[xen stable-4.19] x86/vga: fix mapping of the VGA text buffer

[patchbot@xxxxxxx]

commit e9a46d5fe5deaa91be4931d25f1ffc1ee4dc4d19
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Thu Mar 27 15:03:20 2025 +0100
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Mar 27 15:03:20 2025 +0100

    x86/vga: fix mapping of the VGA text buffer
    
    The call to ioremap_wc() in video_init() will always fail, because
    video_init() is called ahead of vm_init_type(), and so the underlying
    __vmap() call will fail to allocate the linear address space.
    
    Fix by reverting to the previous behavior and use __va() for the VGA text
    buffer, as it's below the 1MB boundary, and thus always mapped in the
    directmap.
    
    Fixes: 81d195c6c0e2 ('x86: introduce ioremap_wc()')
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    master commit: 1ca5f69e35548e5196eadb329e5a3976821dc982
    master date: 2025-03-20 17:16:10 +0100
---
 xen/drivers/video/vga.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/xen/drivers/video/vga.c b/xen/drivers/video/vga.c
index b4d0183261..b577b24619 100644
--- a/xen/drivers/video/vga.c
+++ b/xen/drivers/video/vga.c
@@ -71,7 +71,7 @@ void __init video_init(void)
     {
     case XEN_VGATYPE_TEXT_MODE_3:
         if ( page_is_ram_type(paddr_to_pfn(0xB8000), RAM_TYPE_CONVENTIONAL) ||
-             ((video = ioremap_wc(0xB8000, 0x8000)) == NULL) )
+             ((video = __va(0xB8000)) == NULL) )
             return;
         outw(0x200a, 0x3d4); /* disable cursor */
         columns = vga_console_info.u.text_mode_3.columns;
@@ -158,7 +158,6 @@ void __init video_endboot(void)
         if ( !vgacon_keep )
         {
             memset(video, 0, columns * lines * 2);
-            iounmap(video);
             video = ZERO_BLOCK_PTR;
         }
         break;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.19