Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752439AbbHJMxx (ORCPT ); Mon, 10 Aug 2015 08:53:53 -0400 Received: from smtp.citrix.com ([66.165.176.89]:54257 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751540AbbHJMxv (ORCPT ); Mon, 10 Aug 2015 08:53:51 -0400 X-IronPort-AV: E=Sophos;i="5.15,645,1432598400"; d="scan'208";a="289631001" Date: Mon, 10 Aug 2015 13:52:22 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Julien Grall CC: , , , , , Russell King Subject: Re: [PATCH v3 20/20] arm/xen: Add support for 64KB page granularity In-Reply-To: <1438966019-19322-21-git-send-email-julien.grall@citrix.com> Message-ID: References: <1438966019-19322-1-git-send-email-julien.grall@citrix.com> <1438966019-19322-21-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: 3847 Lines: 102 On Fri, 7 Aug 2015, Julien Grall wrote: > The hypercall interface is always using 4KB page granularity. This is > requiring to use xen page definition macro when we deal with hypercall. > > Note that pfn_to_gfn is working with a Xen pfn (i.e 4KB). We may want to > rename pfn_gfn to make this explicit. > > We also allocate a 64KB page for the shared page even though only the > first 4KB is used. I don't think this is really important for now as it > helps to have the pointer 4KB aligned (XENMEM_add_to_physmap is taking a > Xen PFN). > > Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini > --- > Cc: Stefano Stabellini > Cc: Russell King > > Stefano, I've dropped your reviewed-by given I've updated the doc and do > changes to avoid usage of XEN_PAGE_SHIFT > > Changes in v3: > - s/MFN/GFN/ base on the new naming > - Use virt_to_gfn to avoid use XEN_PAGE_SHIFT > - Drop Stefano's reviewed-by > - Add some docs in arch/arm/asm/xen/page.h > > Changes in v2 > - Add Stefano's reviewed-by > --- > arch/arm/include/asm/xen/page.h | 15 +++++++++++++-- > arch/arm/xen/enlighten.c | 6 +++--- > 2 files changed, 16 insertions(+), 5 deletions(-) > > diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h > index 98c9fc3..e3d94cf 100644 > --- a/arch/arm/include/asm/xen/page.h > +++ b/arch/arm/include/asm/xen/page.h > @@ -28,6 +28,17 @@ typedef struct xpaddr { > > #define INVALID_P2M_ENTRY (~0UL) > > +/* > + * The pseudo-physical frame (pfn) used in all the helpers is always based > + * on Xen page granularity (i.e 4KB). > + * > + * A Linux page may be split across multiple non-contiguous Xen page so we > + * have to keep track with frame based on 4KB page granularity. > + * > + * PV drivers should never make a direct usage of those helpers (particularly > + * pfn_to_gfn and gfn_to_pfn). > + */ > + > unsigned long __pfn_to_mfn(unsigned long pfn); > extern struct rb_root phys_to_mach; > > @@ -64,8 +75,8 @@ static inline unsigned long bfn_to_pfn(unsigned long bfn) > #define bfn_to_local_pfn(bfn) bfn_to_pfn(bfn) > > /* VIRT <-> GUEST conversion */ > -#define virt_to_gfn(v) (pfn_to_gfn(virt_to_pfn(v))) > -#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << PAGE_SHIFT)) > +#define virt_to_gfn(v) (pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT)) > +#define gfn_to_virt(m) (__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT)) > > /* Only used in PV code. But ARM guests are always HVM. */ > static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr) > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index eeeab07..50b4769 100644 > --- a/arch/arm/xen/enlighten.c > +++ b/arch/arm/xen/enlighten.c > @@ -89,8 +89,8 @@ static void xen_percpu_init(void) > pr_info("Xen: initializing cpu%d\n", cpu); > vcpup = per_cpu_ptr(xen_vcpu_info, cpu); > > - info.mfn = __pa(vcpup) >> PAGE_SHIFT; > - info.offset = offset_in_page(vcpup); > + info.mfn = virt_to_gfn(vcpup); > + info.offset = xen_offset_in_page(vcpup); > > err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, cpu, &info); > BUG_ON(err); > @@ -213,7 +213,7 @@ static int __init xen_guest_init(void) > xatp.domid = DOMID_SELF; > xatp.idx = 0; > xatp.space = XENMAPSPACE_shared_info; > - xatp.gpfn = __pa(shared_info_page) >> PAGE_SHIFT; > + xatp.gpfn = virt_to_gfn(shared_info_page); > if (HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp)) > BUG(); > > -- > 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/