Merge tag 'hyperv-fixes-signed-20250311' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Patches to fix Hyper-v framebuffer code (Michael Kelley and Saurabh
   Sengar)

 - Fix for Hyper-V output argument to hypercall that changes page
   visibility (Michael Kelley)

 - Fix for Hyper-V VTL mode (Naman Jain)

* tag 'hyperv-fixes-signed-20250311' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  Drivers: hv: vmbus: Don't release fb_mmio resource in vmbus_free_mmio()
  x86/hyperv: Fix output argument to hypercall that changes page visibility
  fbdev: hyperv_fb: Allow graceful removal of framebuffer
  fbdev: hyperv_fb: Simplify hvfb_putmem
  fbdev: hyperv_fb: Fix hang in kdump kernel when on Hyper-V Gen 2 VMs
  drm/hyperv: Fix address space leak when Hyper-V DRM device is removed
  fbdev: hyperv_fb: iounmap() the correct memory when removing a device
  x86/hyperv/vtl: Stop kernel from probing VTL0 low memory

Author: torvalds

arch/x86/hyperv/hv_vtl.c

@@ -30,6 +30,7 @@ void __init hv_vtl_init_platform(void)
 	x86_platform.realmode_init = x86_init_noop;
 	x86_init.irqs.pre_vector_init = x86_init_noop;
 	x86_init.timers.timer_init = x86_init_noop;
+	x86_init.resources.probe_roms = x86_init_noop;
 
 	/* Avoid searching for BIOS MP tables */
 	x86_init.mpparse.find_mptable = x86_init_noop;

arch/x86/hyperv/ivm.c

@@ -464,7 +464,6 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
 			   enum hv_mem_host_visibility visibility)
 {
 	struct hv_gpa_range_for_visibility *input;
-	u16 pages_processed;
 	u64 hv_status;
 	unsigned long flags;
 
@@ -493,7 +492,7 @@ static int hv_mark_gpa_visibility(u16 count, const u64 pfn[],
 	memcpy((void *)input->gpa_page_list, pfn, count * sizeof(*pfn));
 	hv_status = hv_do_rep_hypercall(
 			HVCALL_MODIFY_SPARSE_GPA_PAGE_HOST_VISIBILITY, count,
-			0, input, &pages_processed);
+			0, input, NULL);
 	local_irq_restore(flags);
 
 	if (hv_result_success(hv_status))

drivers/gpu/drm/hyperv/hyperv_drm_drv.c

@@ -154,6 +154,7 @@ static int hyperv_vmbus_probe(struct hv_device *hdev,
 	return 0;
 
 err_free_mmio:
+	iounmap(hv->vram);
 	vmbus_free_mmio(hv->mem->start, hv->fb_size);
 err_vmbus_close:
 	vmbus_close(hdev->channel);
@@ -172,6 +173,7 @@ static void hyperv_vmbus_remove(struct hv_device *hdev)
 	vmbus_close(hdev->channel);
 	hv_set_drvdata(hdev, NULL);
 
+	iounmap(hv->vram);
 	vmbus_free_mmio(hv->mem->start, hv->fb_size);
 }
 

drivers/hv/vmbus_drv.c

@@ -2262,12 +2262,25 @@ void vmbus_free_mmio(resource_size_t start, resource_size_t size)
 	struct resource *iter;
 
 	mutex_lock(&hyperv_mmio_lock);
+
+	/*
+	 * If all bytes of the MMIO range to be released are within the
+	 * special case fb_mmio shadow region, skip releasing the shadow
+	 * region since no corresponding __request_region() was done
+	 * in vmbus_allocate_mmio().
+	 */
+	if (fb_mmio && start >= fb_mmio->start &&
+	    (start + size - 1 <= fb_mmio->end))
+		goto skip_shadow_release;
+
 	for (iter = hyperv_mmio; iter; iter = iter->sibling) {
 		if ((iter->start >= start + size) || (iter->end <= start))
 			continue;
 
 		__release_region(iter, start, size);
 	}
+
+skip_shadow_release:
 	release_mem_region(start, size);
 	mutex_unlock(&hyperv_mmio_lock);
 

drivers/video/fbdev/hyperv_fb.c

@@ -282,6 +282,8 @@ static uint screen_depth;
 static uint screen_fb_size;
 static uint dio_fb_size; /* FB size for deferred IO */
 
+static void hvfb_putmem(struct fb_info *info);
+
 /* Send message to Hyper-V host */
 static inline int synthvid_send(struct hv_device *hdev,
 				struct synthvid_msg *msg)
@@ -862,6 +864,17 @@ static void hvfb_ops_damage_area(struct fb_info *info, u32 x, u32 y, u32 width,
 		hvfb_ondemand_refresh_throttle(par, x, y, width, height);
 }
 
+/*
+ * fb_ops.fb_destroy is called by the last put_fb_info() call at the end
+ * of unregister_framebuffer() or fb_release(). Do any cleanup related to
+ * framebuffer here.
+ */
+static void hvfb_destroy(struct fb_info *info)
+{
+	hvfb_putmem(info);
+	framebuffer_release(info);
+}
+
 /*
  * TODO: GEN1 codepaths allocate from system or DMA-able memory. Fix the
  *       driver to use the _SYSMEM_ or _DMAMEM_ helpers in these cases.
@@ -877,6 +890,7 @@ static const struct fb_ops hvfb_ops = {
 	.fb_set_par = hvfb_set_par,
 	.fb_setcolreg = hvfb_setcolreg,
 	.fb_blank = hvfb_blank,
+	.fb_destroy	= hvfb_destroy,
 };
 
 /* Get options from kernel paramenter "video=" */
@@ -952,15 +966,15 @@ static phys_addr_t hvfb_get_phymem(struct hv_device *hdev,
 }
 
 /* Release contiguous physical memory */
-static void hvfb_release_phymem(struct hv_device *hdev,
+static void hvfb_release_phymem(struct device *device,
 				phys_addr_t paddr, unsigned int size)
 {
 	unsigned int order = get_order(size);
 
 	if (order <= MAX_PAGE_ORDER)
 		__free_pages(pfn_to_page(paddr >> PAGE_SHIFT), order);
 	else
-		dma_free_coherent(&hdev->device,
+		dma_free_coherent(device,
 				  round_up(size, PAGE_SIZE),
 				  phys_to_virt(paddr),
 				  paddr);
@@ -989,6 +1003,7 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 
 		base = pci_resource_start(pdev, 0);
 		size = pci_resource_len(pdev, 0);
+		aperture_remove_conflicting_devices(base, size, KBUILD_MODNAME);
 
 		/*
 		 * For Gen 1 VM, we can directly use the contiguous memory
@@ -1010,11 +1025,21 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 			goto getmem_done;
 		}
 		pr_info("Unable to allocate enough contiguous physical memory on Gen 1 VM. Using MMIO instead.\n");
+	} else {
+		aperture_remove_all_conflicting_devices(KBUILD_MODNAME);
 	}
 
 	/*
-	 * Cannot use the contiguous physical memory.
-	 * Allocate mmio space for framebuffer.
+	 * Cannot use contiguous physical memory, so allocate MMIO space for
+	 * the framebuffer. At this point in the function, conflicting devices
+	 * that might have claimed the framebuffer MMIO space based on
+	 * screen_info.lfb_base must have already been removed so that
+	 * vmbus_allocate_mmio() does not allocate different MMIO space. If the
+	 * kdump image were to be loaded using kexec_file_load(), the
+	 * framebuffer location in the kdump image would be set from
+	 * screen_info.lfb_base at the time that kdump is enabled. If the
+	 * framebuffer has moved elsewhere, this could be the wrong location,
+	 * causing kdump to hang when efifb (for example) loads.
 	 */
 	dio_fb_size =
 		screen_width * screen_height * screen_depth / 8;
@@ -1051,11 +1076,6 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 	info->screen_size = dio_fb_size;
 
 getmem_done:
-	if (base && size)
-		aperture_remove_conflicting_devices(base, size, KBUILD_MODNAME);
-	else
-		aperture_remove_all_conflicting_devices(KBUILD_MODNAME);
-
 	if (!gen2vm)
 		pci_dev_put(pdev);
 
@@ -1074,16 +1094,16 @@ static int hvfb_getmem(struct hv_device *hdev, struct fb_info *info)
 }
 
 /* Release the framebuffer */
-static void hvfb_putmem(struct hv_device *hdev, struct fb_info *info)
+static void hvfb_putmem(struct fb_info *info)
 {
 	struct hvfb_par *par = info->par;
 
 	if (par->need_docopy) {
 		vfree(par->dio_vp);
-		iounmap(info->screen_base);
+		iounmap(par->mmio_vp);
 		vmbus_free_mmio(par->mem->start, screen_fb_size);
 	} else {
-		hvfb_release_phymem(hdev, info->fix.smem_start,
+		hvfb_release_phymem(info->device, info->fix.smem_start,
 				    screen_fb_size);
 	}
 
@@ -1172,7 +1192,7 @@ static int hvfb_probe(struct hv_device *hdev,
 	if (ret)
 		goto error;
 
-	ret = register_framebuffer(info);
+	ret = devm_register_framebuffer(&hdev->device, info);
 	if (ret) {
 		pr_err("Unable to register framebuffer\n");
 		goto error;
@@ -1197,7 +1217,7 @@ static int hvfb_probe(struct hv_device *hdev,
 
 error:
 	fb_deferred_io_cleanup(info);
-	hvfb_putmem(hdev, info);
+	hvfb_putmem(info);
 error2:
 	vmbus_close(hdev->channel);
 error1:
@@ -1220,14 +1240,10 @@ static void hvfb_remove(struct hv_device *hdev)
 
 	fb_deferred_io_cleanup(info);
 
-	unregister_framebuffer(info);
 	cancel_delayed_work_sync(&par->dwork);
 
 	vmbus_close(hdev->channel);
 	hv_set_drvdata(hdev, NULL);
-
-	hvfb_putmem(hdev, info);
-	framebuffer_release(info);
 }
 
 static int hvfb_suspend(struct hv_device *hdev)