Fixes for 4.9

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.9/drivers-hv-never-allocate-anything-besides-framebuff.patch b/queue-4.9/drivers-hv-never-allocate-anything-besides-framebuff.patch
new file mode 100644 (file)
index 0000000..a283358
--- /dev/null
+++ b/queue-4.9/drivers-hv-never-allocate-anything-besides-framebuff.patch
@@ -0,0 +1,101 @@
+From 1b206da4fd0bdb362ce2d9b6876630edd4267c38 Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Sat, 27 Aug 2022 15:03:45 +0200
+Subject: Drivers: hv: Never allocate anything besides framebuffer from
+ framebuffer memory region
+
+From: Vitaly Kuznetsov <vkuznets@redhat.com>
+
+[ Upstream commit f0880e2cb7e1f8039a048fdd01ce45ab77247221 ]
+
+Passed through PCI device sometimes misbehave on Gen1 VMs when Hyper-V
+DRM driver is also loaded. Looking at IOMEM assignment, we can see e.g.
+
+$ cat /proc/iomem
+...
+f8000000-fffbffff : PCI Bus 0000:00
+  f8000000-fbffffff : 0000:00:08.0
+    f8000000-f8001fff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe
+...
+fe0000000-fffffffff : PCI Bus 0000:00
+  fe0000000-fe07fffff : bb8c4f33-2ba2-4808-9f7f-02f3b4da22fe
+    fe0000000-fe07fffff : 2ba2:00:02.0
+      fe0000000-fe07fffff : mlx4_core
+
+the interesting part is the 'f8000000' region as it is actually the
+VM's framebuffer:
+
+$ lspci -v
+...
+0000:00:08.0 VGA compatible controller: Microsoft Corporation Hyper-V virtual VGA (prog-if 00 [VGA controller])
+       Flags: bus master, fast devsel, latency 0, IRQ 11
+       Memory at f8000000 (32-bit, non-prefetchable) [size=64M]
+...
+
+ hv_vmbus: registering driver hyperv_drm
+ hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] Synthvid Version major 3, minor 5
+ hyperv_drm 0000:00:08.0: vgaarb: deactivate vga console
+ hyperv_drm 0000:00:08.0: BAR 0: can't reserve [mem 0xf8000000-0xfbffffff]
+ hyperv_drm 5620e0c7-8062-4dce-aeb7-520c7ef76171: [drm] Cannot request framebuffer, boot fb still active?
+
+Note: "Cannot request framebuffer" is not a fatal error in
+hyperv_setup_gen1() as the code assumes there's some other framebuffer
+device there but we actually have some other PCI device (mlx4 in this
+case) config space there!
+
+The problem appears to be that vmbus_allocate_mmio() can use dedicated
+framebuffer region to serve any MMIO request from any device. The
+semantics one might assume of a parameter named "fb_overlap_ok"
+aren't implemented because !fb_overlap_ok essentially has no effect.
+The existing semantics are really "prefer_fb_overlap". This patch
+implements the expected and needed semantics, which is to not allocate
+from the frame buffer space when !fb_overlap_ok.
+
+Note, Gen2 VMs are usually unaffected by the issue because
+framebuffer region is already taken by EFI fb (in case kernel supports
+it) but Gen1 VMs may have this region unclaimed by the time Hyper-V PCI
+pass-through driver tries allocating MMIO space if Hyper-V DRM/FB drivers
+load after it. Devices can be brought up in any sequence so let's
+resolve the issue by always ignoring 'fb_mmio' region for non-FB
+requests, even if the region is unclaimed.
+
+Reviewed-by: Michael Kelley <mikelley@microsoft.com>
+Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
+Link: https://lore.kernel.org/r/20220827130345.1320254-4-vkuznets@redhat.com
+Signed-off-by: Wei Liu <wei.liu@kernel.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/hv/vmbus_drv.c | 10 +++++++++-
+ 1 file changed, 9 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c
+index 3248aa7a35b3..cb3e22f10d68 100644
+--- a/drivers/hv/vmbus_drv.c
++++ b/drivers/hv/vmbus_drv.c
+@@ -1186,7 +1186,7 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
+                       bool fb_overlap_ok)
+ {
+       struct resource *iter, *shadow;
+-      resource_size_t range_min, range_max, start;
++      resource_size_t range_min, range_max, start, end;
+       const char *dev_n = dev_name(&device_obj->device);
+       int retval;
+ 
+@@ -1221,6 +1221,14 @@ int vmbus_allocate_mmio(struct resource **new, struct hv_device *device_obj,
+               range_max = iter->end;
+               start = (range_min + align - 1) & ~(align - 1);
+               for (; start + size - 1 <= range_max; start += align) {
++                      end = start + size - 1;
++
++                      /* Skip the whole fb_mmio region if not fb_overlap_ok */
++                      if (!fb_overlap_ok && fb_mmio &&
++                          (((start >= fb_mmio->start) && (start <= fb_mmio->end)) ||
++                           ((end >= fb_mmio->start) && (end <= fb_mmio->end))))
++                              continue;
++
+                       shadow = __request_region(iter, start, size, NULL,
+                                                 IORESOURCE_BUSY);
+                       if (!shadow)
+-- 
+2.35.1
+

diff --git a/queue-4.9/series b/queue-4.9/series
index ccd50b4e018474af9c037864886af1d4bd1aded9..96492be4dcf1c49a49201c7907b5568b56798891 100644 (file)
--- a/queue-4.9/series
+++ b/queue-4.9/series
@@ -26,3 +26,4 @@ net-sunhme-fix-packet-reception-for-len-rx_copy_thre.patch
 serial-create-uart_xmit_advance.patch
 serial-tegra-use-uart_xmit_advance-fixes-icount.tx-accounting.patch
 s390-dasd-fix-oops-in-dasd_alias_get_start_dev-due-to-missing-pavgroup.patch
+drivers-hv-never-allocate-anything-besides-framebuff.patch