On Mon, Jan 19, 2015 at 05:28:41PM +0800, Tiejun Chen wrote:
> Some registers of Intel IGD are mapped in host bridge, so it needs to
> passthrough these registers of physical host bridge to guest because
> emulated host bridge in guest doesn't have these mappings.
>
> Signed-off-by: Tiejun Chen <tiejun.c...@intel.com>
> Signed-off-by: Yang Zhang <yang.z.zh...@intel.com>
> ---
> hw/pci-host/piix.c | 3 ++
> hw/xen/xen_pt.h | 1 +
> hw/xen/xen_pt_graphics.c | 72
> ++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 76 insertions(+)
>
> diff --git a/hw/pci-host/piix.c b/hw/pci-host/piix.c
> index 1468961..0a5a4c7 100644
> --- a/hw/pci-host/piix.c
> +++ b/hw/pci-host/piix.c
> @@ -34,6 +34,7 @@
> #include "sysemu/sysemu.h"
> #include "hw/i386/ioapic.h"
> #include "qapi/visitor.h"
> +#include "hw/xen/xen_pt.h"
>
> /*
> * I440FX chipset data sheet.
> @@ -733,8 +734,10 @@ static void
> xen_igd_passthrough_i440fx_class_init(ObjectClass *klass,
> void *data)
> {
> DeviceClass *dc = DEVICE_CLASS(klass);
> + PCIDeviceClass *k = PCI_DEVICE_CLASS(klass);
>
> dc->desc = "IGD PT XEN Host bridge";
> + k->config_read = xen_igd_pci_read;
> }
>
> static const TypeInfo xen_igd_passthrough_i440fx_info = {
> diff --git a/hw/xen/xen_pt.h b/hw/xen/xen_pt.h
> index 0aa5a93..94cde4a 100644
> --- a/hw/xen/xen_pt.h
> +++ b/hw/xen/xen_pt.h
> @@ -5,6 +5,7 @@
> #include "hw/xen/xen_common.h"
> #include "hw/pci/pci.h"
> #include "xen-host-pci-device.h"
> +uint32_t xen_igd_pci_read(PCIDevice *pci_dev, uint32_t config_addr, int len);
>
> void xen_pt_log(const PCIDevice *d, const char *f, ...) GCC_FMT_ATTR(2, 3);
>
> diff --git a/hw/xen/xen_pt_graphics.c b/hw/xen/xen_pt_graphics.c
> index 3232296..227089b 100644
> --- a/hw/xen/xen_pt_graphics.c
> +++ b/hw/xen/xen_pt_graphics.c
> @@ -4,6 +4,7 @@
> #include "xen_pt.h"
> #include "xen-host-pci-device.h"
> #include "hw/xen/xen_backend.h"
> +#include "hw/pci/pci_bus.h"
>
> typedef struct VGARegion {
> int type; /* Memory or port I/O */
> @@ -188,3 +189,74 @@ int xen_pt_setup_vga(XenPCIPassthroughState *s,
> XenHostPCIDevice *dev)
> cpu_physical_memory_rw(0xc0000, bios, bios_size, 1);
> return 0;
> }
> +
> +/*
> + * Currently we just pass this physical host bridge for IGD, 00:02.0.
> + *
> + * Here pci_dev is just that host bridge, so we have to get that real
> + * passthrough device by that given devfn to avoid other devices access.
> + */
> +static int is_igd_passthrough(PCIDevice *pci_dev)
> +{
> + PCIDevice *f = pci_dev->bus->devices[PCI_DEVFN(2, 0)];
> + if (pci_dev->bus->devices[PCI_DEVFN(2, 0)]) {
> + XenPCIPassthroughState *s = DO_UPCAST(XenPCIPassthroughState, dev,
> f);
> + return (is_igd_vga_passthrough(&s->real_device)
> + && (s->real_device.vendor_id == PCI_VENDOR_ID_INTEL));
> + } else {
> + return 0;
> + }
> +}
> +
> +uint32_t xen_igd_pci_read(PCIDevice *pci_dev, uint32_t config_addr, int len)
> +{
> + XenHostPCIDevice dev;
> + uint32_t val;
> + int r;
> +
> + /* IGD read/write is through the host bridge.
> + */
> + assert(pci_dev->devfn == 0x00);
> +
> + if (!is_igd_passthrough(pci_dev)) {
> + goto read_default;
> + }
> +
> + /* Just work for the i915 driver. */
> + switch (config_addr) {
> + case 0x08: /* revision id */
> + case 0x2c: /* sybsystem vendor id */
> + case 0x2e: /* sybsystem id */
> + case 0x50: /* SNB: processor graphics control register */
> + case 0x52: /* processor graphics control register */
> + case 0xa0: /* top of memory */
Is this host physical memory? If yes how can using it in guest work?
> + case 0xa4: /* SNB: graphics base of stolen memory */
> + case 0xa8: /* SNB: base of GTT stolen memory */
Same question for above two.
> + break;
> + default:
> + /* Just gets the emulated values. */
> + goto read_default;
> + }
> +
> + /* Host read */
> + r = xen_host_pci_device_get(&dev, 0, 0, 0, 0);
> + if (r) {
> + goto err_out;
> + }
> +
> + r = xen_host_pci_get_block(&dev, config_addr, (uint8_t *)&val, len);
> + if (r) {
> + goto err_out;
> + }
> +
> + xen_host_pci_device_put(&dev);
> +
> + return val;
> +
> +read_default:
> + return pci_default_read_config(pci_dev, config_addr, len);
> +
> +err_out:
> + XEN_PT_ERR(pci_dev, "Can't get pci_dev_host_bridge\n");
> + return -1;
> +}
Do any of the above registers change with time?
Does it work if we just read them when device is created
and put in dev->config?
> --
> 1.9.1
