Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753358AbaACTSc (ORCPT ); Fri, 3 Jan 2014 14:18:32 -0500 Received: from andromeda.dapyr.net ([206.212.254.10]:35988 "EHLO andromeda.dapyr.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752436AbaACTSb (ORCPT ); Fri, 3 Jan 2014 14:18:31 -0500 Date: Fri, 3 Jan 2014 15:18:12 -0400 From: Konrad Rzeszutek Wilk To: Stefano Stabellini Cc: Konrad Rzeszutek Wilk , linux-kernel@vger.kernel.org, david.vrabel@citrix.com, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com Subject: Re: [Xen-devel] [PATCH v12 14/18] xen/grant: Implement an grant frame array struct. Message-ID: <20140103191812.GA31994@andromeda.dapyr.net> References: <1388550945-25499-1-git-send-email-konrad.wilk@oracle.com> <1388550945-25499-15-git-send-email-konrad.wilk@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5191 Lines: 138 On Fri, Jan 03, 2014 at 04:53:59PM +0000, Stefano Stabellini wrote: > On Tue, 31 Dec 2013, Konrad Rzeszutek Wilk wrote: > > The 'xen_hvm_resume_frames' used to be an 'unsigned long' > > and contain the virtual address of the grants. That was OK > > for most architectures (PVHVM, ARM) were the grants are contingous > > in memory. That however is not the case for PVH - in which case > > we will have to do a lookup for each virtual address for the PFN. > > > > Instead of doing that, lets make it a structure which will contain > > the array of PFNs, the virtual address and the count of said PFNs. > > > > Also provide a generic functions: gnttab_setup_auto_xlat_frames and > > gnttab_free_auto_xlat_frames to populate said structure with > > appropiate values for PVHVM and ARM. > ^appropriate > > > > To round it off, change the name from 'xen_hvm_resume_frames' to > > a more descriptive one - 'xen_auto_xlat_grant_frames'. > > > > For PVH, in patch "xen/pvh: Piggyback on PVHVM for grant driver" > > we will populate the 'xen_auto_xlat_grant_frames' by ourselves. > > > > Suggested-by: Stefano Stabellini > > Signed-off-by: Konrad Rzeszutek Wilk > > --- > > arch/arm/xen/enlighten.c | 9 +++++++-- > > drivers/xen/grant-table.c | 45 ++++++++++++++++++++++++++++++++++++++++----- > > drivers/xen/platform-pci.c | 10 +++++++--- > > include/xen/grant_table.h | 9 ++++++++- > > 4 files changed, 62 insertions(+), 11 deletions(-) > > > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > > index 8550123..2162172 100644 > > --- a/arch/arm/xen/enlighten.c > > +++ b/arch/arm/xen/enlighten.c > > @@ -208,6 +208,7 @@ static int __init xen_guest_init(void) > > const char *version = NULL; > > const char *xen_prefix = "xen,xen-"; > > struct resource res; > > + unsigned long grant_frames; > > > > node = of_find_compatible_node(NULL, NULL, "xen,xen"); > > if (!node) { > > @@ -224,10 +225,10 @@ static int __init xen_guest_init(void) > > } > > if (of_address_to_resource(node, GRANT_TABLE_PHYSADDR, &res)) > > return 0; > > - xen_hvm_resume_frames = res.start; > > + grant_frames = res.start; > > xen_events_irq = irq_of_parse_and_map(node, 0); > > pr_info("Xen %s support found, events_irq=%d gnttab_frame_pfn=%lx\n", > > - version, xen_events_irq, (xen_hvm_resume_frames >> PAGE_SHIFT)); > > + version, xen_events_irq, (grant_frames >> PAGE_SHIFT)); > > xen_domain_type = XEN_HVM_DOMAIN; > > > > xen_setup_features(); > > @@ -265,6 +266,10 @@ static int __init xen_guest_init(void) > > if (xen_vcpu_info == NULL) > > return -ENOMEM; > > > > + if (gnttab_setup_auto_xlat_frames(grant_frames)) { > > + free_percpu(xen_vcpu_info); > > + return -ENOMEM; > > + } > > gnttab_init(); > > if (!xen_initial_domain()) > > xenbus_probe(NULL); > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > > index cc1b4fa..b117fd6 100644 > > --- a/drivers/xen/grant-table.c > > +++ b/drivers/xen/grant-table.c > > @@ -65,8 +65,8 @@ static unsigned int nr_grant_frames; > > static int gnttab_free_count; > > static grant_ref_t gnttab_free_head; > > static DEFINE_SPINLOCK(gnttab_list_lock); > > -unsigned long xen_hvm_resume_frames; > > -EXPORT_SYMBOL_GPL(xen_hvm_resume_frames); > > +struct grant_frames xen_auto_xlat_grant_frames; > > +EXPORT_SYMBOL_GPL(xen_auto_xlat_grant_frames); > > it should be static now Can't be. The arch/x86/xen/grant-table.c has to use it. I can drop the 'EXPORT_SYMBOL_GPL' though. > > > > static union { > > struct grant_entry_v1 *v1; > > @@ -838,6 +838,40 @@ unsigned int gnttab_max_grant_frames(void) > > } > > EXPORT_SYMBOL_GPL(gnttab_max_grant_frames); > > > > +int gnttab_setup_auto_xlat_frames(unsigned long addr) > > +{ > > + xen_pfn_t *pfn; > > + unsigned int max_nr_gframes = __max_nr_grant_frames(); > > + int i; > > + > > + if (xen_auto_xlat_grant_frames.count) > > + return -EINVAL; > > + > > + pfn = kcalloc(max_nr_gframes, sizeof(pfn[0]), GFP_KERNEL); > > + if (!pfn) > > + return -ENOMEM; > > + for (i = 0; i < max_nr_gframes; i++) > > + pfn[i] = PFN_DOWN(addr + (i * PAGE_SIZE)); > > + > > + xen_auto_xlat_grant_frames.vaddr = addr; > > + xen_auto_xlat_grant_frames.pfn = pfn; > > + xen_auto_xlat_grant_frames.count = max_nr_gframes; > > + > > + return 0; > > +} > > +EXPORT_SYMBOL_GPL(gnttab_setup_auto_xlat_frames); > > + > > +void gnttab_free_auto_xlat_frames(void) > > +{ > > + if (!xen_auto_xlat_grant_frames.count) > > + return; > > + kfree(xen_auto_xlat_grant_frames.pfn); > > + xen_auto_xlat_grant_frames.pfn = NULL; > > + xen_auto_xlat_grant_frames.count = 0; > > + xen_auto_xlat_grant_frames.vaddr = 0; > > +} > > +EXPORT_SYMBOL_GPL(gnttab_free_auto_xlat_frames); > > I would leave vaddr alone in gnttab_setup_auto_xlat_frames and > gnttab_free_auto_xlat_frames Actually, I like David's suggestion. 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