From patchwork Tue Nov 29 06:55:16 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "Wang, Zhi A" X-Patchwork-Id: 9451073 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 7B1B960235 for ; Tue, 29 Nov 2016 07:03:33 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 71B8827DCD for ; Tue, 29 Nov 2016 07:03:33 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6674427E3E; Tue, 29 Nov 2016 07:03:33 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E657727DCD for ; Tue, 29 Nov 2016 07:03:32 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4BF086E1E7; Tue, 29 Nov 2016 07:03:29 +0000 (UTC) X-Original-To: intel-gfx@lists.freedesktop.org Delivered-To: intel-gfx@lists.freedesktop.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2AEB96E1E2 for ; Tue, 29 Nov 2016 07:03:27 +0000 (UTC) Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga104.jf.intel.com with ESMTP; 28 Nov 2016 23:03:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.31,715,1473145200"; d="scan'208";a="791992361" Received: from dev-inno.bj.intel.com ([10.238.135.53]) by FMSMGA003.fm.intel.com with ESMTP; 28 Nov 2016 23:03:24 -0800 From: Zhi Wang To: intel-gfx@lists.freedesktop.org Date: Tue, 29 Nov 2016 14:55:16 +0800 Message-Id: <1480402516-22275-1-git-send-email-zhi.a.wang@intel.com> X-Mailer: git-send-email 1.9.1 MIME-Version: 1.0 Cc: Zhiyuan Lv Subject: [Intel-gfx] [PATCH] drm/i915: Move the release of PT page to the upper caller X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" X-Virus-Scanned: ClamAV using ClamSMTP a PT page will be released if it doesn't contain any meaningful mappings during PPGTT page table shrinking. The PT entry in the upper level will be set to a scratch entry. Normally this works nicely, but in virtualization world, the PPGTT page table is tracked by hypervisor. Releasing the PT page before modifying the upper level PT entry would cause extra efforts. As the tracked page has been returned to OS before losing track from hypervisor, it could be written in any pattern. Hypervisor has to recognize if a page is still being used as a PT page by validating these writing patterns. It's complicated. Better let the guest modify the PT entry in upper level PT first, then release the PT page. Reviewed-by: Chris Wilson Reviewed-by: Michał Winiarski Cc: Michał Winiarski Cc: Michel Thierry Cc: Joonas Lahtinen Cc: Chris Wilson Cc: Zhenyu Wang Cc: Zhiyuan Lv Signed-off-by: Zhi Wang Link: https://patchwork.freedesktop.org/patch/122697/msgid/1479728666-25333-1-git-send-email-zhi.a.wang@intel.com --- drivers/gpu/drm/i915/i915_gem_gtt.c | 18 +++++++----------- 1 file changed, 7 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c index b4bde14..6cee707 100644 --- a/drivers/gpu/drm/i915/i915_gem_gtt.c +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c @@ -736,10 +736,8 @@ static bool gen8_ppgtt_clear_pt(struct i915_address_space *vm, bitmap_clear(pt->used_ptes, pte, num_entries); - if (bitmap_empty(pt->used_ptes, GEN8_PTES)) { - free_pt(to_i915(vm->dev), pt); + if (bitmap_empty(pt->used_ptes, GEN8_PTES)) return true; - } pt_vaddr = kmap_px(pt); @@ -775,13 +773,12 @@ static bool gen8_ppgtt_clear_pd(struct i915_address_space *vm, pde_vaddr = kmap_px(pd); pde_vaddr[pde] = scratch_pde; kunmap_px(ppgtt, pde_vaddr); + free_pt(to_i915(vm->dev), pt); } } - if (bitmap_empty(pd->used_pdes, I915_PDES)) { - free_pd(to_i915(vm->dev), pd); + if (bitmap_empty(pd->used_pdes, I915_PDES)) return true; - } return false; } @@ -795,7 +792,6 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm, uint64_t length) { struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); - struct drm_i915_private *dev_priv = to_i915(vm->dev); struct i915_page_directory *pd; uint64_t pdpe; gen8_ppgtt_pdpe_t *pdpe_vaddr; @@ -813,16 +809,14 @@ static bool gen8_ppgtt_clear_pdp(struct i915_address_space *vm, pdpe_vaddr[pdpe] = scratch_pdpe; kunmap_px(ppgtt, pdpe_vaddr); } + free_pd(to_i915(vm->dev), pd); } } mark_tlbs_dirty(ppgtt); - if (USES_FULL_48BIT_PPGTT(dev_priv) && - bitmap_empty(pdp->used_pdpes, I915_PDPES_PER_PDP(dev_priv))) { - free_pdp(dev_priv, pdp); + if (bitmap_empty(pdp->used_pdpes, I915_PDPES_PER_PDP(dev_priv))) return true; - } return false; } @@ -836,6 +830,7 @@ static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm, uint64_t start, uint64_t length) { + struct drm_i915_private *dev_priv = to_i915(vm->dev); struct i915_hw_ppgtt *ppgtt = i915_vm_to_ppgtt(vm); struct i915_page_directory_pointer *pdp; uint64_t pml4e; @@ -854,6 +849,7 @@ static void gen8_ppgtt_clear_pml4(struct i915_address_space *vm, pml4e_vaddr = kmap_px(pml4); pml4e_vaddr[pml4e] = scratch_pml4e; kunmap_px(ppgtt, pml4e_vaddr); + free_pdp(dev_priv, pdp); } } }