* [PATCH] memory: Skip dirty tracking for un-migratable memory regions
@ 2020-11-16 13:22 Zenghui Yu
2020-11-16 17:46 ` Cornelia Huck
2020-11-16 18:22 ` Paolo Bonzini
0 siblings, 2 replies; 3+ messages in thread
From: Zenghui Yu @ 2020-11-16 13:22 UTC (permalink / raw)
To: qemu-devel, pbonzini
Cc: cohuck, kwankhede, alex.williamson, qemu-arm, Zenghui Yu,
wanghaibin.wang, kvmarm
It makes no sense to track dirty pages for those un-migratable memory
regions (e.g., Memory BAR region of the VFIO PCI device) and doing so
will potentially lead to some unpleasant issues during migration [1].
Skip dirty tracking for those regions by evaluating if the region is
migratable before setting dirty_log_mask (DIRTY_MEMORY_MIGRATION).
[1] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03757.html
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
---
softmmu/memory.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 71951fe4dc..aa393f1bb0 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1806,7 +1806,10 @@ bool memory_region_is_ram_device(MemoryRegion *mr)
uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
{
uint8_t mask = mr->dirty_log_mask;
- if (global_dirty_log && (mr->ram_block || memory_region_is_iommu(mr))) {
+ RAMBlock *rb = mr->ram_block;
+
+ if (global_dirty_log && ((rb && qemu_ram_is_migratable(rb)) ||
+ memory_region_is_iommu(mr))) {
mask |= (1 << DIRTY_MEMORY_MIGRATION);
}
return mask;
--
2.19.1
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] memory: Skip dirty tracking for un-migratable memory regions
2020-11-16 13:22 [PATCH] memory: Skip dirty tracking for un-migratable memory regions Zenghui Yu
@ 2020-11-16 17:46 ` Cornelia Huck
2020-11-16 18:22 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Cornelia Huck @ 2020-11-16 17:46 UTC (permalink / raw)
To: Zenghui Yu
Cc: qemu-devel, kwankhede, alex.williamson, qemu-arm, wanghaibin.wang,
pbonzini, kvmarm
On Mon, 16 Nov 2020 21:22:10 +0800
Zenghui Yu <yuzenghui@huawei.com> wrote:
> It makes no sense to track dirty pages for those un-migratable memory
> regions (e.g., Memory BAR region of the VFIO PCI device) and doing so
> will potentially lead to some unpleasant issues during migration [1].
>
> Skip dirty tracking for those regions by evaluating if the region is
> migratable before setting dirty_log_mask (DIRTY_MEMORY_MIGRATION).
>
> [1] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03757.html
>
> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> ---
> softmmu/memory.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index 71951fe4dc..aa393f1bb0 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1806,7 +1806,10 @@ bool memory_region_is_ram_device(MemoryRegion *mr)
> uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
> {
> uint8_t mask = mr->dirty_log_mask;
> - if (global_dirty_log && (mr->ram_block || memory_region_is_iommu(mr))) {
> + RAMBlock *rb = mr->ram_block;
> +
> + if (global_dirty_log && ((rb && qemu_ram_is_migratable(rb)) ||
> + memory_region_is_iommu(mr))) {
> mask |= (1 << DIRTY_MEMORY_MIGRATION);
> }
> return mask;
Looks reasonable.
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] memory: Skip dirty tracking for un-migratable memory regions
2020-11-16 13:22 [PATCH] memory: Skip dirty tracking for un-migratable memory regions Zenghui Yu
2020-11-16 17:46 ` Cornelia Huck
@ 2020-11-16 18:22 ` Paolo Bonzini
1 sibling, 0 replies; 3+ messages in thread
From: Paolo Bonzini @ 2020-11-16 18:22 UTC (permalink / raw)
To: Zenghui Yu, qemu-devel
Cc: cohuck, kwankhede, alex.williamson, qemu-arm, wanghaibin.wang,
kvmarm
On 16/11/20 14:22, Zenghui Yu wrote:
> It makes no sense to track dirty pages for those un-migratable memory
> regions (e.g., Memory BAR region of the VFIO PCI device) and doing so
> will potentially lead to some unpleasant issues during migration [1].
>
> Skip dirty tracking for those regions by evaluating if the region is
> migratable before setting dirty_log_mask (DIRTY_MEMORY_MIGRATION).
>
> [1] https://lists.gnu.org/archive/html/qemu-devel/2020-11/msg03757.html
>
> Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
> ---
> softmmu/memory.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/softmmu/memory.c b/softmmu/memory.c
> index 71951fe4dc..aa393f1bb0 100644
> --- a/softmmu/memory.c
> +++ b/softmmu/memory.c
> @@ -1806,7 +1806,10 @@ bool memory_region_is_ram_device(MemoryRegion *mr)
> uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
> {
> uint8_t mask = mr->dirty_log_mask;
> - if (global_dirty_log && (mr->ram_block || memory_region_is_iommu(mr))) {
> + RAMBlock *rb = mr->ram_block;
> +
> + if (global_dirty_log && ((rb && qemu_ram_is_migratable(rb)) ||
> + memory_region_is_iommu(mr))) {
> mask |= (1 << DIRTY_MEMORY_MIGRATION);
> }
> return mask;
>
Queued, thanks.
Paolo
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-11-16 17:46 ` Cornelia Huck
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