* [PATCH 0/4] KVM: Dirty page logging (aka live migration) fixes
@ 2007-02-25 12:54 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:54 UTC (permalink / raw)
To: kvm-devel; +Cc: Andrew Morton, linux-kernel
This small patchset plugs a few holes in the kvm dirty page logging
implementation. With these fixes (which really want to be in Linux
2.6.21), one can migrate a running virtual machine from one host to
another. The virtual machine continues executing while its memory image
is transferred, so there is only a minimal pause in service.
The patchset is also available as part of the kvm git tree; see
http://kvm.qumranet.com/kvmwiki/Code.
--
error compiling committee.c: too many arguments to function
-------------------------------------------------------------------------
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^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 1/4] KVM: Add missing calls to mark_page_dirty()
@ 2007-02-25 12:55 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:55 UTC (permalink / raw)
To: kvm-devel; +Cc: linux-kernel, akpm, mingo
A few places where we modify guest memory fail to call mark_page_dirty(),
causing live migration to fail. This adds the missing calls.
Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
drivers/kvm/kvm_main.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index a593d09..edff405 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -228,12 +228,15 @@ int kvm_write_guest(struct kvm_vcpu *vcpu, gva_t addr, unsigned long size,
unsigned now;
unsigned offset;
hva_t guest_buf;
+ gfn_t gfn;
paddr = gva_to_hpa(vcpu, addr);
if (is_error_hpa(paddr))
break;
+ gfn = vcpu->mmu.gva_to_gpa(vcpu, addr) >> PAGE_SHIFT;
+ mark_page_dirty(vcpu->kvm, gfn);
guest_buf = (hva_t)kmap_atomic(
pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
offset = addr & ~PAGE_MASK;
@@ -953,6 +956,7 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
return 0;
page = gfn_to_page(m, gpa >> PAGE_SHIFT);
kvm_mmu_pre_write(vcpu, gpa, bytes);
+ mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
virt = kmap_atomic(page, KM_USER0);
memcpy(virt + offset_in_page(gpa), &val, bytes);
kunmap_atomic(virt, KM_USER0);
@@ -1294,6 +1298,7 @@ static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
if (is_error_hpa(para_state_hpa))
goto err_gp;
+ mark_page_dirty(vcpu->kvm, para_state_gpa >> PAGE_SHIFT);
para_state_page = pfn_to_page(para_state_hpa >> PAGE_SHIFT);
para_state = kmap_atomic(para_state_page, KM_USER0);
@@ -1323,6 +1328,7 @@ static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
vcpu->para_state_gpa = para_state_gpa;
vcpu->hypercall_gpa = hypercall_gpa;
+ mark_page_dirty(vcpu->kvm, hypercall_gpa >> PAGE_SHIFT);
hypercall = kmap_atomic(pfn_to_page(hypercall_hpa >> PAGE_SHIFT),
KM_USER1) + (hypercall_hpa & ~PAGE_MASK);
kvm_arch_ops->patch_hypercall(vcpu, hypercall);
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 1/4] KVM: Add missing calls to mark_page_dirty()
@ 2007-02-25 12:55 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:55 UTC (permalink / raw)
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Cc: akpm-3NddpPZAyC0, linux-kernel-u79uwXL29TY76Z2rM5mHXA
A few places where we modify guest memory fail to call mark_page_dirty(),
causing live migration to fail. This adds the missing calls.
Signed-off-by: Uri Lublin <uril-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm_main.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index a593d09..edff405 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -228,12 +228,15 @@ int kvm_write_guest(struct kvm_vcpu *vcpu, gva_t addr, unsigned long size,
unsigned now;
unsigned offset;
hva_t guest_buf;
+ gfn_t gfn;
paddr = gva_to_hpa(vcpu, addr);
if (is_error_hpa(paddr))
break;
+ gfn = vcpu->mmu.gva_to_gpa(vcpu, addr) >> PAGE_SHIFT;
+ mark_page_dirty(vcpu->kvm, gfn);
guest_buf = (hva_t)kmap_atomic(
pfn_to_page(paddr >> PAGE_SHIFT), KM_USER0);
offset = addr & ~PAGE_MASK;
@@ -953,6 +956,7 @@ static int emulator_write_phys(struct kvm_vcpu *vcpu, gpa_t gpa,
return 0;
page = gfn_to_page(m, gpa >> PAGE_SHIFT);
kvm_mmu_pre_write(vcpu, gpa, bytes);
+ mark_page_dirty(vcpu->kvm, gpa >> PAGE_SHIFT);
virt = kmap_atomic(page, KM_USER0);
memcpy(virt + offset_in_page(gpa), &val, bytes);
kunmap_atomic(virt, KM_USER0);
@@ -1294,6 +1298,7 @@ static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
if (is_error_hpa(para_state_hpa))
goto err_gp;
+ mark_page_dirty(vcpu->kvm, para_state_gpa >> PAGE_SHIFT);
para_state_page = pfn_to_page(para_state_hpa >> PAGE_SHIFT);
para_state = kmap_atomic(para_state_page, KM_USER0);
@@ -1323,6 +1328,7 @@ static int vcpu_register_para(struct kvm_vcpu *vcpu, gpa_t para_state_gpa)
vcpu->para_state_gpa = para_state_gpa;
vcpu->hypercall_gpa = hypercall_gpa;
+ mark_page_dirty(vcpu->kvm, hypercall_gpa >> PAGE_SHIFT);
hypercall = kmap_atomic(pfn_to_page(hypercall_hpa >> PAGE_SHIFT),
KM_USER1) + (hypercall_hpa & ~PAGE_MASK);
kvm_arch_ops->patch_hypercall(vcpu, hypercall);
-------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/4] KVM: Fix dirty page log bitmap size/access calculation
@ 2007-02-25 12:56 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:56 UTC (permalink / raw)
To: kvm-devel; +Cc: linux-kernel, akpm, mingo
Since dirty_bitmap is an unsigned long array, the alignment and size need
to take that into account.
Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
drivers/kvm/kvm_main.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index edff405..e710810 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -792,9 +792,9 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
if (!memslot->dirty_bitmap)
goto out;
- n = ALIGN(memslot->npages, 8) / 8;
+ n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
- for (i = 0; !any && i < n; ++i)
+ for (i = 0; !any && i < n/sizeof(long); ++i)
any = memslot->dirty_bitmap[i];
r = -EFAULT;
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/4] KVM: Fix dirty page log bitmap size/access calculation
@ 2007-02-25 12:56 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:56 UTC (permalink / raw)
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Cc: akpm-3NddpPZAyC0, linux-kernel-u79uwXL29TY76Z2rM5mHXA
Since dirty_bitmap is an unsigned long array, the alignment and size need
to take that into account.
Signed-off-by: Uri Lublin <uril-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm_main.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index edff405..e710810 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -792,9 +792,9 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
if (!memslot->dirty_bitmap)
goto out;
- n = ALIGN(memslot->npages, 8) / 8;
+ n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
- for (i = 0; !any && i < n; ++i)
+ for (i = 0; !any && i < n/sizeof(long); ++i)
any = memslot->dirty_bitmap[i];
r = -EFAULT;
-------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 3/4] kvm: move do_remove_write_access() up
@ 2007-02-25 12:57 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:57 UTC (permalink / raw)
To: kvm-devel; +Cc: linux-kernel, akpm, mingo
To be called from kvm_vm_ioctl_set_memory_region()
Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
drivers/kvm/kvm_main.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index e710810..be7694d 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -611,6 +611,13 @@ void fx_init(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(fx_init);
+static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
+{
+ spin_lock(&vcpu->kvm->lock);
+ kvm_mmu_slot_remove_write_access(vcpu, slot);
+ spin_unlock(&vcpu->kvm->lock);
+}
+
/*
* Allocate some memory and give it an address in the guest physical address
* space.
@@ -756,13 +763,6 @@ out:
return r;
}
-static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
-{
- spin_lock(&vcpu->kvm->lock);
- kvm_mmu_slot_remove_write_access(vcpu, slot);
- spin_unlock(&vcpu->kvm->lock);
-}
-
/*
* Get (and clear) the dirty memory log for a memory slot.
*/
^ permalink raw reply related [flat|nested] 11+ messages in thread* [PATCH 3/4] kvm: move do_remove_write_access() up
@ 2007-02-25 12:57 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:57 UTC (permalink / raw)
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Cc: akpm-3NddpPZAyC0, linux-kernel-u79uwXL29TY76Z2rM5mHXA
To be called from kvm_vm_ioctl_set_memory_region()
Signed-off-by: Uri Lublin <uril-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm_main.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index e710810..be7694d 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -611,6 +611,13 @@ void fx_init(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(fx_init);
+static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
+{
+ spin_lock(&vcpu->kvm->lock);
+ kvm_mmu_slot_remove_write_access(vcpu, slot);
+ spin_unlock(&vcpu->kvm->lock);
+}
+
/*
* Allocate some memory and give it an address in the guest physical address
* space.
@@ -756,13 +763,6 @@ out:
return r;
}
-static void do_remove_write_access(struct kvm_vcpu *vcpu, int slot)
-{
- spin_lock(&vcpu->kvm->lock);
- kvm_mmu_slot_remove_write_access(vcpu, slot);
- spin_unlock(&vcpu->kvm->lock);
-}
-
/*
* Get (and clear) the dirty memory log for a memory slot.
*/
-------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 4/4] KVM: Remove write access permissions when dirty-page-logging is enabled
@ 2007-02-25 12:58 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:58 UTC (permalink / raw)
To: kvm-devel; +Cc: linux-kernel, akpm, mingo
Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl.
If the memory region already exists, we need to remove write accesses,
so writes will be caught, and dirty pages will be logged.
Signed-off-by: Uri Lublin <uril@qumranet.com>
Signed-off-by: Avi Kivity <avi@qumranet.com>
---
drivers/kvm/kvm_main.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index be7694d..e48b4d7 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -748,6 +748,8 @@ raced:
vcpu = vcpu_load_slot(kvm, i);
if (!vcpu)
continue;
+ if (new.flags & KVM_MEM_LOG_DIRTY_PAGES)
+ do_remove_write_access(vcpu, mem->slot);
kvm_mmu_reset_context(vcpu);
vcpu_put(vcpu);
}
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 4/4] KVM: Remove write access permissions when dirty-page-logging is enabled
@ 2007-02-25 12:58 ` Avi Kivity
0 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 12:58 UTC (permalink / raw)
To: kvm-devel-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f
Cc: akpm-3NddpPZAyC0, linux-kernel-u79uwXL29TY76Z2rM5mHXA
Enabling dirty page logging is done using KVM_SET_MEMORY_REGION ioctl.
If the memory region already exists, we need to remove write accesses,
so writes will be caught, and dirty pages will be logged.
Signed-off-by: Uri Lublin <uril-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm_main.c | 2 ++
1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index be7694d..e48b4d7 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -748,6 +748,8 @@ raced:
vcpu = vcpu_load_slot(kvm, i);
if (!vcpu)
continue;
+ if (new.flags & KVM_MEM_LOG_DIRTY_PAGES)
+ do_remove_write_access(vcpu, mem->slot);
kvm_mmu_reset_context(vcpu);
vcpu_put(vcpu);
}
-------------------------------------------------------------------------
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^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 0/4] KVM: Dirty page logging (aka live migration) fixes
2007-02-25 12:54 ` Avi Kivity
` (4 preceding siblings ...)
(?)
@ 2007-02-25 13:11 ` Avi Kivity
-1 siblings, 0 replies; 11+ messages in thread
From: Avi Kivity @ 2007-02-25 13:11 UTC (permalink / raw)
To: kvm-devel; +Cc: linux-kernel, Andrew Morton, Ingo Molnar
Avi Kivity wrote:
> This small patchset plugs a few holes in the kvm dirty page logging
> implementation. With these fixes (which really want to be in Linux
> 2.6.21), one can migrate a running virtual machine from one host to
> another. The virtual machine continues executing while its memory
> image is transferred, so there is only a minimal pause in service.
>
> The patchset is also available as part of the kvm git tree; see
> http://kvm.qumranet.com/kvmwiki/Code.
>
The patches are all
From: Uri Lublin <uril@qumranet.com>
--
error compiling committee.c: too many arguments to function
^ permalink raw reply [flat|nested] 11+ messages in thread