From ea652c2beeaec51035f76aeb976af06858ee85ce Mon Sep 17 00:00:00 2001 From: Tomita Moeko Date: Fri, 6 Dec 2024 20:27:46 +0800 Subject: [PATCH] vfio/igd: emulate GGC register in mmio bar0 MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The GGC register at 0x50 of pci config space is a mirror of the same register at 0x108040 of mmio bar0 [1]. i915 driver also reads that register from mmio bar0 instead of config space. As GGC is programmed and emulated by qemu, the mmio address should also be emulated, in the same way of BDSM register. [1] 4.1.28, 12th Generation Intel Core Processors Datasheet Volume 2 https://www.intel.com/content/www/us/en/content-details/655259 Signed-off-by: Tomita Moeko Reviewed-by: Alex Williamson Link: https://lore.kernel.org/r/20241206122749.9893-9-tomitamoeko@gmail.com Signed-off-by: Cédric Le Goater --- hw/vfio/igd.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/hw/vfio/igd.c b/hw/vfio/igd.c index 4e93af1f8d..828222cad1 100644 --- a/hw/vfio/igd.c +++ b/hw/vfio/igd.c @@ -488,8 +488,10 @@ static const MemoryRegionOps vfio_igd_quirk_mirror_##name = { \ .endianness = DEVICE_LITTLE_ENDIAN, \ }; +VFIO_IGD_QUIRK_MIRROR_REG(IGD_GMCH, ggc) VFIO_IGD_QUIRK_MIRROR_REG(IGD_BDSM_GEN11, bdsm) +#define IGD_GGC_MMIO_OFFSET 0x108040 #define IGD_BDSM_MMIO_OFFSET 0x1080C0 void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr) @@ -518,14 +520,21 @@ void vfio_probe_igd_bar0_quirk(VFIOPCIDevice *vdev, int nr) return; } - quirk = vfio_quirk_alloc(1); + quirk = vfio_quirk_alloc(2); quirk->data = vdev; memory_region_init_io(&quirk->mem[0], OBJECT(vdev), + &vfio_igd_quirk_mirror_ggc, vdev, + "vfio-igd-ggc-quirk", 2); + memory_region_add_subregion_overlap(vdev->bars[0].region.mem, + IGD_GGC_MMIO_OFFSET, &quirk->mem[0], + 1); + + memory_region_init_io(&quirk->mem[1], OBJECT(vdev), &vfio_igd_quirk_mirror_bdsm, vdev, "vfio-igd-bdsm-quirk", 8); memory_region_add_subregion_overlap(vdev->bars[0].region.mem, - IGD_BDSM_MMIO_OFFSET, &quirk->mem[0], + IGD_BDSM_MMIO_OFFSET, &quirk->mem[1], 1); QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next); -- 2.30.2