On 2012-04-02 06:04, David Gibson wrote:
> From: Ben Herrenschmidt <b...@kernel.crashing.org>
>
> If the kernel page size is larger than TARGET_PAGE_SIZE, which
> happens for example on ppc64 with kernels compiled for 64K pages,
> the dirty tracking doesn't work.
>
> Cc: Avi Kivity <a...@redhat.com>
> Cc: Marcelo Tosatti <mtosa...@redhat.com>
>
> Signed-off-by: Benjamin Herrenschmidt <b...@kernel.crashing.org>
> Signed-off-by: David Gibson <da...@gibson.dropbear.id.au>
> ---
> kvm-all.c | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> I've sent this a number of times now, the last couple without comment.
> It fixes a real bug, please apply.
>
> diff --git a/kvm-all.c b/kvm-all.c
> index ba2cee1..7e44429 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -354,6 +354,7 @@ static int
> kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
> unsigned long page_number, c;
> target_phys_addr_t addr, addr1;
> unsigned int len = ((section->size / TARGET_PAGE_SIZE) + HOST_LONG_BITS
> - 1) / HOST_LONG_BITS;
> + unsigned long hpratio = getpagesize() / TARGET_PAGE_SIZE;
>
> /*
> * bitmap-traveling is faster than memory-traveling (for addr...)
> @@ -365,10 +366,11 @@ static int
> kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
> do {
> j = ffsl(c) - 1;
> c &= ~(1ul << j);
> - page_number = i * HOST_LONG_BITS + j;
> + page_number = (i * HOST_LONG_BITS + j) * hpratio;
> addr1 = page_number * TARGET_PAGE_SIZE;
> addr = section->offset_within_region + addr1;
> - memory_region_set_dirty(section->mr, addr, TARGET_PAGE_SIZE);
> + memory_region_set_dirty(section->mr, addr,
> + TARGET_PAGE_SIZE * hpratio);
> } while (c != 0);
> }
> }Ack for this, but - as proposed earlier - please add an assert(TARGET_PAGE_SIZE <= getpagesize()) + comment to kvm_init(). Also, what's about coalesced MMIO? I see that the ring definition depends on [TARGET_]PAGE_SIZE. What page size does the power kernel use for it, and does it make a relevant difference for space? Jan
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