From 95b15e49010299902abd2aa65bcc71e4158b7326 Mon Sep 17 00:00:00 2001
From: Liav A <liavalb@gmail.com>
Date: Tue, 7 Mar 2023 21:04:39 +0200
Subject: [PATCH] Kernel/VirtIO: Ignore Configurations that have length of zero
 bytes

These configurations are simply invalid. Ignoring those allow us to boot
with the virtio-gpu-pci device (in addition to the already supported
virtio-vga PCI device).
---
 Kernel/Bus/VirtIO/Device.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Kernel/Bus/VirtIO/Device.cpp b/Kernel/Bus/VirtIO/Device.cpp
index 7f4c1838a9..81cf8f57d2 100644
--- a/Kernel/Bus/VirtIO/Device.cpp
+++ b/Kernel/Bus/VirtIO/Device.cpp
@@ -113,6 +113,9 @@ UNMAP_AFTER_INIT void Device::initialize()
             }
             config.offset = capability.read32(0x8);
             config.length = capability.read32(0xc);
+            // NOTE: Configuration length of zero is an invalid configuration that should be ignored.
+            if (config.length == 0)
+                continue;
             dbgln_if(VIRTIO_DEBUG, "{}: Found configuration {}, bar: {}, offset: {}, length: {}", m_class_name, (u32)config.cfg_type, config.bar, config.offset, config.length);
             if (config.cfg_type == ConfigurationType::Common)
                 m_use_mmio = true;