Hello Zhenzhong,
On 5/28/25 08:04, 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 <nicol...@nvidia.com>
Signed-off-by: Zhenzhong Duan <zhenzhong.d...@intel.com>
---
include/system/iommufd.h | 4 ++++
backends/iommufd.c | 33 +++++++++++++++++++++++++++++++++
backends/trace-events | 1 +
3 files changed, 38 insertions(+)
diff --git a/include/system/iommufd.h b/include/system/iommufd.h
index cbab75bfbf..5399519626 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_ptr,
+ 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..c8788a6438 100644
--- a/backends/iommufd.c
+++ b/backends/iommufd.c
@@ -311,6 +311,39 @@ 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_ptr,
+ 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_ptr,
Minor, other helpers use a 'data' variable name.
+ };
+
+ 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_ptr,
+ ret ? errno : 0);
+ if (ret) {
+ *entry_num = cache.entry_num;
+ error_setg_errno(errp, errno, "IOMMU_HWPT_INVALIDATE failed:"
+ " totally %d entries, processed %d entries",
+ total_entries, cache.entry_num);
+ } else {
+ g_assert(total_entries == cache.entry_num);
Killing the VMM because a kernel device ioctl failed is brute force.
Can't we update the 'Error *' parameter instead to report that the
invalidation is partial or something went wrong ?
What kind of errors are we trying to catch ?
Looking at the kernel iommufd_hwpt_invalidate() routine and
intel_nested_cache_invalidate_user(), it doesn't seem possible to
return a different number of cache entries. Are you anticipating
other implementations (sMMU) ?
Thanks,
C.
