* [Qemu-devel] [PATCH] kvm: Fix dirty tracking with large kernel page size
@ 2012-03-19 4:57 David Gibson
2012-03-19 10:52 ` Andreas Färber
0 siblings, 1 reply; 3+ messages in thread
From: David Gibson @ 2012-03-19 4:57 UTC (permalink / raw)
To: avi; +Cc: Marcelo Tossatti, qemu-devel, David Gibson
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 <avi@redhat.com>
Cc: Marcelo Tossatti <mtosatti@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
kvm-all.c | 8 +++++---
1 files changed, 5 insertions(+), 3 deletions(-)
diff --git a/kvm-all.c b/kvm-all.c
index ba2cee1..47adc97 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -350,10 +350,11 @@ static int kvm_set_migration_log(int enable)
static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
unsigned long *bitmap)
{
- unsigned int i, j;
+ unsigned int i, j;
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);
}
}
--
1.7.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: Fix dirty tracking with large kernel page size
2012-03-19 4:57 [Qemu-devel] [PATCH] kvm: Fix dirty tracking with large kernel page size David Gibson
@ 2012-03-19 10:52 ` Andreas Färber
2012-03-20 0:26 ` David Gibson
0 siblings, 1 reply; 3+ messages in thread
From: Andreas Färber @ 2012-03-19 10:52 UTC (permalink / raw)
To: David Gibson; +Cc: Marcelo Tossatti, avi, qemu-devel
Am 19.03.2012 05:57, schrieb David Gibson:
> 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 <avi@redhat.com>
> Cc: Marcelo Tossatti <mtosatti@redhat.com>
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> kvm-all.c | 8 +++++---
> 1 files changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index ba2cee1..47adc97 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -350,10 +350,11 @@ static int kvm_set_migration_log(int enable)
> static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
> unsigned long *bitmap)
> {
> - unsigned int i, j;
> + unsigned int i, j;
Unintentional change?
Andreas
> 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);
> }
> }
--
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer; HRB 16746 AG Nürnberg
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: Fix dirty tracking with large kernel page size
2012-03-19 10:52 ` Andreas Färber
@ 2012-03-20 0:26 ` David Gibson
0 siblings, 0 replies; 3+ messages in thread
From: David Gibson @ 2012-03-20 0:26 UTC (permalink / raw)
To: Andreas Färber; +Cc: Marcelo Tossatti, avi, qemu-devel
On Mon, Mar 19, 2012 at 11:52:49AM +0100, Andreas Färber wrote:
> Am 19.03.2012 05:57, schrieb David Gibson:
> > 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 <avi@redhat.com>
> > Cc: Marcelo Tossatti <mtosatti@redhat.com>
> >
> > Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
> > ---
> > kvm-all.c | 8 +++++---
> > 1 files changed, 5 insertions(+), 3 deletions(-)
> >
> > diff --git a/kvm-all.c b/kvm-all.c
> > index ba2cee1..47adc97 100644
> > --- a/kvm-all.c
> > +++ b/kvm-all.c
> > @@ -350,10 +350,11 @@ static int kvm_set_migration_log(int enable)
> > static int kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
> > unsigned long *bitmap)
> > {
> > - unsigned int i, j;
> > + unsigned int i, j;
>
> Unintentional change?
Gah, yes, oops. Corrected version below.
>From 55bd7c4811415c3b1a4825c4907f56117243836b Mon Sep 17 00:00:00 2001
From: Ben Herrenschmidt <benh@kernel.crashing.org>
Date: Tue, 20 Mar 2012 11:22:16 +1100
Subject: [PATCH] kvm: Fix dirty tracking with large kernel page size
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 <avi@redhat.com>
Cc: Marcelo Tossatti <mtosatti@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
kvm-all.c | 6 ++++--
1 files changed, 4 insertions(+), 2 deletions(-)
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);
}
}
--
1.7.9.1
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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2012-03-19 10:52 ` Andreas Färber
2012-03-20 0:26 ` David Gibson
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