Implement PCI emulation #9

ray90514 · 2022-06-21T03:46:33Z

This commit implements PCI emulation.

jserv

Split the proposed changes into two pull requests: one is for PCI emulation, and another is the basis of virtio-blk.

configs/linux.config

jserv

Rework the git commit messages. In order to make it informative, you should mention the following:

Summarize the proposed changes: at least Virtio shall be addressed.
Describe the functionalities of PCI specific changes and the limitation.
How further virtio-blk makes use of the work.
See https://cbea.ms/git-commit/

src/vm.c

src/pci.c

configs/linux.config

src/pci.c

src/vm.h

jserv

Improve your English writing:

There is only a PCI functionality be implemented, which is mapping internal space to io space or mmio space through BAR.

Fix grammar mistakes. Grammarly can help.

src/pci.c

jserv · 2022-06-21T10:05:33Z

It is not worthy to mention "Virtio is a specification of para-virtualization" since the project assumes people know KVM. Instead, you should express the rationale between the proposed change and further pull requests which hopefully build up usable virtio-blk.

src/pci.c

RinHizakura · 2022-06-21T10:43:31Z

src/vm.c

+        serial_handle(&v->serial, run);
+    } else {
+        for (int i = 0; i < run->io.count; i++) {
+            bus_handle_io(&v->io_bus, data, is_write, addr, run->io.size);


Is it make sense to also register serial UART as an io_bus object? So the emulated hardware with read and write method could be implemented on the same abstraction.

Yes, I suppose so.

@RinHizakura, I tend to merge this pull request and then think of further abstractions. Can you create a new issue which consolidates serial UART refactoring?

Sure, I'll create an issue that mentions this later.

Emulate the mechanism to access PCI config spaces on port 0xCF8/0xCFC. There is only a PCI functionality implemented, which is mapping internal space to io space or mmio space through BAR. Each virtio-pci device has its own PCI config space and virtio config space. The PCI config space can be registered to PCI bus by pci_register_dev(). After the PCI device initialization, Guest Linux can access the virtio config space. Our virtio-blk devices is based on virtio-pci. Without option "pci=conf1", the kernel doesn't find a PCI bus and therefore also doesn't find the virtio-blk devices.

jserv · 2022-06-21T11:52:09Z

Thank @ray90514 for contributing!

jserv requested changes Jun 21, 2022

View reviewed changes

ray90514 force-pushed the master branch from 57f9785 to e94000e Compare June 21, 2022 05:34

ray90514 changed the title ~~Implement virtio-blk~~ Implement PCI emulation Jun 21, 2022