Alex Williamson <alex.williamson@xxxxxxxxxx> writes:
> On Wed, 2010-05-19 at 12:00 -0700, Chris Wright wrote:
>> When libvirt launches a guest it first chowns the relevenat
>> /sys/bus/pci/.../config file for an assigned device then drops privileges.
>>
>> This causes an issue for device assignment because despite being file
>> owner, the sysfs config space file checks for CAP_SYS_ADMIN before
>> allowing access to device dependent config space.
>>
>> This adds a new qdev configfd property which allows libvirt to open the
>> sysfs config space file and give qemu an already opened file descriptor.
>> Along with a change pending for the 2.6.35 kernel, this allows the
>> capability check to compare against privileges from when the file was
>> opened.
>
> We need to make configfd be a string option so that we can pass a
> descriptor from libvirt for the hotplug case. Here's a rework.
>
> Signed-off-by: Chris Wright <chrisw@xxxxxxxxxx>
> Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
> ---
>
> diff --git a/hw/device-assignment.c b/hw/device-assignment.c
> index eb31c78..3c5184f 100644
> --- a/hw/device-assignment.c
> +++ b/hw/device-assignment.c
> @@ -37,6 +37,7 @@
> #include "console.h"
> #include "device-assignment.h"
> #include "loader.h"
> +#include "monitor.h"
> #include <pci/pci.h>
>
> /* From linux/ioport.h */
> @@ -612,14 +613,28 @@ static int get_real_device(AssignedDevice *pci_dev, uint16_t r_seg,
>
> snprintf(name, sizeof(name), "%sconfig", dir);
>
> - fd = open(name, O_RDWR);
> - if (fd == -1) {
> - fprintf(stderr, "%s: %s: %m\n", __func__, name);
> - return 1;
> + if (pci_dev->configfd_name && *pci_dev->configfd_name) {
> + if (qemu_isdigit(pci_dev->configfd_name[0])) {
> + dev->config_fd = strtol(pci_dev->configfd_name, NULL, 0);
> + } else {
> + dev->config_fd = monitor_get_fd(cur_mon, pci_dev->configfd_name);
> + if (dev->config_fd < 0) {
> + fprintf(stderr, "%s: (%s) unkown\n", __func__,
> + pci_dev->configfd_name);
> + return 1;
> + }
> + }
Similar to net_handle_fd_param(). What about factoring into a common
helper?
Rest looks good to me.
[...]
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