From patchwork Thu Aug 11 15:32:44 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Umesh Deshpande X-Patchwork-Id: 1057892 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by demeter2.kernel.org (8.14.4/8.14.4) with ESMTP id p7BFaZWT021570 for ; Thu, 11 Aug 2011 15:36:38 GMT Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753045Ab1HKPdG (ORCPT ); Thu, 11 Aug 2011 11:33:06 -0400 Received: from mx1.redhat.com ([209.132.183.28]:60775 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753023Ab1HKPc7 (ORCPT ); Thu, 11 Aug 2011 11:32:59 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id p7BFWwnc012602 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 11 Aug 2011 11:32:59 -0400 Received: from ns3.rdu.redhat.com (ns3.rdu.redhat.com [10.11.255.199]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id p7BFWw9Z028456; Thu, 11 Aug 2011 11:32:58 -0400 Received: from umeshhome.redhat.com (vpn-8-38.rdu.redhat.com [10.11.8.38]) by ns3.rdu.redhat.com (8.13.8/8.13.8) with ESMTP id p7BFWtYk018642; Thu, 11 Aug 2011 11:32:57 -0400 From: Umesh Deshpande To: kvm@vger.kernel.org Cc: quintela@redhat.com, mtosatti@redhat.com, pbonzini@redhat.com, Umesh Deshpande Subject: [RFC PATCH v3 4/4] Separate migration bitmap Date: Thu, 11 Aug 2011 11:32:44 -0400 Message-Id: <6a26e96d5673b9ad909a8b5d67b362c8505d73a5.1313076455.git.udeshpan@redhat.com> In-Reply-To: References: X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter2.kernel.org [140.211.167.43]); Thu, 11 Aug 2011 15:36:38 +0000 (UTC) This patch creates a migration bitmap, which is periodically kept in sync with the qemu bitmap. A separate copy of the dirty bitmap for the migration avoids concurrent access to the qemu bitmap from iothread and migration thread. Signed-off-by: Umesh Deshpande --- arch_init.c | 16 ++++++++------ cpu-all.h | 37 ++++++++++++++++++++++++++++++++++ exec.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 110 insertions(+), 7 deletions(-) diff --git a/arch_init.c b/arch_init.c index f0ddda6..296b7d6 100644 --- a/arch_init.c +++ b/arch_init.c @@ -123,13 +123,13 @@ static int ram_save_block(QEMUFile *f) current_addr = block->offset + offset; do { - if (cpu_physical_memory_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) { + if (migration_bitmap_get_dirty(current_addr, MIGRATION_DIRTY_FLAG)) { uint8_t *p; int cont = (block == last_block) ? RAM_SAVE_FLAG_CONTINUE : 0; - cpu_physical_memory_reset_dirty(current_addr, - current_addr + TARGET_PAGE_SIZE, - MIGRATION_DIRTY_FLAG); + migration_bitmap_reset_dirty(current_addr, + current_addr + TARGET_PAGE_SIZE, + MIGRATION_DIRTY_FLAG); p = block->host + offset; @@ -185,7 +185,7 @@ static ram_addr_t ram_save_remaining(void) ram_addr_t addr; for (addr = block->offset; addr < block->offset + block->length; addr += TARGET_PAGE_SIZE) { - if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) { + if (migration_bitmap_get_dirty(addr, MIGRATION_DIRTY_FLAG)) { count++; } } @@ -265,6 +265,8 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque) return 0; } + sync_migration_bitmap(0, TARGET_PHYS_ADDR_MAX); + if (stage == 1) { RAMBlock *block; bytes_transferred = 0; @@ -276,9 +278,9 @@ int ram_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque) QLIST_FOREACH(block, &ram_list.blocks, next) { for (addr = block->offset; addr < block->offset + block->length; addr += TARGET_PAGE_SIZE) { - if (!cpu_physical_memory_get_dirty(addr, + if (!migration_bitmap_get_dirty(addr, MIGRATION_DIRTY_FLAG)) { - cpu_physical_memory_set_dirty(addr); + migration_bitmap_set_dirty(addr); } } } diff --git a/cpu-all.h b/cpu-all.h index 6a5dbb3..34a225b 100644 --- a/cpu-all.h +++ b/cpu-all.h @@ -934,6 +934,7 @@ typedef struct RAMBlock { typedef struct RAMList { QemuMutex mutex; uint8_t *phys_dirty; + uint8_t *migration_bitmap; QLIST_HEAD(ram, RAMBlock) blocks; } RAMList; extern RAMList ram_list; @@ -1006,8 +1007,44 @@ static inline void cpu_physical_memory_mask_dirty_range(ram_addr_t start, } } + + void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, int dirty_flags); + +static inline int migration_bitmap_get_dirty(ram_addr_t addr, + int dirty_flags) +{ + return ram_list.migration_bitmap[addr >> TARGET_PAGE_BITS] & dirty_flags; +} + +static inline void migration_bitmap_set_dirty(ram_addr_t addr) +{ + ram_list.migration_bitmap[addr >> TARGET_PAGE_BITS] = 0xff; +} + +static inline void migration_bitmap_mask_dirty_range(ram_addr_t start, + int length, + int dirty_flags) +{ + int i, mask, len; + uint8_t *p; + + len = length >> TARGET_PAGE_BITS; + mask = ~dirty_flags; + p = ram_list.migration_bitmap + (start >> TARGET_PAGE_BITS); + for (i = 0; i < len; i++) { + p[i] &= mask; + } +} + + +void migration_bitmap_reset_dirty(ram_addr_t start, + ram_addr_t end, + int dirty_flags); + +void sync_migration_bitmap(ram_addr_t start, ram_addr_t end); + void cpu_tlb_update_dirty(CPUState *env); int cpu_physical_memory_set_dirty_tracking(int enable); diff --git a/exec.c b/exec.c index 7bfb36f..f758c4e 100644 --- a/exec.c +++ b/exec.c @@ -2106,6 +2106,10 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, abort(); } + if (kvm_enabled()) { + return; + } + for(env = first_cpu; env != NULL; env = env->next_cpu) { int mmu_idx; for (mmu_idx = 0; mmu_idx < NB_MMU_MODES; mmu_idx++) { @@ -2114,8 +2118,61 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, start1, length); } } + +} + +void migration_bitmap_reset_dirty(ram_addr_t start, ram_addr_t end, + int dirty_flags) +{ + unsigned long length, start1; + + start &= TARGET_PAGE_MASK; + end = TARGET_PAGE_ALIGN(end); + + length = end - start; + if (length == 0) { + return; + } + + migration_bitmap_mask_dirty_range(start, length, dirty_flags); + + /* we modify the TLB cache so that the dirty bit will be set again + when accessing the range */ + start1 = (unsigned long)qemu_safe_ram_ptr(start); + /* Check that we don't span multiple blocks - this breaks the + address comparisons below. */ + if ((unsigned long)qemu_safe_ram_ptr(end - 1) - start1 + != (end - 1) - start) { + abort(); + } +} + +void sync_migration_bitmap(ram_addr_t start, ram_addr_t end) +{ + unsigned long length, len, i; + ram_addr_t addr; + start &= TARGET_PAGE_MASK; + end = TARGET_PAGE_ALIGN(end); + + length = end - start; + if (length == 0) { + return; + } + + len = length >> TARGET_PAGE_BITS; + for (i = 0; i < len; i++) { + addr = i << TARGET_PAGE_BITS; + if (cpu_physical_memory_get_dirty(addr, MIGRATION_DIRTY_FLAG)) { + migration_bitmap_set_dirty(addr); + cpu_physical_memory_reset_dirty(addr, addr + TARGET_PAGE_SIZE, + MIGRATION_DIRTY_FLAG); + } + } + } + + int cpu_physical_memory_set_dirty_tracking(int enable) { int ret = 0; @@ -2981,6 +3038,13 @@ ram_addr_t qemu_ram_alloc_from_ptr(DeviceState *dev, const char *name, memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS), 0xff, size >> TARGET_PAGE_BITS); + ram_list.migration_bitmap = qemu_realloc(ram_list.phys_dirty, + last_ram_offset() >> + TARGET_PAGE_BITS); + + memset(ram_list.migration_bitmap + (new_block->offset >> TARGET_PAGE_BITS), + 0xff, size >> TARGET_PAGE_BITS); + qemu_mutex_unlock_ramlist(); if (kvm_enabled())