From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932902Ab0JRPys (ORCPT ); Mon, 18 Oct 2010 11:54:48 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:57342 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932167Ab0JRPyr (ORCPT >); Mon, 18 Oct 2010 11:54:47 -0400 Date: Mon, 18 Oct 2010 11:54:12 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, Jeremy.Fitzhardinge@citrix.com, Ian Campbell Subject: Re: [PATCH v3 08/10] xen: use host E820 map for dom0 Message-ID: <20101018155412.GD27373@dumpdata.com> References: <1286901770-8612-8-git-send-email-Stefano.Stabellini@eu.citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1286901770-8612-8-git-send-email-Stefano.Stabellini@eu.citrix.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 12, 2010 at 05:42:48PM +0100, Stefano Stabellini wrote: > From: Ian Campbell > > When running as initial domain, get the real physical memory map from > xen using the XENMEM_machine_memory_map hypercall and use it to setup > the e820 regions. > > Signed-off-by: Ian Campbell > Signed-off-by: Jeremy Fitzhardinge > Signed-off-by: Stefano Stabellini > --- > arch/x86/xen/setup.c | 43 +++++++++++++++++++++++++++++++++++++-- > include/xen/interface/memory.h | 28 ++++++++++++++++++++++++++ > 2 files changed, 68 insertions(+), 3 deletions(-) > > diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c > index 62ceb78..b08aac2 100644 > --- a/arch/x86/xen/setup.c > +++ b/arch/x86/xen/setup.c > @@ -107,14 +107,51 @@ static unsigned long __init xen_return_unused_memory(unsigned long max_pfn, > > char * __init xen_memory_setup(void) > { > + static __initdata struct e820entry map[E820MAX]; > + > unsigned long max_pfn = xen_start_info->nr_pages; > + struct xen_memory_map memmap; > + unsigned long long mem_end; > + int op; > + int rc; > + int i; > > max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); > + mem_end = PFN_PHYS((u64)max_pfn); > + > + memmap.nr_entries = E820MAX; > + set_xen_guest_handle(memmap.buffer, map); > + > + op = xen_initial_domain() ? > + XENMEM_machine_memory_map : > + XENMEM_memory_map; > + rc = HYPERVISOR_memory_op(op, &memmap); > + if (rc == -ENOSYS) { > + memmap.nr_entries = 1; > + map[0].addr = 0ULL; > + map[0].size = mem_end; > + /* 8MB slack (to balance backend allocations). */ > + map[0].size += 8ULL << 20; > + map[0].type = E820_RAM; > + rc = 0; > + } > + BUG_ON(rc); > > e820.nr_map = 0; > - > - e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM); > - > + for (i = 0; i < memmap.nr_entries; i++) { > + unsigned long long end = map[i].addr + map[i].size; > + if (map[i].type == E820_RAM) { > + if (map[i].addr > mem_end) > + continue; Would it make sense to print out a message saying something to the effect of: "You need to increase the CONFIG_XEN_MAX_DOMAIN_MEMORY value to take advantage of the extra %d gobs of memory!\n", map[i].size Or will this be unneccessary with the later changes that Jeremy has for the balloon work? > + if (end > mem_end) { > + /* Truncate region to max_mem. */ > + map[i].size -= end - mem_end; > + } > + } > + if (map[i].size > 0) > + e820_add_region(map[i].addr, map[i].size, map[i].type); > + } > + > /* > * Even though this is normal, usable memory under Xen, reserve > * ISA memory anyway because too many things think they can poke > diff --git a/include/xen/interface/memory.h b/include/xen/interface/memory.h > index d3938d3..4c4b817 100644 > --- a/include/xen/interface/memory.h > +++ b/include/xen/interface/memory.h > @@ -186,6 +186,34 @@ struct xen_translate_gpfn_list { > }; > DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list); > > +/* > + * Returns the pseudo-physical memory map as it was when the domain > + * was started (specified by XENMEM_set_memory_map). > + * arg == addr of struct xen_memory_map. > + */ > +#define XENMEM_memory_map 9 > +struct xen_memory_map { > + /* > + * On call the number of entries which can be stored in buffer. On > + * return the number of entries which have been stored in > + * buffer. > + */ > + unsigned int nr_entries; > + > + /* > + * Entries in the buffer are in the same format as returned by the > + * BIOS INT 0x15 EAX=0xE820 call. > + */ > + GUEST_HANDLE(void) buffer; > +}; > +DEFINE_GUEST_HANDLE_STRUCT(xen_memory_map); > + > +/* > + * Returns the real physical memory map. Passes the same structure as > + * XENMEM_memory_map. > + * arg == addr of struct xen_memory_map. > + */ > +#define XENMEM_machine_memory_map 10 > > /* > * Prevent the balloon driver from changing the memory reservation > -- > 1.5.6.5