From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konrad Rzeszutek Wilk Subject: Re: [PATCH v8 17/19] grant-table: call set_phys_to_machine after mapping grant refs Date: Wed, 23 Oct 2013 10:04:57 -0400 Message-ID: <20131023140457.GC27771@phenom.dumpdata.com> References: <1382031814-8782-17-git-send-email-stefano.stabellini@eu.citrix.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <1382031814-8782-17-git-send-email-stefano.stabellini@eu.citrix.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Stefano Stabellini Cc: xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Ian.Campbell@citrix.com List-Id: xen-devel@lists.xenproject.org On Thu, Oct 17, 2013 at 06:43:32PM +0100, Stefano Stabellini wrote: > When mapping/unmapping grant refs, call > set_phys_to_machine to update the P2M with the new mappings for > autotranslate guests. Heh. That sounds so odd (p2m + xlat). Can you add a sentence saying that this is a mostly a nop on x86 please? (Well, the call to set_phys_to_machine does end up with this check: if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) { BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY); return true; } But that should be a fairly small amount of code. > > Signed-off-by: Stefano Stabellini > --- > drivers/xen/grant-table.c | 17 +++++++++++++++-- > 1 files changed, 15 insertions(+), 2 deletions(-) > > diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c > index 04cdeb8..a36cb03 100644 > --- a/drivers/xen/grant-table.c > +++ b/drivers/xen/grant-table.c > @@ -49,6 +49,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -889,8 +890,15 @@ int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops, > gnttab_retry_eagain_gop(GNTTABOP_map_grant_ref, map_ops + i, > &map_ops[i].status, __func__); > > - if (xen_feature(XENFEAT_auto_translated_physmap)) > + if (xen_feature(XENFEAT_auto_translated_physmap)) { > + 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); > + } > return ret; > + } > > if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > arch_enter_lazy_mmu_mode(); > @@ -933,8 +941,13 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops, > if (ret) > return ret; > > - if (xen_feature(XENFEAT_auto_translated_physmap)) > + if (xen_feature(XENFEAT_auto_translated_physmap)) { > + for (i = 0; i < count; i++) { > + set_phys_to_machine(unmap_ops[i].host_addr >> PAGE_SHIFT, > + INVALID_P2M_ENTRY); > + } > return ret; > + } > > if (!in_interrupt() && paravirt_get_lazy_mode() == PARAVIRT_LAZY_NONE) { > arch_enter_lazy_mmu_mode(); > -- > 1.7.2.5 >