* Build an e820 map. */ >> + entries[e820_index].addr =3D cur_pages << PAGE_SHIFT; >> + entries[e820_index].size =3D vmemranges[vmemid].end - >> + entries[e820_index].addr; >> + entries[e820_index++].type =3D E820_RAM; >> + >> while ( (rc =3D=3D 0) && (end_pages > cur_pages) ) >> { >> /* Clip count to maximum 1GB extent. */ >> @@ -1509,6 +1529,13 @@ static int meminit_hvm(struct xc_dom_image *dom) >> DPRINTF(" 2MB PAGES: 0x%016lx\n", stat_2mb_pages); >> DPRINTF(" 1GB PAGES: 0x%016lx\n", stat_1gb_pages); >> = >> + rc =3D xc_domain_set_memory_map(xch, domid, entries, e820_index); >> + if ( rc !=3D 0 ) >> + { >> + DOMPRINTF("unable to set memory map."); >> + goto error_out; >> + } >> + > = > I think in RDM series there is already a memory map generated in libxl. > = > You might want to move this to libxl, which is supposed to be the > arbitrator of what a guest should look like. > = > What do you think? I would like to do that, the only problem I see is that libxl doesn't have any notion of the "special pages", so it doesn't know the size of the hole it has to made. I guess one solution would be moving the defines at the top of xc_dom_x86.c to a public libxc header so libxl can pick up the size and position of the hole. Roger.