Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Sasha Levin
On Mon, 2011-12-12 at 20:10 +0200, Avi Kivity wrote: > On 12/12/2011 04:47 PM, Sasha Levin wrote: > > This patch mmaps guest kernel into it's own memory slot instead of reading > > it into the memory. > > > > - } else { > > - /* First RAM range from zero to the PCI gap: */ > > > > +

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Avi Kivity
On 12/12/2011 04:47 PM, Sasha Levin wrote: > This patch mmaps guest kernel into it's own memory slot instead of reading > it into the memory. > > - } else { > - /* First RAM range from zero to the PCI gap: */ > > + /* Mapped kernel */ > + phys_start = BZ_KE

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Avi Kivity
On 12/12/2011 04:47 PM, Sasha Levin wrote: > This patch mmaps guest kernel into it's own memory slot instead of reading > it into the memory. > > The advantages are: > - Smaller memory footprint (same effect as KSM if running multiple guests) > - Faster loading of larger kernels. > How many COW

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Avi Kivity
On 12/12/2011 08:14 PM, Sasha Levin wrote: > On Mon, 2011-12-12 at 17:59 +0200, Pekka Enberg wrote: > > On Mon, Dec 12, 2011 at 4:47 PM, Sasha Levin > > wrote: > > > + /* mmap the actual kernel */ > > > + kvm->bz_fd = dup(fd_kernel); > > > + kvm->bz_len = st.st_size; > > > +

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Andrew Walrond
On Mon, Dec 12, 2011 at 07:47:35PM +0200, Sasha Levin wrote: > > Another usecase which I've only first heard about couple of days ago is > loading extremely large bzImages. Those images are 300MB+ in size and > come with built in filesystem. Apparently it's some sort of a livecd > variant. > Hav

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Ingo Molnar
* Sasha Levin wrote: > + kvm->bz_start = mmap(NULL, kvm->bz_len, PROT_READ | PROT_WRITE, > + MAP_PRIVATE, kvm->bz_fd, setup_end); > > + /* NOP everything before the kernel start */ > + memset(kvm->bz_start, 0x90, setup_size - setup_end); You should real

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Sasha Levin
On Mon, 2011-12-12 at 17:59 +0200, Pekka Enberg wrote: > On Mon, Dec 12, 2011 at 4:47 PM, Sasha Levin wrote: > > + /* mmap the actual kernel */ > > + kvm->bz_fd = dup(fd_kernel); > > + kvm->bz_len = st.st_size; > > + setup_end = ALIGN(setup_size - PAGE_SIZE, PAGE_SIZE); /*

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Pekka Enberg
On Mon, Dec 12, 2011 at 4:47 PM, Sasha Levin wrote: > +       /* mmap the actual kernel */ > +       kvm->bz_fd = dup(fd_kernel); > +       kvm->bz_len = st.st_size; > +       setup_end = ALIGN(setup_size - PAGE_SIZE, PAGE_SIZE); /* Need it > aligned to PAGE_SIZE */ > +       kvm->bz_start = mmap

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Sasha Levin
On Mon, 2011-12-12 at 16:54 +0200, Pekka Enberg wrote: > On Mon, Dec 12, 2011 at 4:47 PM, Sasha Levin wrote: > > This patch mmaps guest kernel into it's own memory slot instead of reading > > it into the memory. > > > > The advantages are: > > - Smaller memory footprint (same effect as KSM if run

Re: [PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Pekka Enberg
On Mon, Dec 12, 2011 at 4:47 PM, Sasha Levin wrote: > This patch mmaps guest kernel into it's own memory slot instead of reading > it into the memory. > > The advantages are: >  - Smaller memory footprint (same effect as KSM if running multiple guests) KSM isn't free so it's smaller footprint wit

[PATCH] kvm tools: mmap guest kernel instead of reading it into memory

2011-12-12 Thread Sasha Levin
This patch mmaps guest kernel into it's own memory slot instead of reading it into the memory. The advantages are: - Smaller memory footprint (same effect as KSM if running multiple guests) - Faster loading of larger kernels. Suggested-by: "Sweeney, Andrew John" Signed-off-by: Sasha Levin ---