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Michael KelleyandGreg Kroah-Hartman
78792d25b6
commit99f1c46011upstream. netvsc_dma_map() and netvsc_dma_unmap() currently check the cp_partial flag and adjust the page_count so that pagebuf entries for the RNDIS portion of the message are skipped when it has already been copied into a send buffer. But this adjustment has already been made by code in netvsc_send(). The duplicate adjustment causes some pagebuf entries to not be mapped. In a normal VM, this doesn't break anything because the mapping doesn’t change the PFN. But in a Confidential VM, dma_map_single() does bounce buffering and provides a different PFN. Failing to do the mapping causes the wrong PFN to be passed to Hyper-V, and various errors ensue. Fix this by removing the duplicate adjustment in netvsc_dma_map() and netvsc_dma_unmap(). Fixes:846da38de0("net: netvsc: Add Isolation VM support for netvsc driver") Cc: stable@vger.kernel.org Signed-off-by: Michael Kelley <mikelley@microsoft.com> Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com> Link: https://lore.kernel.org/r/1675135986-254490-1-git-send-email-mikelley@microsoft.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>