On Mon, Feb 19, 2024 at 07:16:06PM +0100, Marek Marczykowski-Górecki wrote: > From: Frédéric Pierret (fepitre) <frederic.pier...@qubes-os.org>
This shouldn't be here, it's my patch.
> When running in a stubdomain, the config space access via sysfs needs to
> use BDF as seen inside stubdomain (connected via xen-pcifront), which is
> different from the real BDF. For other purposes (hypercall parameters
> etc), the real BDF needs to be used.
> Get the in-stubdomain BDF by looking up relevant PV PCI xenstore
> entries.
>
> Signed-off-by: Marek Marczykowski-Górecki <marma...@invisiblethingslab.com>
> ---
> hw/xen/xen-host-pci-device.c | 77 +++++++++++++++++++++++++++++++++++-
> hw/xen/xen-host-pci-device.h | 6 +++
> 2 files changed, 82 insertions(+), 1 deletion(-)
>
> diff --git a/hw/xen/xen-host-pci-device.c b/hw/xen/xen-host-pci-device.c
> index 8c6e9a1716..3f8a6f84a8 100644
> --- a/hw/xen/xen-host-pci-device.c
> +++ b/hw/xen/xen-host-pci-device.c
> @@ -9,6 +9,7 @@
> #include "qemu/osdep.h"
> #include "qapi/error.h"
> #include "qemu/cutils.h"
> +#include "hw/xen/xen-legacy-backend.h"
> #include "xen-host-pci-device.h"
>
> #define XEN_HOST_PCI_MAX_EXT_CAP \
> @@ -33,13 +34,76 @@
> #define IORESOURCE_PREFETCH 0x00001000 /* No side effects */
> #define IORESOURCE_MEM_64 0x00100000
>
> +static void xen_host_pci_fill_local_addr(XenHostPCIDevice *d, Error **errp)
> +{
> + unsigned int num_devs, len, i;
> + unsigned int domain, bus, dev, func;
> + char *be_path = NULL;
> + char path[80];
> + char *msg = NULL;
> +
> + be_path = qemu_xen_xs_read(xenstore, 0, "device/pci/0/backend", &len);
> + if (!be_path)
> + goto err_out;
> + snprintf(path, sizeof(path), "%s/num_devs", be_path);
> + msg = qemu_xen_xs_read(xenstore, 0, path, &len);
> + if (!msg)
> + goto err_out;
> +
> + if (sscanf(msg, "%u", &num_devs) != 1) {
> + error_setg(errp, "Failed to parse %s (%s)\n", msg, path);
> + goto err_out;
> + }
> + free(msg);
> +
> + for (i = 0; i < num_devs; i++) {
> + snprintf(path, sizeof(path), "%s/dev-%u", be_path, i);
> + msg = qemu_xen_xs_read(xenstore, 0, path, &len);
> + if (!msg) {
> + error_setg(errp, "Failed to read %s\n", path);
> + goto err_out;
> + }
> + if (sscanf(msg, "%x:%x:%x.%x", &domain, &bus, &dev, &func) != 4) {
> + error_setg(errp, "Failed to parse %s (%s)\n", msg, path);
> + goto err_out;
> + }
> + free(msg);
> + if (domain != d->domain ||
> + bus != d->bus ||
> + dev != d->dev ||
> + func!= d->func)
> + continue;
> + snprintf(path, sizeof(path), "%s/vdev-%u", be_path, i);
> + msg = qemu_xen_xs_read(xenstore, 0, path, &len);
> + if (!msg) {
> + error_setg(errp, "Failed to read %s\n", path);
> + goto out;
> + }
> + if (sscanf(msg, "%x:%x:%x.%x", &domain, &bus, &dev, &func) != 4) {
> + error_setg(errp, "Failed to parse %s (%s)\n", msg, path);
> + goto err_out;
> + }
> + free(msg);
> + d->local_domain = domain;
> + d->local_bus = bus;
> + d->local_dev = dev;
> + d->local_func = func;
> + goto out;
> + }
> +
> +err_out:
> + free(msg);
> +out:
> + free(be_path);
> +}
> +
> static void xen_host_pci_sysfs_path(const XenHostPCIDevice *d,
> const char *name, char *buf, ssize_t
> size)
> {
> int rc;
>
> rc = snprintf(buf, size, "/sys/bus/pci/devices/%04x:%02x:%02x.%d/%s",
> - d->domain, d->bus, d->dev, d->func, name);
> + d->local_domain, d->local_bus, d->local_dev,
> d->local_func, name);
> assert(rc >= 0 && rc < size);
> }
>
> @@ -342,6 +406,17 @@ void xen_host_pci_device_get(XenHostPCIDevice *d,
> uint16_t domain,
> d->dev = dev;
> d->func = func;
>
> + if (xen_is_stubdomain) {
> + xen_host_pci_fill_local_addr(d, errp);
> + if (*errp)
> + goto error;
> + } else {
> + d->local_domain = d->domain;
> + d->local_bus = d->bus;
> + d->local_dev = d->dev;
> + d->local_func = d->func;
> + }
> +
> xen_host_pci_config_open(d, errp);
> if (*errp) {
> goto error;
> diff --git a/hw/xen/xen-host-pci-device.h b/hw/xen/xen-host-pci-device.h
> index 4d8d34ecb0..270dcb27f7 100644
> --- a/hw/xen/xen-host-pci-device.h
> +++ b/hw/xen/xen-host-pci-device.h
> @@ -23,6 +23,12 @@ typedef struct XenHostPCIDevice {
> uint8_t dev;
> uint8_t func;
>
> + /* different from the above in case of stubdomain */
> + uint16_t local_domain;
> + uint8_t local_bus;
> + uint8_t local_dev;
> + uint8_t local_func;
> +
> uint16_t vendor_id;
> uint16_t device_id;
> uint32_t class_code;
> --
> 2.43.0
>
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
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