Re: [Qemu-devel] [RFC PATCH 1/8] qtest: add libqos

[Kevin Wolf <kwolf@redhat.com>]

Am 05.03.2013 um 14:53 hat Anthony Liguori geschrieben:
> This includes basic PCI support.
> 
> Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

> +static void *qpci_pc_iomap(QPCIBus *bus, QPCIDevice *dev, int barno)
> +{
> +    QPCIBusPC *s = container_of(bus, QPCIBusPC, bus);
> +    static const int bar_reg_map[] = {
> +        PCI_BASE_ADDRESS_0, PCI_BASE_ADDRESS_1, PCI_BASE_ADDRESS_2,
> +        PCI_BASE_ADDRESS_3, PCI_BASE_ADDRESS_4, PCI_BASE_ADDRESS_5,
> +    };
> +    int bar_reg;
> +    uint32_t addr;
> +    uint64_t size;
> +
> +    g_assert(barno >= 0 && barno <= 5);
> +    bar_reg = bar_reg_map[barno];
> +
> +    qpci_config_writel(dev, bar_reg, 0xFFFFFFFF);
> +    addr = qpci_config_readl(dev, bar_reg);
> +
> +    size = (1ULL << ctol(addr));

This doesn't look right. It should be something like:

    size = (1ULL << ctzl(addr & ~0x3));

In fact, what must be masked out differs for I/O (0x3) and memory (0xf).

> --- /dev/null
> +++ b/tests/libqos/pci.c
> @@ -0,0 +1,108 @@
> +#include "libqos/pci.h"
> +
> +#include "hw/pci/pci_regs.h"
> +#include <glib.h>
> +
> +#include <stdio.h>
> +
> +QPCIDevice *qpci_device_find(QPCIBus *bus, int devfn)
> +{
> +    QPCIDevice *dev;
> +
> +    dev = g_malloc0(sizeof(*dev));

Where is the matching free? I can't seem to destroy a device I
once queried.

> +    dev->bus = bus;
> +    dev->devfn = devfn;
> +
> +    if (qpci_config_readw(dev, PCI_VENDOR_ID) == 0xFFFF) {
> +        printf("vendor id is %x\n", qpci_config_readw(dev, PCI_VENDOR_ID));
> +        g_free(dev);
> +        return NULL;
> +    }
> +
> +    return dev;
> +}
> +
> +void qpci_device_enable(QPCIDevice *dev)
> +{
> +    uint16_t cmd;
> +
> +    /* FIXME -- does this need to be a bus callout? */
> +    cmd = qpci_config_readw(dev, PCI_COMMAND);
> +    cmd |= PCI_COMMAND_IO | PCI_COMMAND_MEMORY;
> +    qpci_config_writew(dev, PCI_COMMAND, cmd);
> +}

Wouldn't it make sense to enable bus mastering here as well? Forgetting
to do this manually is a trap that's easy to fall in...

Kevin