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  • 1.  [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X

    Posted 09-13-2022 06:54
    In commit 6a83c1d41748 ("pci: set ISR bit on config change with MSI-X"),
    device is required to set ISR bit on config change even when MSI-X enabled.

    This update other ISR related description for above commit.

    Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
    ---
    content.tex | 13 ++++++++-----
    1 file changed, 8 insertions(+), 5 deletions(-)

    diff --git a/content.tex b/content.tex
    index e863709..01a4bfe 100644
    --- a/content.tex
    +++ b/content.tex
    @@ -1158,10 +1158,10 @@ \subsubsection{ISR status capability}\label{sec:Virtio Transport Options / Virti
    \end{tabular}

    To avoid an extra access, simply reading this register resets it to 0 and
    -causes the device to de-assert the interrupt.
    +causes the device to de-assert the interrupt when using INT\#x interrupt.

    In this way, driver read of ISR status causes the device to de-assert
    -an interrupt.
    +an INT\#x interrupt.

    See sections \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Used Buffer Notifications} and \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Notification of Device Configuration Changes} for how this is used.

    @@ -1511,7 +1511,7 @@ \subsubsection{Device Initialization}\label{sec:Virtio Transport Options / Virti

    When MSI-X capability is present and enabled in the device
    (through standard PCI configuration space) \field{config_msix_vector} and \field{queue_msix_vector} are used to map configuration change and queue
    -interrupts to MSI-X vectors. In this case, the ISR Status is unused.
    +interrupts to MSI-X vectors.

    Writing a valid MSI-X Table entry number, 0 to 0x7FF, to
    \field{config_msix_vector}/\field{queue_msix_vector} maps interrupts triggered
    @@ -1681,6 +1681,7 @@ \subsubsection{Notification of Device Configuration Changes}\label{sec:Virtio Tr

    \item If MSI-X capability is enabled:
    \begin{enumerate}
    + \item Set the second lower bit of the ISR Status field for the device.
    \item If \field{config_msix_vector} is not NO_VECTOR,
    request the appropriate MSI-X interrupt message for the
    device, \field{config_msix_vector} sets the MSI-X Table entry
    @@ -1718,13 +1719,15 @@ \subsubsection{Driver Handling Interrupts}\label{sec:Virtio Transport Options /
    \end{itemize}
    \item If MSI-X capability is enabled:
    \begin{itemize}
    + \item Read the ISR Status field, which will reset it to zero.
    \item
    Look through all virtqueues mapped to that MSI-X vector for the
    device, to see if any progress has been made by the device
    which requires servicing.
    \item
    - If the MSI-X vector is equal to \field{config_msix_vector},
    - re-examine the configuration space to see what changed.
    + If the second lower bit of ISR Status filed is set and the
    + MSI-X vector is equal to \field{config_msix_vector}, re-examine
    + the configuration space to see what changed.
    \end{itemize}
    \end{itemize}

    --
    2.33.0




  • 2.  ??: [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X

    Posted 12-17-2022 12:49
    Fixes: https://github.com/oasis-tcs/virtio-spec/issues/145

    Hi all TC members:
    This is to request a vote on resolving the above issue.

    Thanks,
    Keqian


    -----????-----
    ???: virtio-comment@lists.oasis-open.org <virtio-comment@lists.oasis-open.org> ?? Keqian Zhu
    ????: 2022?9?13? 14:54
    ???: virtio-comment@lists.oasis-open.org
    ??: mst@redhat.com; Wanghaibin (D) <wanghaibin.wang@huawei.com>; sundongxu (A) <sundongxu3@huawei.com>
    ??: [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X

    In commit 6a83c1d41748 ("pci: set ISR bit on config change with MSI-X"), device is required to set ISR bit on config change even when MSI-X enabled.

    This update other ISR related description for above commit.

    Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
    ---
    content.tex | 13 ++++++++-----
    1 file changed, 8 insertions(+), 5 deletions(-)

    diff --git a/content.tex b/content.tex
    index e863709..01a4bfe 100644
    --- a/content.tex
    +++ b/content.tex
    @@ -1158,10 +1158,10 @@ \subsubsection{ISR status capability}\label{sec:Virtio Transport Options / Virti \end{tabular}

    To avoid an extra access, simply reading this register resets it to 0 and -causes the device to de-assert the interrupt.
    +causes the device to de-assert the interrupt when using INT\#x interrupt.

    In this way, driver read of ISR status causes the device to de-assert -an interrupt.
    +an INT\#x interrupt.

    See sections \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Used Buffer Notifications} and \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Notification of Device Configuration Changes} for how this is used.

    @@ -1511,7 +1511,7 @@ \subsubsection{Device Initialization}\label{sec:Virtio Transport Options / Virti

    When MSI-X capability is present and enabled in the device (through standard PCI configuration space) \field{config_msix_vector} and \field{queue_msix_vector} are used to map configuration change and queue -interrupts to MSI-X vectors. In this case, the ISR Status is unused.
    +interrupts to MSI-X vectors.

    Writing a valid MSI-X Table entry number, 0 to 0x7FF, to \field{config_msix_vector}/\field{queue_msix_vector} maps interrupts triggered @@ -1681,6 +1681,7 @@ \subsubsection{Notification of Device Configuration Changes}\label{sec:Virtio Tr

    \item If MSI-X capability is enabled:
    \begin{enumerate}
    + \item Set the second lower bit of the ISR Status field for the device.
    \item If \field{config_msix_vector} is not NO_VECTOR,
    request the appropriate MSI-X interrupt message for the
    device, \field{config_msix_vector} sets the MSI-X Table entry @@ -1718,13 +1719,15 @@ \subsubsection{Driver Handling Interrupts}\label{sec:Virtio Transport Options /
    \end{itemize}
    \item If MSI-X capability is enabled:
    \begin{itemize}
    + \item Read the ISR Status field, which will reset it to zero.
    \item
    Look through all virtqueues mapped to that MSI-X vector for the
    device, to see if any progress has been made by the device
    which requires servicing.
    \item
    - If the MSI-X vector is equal to \field{config_msix_vector},
    - re-examine the configuration space to see what changed.
    + If the second lower bit of ISR Status filed is set and the
    + MSI-X vector is equal to \field{config_msix_vector}, re-examine
    + the configuration space to see what changed.
    \end{itemize}
    \end{itemize}

    --
    2.33.0


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  • 3.  Re:

    Posted 12-19-2022 12:22
    On Sat, Dec 17 2022, zhukeqian <zhukeqian1@huawei.com> wrote:

    > Fixes: https://github.com/oasis-tcs/virtio-spec/issues/145
    >
    > Hi all TC members:
    > This is to request a vote on resolving the above issue.

    I had hoped that someone familiar with this would review this
    patch... I've noted a typo below.

    Also, as the end-of-year holiday season is starting in most western
    countries, it is better to defer any voting to January.

    >
    > Thanks,
    > Keqian
    >
    >
    > -----????-----
    > ???: virtio-comment@lists.oasis-open.org <virtio-comment@lists.oasis-open.org> ?? Keqian Zhu
    > ????: 2022?9?13? 14:54
    > ???: virtio-comment@lists.oasis-open.org
    > ??: mst@redhat.com; Wanghaibin (D) <wanghaibin.wang@huawei.com>; sundongxu (A) <sundongxu3@huawei.com>
    > ??: [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X
    >
    > In commit 6a83c1d41748 ("pci: set ISR bit on config change with MSI-X"), device is required to set ISR bit on config change even when MSI-X enabled.
    >
    > This update other ISR related description for above commit.
    >
    > Signed-off-by: Keqian Zhu <zhukeqian1@huawei.com>
    > ---
    > content.tex | 13 ++++++++-----
    > 1 file changed, 8 insertions(+), 5 deletions(-)
    >
    > diff --git a/content.tex b/content.tex
    > index e863709..01a4bfe 100644
    > --- a/content.tex
    > +++ b/content.tex
    > @@ -1158,10 +1158,10 @@ \subsubsection{ISR status capability}\label{sec:Virtio Transport Options / Virti \end{tabular}
    >
    > To avoid an extra access, simply reading this register resets it to 0 and -causes the device to de-assert the interrupt.
    > +causes the device to de-assert the interrupt when using INT\#x interrupt.
    >
    > In this way, driver read of ISR status causes the device to de-assert -an interrupt.
    > +an INT\#x interrupt.
    >
    > See sections \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Used Buffer Notifications} and \ref{sec:Virtio Transport Options / Virtio Over PCI Bus / PCI-specific Initialization And Device Operation / Notification of Device Configuration Changes} for how this is used.
    >
    > @@ -1511,7 +1511,7 @@ \subsubsection{Device Initialization}\label{sec:Virtio Transport Options / Virti
    >
    > When MSI-X capability is present and enabled in the device (through standard PCI configuration space) \field{config_msix_vector} and \field{queue_msix_vector} are used to map configuration change and queue -interrupts to MSI-X vectors. In this case, the ISR Status is unused.
    > +interrupts to MSI-X vectors.
    >
    > Writing a valid MSI-X Table entry number, 0 to 0x7FF, to \field{config_msix_vector}/\field{queue_msix_vector} maps interrupts triggered @@ -1681,6 +1681,7 @@ \subsubsection{Notification of Device Configuration Changes}\label{sec:Virtio Tr
    >
    > \item If MSI-X capability is enabled:
    > \begin{enumerate}
    > + \item Set the second lower bit of the ISR Status field for the device.
    > \item If \field{config_msix_vector} is not NO_VECTOR,
    > request the appropriate MSI-X interrupt message for the
    > device, \field{config_msix_vector} sets the MSI-X Table entry @@ -1718,13 +1719,15 @@ \subsubsection{Driver Handling Interrupts}\label{sec:Virtio Transport Options /
    > \end{itemize}
    > \item If MSI-X capability is enabled:
    > \begin{itemize}
    > + \item Read the ISR Status field, which will reset it to zero.
    > \item
    > Look through all virtqueues mapped to that MSI-X vector for the
    > device, to see if any progress has been made by the device
    > which requires servicing.
    > \item
    > - If the MSI-X vector is equal to \field{config_msix_vector},
    > - re-examine the configuration space to see what changed.
    > + If the second lower bit of ISR Status filed is set and the

    "of the ISR Status field", I guess?

    > + MSI-X vector is equal to \field{config_msix_vector}, re-examine
    > + the configuration space to see what changed.
    > \end{itemize}
    > \end{itemize}




  • 4.  ??: [virtio-comment] Re: ??: [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X

    Posted 12-20-2022 09:21
    Hi Cornelia,

    -----????-----
    ???: virtio-comment@lists.oasis-open.org <virtio-comment@lists.oasis-open.org> ?? Cornelia Huck
    ????: 2022?12?19? 20:22
    ???: zhukeqian <zhukeqian1@huawei.com>; zhukeqian <zhukeqian1@huawei.com>; virtio-comment@lists.oasis-open.org
    ??: mst@redhat.com; Wanghaibin (D) <wanghaibin.wang@huawei.com>; sundongxu (A) <sundongxu3@huawei.com>; Chentao (Boby) <boby.chen@huawei.com>; Zhangbo (Oscar) <oscar.zhangbo@huawei.com>; zhukeqian <zhukeqian1@huawei.com>
    ??: [virtio-comment] Re: ??: [virtio-comment][PATCH v2] pci: Update ISR related description about MSI-X

    On Sat, Dec 17 2022, zhukeqian <zhukeqian1@huawei.com> wrote:

    >> Fixes: https://github.com/oasis-tcs/virtio-spec/issues/145
    >>
    >> Hi all TC members:
    >> This is to request a vote on resolving the above issue.
    >
    >I had hoped that someone familiar with this would review this patch... I've noted a typo below.
    >
    >Also, as the end-of-year holiday season is starting in most western countries, it is better to defer any voting to January.
    >
    >
    >
    >>
    [...]
    >> \item
    >> - If the MSI-X vector is equal to \field{config_msix_vector},
    >> - re-examine the configuration space to see what changed.
    >> + If the second lower bit of ISR Status filed is set and the
    >
    >"of the ISR Status field", I guess?

    Right.

    I will send new version and request a vote after TC members come back :).

    Thanks,
    Keqian

    >
    >> + MSI-X vector is equal to \field{config_msix_vector}, re-examine
    >> + the configuration space to see what changed.
    >> \end{itemize}
    >> \end{itemize}