From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754751AbbGIUqK (ORCPT ); Thu, 9 Jul 2015 16:46:10 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:2082 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754726AbbGIUqA (ORCPT ); Thu, 9 Jul 2015 16:46:00 -0400 X-IronPort-AV: E=Sophos;i="5.15,442,1432598400"; d="scan'208";a="282742094" From: Julien Grall To: CC: , , , , "Julien Grall" , Konrad Rzeszutek Wilk , Boris Ostrovsky , "David Vrabel" Subject: [PATCH v2 19/20] xen/privcmd: Add support for Linux 64KB page granularity Date: Thu, 9 Jul 2015 21:42:31 +0100 Message-ID: <1436474552-31789-20-git-send-email-julien.grall@citrix.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> References: <1436474552-31789-1-git-send-email-julien.grall@citrix.com> MIME-Version: 1.0 Content-Type: text/plain X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The hypercall interface (as well as the toolstack) is always using 4KB page granularity. When the toolstack is asking for mapping a series of guest PFN in a batch, it expects to have the page map contiguously in its virtual memory. When Linux is using 64KB page granularity, the privcmd driver will have to map multiple Xen PFN in a single Linux page. Note that this solution works on page granularity which is a multiple of 4KB. Signed-off-by: Julien Grall Cc: Konrad Rzeszutek Wilk Cc: Boris Ostrovsky Cc: David Vrabel --- Changes in v2: - Use xen_apply_to_page --- drivers/xen/privcmd.c | 8 +-- drivers/xen/xlate_mmu.c | 127 +++++++++++++++++++++++++++++++++--------------- 2 files changed, 92 insertions(+), 43 deletions(-) diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 5a29616..e8714b4 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -446,7 +446,7 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version) return -EINVAL; } - nr_pages = m.num; + nr_pages = DIV_ROUND_UP_ULL(m.num, PAGE_SIZE / XEN_PAGE_SIZE); if ((m.num <= 0) || (nr_pages > (LONG_MAX >> PAGE_SHIFT))) return -EINVAL; @@ -494,7 +494,7 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version) goto out_unlock; } if (xen_feature(XENFEAT_auto_translated_physmap)) { - ret = alloc_empty_pages(vma, m.num); + ret = alloc_empty_pages(vma, nr_pages); if (ret < 0) goto out_unlock; } else @@ -518,6 +518,7 @@ static long privcmd_ioctl_mmap_batch(void __user *udata, int version) state.global_error = 0; state.version = version; + BUILD_BUG_ON(((PAGE_SIZE / sizeof(xen_pfn_t)) % XEN_PFN_PER_PAGE) != 0); /* mmap_batch_fn guarantees ret == 0 */ BUG_ON(traverse_pages_block(m.num, sizeof(xen_pfn_t), &pagelist, mmap_batch_fn, &state)); @@ -582,12 +583,13 @@ static void privcmd_close(struct vm_area_struct *vma) { struct page **pages = vma->vm_private_data; int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + int nr_pfn = (vma->vm_end - vma->vm_start) >> XEN_PAGE_SHIFT; int rc; if (!xen_feature(XENFEAT_auto_translated_physmap) || !numpgs || !pages) return; - rc = xen_unmap_domain_mfn_range(vma, numpgs, pages); + rc = xen_unmap_domain_mfn_range(vma, nr_pfn, pages); if (rc == 0) free_xenballooned_pages(numpgs, pages); else diff --git a/drivers/xen/xlate_mmu.c b/drivers/xen/xlate_mmu.c index 58a5389..1fac17c 100644 --- a/drivers/xen/xlate_mmu.c +++ b/drivers/xen/xlate_mmu.c @@ -38,31 +38,9 @@ #include #include -/* map fgmfn of domid to lpfn in the current domain */ -static int map_foreign_page(unsigned long lpfn, unsigned long fgmfn, - unsigned int domid) -{ - int rc; - struct xen_add_to_physmap_range xatp = { - .domid = DOMID_SELF, - .foreign_domid = domid, - .size = 1, - .space = XENMAPSPACE_gmfn_foreign, - }; - xen_ulong_t idx = fgmfn; - xen_pfn_t gpfn = lpfn; - int err = 0; - - set_xen_guest_handle(xatp.idxs, &idx); - set_xen_guest_handle(xatp.gpfns, &gpfn); - set_xen_guest_handle(xatp.errs, &err); - - rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp); - return rc < 0 ? rc : err; -} - struct remap_data { xen_pfn_t *fgmfn; /* foreign domain's gmfn */ + xen_pfn_t *efgmfn; /* pointer to the end of the fgmfn array */ pgprot_t prot; domid_t domid; struct vm_area_struct *vma; @@ -71,24 +49,75 @@ struct remap_data { struct xen_remap_mfn_info *info; int *err_ptr; int mapped; + + /* Hypercall parameters */ + int h_errs[XEN_PFN_PER_PAGE]; + xen_ulong_t h_idxs[XEN_PFN_PER_PAGE]; + xen_pfn_t h_gpfns[XEN_PFN_PER_PAGE]; + + int h_iter; /* Iterator */ }; +static int setup_hparams(struct page *page, unsigned long pfn, void *data) +{ + struct remap_data *info = data; + + /* We may not have enough domain's gmfn to fill a Linux Page */ + if (info->fgmfn == info->efgmfn) + return 0; + + info->h_idxs[info->h_iter] = *info->fgmfn; + info->h_gpfns[info->h_iter] = pfn; + info->h_errs[info->h_iter] = 0; + info->h_iter++; + + info->fgmfn++; + + return 0; +} + static int remap_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr, void *data) { struct remap_data *info = data; struct page *page = info->pages[info->index++]; - unsigned long pfn = page_to_pfn(page); - pte_t pte = pte_mkspecial(pfn_pte(pfn, info->prot)); + pte_t pte = pte_mkspecial(pfn_pte(page_to_pfn(page), info->prot)); int rc; + uint32_t i; + struct xen_add_to_physmap_range xatp = { + .domid = DOMID_SELF, + .foreign_domid = info->domid, + .space = XENMAPSPACE_gmfn_foreign, + }; - rc = map_foreign_page(pfn, *info->fgmfn, info->domid); - *info->err_ptr++ = rc; - if (!rc) { - set_pte_at(info->vma->vm_mm, addr, ptep, pte); - info->mapped++; + info->h_iter = 0; + + /* setup_hparams guarantees ret == 0 */ + BUG_ON(xen_apply_to_page(page, setup_hparams, info)); + + set_xen_guest_handle(xatp.idxs, info->h_idxs); + set_xen_guest_handle(xatp.gpfns, info->h_gpfns); + set_xen_guest_handle(xatp.errs, info->h_errs); + xatp.size = info->h_iter; + + rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp); + + /* info->err_ptr expect to have one error status per Xen PFN */ + for (i = 0; i < info->h_iter; i++) { + int err = (rc < 0) ? rc : info->h_errs[i]; + + *(info->err_ptr++) = err; + if (!err) + info->mapped++; } - info->fgmfn++; + + /* + * Note: The hypercall will return 0 in most of the case if even if + * all the fgmfn are not mapped. We still have to update the pte + * as the userspace may decide to continue. + */ + if (!rc) + set_pte_at(info->vma->vm_mm, addr, ptep, pte); return 0; } @@ -102,13 +131,14 @@ int xen_xlate_remap_gfn_array(struct vm_area_struct *vma, { int err; struct remap_data data; - unsigned long range = nr << PAGE_SHIFT; + unsigned long range = round_up(nr, XEN_PFN_PER_PAGE) << XEN_PAGE_SHIFT; /* Kept here for the purpose of making sure code doesn't break x86 PVOPS */ BUG_ON(!((vma->vm_flags & (VM_PFNMAP | VM_IO)) == (VM_PFNMAP | VM_IO))); data.fgmfn = mfn; + data.efgmfn = mfn + nr; data.prot = prot; data.domid = domid; data.vma = vma; @@ -123,21 +153,38 @@ int xen_xlate_remap_gfn_array(struct vm_area_struct *vma, } EXPORT_SYMBOL_GPL(xen_xlate_remap_gfn_array); +static int unmap_gfn(struct page *page, unsigned long pfn, void *data) +{ + int *nr = data; + struct xen_remove_from_physmap xrp; + + /* The Linux Page may not have been fully mapped to Xen */ + if (!*nr) + return 0; + + xrp.domid = DOMID_SELF; + xrp.gpfn = pfn; + (void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp); + + (*nr)--; + + return 0; +} + int xen_xlate_unmap_gfn_range(struct vm_area_struct *vma, int nr, struct page **pages) { int i; + int nr_page = round_up(nr, XEN_PFN_PER_PAGE); - for (i = 0; i < nr; i++) { - struct xen_remove_from_physmap xrp; - unsigned long pfn; + for (i = 0; i < nr_page; i++) { + /* unmap_gfn guarantees ret == 0 */ + BUG_ON(xen_apply_to_page(pages[i], unmap_gfn, &nr)); + } - pfn = page_to_pfn(pages[i]); + /* We should have consume every xen page */ + BUG_ON(nr != 0); - xrp.domid = DOMID_SELF; - xrp.gpfn = pfn; - (void)HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp); - } return 0; } EXPORT_SYMBOL_GPL(xen_xlate_unmap_gfn_range); -- 2.1.4