From patchwork Thu Jan 8 17:34:07 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Roth X-Patchwork-Id: 426818 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 168E0140129 for ; Fri, 9 Jan 2015 05:26:42 +1100 (AEDT) Received: from localhost ([::1]:47627 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9Hn6-0003FE-9J for incoming@patchwork.ozlabs.org; Thu, 08 Jan 2015 13:26:40 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60753) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9H0H-0004fz-DF for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:36:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Y9Gzw-0006rP-Et for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:36:13 -0500 Received: from e31.co.us.ibm.com ([32.97.110.149]:56903) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Y9Gzw-0006ql-6H for qemu-devel@nongnu.org; Thu, 08 Jan 2015 12:35:52 -0500 Received: from /spool/local by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Thu, 8 Jan 2015 10:35:50 -0700 Received: from b03cxnp07028.gho.boulder.ibm.com (b03cxnp07028.gho.boulder.ibm.com [9.17.130.15]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id A232D19D803E; Thu, 8 Jan 2015 10:24:27 -0700 (MST) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp07028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t08HYcuv30801982; Thu, 8 Jan 2015 10:34:38 -0700 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t08HZnEO023676; Thu, 8 Jan 2015 10:35:50 -0700 Received: from localhost (morrigu.austin.ibm.com [9.41.105.45]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVin) with ESMTP id t08HZm2m023548; Thu, 8 Jan 2015 10:35:48 -0700 From: Michael Roth To: qemu-devel@nongnu.org Date: Thu, 8 Jan 2015 11:34:07 -0600 Message-Id: <1420738472-23267-64-git-send-email-mdroth@linux.vnet.ibm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1420738472-23267-1-git-send-email-mdroth@linux.vnet.ibm.com> References: <1420738472-23267-1-git-send-email-mdroth@linux.vnet.ibm.com> X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15010817-8236-0000-0000-000008730EC5 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 32.97.110.149 Cc: qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH 63/88] exec: Handle multipage ranges in invalidate_and_set_dirty() X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Peter Maydell The code in invalidate_and_set_dirty() needs to handle addr/length combinations which cross guest physical page boundaries. This can happen, for example, when disk I/O reads large blocks into guest RAM which previously held code that we have cached translations for. Unfortunately we were only checking the clean/dirty status of the first page in the range, and then were calling a tb_invalidate function which only handles ranges that don't cross page boundaries. Fix the function to deal with multipage ranges. The symptoms of this bug were that guest code would misbehave (eg segfault), in particular after a guest reboot but potentially any time the guest reused a page of its physical RAM for new code. Cc: qemu-stable@nongnu.org Signed-off-by: Peter Maydell Reviewed-by: Paolo Bonzini Message-id: 1416167061-13203-1-git-send-email-peter.maydell@linaro.org (cherry picked from commit f874bf905ff2f8dcc17acbfc61e49a92a6f4d04b) Signed-off-by: Michael Roth --- exec.c | 6 ++---- include/exec/ram_addr.h | 25 +++++++++++++++++++++++++ 2 files changed, 27 insertions(+), 4 deletions(-) diff --git a/exec.c b/exec.c index a7d7daa..bfee04a 100644 --- a/exec.c +++ b/exec.c @@ -2009,10 +2009,8 @@ int cpu_memory_rw_debug(CPUState *cpu, target_ulong addr, static void invalidate_and_set_dirty(hwaddr addr, hwaddr length) { - if (cpu_physical_memory_is_clean(addr)) { - /* invalidate code */ - tb_invalidate_phys_page_range(addr, addr + length, 0); - /* set dirty bit */ + if (cpu_physical_memory_range_includes_clean(addr, length)) { + tb_invalidate_phys_range(addr, addr + length, 0); cpu_physical_memory_set_dirty_range_nocode(addr, length); } xen_modified_memory(addr, length); diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 6593be1..e50e71c 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -49,6 +49,21 @@ static inline bool cpu_physical_memory_get_dirty(ram_addr_t start, return next < end; } +static inline bool cpu_physical_memory_get_clean(ram_addr_t start, + ram_addr_t length, + unsigned client) +{ + unsigned long end, page, next; + + assert(client < DIRTY_MEMORY_NUM); + + end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; + page = start >> TARGET_PAGE_BITS; + next = find_next_zero_bit(ram_list.dirty_memory[client], end, page); + + return next < end; +} + static inline bool cpu_physical_memory_get_dirty_flag(ram_addr_t addr, unsigned client) { @@ -64,6 +79,16 @@ static inline bool cpu_physical_memory_is_clean(ram_addr_t addr) return !(vga && code && migration); } +static inline bool cpu_physical_memory_range_includes_clean(ram_addr_t start, + ram_addr_t length) +{ + bool vga = cpu_physical_memory_get_clean(start, length, DIRTY_MEMORY_VGA); + bool code = cpu_physical_memory_get_clean(start, length, DIRTY_MEMORY_CODE); + bool migration = + cpu_physical_memory_get_clean(start, length, DIRTY_MEMORY_MIGRATION); + return vga || code || migration; +} + static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr, unsigned client) {