From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1KdR3i-0007Q4-SA for qemu-devel@nongnu.org; Wed, 10 Sep 2008 10:52:42 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1KdR3h-0007P4-Ao for qemu-devel@nongnu.org; Wed, 10 Sep 2008 10:52:42 -0400 Received: from [199.232.76.173] (port=54715 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1KdR3g-0007Os-Im for qemu-devel@nongnu.org; Wed, 10 Sep 2008 10:52:40 -0400 Received: from rv-out-0708.google.com ([209.85.198.246]:5258) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1KdR3g-0005sX-9O for qemu-devel@nongnu.org; Wed, 10 Sep 2008 10:52:40 -0400 Received: by rv-out-0708.google.com with SMTP id f25so2192834rvb.22 for ; Wed, 10 Sep 2008 07:52:39 -0700 (PDT) Message-ID: <5d6222a80809100752t75a68593p86cebe5d490bdca@mail.gmail.com> Date: Wed, 10 Sep 2008 11:52:39 -0300 From: "Glauber Costa" Subject: Re: [Qemu-devel] [PATCH 4/10] Add dirty tracking for live migration In-Reply-To: <1220989802-13706-5-git-send-email-aliguori@us.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <1220989802-13706-1-git-send-email-aliguori@us.ibm.com> <1220989802-13706-5-git-send-email-aliguori@us.ibm.com> Reply-To: qemu-devel@nongnu.org List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Chris Wright , Uri Lublin , Anthony Liguori , kvm@vger.kernel.org On Tue, Sep 9, 2008 at 4:49 PM, Anthony Liguori wrote: > This patch adds a dirty tracking bit for live migration. We use 0x08 because > kqemu uses 0x04. For which purpose, and where is it? I think it deserves at least a comment on the source itself for future generations. > > Signed-off-by: Anthony Liguori > > diff --git a/cpu-all.h b/cpu-all.h > index d350b30..fdac353 100644 > --- a/cpu-all.h > +++ b/cpu-all.h > @@ -944,6 +944,7 @@ int cpu_memory_rw_debug(CPUState *env, target_ulong addr, > > #define VGA_DIRTY_FLAG 0x01 > #define CODE_DIRTY_FLAG 0x02 > +#define MIGRATION_DIRTY_FLAG 0x08 > > /* read dirty bit (return 0 or 1) */ > static inline int cpu_physical_memory_is_dirty(ram_addr_t addr) > @@ -966,6 +967,10 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, > int dirty_flags); > void cpu_tlb_update_dirty(CPUState *env); > > +int cpu_physical_memory_set_dirty_tracking(int enable); > + > +int cpu_physical_memory_get_dirty_tracking(void); > + > void dump_exec_info(FILE *f, > int (*cpu_fprintf)(FILE *f, const char *fmt, ...)); > > diff --git a/exec.c b/exec.c > index 3ab4ad0..9dba5c8 100644 > --- a/exec.c > +++ b/exec.c > @@ -38,6 +38,7 @@ > #include "qemu-common.h" > #include "tcg.h" > #include "hw/hw.h" > +#include "osdep.h" > #if defined(CONFIG_USER_ONLY) > #include > #endif > @@ -113,6 +114,7 @@ ram_addr_t phys_ram_size; > int phys_ram_fd; > uint8_t *phys_ram_base; > uint8_t *phys_ram_dirty; > +static int in_migration; > static ram_addr_t phys_ram_alloc_offset = 0; > #endif > > @@ -1777,6 +1779,17 @@ void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t end, > } > } > > +int cpu_physical_memory_set_dirty_tracking(int enable) > +{ > + in_migration = enable; > + return 0; > +} > + > +int cpu_physical_memory_get_dirty_tracking(void) > +{ > + return in_migration; > +} > + > static inline void tlb_update_dirty(CPUTLBEntry *tlb_entry) > { > ram_addr_t ram_addr; > @@ -2932,9 +2945,19 @@ void stl_phys_notdirty(target_phys_addr_t addr, uint32_t val) > io_index = (pd >> IO_MEM_SHIFT) & (IO_MEM_NB_ENTRIES - 1); > io_mem_write[io_index][2](io_mem_opaque[io_index], addr, val); > } else { > - ptr = phys_ram_base + (pd & TARGET_PAGE_MASK) + > - (addr & ~TARGET_PAGE_MASK); > + unsigned long addr1 = (pd & TARGET_PAGE_MASK) + (addr & ~TARGET_PAGE_MASK); > + ptr = phys_ram_base + addr1; > stl_p(ptr, val); > + > + if (unlikely(in_migration)) { > + if (!cpu_physical_memory_is_dirty(addr1)) { > + /* invalidate code */ > + tb_invalidate_phys_page_range(addr1, addr1 + 4, 0); > + /* set dirty bit */ > + phys_ram_dirty[addr1 >> TARGET_PAGE_BITS] |= > + (0xff & ~CODE_DIRTY_FLAG); > + } > + } > } > } did you mean MIGRATION_DIRTY_FLAG? -- Glauber Costa. "Free as in Freedom" http://glommer.net "The less confident you are, the more serious you have to act."