[PATCH 4.9 10/60] drm/i915: Fix GVT-g PVINFO version compatibility check

Greg Kroah-Hartman
2017-06-19T15:23:06Z

From: Zhenyu Wang <zhenyuw@linux.intel.com>

commit c380f681245d7ae57f17d9ebbbe8f8f1557ee1fb upstream.

Current it's strictly checked if PVINFO version matches 1.0
for GVT-g i915 guest which doesn't help for compatibility at
all and forces GVT-g host can't extend PVINFO easily with version
bump for real compatibility check.

This fixes that to check minimal required PVINFO version instead.

v2:
- drop unneeded version macro
- use only major version for sanity check

v3:
- fix up PVInfo value with kernel type
- one indent fix

Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chuanxiao Dong <chuanxiao.dong@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170609074805.5101-1-zhenyuw@linux.intel.com
(cherry picked from commit 0c8792d00d38de85b6ceb1dd67d3ee009d7c8e42)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/i915/i915_pvinfo.h | 8 ++------
drivers/gpu/drm/i915/i915_vgpu.c | 10 ++++------
2 files changed, 6 insertions(+), 12 deletions(-)

--- a/drivers/gpu/drm/i915/i915_pvinfo.h
+++ b/drivers/gpu/drm/i915/i915_pvinfo.h
@@ -36,10 +36,6 @@
#define VGT_VERSION_MAJOR 1
#define VGT_VERSION_MINOR 0

-#define INTEL_VGT_IF_VERSION_ENCODE(major, minor) ((major) << 16 | (minor))
-#define INTEL_VGT_IF_VERSION \
- INTEL_VGT_IF_VERSION_ENCODE(VGT_VERSION_MAJOR, VGT_VERSION_MINOR)
-
/*
* notifications from guest to vgpu device model
*/
@@ -55,8 +51,8 @@ enum vgt_g2v_type {

struct vgt_if {
u64 magic; /* VGT_MAGIC */
- uint16_t version_major;
- uint16_t version_minor;
+ u16 version_major;
+ u16 version_minor;
u32 vgt_id; /* ID of vGT instance */
u32 rsv1[12]; /* pad to offset 0x40 */
/*
--- a/drivers/gpu/drm/i915/i915_vgpu.c
+++ b/drivers/gpu/drm/i915/i915_vgpu.c
@@ -60,8 +60,8 @@
*/
void i915_check_vgpu(struct drm_i915_private *dev_priv)
{
- uint64_t magic;
- uint32_t version;
+ u64 magic;
+ u16 version_major;

BUILD_BUG_ON(sizeof(struct vgt_if) != VGT_PVINFO_SIZE);

@@ -69,10 +69,8 @@ void i915_check_vgpu(struct drm_i915_pri
if (magic != VGT_MAGIC)
return;

- version = INTEL_VGT_IF_VERSION_ENCODE(
- __raw_i915_read16(dev_priv, vgtif_reg(version_major)),
- __raw_i915_read16(dev_priv, vgtif_reg(version_minor)));
- if (version != INTEL_VGT_IF_VERSION) {
+ version_major = __raw_i915_read16(dev_priv, vgtif_reg(version_major));
+ if (version_major < VGT_VERSION_MAJOR) {
DRM_INFO("VGT interface version mismatch!\n");
return;
}