The virtio vhost-user device has shared memory resources. Therefore, it uses the VIRTIO_PCI_CAP_SHARED_MEMORY_CFG capability to standardize those resources through the PCI Configuration Space. This patch synchronizes the virtio vhost-user device spec with the following shared memory resources PATCH:
https://lists.oasis-open.org/archives/virtio-dev/201902/msg00142.html Cc: Dr. David Alan Gilbert <dgilb...@redhat.com> Signed-off-by: Nikos Dragazis <ndraga...@arrikto.com> --- virtio-vhost-user.tex | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/virtio-vhost-user.tex b/virtio-vhost-user.tex index 7a8cd9c..d1305dd 100644 --- a/virtio-vhost-user.tex +++ b/virtio-vhost-user.tex @@ -320,7 +320,22 @@ \subsubsection{Notification structure layout}\label{sec:Device Types / Vhost-use \subsubsection{Shared memory capability}\label{sec:Device Types / Vhost-user Device Backend / Additional Device Resources over PCI / Shared Memory capability} The shared memory location is found using the VIRTIO_PCI_CAP_SHARED_MEMORY_CFG -capability. +capability. Using the additional \field{offset_hi} and \field{length_hi} +fields following the SHARED_MEMORY_CFG capability structure, the shared +memory region's 64-bit BAR offset is calculated as follows: + +\begin{lstlisting} + offset_hi << 32 + cap.offset +\end{lstlisting} + +and the shared memory region's 64-bit length is calculated as follows: + +\begin{lstlisting} + length_hi << 32 + cap.length +\end{lstlisting} + +The \field{cap.offset} and \field{cap.length} fields are taken from the +SHARED_MEMORY_CFG capability structure. \devicenormative{\paragraph}{Shared Memory capability}{Device Types / Vhost-user Device Backend / Additional Device Resources over PCI / Shared Memory capability} The device MUST present exactly one shared memory capability. -- 2.17.1 --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscr...@lists.oasis-open.org For additional commands, e-mail: virtio-dev-h...@lists.oasis-open.org
