Re: [Qemu-devel] BIT_WORD(start >> TARGET_PAGE_BITS)
thank you so much Eric Sorry for too questions I certainly follow your guide thanks a lot On Fri, Jun 30, 2017 at 5:49 PM, Eric Blake wrote: > On 06/30/2017 08:02 AM, ali saeedi wrote: > > Hello > > what does the following code do? > > 'unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS)' ? > > I've noticed you've been asking a lot of questions (each as a new > thread, rather than replying to previous answers), that seem like you > are not trying very hard to read the code and find an answer for > yourself. Rather than just answer you, I'm going to try to teach you > how to read the source and answer the question yourself. You may also > get better answers to your future questions if you ask in the form of > "this code is confusing me, I think it means this, based on what I read > at xyz, but would like confirmation or correction" (showing WHAT you > have already researched) rather than just "what does this code do" (and > making it feel like you are off-loading the research work onto others). > > First, figure out what BIT_WORD does: > > $ git grep 'define BIT_WORD' > > That should have only one hit, in include/qemu/bitops.h. Reading it in > context doesn't have any more comments, but it looks like it is > computing the number of bits that are available in a word, and looks > like it is defining a word to be the type most efficiently operated on > for the current ABI (a long is 32 bits on a 32-bit OS, and 64 bits on a > 64-bit OS). > > It also looks like you are scaling a start address by the number of bits > in a target page. > > So it probably means you are computing the index for which page 'start' > occurs on (depending on values, it might mean that 'start == 0x0' is > page 0, 'start == 0x1' is page 1, and so on), where start is > initially in the form of the number of bits per page. > > -- > Eric Blake, Principal Software Engineer > Red Hat, Inc. +1-919-301-3266 > Virtualization: qemu.org | libvirt.org > >
[Qemu-devel] BIT_WORD(start >> TARGET_PAGE_BITS)
Hello what does the following code do? 'unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS)' ? thanks a lot
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[Qemu-devel] DIRTY_MEMORY_BLOCK_SIZE;
Hello what does 'DIRTY_MEMORY_BLOCK_SIZE' mean? is it the number of words in a block? or number of pages in a block? or number of bytes in a block? thanks a lot
[Qemu-devel] Fwd: migration_bitmap_sync()
-- Forwarded message -- From: ali saeedi Date: Sat, Jun 24, 2017 at 2:50 PM Subject: migration_bitmap_sync() To: qemu-devel@nongnu.org Hello What does ' migration_bitmap_sync()' function do? thanks a lot
[Qemu-devel] migration_bitmap_sync()
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Re: [Qemu-devel] TARGET_PAGE_BITS
thank you for answer
So. why do we have right shift in qemu by "TARGET_PAGE_BITS" ? for exampe
in below code, what does it mean?
static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
ram_addr_t length)
{
unsigned long end, page;
end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
page = start >> TARGET_PAGE_BITS;
...
}
thanks a lot
On Fri, Jun 23, 2017 at 7:11 PM, Alex Bennée wrote:
>
> ali saeedi writes:
>
> > Hello
> > What does TARGET_PAGE_BITS mean in qemu code?
>
> It's the page size of the target. e.g.
>
> TARGET_PAGE_BITS 12
>
> 1 << 12 = 4096 = 4k pages
>
>
> > thanks a lot
>
>
> --
> Alex Bennée
>
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Hello thanks for your answer Do i code in kernel space for writing this API? Please give me more guide about what should i do to write this API. thanks a lot On Thu, May 25, 2017 at 5:50 PM, Xiao Guangrong wrote: > > No API directly supports your case, but you can do it in KVM by using > page-track mechanism. > > > > On 05/25/2017 08:26 PM, ali saeedi wrote: > >> Hello >> How can i receive an event when a page or block is dirtied in qemu code? >> thanks a lot >> >>
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