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[virtio-dev] [PATCH v2 3/5] virtio-mmio: Add feature bit for MMIO MSI
From: |
Jing Liu |
Subject: |
[virtio-dev] [PATCH v2 3/5] virtio-mmio: Add feature bit for MMIO MSI |
Date: |
Tue, 21 Jan 2020 21:54:31 +0800 |
The current MMIO transport layer uses a single, dedicated interrupt
signal, which brings performance penalty. Add a feature bit (40)
for introducing MSI capability.
Co-developed-by: Chao Peng <address@hidden>
Signed-off-by: Chao Peng <address@hidden>
Co-developed-by: Liu Jiang <address@hidden>
Signed-off-by: Liu Jiang <address@hidden>
Co-developed-by: Zha Bin <address@hidden>
Signed-off-by: Zha Bin <address@hidden>
Signed-off-by: Jing Liu <address@hidden>
---
content.tex | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/content.tex b/content.tex
index 5881253..ff151ba 100644
--- a/content.tex
+++ b/content.tex
@@ -5840,6 +5840,9 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved
Feature Bits}
\item[VIRTIO_F_MMIO_NOTIFICATION(39)] This feature indicates
that the device supports enhanced notification mechanism on
MMIO transport layer.
+ \item[VIRTIO_F_MMIO_MSI(40)] This feature indicates that the
+ device supports Message Signal Interrupts (MSI) mechanism on
+ MMIO transport layer.
\drivernormative{\section}{Reserved Feature Bits}{Reserved Feature Bits}
@@ -5875,6 +5878,10 @@ \chapter{Reserved Feature Bits}\label{sec:Reserved
Feature Bits}
A driver SHOULD accept VIRTIO_F_MMIO_NOTIFICATION if it is offered.
+A driver SHOULD accept VIRTIO_F_MMIO_MSI if it is offered.
+If VIRTIO_F_MMIO_MSI has been negotiated, a driver MUST try to
+set up MSI at first priority.
+
\devicenormative{\section}{Reserved Feature Bits}{Reserved Feature Bits}
A device MUST offer VIRTIO_F_VERSION_1. A device MAY fail to operate further
--
2.7.4