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[PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-managed HWPT

Zhenzhong Duan posted 4 patches 5 months, 2 weeks ago
Maintainers: Yi Liu <yi.l.liu@intel.com>, Eric Auger <eric.auger@redhat.com>, Zhenzhong Duan <zhenzhong.duan@intel.com>, Alex Williamson <alex.williamson@redhat.com>, "Cédric Le Goater" <clg@redhat.com>
There is a newer version of this series
[PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-managed HWPT
Posted by Zhenzhong Duan 5 months, 2 weeks ago 
This helper passes cache invalidation request from guest to invalidate
stage-1 page table cache in host hardware.

Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
---
 include/system/iommufd.h |  4 ++++
 backends/iommufd.c       | 36 ++++++++++++++++++++++++++++++++++++
 backends/trace-events    |  1 +
 3 files changed, 41 insertions(+)

diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index cbab75bfbf..83ab8e1e4c 100644
--- a/include/system/iommufd.h
+++ b/include/system/iommufd.h
@@ -61,6 +61,10 @@ bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
                                       uint64_t iova, ram_addr_t size,
                                       uint64_t page_size, uint64_t *data,
                                       Error **errp);
+bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
+                                      uint32_t data_type, uint32_t entry_len,
+                                      uint32_t *entry_num, void *data,
+                                      Error **errp);
 
 #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
 #endif
diff --git a/backends/iommufd.c b/backends/iommufd.c
index b73f75cd0b..8bcdb60fe7 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -311,6 +311,42 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
     return true;
 }
 
+bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
+                                      uint32_t data_type, uint32_t entry_len,
+                                      uint32_t *entry_num, void *data,
+                                      Error **errp)
+{
+    int ret, fd = be->fd;
+    uint32_t total_entries = *entry_num;
+    struct iommu_hwpt_invalidate cache = {
+        .size = sizeof(cache),
+        .hwpt_id = id,
+        .data_type = data_type,
+        .entry_len = entry_len,
+        .entry_num = total_entries,
+        .data_uptr = (uintptr_t)data,
+    };
+
+    ret = ioctl(fd, IOMMU_HWPT_INVALIDATE, &cache);
+    trace_iommufd_backend_invalidate_cache(fd, id, data_type, entry_len,
+                                           total_entries, cache.entry_num,
+                                           (uintptr_t)data, ret ? errno : 0);
+    *entry_num = cache.entry_num;
+
+    if (ret) {
+        error_setg_errno(errp, errno, "IOMMU_HWPT_INVALIDATE failed:"
+                         " total %d entries, processed %d entries",
+                         total_entries, cache.entry_num);
+    } else if (total_entries != cache.entry_num) {
+        error_setg(errp, "IOMMU_HWPT_INVALIDATE succeed but with unprocessed"
+                         " entries: total %d entries, processed %d entries."
+                         " Kernel BUG?!", total_entries, cache.entry_num);
+        return false;
+    }
+
+    return !ret;
+}
+
 static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
 {
     HostIOMMUDeviceCaps *caps = &hiod->caps;
diff --git a/backends/trace-events b/backends/trace-events
index 40811a3162..7278214ea5 100644
--- a/backends/trace-events
+++ b/backends/trace-events
@@ -18,3 +18,4 @@ iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, uint32_t pt_id, uint32_
 iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%d)"
 iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) " iommufd=%d hwpt=%u enable=%d (%d)"
 iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
+iommufd_backend_invalidate_cache(int iommufd, uint32_t id, uint32_t data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, uint64_t data_ptr, int ret) " iommufd=%d id=%u data_type=%u entry_len=%u entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"
-- 
2.34.1
Re: [PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-managed HWPT
Posted by Eric Auger 5 months, 2 weeks ago 
Hi Zhenzhong,

On 5/30/25 11:35 AM, Zhenzhong Duan wrote:
> This helper passes cache invalidation request from guest to invalidate
> stage-1 page table cache in host hardware.
>
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
> ---
>  include/system/iommufd.h |  4 ++++
>  backends/iommufd.c       | 36 ++++++++++++++++++++++++++++++++++++
>  backends/trace-events    |  1 +
>  3 files changed, 41 insertions(+)
>
> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
> index cbab75bfbf..83ab8e1e4c 100644
> --- a/include/system/iommufd.h
> +++ b/include/system/iommufd.h
> @@ -61,6 +61,10 @@ bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
>                                        uint64_t iova, ram_addr_t size,
>                                        uint64_t page_size, uint64_t *data,
>                                        Error **errp);
> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
> +                                      uint32_t data_type, uint32_t entry_len,
> +                                      uint32_t *entry_num, void *data,
> +                                      Error **errp);
>  
>  #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
>  #endif
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index b73f75cd0b..8bcdb60fe7 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -311,6 +311,42 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
>      return true;
>  }
>  
> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
> +                                      uint32_t data_type, uint32_t entry_len,
> +                                      uint32_t *entry_num, void *data,
> +                                      Error **errp)
> +{
> +    int ret, fd = be->fd;
> +    uint32_t total_entries = *entry_num;
> +    struct iommu_hwpt_invalidate cache = {
> +        .size = sizeof(cache),
> +        .hwpt_id = id,
> +        .data_type = data_type,
> +        .entry_len = entry_len,
> +        .entry_num = total_entries,
> +        .data_uptr = (uintptr_t)data,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_HWPT_INVALIDATE, &cache);
> +    trace_iommufd_backend_invalidate_cache(fd, id, data_type, entry_len,
> +                                           total_entries, cache.entry_num,
> +                                           (uintptr_t)data, ret ? errno : 0);
> +    *entry_num = cache.entry_num;
> +
> +    if (ret) {
> +        error_setg_errno(errp, errno, "IOMMU_HWPT_INVALIDATE failed:"
> +                         " total %d entries, processed %d entries",
> +                         total_entries, cache.entry_num);
> +    } else if (total_entries != cache.entry_num) {
> +        error_setg(errp, "IOMMU_HWPT_INVALIDATE succeed but with unprocessed"
> +                         " entries: total %d entries, processed %d entries."
> +                         " Kernel BUG?!", total_entries, cache.entry_num);
Can this happen? Isn't it a failure case?

Besides
Reviewed-by: Eric Auger <eric.auger@redhat.com>


Eric
> +        return false;
> +    }
> +
> +    return !ret;
> +}
> +
>  static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
>  {
>      HostIOMMUDeviceCaps *caps = &hiod->caps;
> diff --git a/backends/trace-events b/backends/trace-events
> index 40811a3162..7278214ea5 100644
> --- a/backends/trace-events
> +++ b/backends/trace-events
> @@ -18,3 +18,4 @@ iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, uint32_t pt_id, uint32_
>  iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%d)"
>  iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) " iommufd=%d hwpt=%u enable=%d (%d)"
>  iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
> +iommufd_backend_invalidate_cache(int iommufd, uint32_t id, uint32_t data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, uint64_t data_ptr, int ret) " iommufd=%d id=%u data_type=%u entry_len=%u entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"
RE: [PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-managed HWPT
Posted by Duan, Zhenzhong 5 months, 2 weeks ago 
Hi Eric,

>-----Original Message-----
>From: Eric Auger <eric.auger@redhat.com>
>Sent: Tuesday, June 3, 2025 8:21 PM
>To: Duan, Zhenzhong <zhenzhong.duan@intel.com>; qemu-devel@nongnu.org
>Cc: alex.williamson@redhat.com; clg@redhat.com; mst@redhat.com;
>jasowang@redhat.com; peterx@redhat.com; ddutile@redhat.com;
>jgg@nvidia.com; nicolinc@nvidia.com; shameerali.kolothum.thodi@huawei.com;
>joao.m.martins@oracle.com; clement.mathieu--drif@eviden.com; Tian, Kevin
><kevin.tian@intel.com>; Liu, Yi L <yi.l.liu@intel.com>; Peng, Chao P
><chao.p.peng@intel.com>
>Subject: Re: [PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-
>managed HWPT
>
>Hi Zhenzhong,
>
>On 5/30/25 11:35 AM, Zhenzhong Duan wrote:
>> This helper passes cache invalidation request from guest to invalidate
>> stage-1 page table cache in host hardware.
>>
>> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
>> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>> ---
>>  include/system/iommufd.h |  4 ++++
>>  backends/iommufd.c       | 36 ++++++++++++++++++++++++++++++++++++
>>  backends/trace-events    |  1 +
>>  3 files changed, 41 insertions(+)
>>
>> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
>> index cbab75bfbf..83ab8e1e4c 100644
>> --- a/include/system/iommufd.h
>> +++ b/include/system/iommufd.h
>> @@ -61,6 +61,10 @@ bool
>iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
>>                                        uint64_t iova, ram_addr_t size,
>>                                        uint64_t page_size, uint64_t *data,
>>                                        Error **errp);
>> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
>> +                                      uint32_t data_type, uint32_t entry_len,
>> +                                      uint32_t *entry_num, void *data,
>> +                                      Error **errp);
>>
>>  #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD
>TYPE_HOST_IOMMU_DEVICE "-iommufd"
>>  #endif
>> diff --git a/backends/iommufd.c b/backends/iommufd.c
>> index b73f75cd0b..8bcdb60fe7 100644
>> --- a/backends/iommufd.c
>> +++ b/backends/iommufd.c
>> @@ -311,6 +311,42 @@ bool
>iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
>>      return true;
>>  }
>>
>> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
>> +                                      uint32_t data_type, uint32_t entry_len,
>> +                                      uint32_t *entry_num, void *data,
>> +                                      Error **errp)
>> +{
>> +    int ret, fd = be->fd;
>> +    uint32_t total_entries = *entry_num;
>> +    struct iommu_hwpt_invalidate cache = {
>> +        .size = sizeof(cache),
>> +        .hwpt_id = id,
>> +        .data_type = data_type,
>> +        .entry_len = entry_len,
>> +        .entry_num = total_entries,
>> +        .data_uptr = (uintptr_t)data,
>> +    };
>> +
>> +    ret = ioctl(fd, IOMMU_HWPT_INVALIDATE, &cache);
>> +    trace_iommufd_backend_invalidate_cache(fd, id, data_type, entry_len,
>> +                                           total_entries, cache.entry_num,
>> +                                           (uintptr_t)data, ret ? errno : 0);
>> +    *entry_num = cache.entry_num;
>> +
>> +    if (ret) {
>> +        error_setg_errno(errp, errno, "IOMMU_HWPT_INVALIDATE failed:"
>> +                         " total %d entries, processed %d entries",
>> +                         total_entries, cache.entry_num);
>> +    } else if (total_entries != cache.entry_num) {
>> +        error_setg(errp, "IOMMU_HWPT_INVALIDATE succeed but with
>unprocessed"
>> +                         " entries: total %d entries, processed %d entries."
>> +                         " Kernel BUG?!", total_entries, cache.entry_num);
>Can this happen? Isn't it a failure case?

It shouldn't happen except kernel has a bug. It's a failure case, so false is returned.

Thanks
Zhenzhong

>
>Besides
>Reviewed-by: Eric Auger <eric.auger@redhat.com>
>
>
>Eric
>> +        return false;
>> +    }
>> +
>> +    return !ret;
>> +}
>> +
>>  static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error
>**errp)
>>  {
>>      HostIOMMUDeviceCaps *caps = &hiod->caps;
>> diff --git a/backends/trace-events b/backends/trace-events
>> index 40811a3162..7278214ea5 100644
>> --- a/backends/trace-events
>> +++ b/backends/trace-events
>> @@ -18,3 +18,4 @@ iommufd_backend_alloc_hwpt(int iommufd, uint32_t
>dev_id, uint32_t pt_id, uint32_
>>  iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d
>id=%d (%d)"
>>  iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret)
>" iommufd=%d hwpt=%u enable=%d (%d)"
>>  iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t
>iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u
>iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
>> +iommufd_backend_invalidate_cache(int iommufd, uint32_t id, uint32_t
>data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, uint64_t
>data_ptr, int ret) " iommufd=%d id=%u data_type=%u entry_len=%u
>entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"
Re: [PATCH v2 1/4] backends/iommufd: Add a helper to invalidate user-managed HWPT
Posted by Cédric Le Goater 5 months, 2 weeks ago 
On 5/30/25 11:35, Zhenzhong Duan wrote:
> This helper passes cache invalidation request from guest to invalidate
> stage-1 page table cache in host hardware.
> 
> Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
> Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>



Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.


> ---
>   include/system/iommufd.h |  4 ++++
>   backends/iommufd.c       | 36 ++++++++++++++++++++++++++++++++++++
>   backends/trace-events    |  1 +
>   3 files changed, 41 insertions(+)
> 
> diff --git a/include/system/iommufd.h b/include/system/iommufd.h
> index cbab75bfbf..83ab8e1e4c 100644
> --- a/include/system/iommufd.h
> +++ b/include/system/iommufd.h
> @@ -61,6 +61,10 @@ bool iommufd_backend_get_dirty_bitmap(IOMMUFDBackend *be, uint32_t hwpt_id,
>                                         uint64_t iova, ram_addr_t size,
>                                         uint64_t page_size, uint64_t *data,
>                                         Error **errp);
> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
> +                                      uint32_t data_type, uint32_t entry_len,
> +                                      uint32_t *entry_num, void *data,
> +                                      Error **errp);
>   
>   #define TYPE_HOST_IOMMU_DEVICE_IOMMUFD TYPE_HOST_IOMMU_DEVICE "-iommufd"
>   #endif
> diff --git a/backends/iommufd.c b/backends/iommufd.c
> index b73f75cd0b..8bcdb60fe7 100644
> --- a/backends/iommufd.c
> +++ b/backends/iommufd.c
> @@ -311,6 +311,42 @@ bool iommufd_backend_get_device_info(IOMMUFDBackend *be, uint32_t devid,
>       return true;
>   }
>   
> +bool iommufd_backend_invalidate_cache(IOMMUFDBackend *be, uint32_t id,
> +                                      uint32_t data_type, uint32_t entry_len,
> +                                      uint32_t *entry_num, void *data,
> +                                      Error **errp)
> +{
> +    int ret, fd = be->fd;
> +    uint32_t total_entries = *entry_num;
> +    struct iommu_hwpt_invalidate cache = {
> +        .size = sizeof(cache),
> +        .hwpt_id = id,
> +        .data_type = data_type,
> +        .entry_len = entry_len,
> +        .entry_num = total_entries,
> +        .data_uptr = (uintptr_t)data,
> +    };
> +
> +    ret = ioctl(fd, IOMMU_HWPT_INVALIDATE, &cache);
> +    trace_iommufd_backend_invalidate_cache(fd, id, data_type, entry_len,
> +                                           total_entries, cache.entry_num,
> +                                           (uintptr_t)data, ret ? errno : 0);
> +    *entry_num = cache.entry_num;
> +
> +    if (ret) {
> +        error_setg_errno(errp, errno, "IOMMU_HWPT_INVALIDATE failed:"
> +                         " total %d entries, processed %d entries",
> +                         total_entries, cache.entry_num);
> +    } else if (total_entries != cache.entry_num) {
> +        error_setg(errp, "IOMMU_HWPT_INVALIDATE succeed but with unprocessed"
> +                         " entries: total %d entries, processed %d entries."
> +                         " Kernel BUG?!", total_entries, cache.entry_num);
> +        return false;
> +    }
> +
> +    return !ret;
> +}
> +
>   static int hiod_iommufd_get_cap(HostIOMMUDevice *hiod, int cap, Error **errp)
>   {
>       HostIOMMUDeviceCaps *caps = &hiod->caps;
> diff --git a/backends/trace-events b/backends/trace-events
> index 40811a3162..7278214ea5 100644
> --- a/backends/trace-events
> +++ b/backends/trace-events
> @@ -18,3 +18,4 @@ iommufd_backend_alloc_hwpt(int iommufd, uint32_t dev_id, uint32_t pt_id, uint32_
>   iommufd_backend_free_id(int iommufd, uint32_t id, int ret) " iommufd=%d id=%d (%d)"
>   iommufd_backend_set_dirty(int iommufd, uint32_t hwpt_id, bool start, int ret) " iommufd=%d hwpt=%u enable=%d (%d)"
>   iommufd_backend_get_dirty_bitmap(int iommufd, uint32_t hwpt_id, uint64_t iova, uint64_t size, uint64_t page_size, int ret) " iommufd=%d hwpt=%u iova=0x%"PRIx64" size=0x%"PRIx64" page_size=0x%"PRIx64" (%d)"
> +iommufd_backend_invalidate_cache(int iommufd, uint32_t id, uint32_t data_type, uint32_t entry_len, uint32_t entry_num, uint32_t done_num, uint64_t data_ptr, int ret) " iommufd=%d id=%u data_type=%u entry_len=%u entry_num=%u done_num=%u data_ptr=0x%"PRIx64" (%d)"

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