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Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability |
Date: |
Thu, 2 Jul 2015 20:48:14 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.0.1 |
On 02/07/2015 15:00, Michael S. Tsirkin wrote:
> + cfg = (void *)(proxy->pci_dev.config + proxy->config_cap);
> + off = le32_to_cpu(cfg->cap.offset);
> + len = le32_to_cpu(cfg->cap.length);
> +
> + if ((len == 1 || len == 2 || len == 4)) {
> + address_space_write(&proxy->modern_as, off,
> + MEMTXATTRS_UNSPECIFIED,
> + cfg->pci_cfg_data, len);
> + }
This parses pci_cfg_data in target endianness I think. You just want to
move the little-endian value from the config cap to the little-endian
value in the modern_as, so you need to use ldl_le_p and
address_space_stl_le.
> + }
> +}
> +
> +static uint32_t virtio_read_config(PCIDevice *pci_dev,
> + uint32_t address, int len)
> +{
> + VirtIOPCIProxy *proxy = DO_UPCAST(VirtIOPCIProxy, pci_dev, pci_dev);
> + struct virtio_pci_cfg_cap *cfg;
> +
> + if (proxy->config_cap &&
> + ranges_overlap(address, len, proxy->config_cap + offsetof(struct
> virtio_pci_cfg_cap,
> +
> pci_cfg_data),
> + sizeof cfg->pci_cfg_data)) {
> + uint32_t off;
> + uint32_t len;
> +
> + cfg = (void *)(proxy->pci_dev.config + proxy->config_cap);
> + off = le32_to_cpu(cfg->cap.offset);
> + len = le32_to_cpu(cfg->cap.length);
> +
> + if ((len == 1 || len == 2 || len == 4)) {
> + address_space_read(&proxy->modern_as, off,
> + MEMTXATTRS_UNSPECIFIED,
> + cfg->pci_cfg_data, len);
Same here, use address_space_ldl_le to read into an int, and stl_le_p to
write into cfg->pci_cfg_data.
The best way to check it, of course, is to write a unit test! :) But
you could also use a Linux BE guest on LE host.
Everything else looks good.
Paolo
- [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/02
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability,
Paolo Bonzini <=
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/02
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Paolo Bonzini, 2015/07/02
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/04
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Paolo Bonzini, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Paolo Bonzini, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Peter Maydell, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Michael S. Tsirkin, 2015/07/06
- Re: [Qemu-devel] [PATCH] virtio-pci: implement cfg capability, Peter Maydell, 2015/07/06