diff --git a/drivers/gpu/drm/i915/gvt/cfg_space.c b/drivers/gpu/drm/i915/gvt/cfg_space.c index a77e050b85a3416153eab5eaeaaadf0928bbc2d2..b7d7721e72faddc2a2d4fc76d69d795b8053cfad 100644 --- a/drivers/gpu/drm/i915/gvt/cfg_space.c +++ b/drivers/gpu/drm/i915/gvt/cfg_space.c @@ -41,6 +41,54 @@ enum { INTEL_GVT_PCI_BAR_MAX, }; +/* bitmap for writable bits (RW or RW1C bits, but cannot co-exist in one + * byte) byte by byte in standard pci configuration space. (not the full + * 256 bytes.) + */ +static const u8 pci_cfg_space_rw_bmp[PCI_INTERRUPT_LINE + 4] = { + [PCI_COMMAND] = 0xff, 0x07, + [PCI_STATUS] = 0x00, 0xf9, /* the only one RW1C byte */ + [PCI_CACHE_LINE_SIZE] = 0xff, + [PCI_BASE_ADDRESS_0 ... PCI_CARDBUS_CIS - 1] = 0xff, + [PCI_ROM_ADDRESS] = 0x01, 0xf8, 0xff, 0xff, + [PCI_INTERRUPT_LINE] = 0xff, +}; + +/** + * vgpu_pci_cfg_mem_write - write virtual cfg space memory + * + * Use this function to write virtual cfg space memory. + * For standard cfg space, only RW bits can be changed, + * and we emulates the RW1C behavior of PCI_STATUS register. + */ +static void vgpu_pci_cfg_mem_write(struct intel_vgpu *vgpu, unsigned int off, + u8 *src, unsigned int bytes) +{ + u8 *cfg_base = vgpu_cfg_space(vgpu); + u8 mask, new, old; + int i = 0; + + for (; i < bytes && (off + i < sizeof(pci_cfg_space_rw_bmp)); i++) { + mask = pci_cfg_space_rw_bmp[off + i]; + old = cfg_base[off + i]; + new = src[i] & mask; + + /** + * The PCI_STATUS high byte has RW1C bits, here + * emulates clear by writing 1 for these bits. + * Writing a 0b to RW1C bits has no effect. + */ + if (off + i == PCI_STATUS + 1) + new = (~new & old) & mask; + + cfg_base[off + i] = (old & ~mask) | new; + } + + /* For other configuration space directly copy as it is. */ + if (i < bytes) + memcpy(cfg_base + off + i, src + i, bytes - i); +} + /** * intel_vgpu_emulate_cfg_read - emulate vGPU configuration space read * @@ -123,7 +171,7 @@ static int emulate_pci_command_write(struct intel_vgpu *vgpu, u8 changed = old ^ new; int ret; - memcpy(vgpu_cfg_space(vgpu) + offset, p_data, bytes); + vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes); if (!(changed & PCI_COMMAND_MEMORY)) return 0; @@ -277,10 +325,10 @@ int intel_vgpu_emulate_cfg_write(struct intel_vgpu *vgpu, unsigned int offset, if (ret) return ret; - memcpy(vgpu_cfg_space(vgpu) + offset, p_data, bytes); + vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes); break; default: - memcpy(vgpu_cfg_space(vgpu) + offset, p_data, bytes); + vgpu_pci_cfg_mem_write(vgpu, offset, p_data, bytes); break; } return 0;