[PATCH 4.13 032/110] drm/i915/gvt: Fix incorrect PCI BARs reporting

From: Greg Kroah-Hartman
Date: Tue Oct 03 2017 - 08:32:42 EST


4.13-stable review patch. If anyone has any objections, please let me know.

------------------

From: Changbin Du <changbin.du@xxxxxxxxx>

commit 7b4dc3c0da0d66e7b20a826c537d41bb73e4df54 upstream.

Looking at our virtual PCI device, we can see surprising Region 4 and Region 5.
00:10.0 VGA compatible controller: Intel Corporation Sky Lake Integrated Graphics (rev 06) (prog-if 00 [VGA controller])
....
Region 0: Memory at 140000000 (64-bit, non-prefetchable) [size=16M]
Region 2: Memory at 180000000 (64-bit, prefetchable) [size=1G]
Region 4: Memory at <ignored> (32-bit, non-prefetchable)
Region 5: Memory at <ignored> (32-bit, non-prefetchable)
Expansion ROM at febd6000 [disabled] [size=2K]

The fact is that we only implemented BAR0 and BAR2. Surprising Region 4 and
Region 5 are shown because we report their size as 0xffffffff. They should
report size 0 instead.

BTW, the physical GPU has a PIO BAR. GVTg hasn't implemented PIO access, so
we ignored this BAR for vGPU device.

v2: fix BAR size value calculation.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=1458032
Signed-off-by: Changbin Du <changbin.du@xxxxxxxxx>
Signed-off-by: Zhenyu Wang <zhenyuw@xxxxxxxxxxxxxxx>
(cherry picked from commit f1751362d6357a90bc6e53176cec715ff2dbed74)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/i915/gvt/cfg_space.c | 113 ++++++++++++++---------------------
1 file changed, 48 insertions(+), 65 deletions(-)

--- a/drivers/gpu/drm/i915/gvt/cfg_space.c
+++ b/drivers/gpu/drm/i915/gvt/cfg_space.c
@@ -197,78 +197,65 @@ static int emulate_pci_command_write(str
static int emulate_pci_bar_write(struct intel_vgpu *vgpu, unsigned int offset,
void *p_data, unsigned int bytes)
{
- unsigned int bar_index =
- (rounddown(offset, 8) % PCI_BASE_ADDRESS_0) / 8;
u32 new = *(u32 *)(p_data);
bool lo = IS_ALIGNED(offset, 8);
u64 size;
int ret = 0;
bool mmio_enabled =
vgpu_cfg_space(vgpu)[PCI_COMMAND] & PCI_COMMAND_MEMORY;
+ struct intel_vgpu_pci_bar *bars = vgpu->cfg_space.bar;

- if (WARN_ON(bar_index >= INTEL_GVT_PCI_BAR_MAX))
- return -EINVAL;
-
+ /*
+ * Power-up software can determine how much address
+ * space the device requires by writing a value of
+ * all 1's to the register and then reading the value
+ * back. The device will return 0's in all don't-care
+ * address bits.
+ */
if (new == 0xffffffff) {
- /*
- * Power-up software can determine how much address
- * space the device requires by writing a value of
- * all 1's to the register and then reading the value
- * back. The device will return 0's in all don't-care
- * address bits.
- */
- size = vgpu->cfg_space.bar[bar_index].size;
- if (lo) {
- new = rounddown(new, size);
- } else {
- u32 val = vgpu_cfg_space(vgpu)[rounddown(offset, 8)];
- /* for 32bit mode bar it returns all-0 in upper 32
- * bit, for 64bit mode bar it will calculate the
- * size with lower 32bit and return the corresponding
- * value
+ switch (offset) {
+ case PCI_BASE_ADDRESS_0:
+ case PCI_BASE_ADDRESS_1:
+ size = ~(bars[INTEL_GVT_PCI_BAR_GTTMMIO].size -1);
+ intel_vgpu_write_pci_bar(vgpu, offset,
+ size >> (lo ? 0 : 32), lo);
+ /*
+ * Untrap the BAR, since guest hasn't configured a
+ * valid GPA
*/
- if (val & PCI_BASE_ADDRESS_MEM_TYPE_64)
- new &= (~(size-1)) >> 32;
- else
- new = 0;
- }
- /*
- * Unmapp & untrap the BAR, since guest hasn't configured a
- * valid GPA
- */
- switch (bar_index) {
- case INTEL_GVT_PCI_BAR_GTTMMIO:
ret = trap_gttmmio(vgpu, false);
break;
- case INTEL_GVT_PCI_BAR_APERTURE:
+ case PCI_BASE_ADDRESS_2:
+ case PCI_BASE_ADDRESS_3:
+ size = ~(bars[INTEL_GVT_PCI_BAR_APERTURE].size -1);
+ intel_vgpu_write_pci_bar(vgpu, offset,
+ size >> (lo ? 0 : 32), lo);
ret = map_aperture(vgpu, false);
break;
+ default:
+ /* Unimplemented BARs */
+ intel_vgpu_write_pci_bar(vgpu, offset, 0x0, false);
}
- intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
} else {
- /*
- * Unmapp & untrap the old BAR first, since guest has
- * re-configured the BAR
- */
- switch (bar_index) {
- case INTEL_GVT_PCI_BAR_GTTMMIO:
- ret = trap_gttmmio(vgpu, false);
+ switch (offset) {
+ case PCI_BASE_ADDRESS_0:
+ case PCI_BASE_ADDRESS_1:
+ /*
+ * Untrap the old BAR first, since guest has
+ * re-configured the BAR
+ */
+ trap_gttmmio(vgpu, false);
+ intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
+ ret = trap_gttmmio(vgpu, mmio_enabled);
break;
- case INTEL_GVT_PCI_BAR_APERTURE:
- ret = map_aperture(vgpu, false);
+ case PCI_BASE_ADDRESS_2:
+ case PCI_BASE_ADDRESS_3:
+ map_aperture(vgpu, false);
+ intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
+ ret = map_aperture(vgpu, mmio_enabled);
break;
- }
- intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
- /* Track the new BAR */
- if (mmio_enabled) {
- switch (bar_index) {
- case INTEL_GVT_PCI_BAR_GTTMMIO:
- ret = trap_gttmmio(vgpu, true);
- break;
- case INTEL_GVT_PCI_BAR_APERTURE:
- ret = map_aperture(vgpu, true);
- break;
- }
+ default:
+ intel_vgpu_write_pci_bar(vgpu, offset, new, lo);
}
}
return ret;
@@ -299,10 +286,7 @@ int intel_vgpu_emulate_cfg_write(struct
}

switch (rounddown(offset, 4)) {
- case PCI_BASE_ADDRESS_0:
- case PCI_BASE_ADDRESS_1:
- case PCI_BASE_ADDRESS_2:
- case PCI_BASE_ADDRESS_3:
+ case PCI_BASE_ADDRESS_0 ... PCI_BASE_ADDRESS_5:
if (WARN_ON(!IS_ALIGNED(offset, 4)))
return -EINVAL;
return emulate_pci_bar_write(vgpu, offset, p_data, bytes);
@@ -344,7 +328,6 @@ void intel_vgpu_init_cfg_space(struct in
struct intel_gvt *gvt = vgpu->gvt;
const struct intel_gvt_device_info *info = &gvt->device_info;
u16 *gmch_ctl;
- int i;

memcpy(vgpu_cfg_space(vgpu), gvt->firmware.cfg_space,
info->cfg_space_size);
@@ -371,13 +354,13 @@ void intel_vgpu_init_cfg_space(struct in
*/
memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_1, 0, 4);
memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_3, 0, 4);
+ memset(vgpu_cfg_space(vgpu) + PCI_BASE_ADDRESS_4, 0, 8);
memset(vgpu_cfg_space(vgpu) + INTEL_GVT_PCI_OPREGION, 0, 4);

- for (i = 0; i < INTEL_GVT_MAX_BAR_NUM; i++) {
- vgpu->cfg_space.bar[i].size = pci_resource_len(
- gvt->dev_priv->drm.pdev, i * 2);
- vgpu->cfg_space.bar[i].tracked = false;
- }
+ vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_GTTMMIO].size =
+ pci_resource_len(gvt->dev_priv->drm.pdev, 0);
+ vgpu->cfg_space.bar[INTEL_GVT_PCI_BAR_APERTURE].size =
+ pci_resource_len(gvt->dev_priv->drm.pdev, 2);
}

/**