[PATCH v5 0/2] hyperv-fb: add support for generation 2 virtual machines

  Hi,

This patch series adds support for uefi-based gen2 virtual machines
to the hyperv-fb driver.  It depends on a few vmbus changes which are
staged in Greg's char-misc tree (and linux-next).

Patch #1 implements gen2 vm support for hyperv-fb.

Patch #2 unregisters efifb early to make sure the framebuffer isn't used
any more while hyperv-fb initialization is in progress.

v5 changes:
 - call remove_conflicting_framebuffers() only on gen2
   virtual machines.

v4 changes:
 - use KBUILD_MODNAME everywhere for consistent naming.
 - drop the two patches which Greg has staged in char-misc.

please apply,
  Gerd

Gerd Hoffmann (2):
  hyperv-fb: add support for generation 2 virtual machines.
  hyperv-fb: kick off efifb early

 drivers/video/hyperv_fb.c | 88 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 62 insertions(+), 26 deletions(-)

-- 
1.8.3.1

UEFI-based generation 2 virtual machines support vmbus devices only.
There is no pci bus.  Thus they use a different mechanism for the
graphics framebuffer:  Instead of using the vga pci bar a chunk of
memory muct be allocated from the hyperv mmio region declared using
APCI.  This patch implements support for it.

Based on a patch by Haiyang Zhang [off-list ref]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/video/hyperv_fb.c | 86 +++++++++++++++++++++++++++++++++--------------
 1 file changed, 60 insertions(+), 26 deletions(-)

diff --git a/drivers/video/hyperv_fb.c b/drivers/video/hyperv_fb.c
index 130708f..b7b3dd0 100644
--- a/drivers/video/hyperv_fb.c
+++ b/drivers/video/hyperv_fb.c

@@ -42,6 +42,7 @@
 #include <linux/completion.h>
 #include <linux/fb.h>
 #include <linux/pci.h>
+#include <linux/efi.h>
 
 #include <linux/hyperv.h>
 

@@ -212,6 +213,7 @@ struct synthvid_msg {
 
 struct hvfb_par {
 	struct fb_info *info;
+	struct resource mem;
 	bool fb_ready; /* fb device is ready */
 	struct completion wait;
 	u32 synthvid_version;

@@ -460,13 +462,13 @@ static int synthvid_connect_vsp(struct hv_device *hdev)
 		goto error;
 	}
 
-	if (par->synthvid_version = SYNTHVID_VERSION_WIN7) {
+	if (par->synthvid_version = SYNTHVID_VERSION_WIN7)
 		screen_depth = SYNTHVID_DEPTH_WIN7;
-		screen_fb_size = SYNTHVID_FB_SIZE_WIN7;
-	} else {
+	else
 		screen_depth = SYNTHVID_DEPTH_WIN8;
-		screen_fb_size = SYNTHVID_FB_SIZE_WIN8;
-	}
+
+	screen_fb_size = hdev->channel->offermsg.offer.
+				mmio_megabytes * 1024 * 1024;
 
 	return 0;
 

@@ -627,26 +629,46 @@ static void hvfb_get_option(struct fb_info *info)
 /* Get framebuffer memory from Hyper-V video pci space */
 static int hvfb_getmem(struct fb_info *info)
 {
-	struct pci_dev *pdev;
-	ulong fb_phys;
+	struct hvfb_par *par = info->par;
+	struct pci_dev *pdev  = NULL;
 	void __iomem *fb_virt;
+	int gen2vm = efi_enabled(EFI_BOOT);
+	int ret;
 
-	pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
+	par->mem.name = KBUILD_MODNAME;
+	par->mem.flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+	if (gen2vm) {
+		ret = allocate_resource(&hyperv_mmio, &par->mem,
+					screen_fb_size,
+					0, -1,
+					screen_fb_size,
+					NULL, NULL);
+		if (ret != 0) {
+			pr_err("Unable to allocate framebuffer memory\n");
+			return -ENODEV;
+		}
+	} else {
+		pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
 			      PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
-	if (!pdev) {
-		pr_err("Unable to find PCI Hyper-V video\n");
-		return -ENODEV;
-	}
+		if (!pdev) {
+			pr_err("Unable to find PCI Hyper-V video\n");
+			return -ENODEV;
+		}
 
-	if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
-	    pci_resource_len(pdev, 0) < screen_fb_size)
-		goto err1;
+		if (!(pci_resource_flags(pdev, 0) & IORESOURCE_MEM) ||
+		    pci_resource_len(pdev, 0) < screen_fb_size)
+			goto err1;
 
-	fb_phys = pci_resource_end(pdev, 0) - screen_fb_size + 1;
-	if (!request_mem_region(fb_phys, screen_fb_size, KBUILD_MODNAME))
-		goto err1;
+		par->mem.end = pci_resource_end(pdev, 0);
+		par->mem.start = par->mem.end - screen_fb_size + 1;
+		ret = request_resource(&pdev->resource[0], &par->mem);
+		if (ret != 0) {
+			pr_err("Unable to request framebuffer memory\n");
+			goto err1;
+		}
+	}
 
-	fb_virt = ioremap(fb_phys, screen_fb_size);
+	fb_virt = ioremap(par->mem.start, screen_fb_size);
 	if (!fb_virt)
 		goto err2;
 

@@ -654,30 +676,42 @@ static int hvfb_getmem(struct fb_info *info)
 	if (!info->apertures)
 		goto err3;
 
-	info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
-	info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
-	info->fix.smem_start = fb_phys;
+	if (gen2vm) {
+		info->apertures->ranges[0].base = screen_info.lfb_base;
+		info->apertures->ranges[0].size = screen_info.lfb_size;
+	} else {
+		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
+		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);
+	}
+
+	info->fix.smem_start = par->mem.start;
 	info->fix.smem_len = screen_fb_size;
 	info->screen_base = fb_virt;
 	info->screen_size = screen_fb_size;
 
-	pci_dev_put(pdev);
+	if (!gen2vm)
+		pci_dev_put(pdev);
+
 	return 0;
 
 err3:
 	iounmap(fb_virt);
 err2:
-	release_mem_region(fb_phys, screen_fb_size);
+	release_resource(&par->mem);
 err1:
-	pci_dev_put(pdev);
+	if (!gen2vm)
+		pci_dev_put(pdev);
+
 	return -ENOMEM;
 }
 
 /* Release the framebuffer */
 static void hvfb_putmem(struct fb_info *info)
 {
+	struct hvfb_par *par = info->par;
+
 	iounmap(info->screen_base);
-	release_mem_region(info->fix.smem_start, screen_fb_size);
+	release_resource(&par->mem);
 }
 
 

-- 
1.8.3.1

Remove firmware framebuffer before initializing hyperv-fb.  Needed
on gen2 virtual machines.   Letting register_framebuffer handle the
switchover results in efifb still being active while hyperv graphics
are initialized, which in turn can make the linux kernel hang.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 drivers/video/hyperv_fb.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/video/hyperv_fb.c b/drivers/video/hyperv_fb.c
index b7b3dd0..e23392e 100644
--- a/drivers/video/hyperv_fb.c
+++ b/drivers/video/hyperv_fb.c

@@ -679,6 +679,8 @@ static int hvfb_getmem(struct fb_info *info)
 	if (gen2vm) {
 		info->apertures->ranges[0].base = screen_info.lfb_base;
 		info->apertures->ranges[0].size = screen_info.lfb_size;
+		remove_conflicting_framebuffers(info->apertures,
+						KBUILD_MODNAME, false);
 	} else {
 		info->apertures->ranges[0].base = pci_resource_start(pdev, 0);
 		info->apertures->ranges[0].size = pci_resource_len(pdev, 0);

-- 
1.8.3.1

-----Original Message-----
From: Gerd Hoffmann [mailto:kraxel@redhat.com]
Sent: Wednesday, February 26, 2014 5:51 AM
To: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org; gregkh@linuxfoundation.org; KY Srinivasan;
Abhishek Gupta (LIS); Haiyang Zhang; jasowang@redhat.com;
tomi.valkeinen@ti.com; devel@linuxdriverproject.org; Gerd Hoffmann; Jean-
Christophe Plagniol-Villard
Subject: [PATCH v5 2/2] hyperv-fb: kick off efifb early

Remove firmware framebuffer before initializing hyperv-fb.  Needed
on gen2 virtual machines.   Letting register_framebuffer handle the
switchover results in efifb still being active while hyperv graphics
are initialized, which in turn can make the linux kernel hang.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Thank you!

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

-----Original Message-----
From: linux-fbdev-owner@vger.kernel.org [mailto:linux-fbdev-
owner@vger.kernel.org] On Behalf Of Gerd Hoffmann
Sent: Wednesday, February 26, 2014 5:51 AM
To: linux-fbdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org; gregkh@linuxfoundation.org; KY Srinivasan;
Abhishek Gupta (LIS); Haiyang Zhang; jasowang@redhat.com;
tomi.valkeinen@ti.com; devel@linuxdriverproject.org; Gerd Hoffmann; Jean-
Christophe Plagniol-Villard
Subject: [PATCH v5 1/2] hyperv-fb: add support for generation 2 virtual
machines.

UEFI-based generation 2 virtual machines support vmbus devices only.
There is no pci bus.  Thus they use a different mechanism for the
graphics framebuffer:  Instead of using the vga pci bar a chunk of
memory muct be allocated from the hyperv mmio region declared using
APCI.  This patch implements support for it.

Based on a patch by Haiyang Zhang [off-list ref]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

Thank you!

Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>

On 26/02/14 12:51, Gerd Hoffmann wrote:

  Hi,

This patch series adds support for uefi-based gen2 virtual machines
to the hyperv-fb driver.  It depends on a few vmbus changes which are
staged in Greg's char-misc tree (and linux-next).

Depends how? Patches that depend on other patches should be merged via
the same tree to avoid compile or functional breaks.

 Tomi

On Fr, 2014-02-28 at 11:01 +0200, Tomi Valkeinen wrote:

On 26/02/14 12:51, Gerd Hoffmann wrote:

quoted

  Hi,

This patch series adds support for uefi-based gen2 virtual machines
to the hyperv-fb driver.  It depends on a few vmbus changes which are
staged in Greg's char-misc tree (and linux-next).

Depends how?

Will fail to build without the vmbus patches.

Patches that depend on other patches should be merged via
the same tree to avoid compile or functional breaks.

I think Greg will happily merge them through char-misc if he gets your
fbdev maintainer ACK for the patches.

cheers,
  Gerd

On 28/02/14 12:19, Gerd Hoffmann wrote:

On Fr, 2014-02-28 at 11:01 +0200, Tomi Valkeinen wrote:

quoted

On 26/02/14 12:51, Gerd Hoffmann wrote:

quoted

  Hi,

This patch series adds support for uefi-based gen2 virtual machines
to the hyperv-fb driver.  It depends on a few vmbus changes which are
staged in Greg's char-misc tree (and linux-next).

Depends how?

Will fail to build without the vmbus patches.

quoted

Patches that depend on other patches should be merged via
the same tree to avoid compile or functional breaks.

I think Greg will happily merge them through char-misc if he gets your
fbdev maintainer ACK for the patches.

Ok. It's usually good to mention if only an ack is needed (and from
whom). You did send this to fbdev, and said "please apply". So I already
applied it, until I realized you said there are dependencies.

So:

Acked-by: Tomi Valkeinen <redacted>

 Tomi