vmw_kms_readback(9)

📦 version 7.3.1, in nixpkgs unstable

💖 vmw_kms_readback(9) 💖

okay so bestie, welcome to the Kernel API Manual page for vmw_kms_readback(9) — yes that's the whole title, we're fancy here ✨ this is the readback function and honestly it's giving "quietly important" main character energy 🫶

🌸 NAME 🌸

vmw_kms_readback — Perform a readback from the screen system to a buffer-object backed framebuffer.

like, it grabs what's on the screen and puts it into a buffer-object backed framebuffer. that's the whole vibe check 💅

✨ SYNOPSIS ✨

int vmw_kms_readback (struct vmw_private *dev_priv , struct drm_file
*file_priv , struct vmw_framebuffer *vfb , struct drm_vmw_fence_rep
__user *user_fence_rep , struct drm_vmw_rect *vclips , uint32_t
num_clips );

no cap, that's the exact signature, don't come for me 😭

🎀 ARGUMENTS 🎀

okay so here's who's who in the group chat:

  • dev_priv — Pointer to the device private structure. the main character of device data 🔥
  • file_priv — Pointer to a struct drm_file identifying the caller. Must be set to NULL if user_fence_rep is NULL. periodt, that's a hard rule 💀
  • vfb — Pointer to the buffer-object backed framebuffer. the actual canvas bestie 🦋
  • user_fence_rep — User-space provided structure for fence information. Must be set to non-NULL if file_priv is non-NULL. it's giving "they come as a pair" 👑
  • vclips — Array of clip rects. literally an array, of rects, for clipping ✂️✨
  • num_clips — Number of clip rects in vclips. so like, how many of them there are 🌸
lowkey important: those file_priv / user_fence_rep rules go both ways — the original says it twice, so I'm saying it twice. they're a package deal or nothing at all 🙈

🌈 DESCRIPTION 🌈

Returns 0 on success, negative error code on failure. and -ERESTARTSYS if interrupted 😭 (yes, that's a real one, an interrupted call).

that's it, that's the description — short and iconic, we love a concise queen 💜

🧚 SEE ALSO 🧚

the kernel file lives at ./drivers/gpu/drm/vmwgfx/vmwgfx_kms.c — go read it if you're nosy, i support it 💅

and here's the whole squad of related pages, all of them, not skipping a single one:

🫶 that's the page! go read the see-alsos, they're all in their vmwgfx era together.

okay bye bestie, this one came from ./drivers/gpu/drm/vmwgfx and it's dated October 2026 — so like, from the future, slay 💅✨🎀

📦 where this page comes from