From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mukesh Rathor Subject: Re: [PATCH v1 6/8]: PVH ballooning and grant changes Date: Tue, 25 Sep 2012 18:22:06 -0700 Message-ID: <20120925182206.1d9c7b52@mantra.us.oracle.com> References: <20120921121928.1c5765bc@mantra.us.oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Stefano Stabellini Cc: "Xen-devel@lists.xensource.com" , Ian Campbell , Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org On Mon, 24 Sep 2012 14:55:06 +0100 Stefano Stabellini wrote: > On Fri, 21 Sep 2012, Mukesh Rathor wrote: > > --- > > drivers/xen/balloon.c | 35 > > ++++++++++++++++++++++++++++------- drivers/xen/gntdev.c | > > 3 ++- drivers/xen/grant-table.c | 25 +++++++++++++++++++++---- > > 3 files changed, 51 insertions(+), 12 deletions(-) > > > > diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c > > index 31ab82f..85a6917 100644 > > --- a/drivers/xen/balloon.c > > +++ b/drivers/xen/balloon.c > > @@ -358,10 +358,21 @@ static enum bp_state > > increase_reservation(unsigned long nr_pages) > > BUG_ON(!xen_feature(XENFEAT_auto_translated_physmap) && > > phys_to_machine_mapping_valid(pfn)); > > - set_phys_to_machine(pfn, frame_list[i]); > > + if (xen_pv_domain() && > > + xen_feature(XENFEAT_auto_translated_physmap)) { > > + /* PVH: we just need to update native page > > table */ > > + pte_t *ptep; > > + unsigned int level; > > + void *addr = __va(pfn << PAGE_SHIFT); > > + ptep = lookup_address((unsigned long)addr, > > &level); > > + set_pte(ptep, pfn_pte(pfn, PAGE_KERNEL)); > > + } else > > + set_phys_to_machine(pfn, frame_list[i]); > > > > > /* Link back into the page tables if not highmem. > > */ > > - if (xen_pv_domain() && !PageHighMem(page)) { > > + if (xen_pv_domain() && !PageHighMem(page) && > > + !xen_feature(XENFEAT_auto_translated_physmap)) > > { + > > int ret; > > ret = HYPERVISOR_update_va_mapping( > > (unsigned long)__va(pfn << > > PAGE_SHIFT), @@ -418,12 +429,21 @@ static enum bp_state > > decrease_reservation(unsigned long nr_pages, gfp_t gfp) > > scrub_page(page); > > if (xen_pv_domain() && !PageHighMem(page)) { > > - ret = HYPERVISOR_update_va_mapping( > > - (unsigned long)__va(pfn << > > PAGE_SHIFT), > > - __pte_ma(0), 0); > > - BUG_ON(ret); > > + if > > (xen_feature(XENFEAT_auto_translated_physmap)) { > > + unsigned int level; > > + pte_t *ptep; > > + void *addr = __va(pfn << > > PAGE_SHIFT); > > + ptep = lookup_address((unsigned > > long)addr, > > + &level); > > + set_pte(ptep, __pte(0)); > > + > > + } else { > > + ret = HYPERVISOR_update_va_mapping( > > + (unsigned long)__va(pfn << > > PAGE_SHIFT), > > + __pte_ma(0), 0); > > + BUG_ON(ret); > > + } > > } > > - > > } > > > > /* Ensure that ballooned highmem pages don't have kmaps. */ > > @@ -433,6 +453,7 @@ static enum bp_state > > decrease_reservation(unsigned long nr_pages, gfp_t gfp) /* No more > > mappings: invalidate P2M and add to balloon. */ for (i = 0; i < > > nr_pages; i++) { pfn = mfn_to_pfn(frame_list[i]); > > + /* PVH note: following will noop for auto > > translated */ __set_phys_to_machine(pfn, INVALID_P2M_ENTRY); > > balloon_append(pfn_to_page(pfn)); > > } > > Maybe we need a function "update_mapping" internal to balloon.c that > would be set to HYPERVISOR_update_va_mapping for pv guests, set_pte > for pvh guests and nothing for pv on hvm guests. > > Speaking of which, why do pvh guests need a set_pte while pv on hvm > guests don't? I would think that their behaviour should be the same > regarding ballooning. you are right, I can remove it. Not sure why I've it there. Cant recall.