diff mbox series

[v27,14/17] vfio: Dirty page tracking when vIOMMU is enabled

Message ID 1603365127-14202-15-git-send-email-kwankhede@nvidia.com (mailing list archive)
State New, archived
Headers show
Series Add migration support for VFIO devices | expand

Commit Message

Kirti Wankhede Oct. 22, 2020, 11:12 a.m. UTC 
When vIOMMU is enabled, register MAP notifier from log_sync when all
devices in container are in stop and copy phase of migration. Call replay
and get dirty pages from notifier callback.

Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
---
 hw/vfio/common.c              | 95 ++++++++++++++++++++++++++++++++++++++++---
 hw/vfio/trace-events          |  1 +
 include/hw/vfio/vfio-common.h |  1 +
 3 files changed, 91 insertions(+), 6 deletions(-)

Comments

Alex Williamson Oct. 22, 2020, 8:37 p.m. UTC | #1 
On Thu, 22 Oct 2020 16:42:04 +0530
Kirti Wankhede <kwankhede@nvidia.com> wrote:

> When vIOMMU is enabled, register MAP notifier from log_sync when all
> devices in container are in stop and copy phase of migration. Call replay
> and get dirty pages from notifier callback.
> 
> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
> ---
>  hw/vfio/common.c              | 95 ++++++++++++++++++++++++++++++++++++++++---
>  hw/vfio/trace-events          |  1 +
>  include/hw/vfio/vfio-common.h |  1 +
>  3 files changed, 91 insertions(+), 6 deletions(-)
> 
> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
> index 2634387df948..98c2b1f9b190 100644
> --- a/hw/vfio/common.c
> +++ b/hw/vfio/common.c
> @@ -442,8 +442,8 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section)
>  }
>  
>  /* Called with rcu_read_lock held.  */
> -static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
> -                           bool *read_only)
> +static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
> +                               ram_addr_t *ram_addr, bool *read_only)
>  {
>      MemoryRegion *mr;
>      hwaddr xlat;
> @@ -474,8 +474,17 @@ static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
>          return false;
>      }
>  
> -    *vaddr = memory_region_get_ram_ptr(mr) + xlat;
> -    *read_only = !writable || mr->readonly;
> +    if (vaddr) {
> +        *vaddr = memory_region_get_ram_ptr(mr) + xlat;
> +    }
> +
> +    if (ram_addr) {
> +        *ram_addr = memory_region_get_ram_addr(mr) + xlat;
> +    }
> +
> +    if (read_only) {
> +        *read_only = !writable || mr->readonly;
> +    }
>  
>      return true;
>  }
> @@ -485,7 +494,6 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>      VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n);
>      VFIOContainer *container = giommu->container;
>      hwaddr iova = iotlb->iova + giommu->iommu_offset;
> -    bool read_only;
>      void *vaddr;
>      int ret;
>  
> @@ -501,7 +509,9 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>      rcu_read_lock();
>  
>      if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
> -        if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
> +        bool read_only;
> +
> +        if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
>              goto out;
>          }
>          /*
> @@ -899,11 +909,84 @@ err_out:
>      return ret;
>  }
>  
> +static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
> +{
> +    VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, dirty_notify);
> +    VFIOContainer *container = giommu->container;
> +    hwaddr iova = iotlb->iova + giommu->iommu_offset;
> +    ram_addr_t translated_addr;
> +
> +    trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask);
> +
> +    if (iotlb->target_as != &address_space_memory) {
> +        error_report("Wrong target AS \"%s\", only system memory is allowed",
> +                     iotlb->target_as->name ? iotlb->target_as->name : "none");
> +        return;
> +    }
> +
> +    rcu_read_lock();
> +
> +    if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) {
> +        int ret;
> +
> +        ret = vfio_get_dirty_bitmap(container, iova, iotlb->addr_mask + 1,
> +                                    translated_addr);
> +        if (ret) {
> +            error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
> +                         "0x%"HWADDR_PRIx") = %d (%m)",
> +                         container, iova,
> +                         iotlb->addr_mask + 1, ret);
> +        }
> +    }
> +
> +    rcu_read_unlock();
> +}
> +
>  static int vfio_sync_dirty_bitmap(VFIOContainer *container,
>                                    MemoryRegionSection *section)
>  {
>      ram_addr_t ram_addr;
>  
> +    if (memory_region_is_iommu(section->mr)) {
> +        VFIOGuestIOMMU *giommu;
> +        int ret = 0;
> +
> +        QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
> +            if (MEMORY_REGION(giommu->iommu) == section->mr &&
> +                giommu->n.start == section->offset_within_region) {
> +                Int128 llend;
> +                Error *err = NULL;
> +                int idx = memory_region_iommu_attrs_to_index(giommu->iommu,
> +                                                       MEMTXATTRS_UNSPECIFIED);
> +
> +                llend = int128_add(int128_make64(section->offset_within_region),
> +                                   section->size);
> +                llend = int128_sub(llend, int128_one());
> +
> +                iommu_notifier_init(&giommu->dirty_notify,
> +                                    vfio_iommu_map_dirty_notify,
> +                                    IOMMU_NOTIFIER_MAP,
> +                                    section->offset_within_region,
> +                                    int128_get64(llend),
> +                                    idx);
> +                ret = memory_region_register_iommu_notifier(section->mr,
> +                                                  &giommu->dirty_notify, &err);
> +                if (ret) {
> +                    error_report_err(err);
> +                    break;
> +                }
> +
> +                memory_region_iommu_replay(giommu->iommu,
> +                                           &giommu->dirty_notify);
> +
> +                memory_region_unregister_iommu_notifier(section->mr,
> +                                                        &giommu->dirty_notify);


Is it necessary to do the register/unregister?  It seemed to me that
perhaps we could do a replay independent of those.

I'd also be tempted to move dirty_notify to a temporary object rather
than store it on the giommu for such a brief usage, ie. define:

struct giommu_dirty_notfier {
    IOMMUNotifier n;
    VFIOGuestIOMMU *giommu;
}

struct giommu_dirty_notfier n = { .giommu = giommu };

iommu_notifier_init(&n,...);

memory_region_iommu_replay(giommu->iommu, &n);
...

struct giommu_dirty_notfier *ndnotifier = container_of(n, struct giommu_dirty_notfier, n);
VFIOGuestIOMMU *giommu = n->giommu;

It's nice that we remove the extra bloat of the list/tree entirely with
this approach.  Thanks,

Alex

> +                break;
> +            }
> +        }
> +        return ret;
> +    }
> +
>      ram_addr = memory_region_get_ram_addr(section->mr) +
>                 section->offset_within_region;
>  
> diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
> index c3b35aa2cce8..d9cb8998a228 100644
> --- a/hw/vfio/trace-events
> +++ b/hw/vfio/trace-events
> @@ -163,3 +163,4 @@ vfio_load_device_config_state(const char *name) " (%s)"
>  vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
>  vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
>  vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64
> +vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu dirty @ 0x%"PRIx64" - 0x%"PRIx64
> diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
> index b1c1b18fd228..92872fae59ee 100644
> --- a/include/hw/vfio/vfio-common.h
> +++ b/include/hw/vfio/vfio-common.h
> @@ -99,6 +99,7 @@ typedef struct VFIOGuestIOMMU {
>      IOMMUMemoryRegion *iommu;
>      hwaddr iommu_offset;
>      IOMMUNotifier n;
> +    IOMMUNotifier dirty_notify;
>      QLIST_ENTRY(VFIOGuestIOMMU) giommu_next;
>  } VFIOGuestIOMMU;
>
Kirti Wankhede Oct. 23, 2020, 7:55 a.m. UTC | #2 
On 10/23/2020 2:07 AM, Alex Williamson wrote:
> On Thu, 22 Oct 2020 16:42:04 +0530
> Kirti Wankhede <kwankhede@nvidia.com> wrote:
> 
>> When vIOMMU is enabled, register MAP notifier from log_sync when all
>> devices in container are in stop and copy phase of migration. Call replay
>> and get dirty pages from notifier callback.
>>
>> Suggested-by: Alex Williamson <alex.williamson@redhat.com>
>> Signed-off-by: Kirti Wankhede <kwankhede@nvidia.com>
>> ---
>>   hw/vfio/common.c              | 95 ++++++++++++++++++++++++++++++++++++++++---
>>   hw/vfio/trace-events          |  1 +
>>   include/hw/vfio/vfio-common.h |  1 +
>>   3 files changed, 91 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>> index 2634387df948..98c2b1f9b190 100644
>> --- a/hw/vfio/common.c
>> +++ b/hw/vfio/common.c
>> @@ -442,8 +442,8 @@ static bool vfio_listener_skipped_section(MemoryRegionSection *section)
>>   }
>>   
>>   /* Called with rcu_read_lock held.  */
>> -static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
>> -                           bool *read_only)
>> +static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
>> +                               ram_addr_t *ram_addr, bool *read_only)
>>   {
>>       MemoryRegion *mr;
>>       hwaddr xlat;
>> @@ -474,8 +474,17 @@ static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
>>           return false;
>>       }
>>   
>> -    *vaddr = memory_region_get_ram_ptr(mr) + xlat;
>> -    *read_only = !writable || mr->readonly;
>> +    if (vaddr) {
>> +        *vaddr = memory_region_get_ram_ptr(mr) + xlat;
>> +    }
>> +
>> +    if (ram_addr) {
>> +        *ram_addr = memory_region_get_ram_addr(mr) + xlat;
>> +    }
>> +
>> +    if (read_only) {
>> +        *read_only = !writable || mr->readonly;
>> +    }
>>   
>>       return true;
>>   }
>> @@ -485,7 +494,6 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>>       VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n);
>>       VFIOContainer *container = giommu->container;
>>       hwaddr iova = iotlb->iova + giommu->iommu_offset;
>> -    bool read_only;
>>       void *vaddr;
>>       int ret;
>>   
>> @@ -501,7 +509,9 @@ static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>>       rcu_read_lock();
>>   
>>       if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
>> -        if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
>> +        bool read_only;
>> +
>> +        if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
>>               goto out;
>>           }
>>           /*
>> @@ -899,11 +909,84 @@ err_out:
>>       return ret;
>>   }
>>   
>> +static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
>> +{
>> +    VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, dirty_notify);
>> +    VFIOContainer *container = giommu->container;
>> +    hwaddr iova = iotlb->iova + giommu->iommu_offset;
>> +    ram_addr_t translated_addr;
>> +
>> +    trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask);
>> +
>> +    if (iotlb->target_as != &address_space_memory) {
>> +        error_report("Wrong target AS \"%s\", only system memory is allowed",
>> +                     iotlb->target_as->name ? iotlb->target_as->name : "none");
>> +        return;
>> +    }
>> +
>> +    rcu_read_lock();
>> +
>> +    if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) {
>> +        int ret;
>> +
>> +        ret = vfio_get_dirty_bitmap(container, iova, iotlb->addr_mask + 1,
>> +                                    translated_addr);
>> +        if (ret) {
>> +            error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
>> +                         "0x%"HWADDR_PRIx") = %d (%m)",
>> +                         container, iova,
>> +                         iotlb->addr_mask + 1, ret);
>> +        }
>> +    }
>> +
>> +    rcu_read_unlock();
>> +}
>> +
>>   static int vfio_sync_dirty_bitmap(VFIOContainer *container,
>>                                     MemoryRegionSection *section)
>>   {
>>       ram_addr_t ram_addr;
>>   
>> +    if (memory_region_is_iommu(section->mr)) {
>> +        VFIOGuestIOMMU *giommu;
>> +        int ret = 0;
>> +
>> +        QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
>> +            if (MEMORY_REGION(giommu->iommu) == section->mr &&
>> +                giommu->n.start == section->offset_within_region) {
>> +                Int128 llend;
>> +                Error *err = NULL;
>> +                int idx = memory_region_iommu_attrs_to_index(giommu->iommu,
>> +                                                       MEMTXATTRS_UNSPECIFIED);
>> +
>> +                llend = int128_add(int128_make64(section->offset_within_region),
>> +                                   section->size);
>> +                llend = int128_sub(llend, int128_one());
>> +
>> +                iommu_notifier_init(&giommu->dirty_notify,
>> +                                    vfio_iommu_map_dirty_notify,
>> +                                    IOMMU_NOTIFIER_MAP,
>> +                                    section->offset_within_region,
>> +                                    int128_get64(llend),
>> +                                    idx);
>> +                ret = memory_region_register_iommu_notifier(section->mr,
>> +                                                  &giommu->dirty_notify, &err);
>> +                if (ret) {
>> +                    error_report_err(err);
>> +                    break;
>> +                }
>> +
>> +                memory_region_iommu_replay(giommu->iommu,
>> +                                           &giommu->dirty_notify);
>> +
>> +                memory_region_unregister_iommu_notifier(section->mr,
>> +                                                        &giommu->dirty_notify);
> 
> 
> Is it necessary to do the register/unregister?  It seemed to me that
> perhaps we could do a replay independent of those.
> 

Earlier I thought to do a replay, we need to regsiter. But you are 
right, I verified replay works without registering.

> I'd also be tempted to move dirty_notify to a temporary object rather
> than store it on the giommu for such a brief usage, ie. define:
> 
> struct giommu_dirty_notfier {
>      IOMMUNotifier n;
>      VFIOGuestIOMMU *giommu;
> }
> 
> struct giommu_dirty_notfier n = { .giommu = giommu };
> 
> iommu_notifier_init(&n,...);
> 
> memory_region_iommu_replay(giommu->iommu, &n);
> ...
> 
> struct giommu_dirty_notfier *ndnotifier = container_of(n, struct giommu_dirty_notfier, n);
> VFIOGuestIOMMU *giommu = n->giommu;
> 
> It's nice that we remove the extra bloat of the list/tree entirely with
> this approach.  Thanks,
> 

Thanks for your suggestion. Changing as you suggested above.

Thanks,
Kirti
diff mbox series

Patch

diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index 2634387df948..98c2b1f9b190 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -442,8 +442,8 @@  static bool vfio_listener_skipped_section(MemoryRegionSection *section)
 }
 
 /* Called with rcu_read_lock held.  */
-static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
-                           bool *read_only)
+static bool vfio_get_xlat_addr(IOMMUTLBEntry *iotlb, void **vaddr,
+                               ram_addr_t *ram_addr, bool *read_only)
 {
     MemoryRegion *mr;
     hwaddr xlat;
@@ -474,8 +474,17 @@  static bool vfio_get_vaddr(IOMMUTLBEntry *iotlb, void **vaddr,
         return false;
     }
 
-    *vaddr = memory_region_get_ram_ptr(mr) + xlat;
-    *read_only = !writable || mr->readonly;
+    if (vaddr) {
+        *vaddr = memory_region_get_ram_ptr(mr) + xlat;
+    }
+
+    if (ram_addr) {
+        *ram_addr = memory_region_get_ram_addr(mr) + xlat;
+    }
+
+    if (read_only) {
+        *read_only = !writable || mr->readonly;
+    }
 
     return true;
 }
@@ -485,7 +494,6 @@  static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, n);
     VFIOContainer *container = giommu->container;
     hwaddr iova = iotlb->iova + giommu->iommu_offset;
-    bool read_only;
     void *vaddr;
     int ret;
 
@@ -501,7 +509,9 @@  static void vfio_iommu_map_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
     rcu_read_lock();
 
     if ((iotlb->perm & IOMMU_RW) != IOMMU_NONE) {
-        if (!vfio_get_vaddr(iotlb, &vaddr, &read_only)) {
+        bool read_only;
+
+        if (!vfio_get_xlat_addr(iotlb, &vaddr, NULL, &read_only)) {
             goto out;
         }
         /*
@@ -899,11 +909,84 @@  err_out:
     return ret;
 }
 
+static void vfio_iommu_map_dirty_notify(IOMMUNotifier *n, IOMMUTLBEntry *iotlb)
+{
+    VFIOGuestIOMMU *giommu = container_of(n, VFIOGuestIOMMU, dirty_notify);
+    VFIOContainer *container = giommu->container;
+    hwaddr iova = iotlb->iova + giommu->iommu_offset;
+    ram_addr_t translated_addr;
+
+    trace_vfio_iommu_map_dirty_notify(iova, iova + iotlb->addr_mask);
+
+    if (iotlb->target_as != &address_space_memory) {
+        error_report("Wrong target AS \"%s\", only system memory is allowed",
+                     iotlb->target_as->name ? iotlb->target_as->name : "none");
+        return;
+    }
+
+    rcu_read_lock();
+
+    if (vfio_get_xlat_addr(iotlb, NULL, &translated_addr, NULL)) {
+        int ret;
+
+        ret = vfio_get_dirty_bitmap(container, iova, iotlb->addr_mask + 1,
+                                    translated_addr);
+        if (ret) {
+            error_report("vfio_iommu_map_dirty_notify(%p, 0x%"HWADDR_PRIx", "
+                         "0x%"HWADDR_PRIx") = %d (%m)",
+                         container, iova,
+                         iotlb->addr_mask + 1, ret);
+        }
+    }
+
+    rcu_read_unlock();
+}
+
 static int vfio_sync_dirty_bitmap(VFIOContainer *container,
                                   MemoryRegionSection *section)
 {
     ram_addr_t ram_addr;
 
+    if (memory_region_is_iommu(section->mr)) {
+        VFIOGuestIOMMU *giommu;
+        int ret = 0;
+
+        QLIST_FOREACH(giommu, &container->giommu_list, giommu_next) {
+            if (MEMORY_REGION(giommu->iommu) == section->mr &&
+                giommu->n.start == section->offset_within_region) {
+                Int128 llend;
+                Error *err = NULL;
+                int idx = memory_region_iommu_attrs_to_index(giommu->iommu,
+                                                       MEMTXATTRS_UNSPECIFIED);
+
+                llend = int128_add(int128_make64(section->offset_within_region),
+                                   section->size);
+                llend = int128_sub(llend, int128_one());
+
+                iommu_notifier_init(&giommu->dirty_notify,
+                                    vfio_iommu_map_dirty_notify,
+                                    IOMMU_NOTIFIER_MAP,
+                                    section->offset_within_region,
+                                    int128_get64(llend),
+                                    idx);
+                ret = memory_region_register_iommu_notifier(section->mr,
+                                                  &giommu->dirty_notify, &err);
+                if (ret) {
+                    error_report_err(err);
+                    break;
+                }
+
+                memory_region_iommu_replay(giommu->iommu,
+                                           &giommu->dirty_notify);
+
+                memory_region_unregister_iommu_notifier(section->mr,
+                                                        &giommu->dirty_notify);
+                break;
+            }
+        }
+        return ret;
+    }
+
     ram_addr = memory_region_get_ram_addr(section->mr) +
                section->offset_within_region;
 
diff --git a/hw/vfio/trace-events b/hw/vfio/trace-events
index c3b35aa2cce8..d9cb8998a228 100644
--- a/hw/vfio/trace-events
+++ b/hw/vfio/trace-events
@@ -163,3 +163,4 @@  vfio_load_device_config_state(const char *name) " (%s)"
 vfio_load_state(const char *name, uint64_t data) " (%s) data 0x%"PRIx64
 vfio_load_state_device_data(const char *name, uint64_t data_offset, uint64_t data_size) " (%s) Offset 0x%"PRIx64" size 0x%"PRIx64
 vfio_get_dirty_bitmap(int fd, uint64_t iova, uint64_t size, uint64_t bitmap_size, uint64_t start) "container fd=%d, iova=0x%"PRIx64" size= 0x%"PRIx64" bitmap_size=0x%"PRIx64" start=0x%"PRIx64
+vfio_iommu_map_dirty_notify(uint64_t iova_start, uint64_t iova_end) "iommu dirty @ 0x%"PRIx64" - 0x%"PRIx64
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index b1c1b18fd228..92872fae59ee 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -99,6 +99,7 @@  typedef struct VFIOGuestIOMMU {
     IOMMUMemoryRegion *iommu;
     hwaddr iommu_offset;
     IOMMUNotifier n;
+    IOMMUNotifier dirty_notify;
     QLIST_ENTRY(VFIOGuestIOMMU) giommu_next;
 } VFIOGuestIOMMU;