On 10/24/24 05:06, Jiqian Chen wrote:
> diff --git a/hw/xen/xen_pt.c b/hw/xen/xen_pt.c
> index 3635d1b39f79..5b10d501d566 100644
> --- a/hw/xen/xen_pt.c
> +++ b/hw/xen/xen_pt.c
> @@ -766,6 +766,50 @@ static void xen_pt_destroy(PCIDevice *d) {
> }
> /* init */
>
> +#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 42000
> +static bool xen_pt_need_gsi(void)
> +{
> + FILE *fp;
> + int len;
> + char type[10];
A brief in-code comment to explain how you arrived at 10 would be
appreciated.
> + const char *guest_type = "/sys/hypervisor/guest_type";
> +
> + fp = fopen(guest_type, "r");
> + if (fp == NULL) {
> + error_report("Cannot open %s: %s", guest_type, strerror(errno));
> + return false;
> + }
> + fgets(type, sizeof(type), fp);
Please check the return value of fgets.
> + fclose(fp);
> +
> + len = strlen(type);
Before passing to strlen, is "type" always guaranteed to have a
terminating '\0' character?
> + if (len) {
> + type[len - 1] = '\0';
> + if (!strcmp(type, "PVH")) {
> + return true;
> + }
> + }
> + return false;
> +}
> +
> +static int xen_pt_map_pirq_for_gsi(PCIDevice *d, int *pirq)
> +{
> + int gsi;
> + XenPCIPassthroughState *s = XEN_PT_DEVICE(d);
> +
> + gsi = xc_pcidev_get_gsi(xen_xc,
> + PCI_SBDF(s->real_device.domain,
> + s->real_device.bus,
> + s->real_device.dev,
> + s->real_device.func));
> + if (gsi >= 0) {
> + return xc_physdev_map_pirq_gsi(xen_xc, xen_domid, gsi, pirq);
> + }
> +
> + return gsi;
> +}
> +#endif
> +
> static void xen_pt_realize(PCIDevice *d, Error **errp)
> {
> ERRP_GUARD();
> @@ -847,7 +891,16 @@ static void xen_pt_realize(PCIDevice *d, Error **errp)
> goto out;
> }
>
> +#if CONFIG_XEN_CTRL_INTERFACE_VERSION >= 42000
> + if (xen_pt_need_gsi()) {
> + rc = xen_pt_map_pirq_for_gsi(d, &pirq);
> + } else {
> + rc = xc_physdev_map_pirq(xen_xc, xen_domid, machine_irq, &pirq);
> + }
> +#else
> rc = xc_physdev_map_pirq(xen_xc, xen_domid, machine_irq, &pirq);
> +#endif
> +
> if (rc < 0) {
> XEN_PT_ERR(d, "Mapping machine irq %u to pirq %i failed, (err:
> %d)\n",
> machine_irq, pirq, errno);
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index eb26cac81098..07805aa8a5f3 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -23,6 +23,10 @@ extern bool pci_available;
> #define PCI_SLOT_MAX 32
> #define PCI_FUNC_MAX 8
>
> +#define PCI_SBDF(seg, bus, dev, func) \
> + ((((uint32_t)(seg)) << 16) | \
> + (PCI_BUILD_BDF(bus, PCI_DEVFN(dev, func))))
> +
> /* Class, Vendor and Device IDs from Linux's pci_ids.h */
> #include "hw/pci/pci_ids.h"
>
