Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755553AbbGPPsR (ORCPT ); Thu, 16 Jul 2015 11:48:17 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:28199 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751788AbbGPPsQ (ORCPT ); Thu, 16 Jul 2015 11:48:16 -0400 X-IronPort-AV: E=Sophos;i="5.15,488,1432598400"; d="scan'208";a="284773201" Date: Thu, 16 Jul 2015 16:47:09 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Julien Grall CC: , , , , , David Vrabel , Russell King , Konrad Rzeszutek Wilk , Boris Ostrovsky Subject: Re: [PATCH v2 14/20] xen/grant-table: Make it running on 64KB granularity In-Reply-To: <1436474552-31789-15-git-send-email-julien.grall@citrix.com> Message-ID: References: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> <1436474552-31789-15-git-send-email-julien.grall@citrix.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3558 Lines: 95 On Thu, 9 Jul 2015, Julien Grall wrote: > The Xen interface is using 4KB page granularity. This means that each > grant is 4KB. > > The current implementation allocates a Linux page per grant. On Linux > using 64KB page granularity, only the first 4KB of the page will be > used. > > We could decrease the memory wasted by sharing the page with multiple > grant. It will require some care with the {Set,Clear}ForeignPage macro. > > Note that no changes has been made in the x86 code because both Linux > and Xen will only use 4KB page granularity. > > Signed-off-by: Julien Grall > Reviewed-by: David Vrabel > Cc: Stefano Stabellini > Cc: Russell King > Cc: Konrad Rzeszutek Wilk > Cc: Boris Ostrovsky > --- > Changes in v2 > - Add David's reviewed-by > --- > arch/arm/xen/p2m.c | 6 +++--- > drivers/xen/grant-table.c | 6 +++--- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/xen/p2m.c b/arch/arm/xen/p2m.c > index 887596c..0ed01f2 100644 > --- a/arch/arm/xen/p2m.c > +++ b/arch/arm/xen/p2m.c > @@ -93,8 +93,8 @@ int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops, > for (i = 0; i < count; i++) { > if (map_ops[i].status) > continue; > - set_phys_to_machine(map_ops[i].host_addr >> PAGE_SHIFT, > - map_ops[i].dev_bus_addr >> PAGE_SHIFT); > + set_phys_to_machine(map_ops[i].host_addr >> XEN_PAGE_SHIFT, > + map_ops[i].dev_bus_addr >> XEN_PAGE_SHIFT); > } > > return 0; > @@ -108,7 +108,7 @@ int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops, > int i; > > for (i = 0; i < count; i++) { > - set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, > + set_phys_to_machine(unmap_ops[i].host_addr >> XEN_PAGE_SHIFT, > INVALID_P2M_ENTRY); > } > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 3679293..0a1f903 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c The arm part is fine, but aren't you missing the change to RPP and SPP? > @@ -668,7 +668,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) > if (xen_auto_xlat_grant_frames.count) > return -EINVAL; > > - vaddr = xen_remap(addr, PAGE_SIZE * max_nr_gframes); > + vaddr = xen_remap(addr, XEN_PAGE_SIZE * max_nr_gframes); > if (vaddr == NULL) { > pr_warn("Failed to ioremap gnttab share frames (addr=%pa)!\n", > &addr); > @@ -680,7 +680,7 @@ int gnttab_setup_auto_xlat_frames(phys_addr_t addr) > return -ENOMEM; > } > for (i = 0; i < max_nr_gframes; i++) > - pfn[i] = PFN_DOWN(addr) + i; > + pfn[i] = XEN_PFN_DOWN(addr) + i; > > xen_auto_xlat_grant_frames.vaddr = vaddr; > xen_auto_xlat_grant_frames.pfn = pfn; > @@ -1004,7 +1004,7 @@ static void gnttab_request_version(void) > { > /* Only version 1 is used, which will always be available. */ > grant_table_version = 1; > - grefs_per_grant_frame = PAGE_SIZE / sizeof(struct grant_entry_v1); > + grefs_per_grant_frame = XEN_PAGE_SIZE / sizeof(struct grant_entry_v1); > gnttab_interface = &gnttab_v1_ops; > > pr_info("Grant tables using version %d layout\n", grant_table_version); > -- > 2.1.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/