After merging the tip tree, today's linux-next build (x86_64 allmodconfig)
failed like this:

arch/x86/kernel/fpu/core.c: In function 'fpu_alloc_guest_fpstate':
arch/x86/kernel/fpu/core.c:187:12: error: implicit declaration of function 'vzalloc'; did you mean 'kzalloc'? [-Werror=implicit-function-declaration]
  187 |  fpstate = vzalloc(size);
      |            ^~~~~~~
      |            kzalloc
arch/x86/kernel/fpu/core.c:187:10: error: assignment to 'struct fpstate *' from 'int' makes pointer from integer without a cast [-Werror=int-conversion]
  187 |  fpstate = vzalloc(size);
      |          ^
arch/x86/kernel/fpu/core.c: In function 'fpu_free_guest_fpstate':
arch/x86/kernel/fpu/core.c:212:2: error: implicit declaration of function 'vfree'; did you mean 'kfree'? [-Werror=implicit-function-declaration]
  212 |  vfree(fps);
      |  ^~~~~
      |  kfree
cc1: all warnings being treated as errors

Caused by commit

  69f6ed1d14c6 ("x86/fpu: Provide infrastructure for KVM FPU cleanup")

I have applied the following patch for today (because it was quicker
than using the tip tree from next-20211022).

From: Stephen Rothwell <redacted>
Date: Mon, 25 Oct 2021 15:04:13 +1100
Subject: [PATCH] x86/fpu: include vmalloc.h for vzalloc etc

Fixes: 69f6ed1d14c6 ("x86/fpu: Provide infrastructure for KVM FPU cleanup")
Signed-off-by: Stephen Rothwell <redacted>
---
 arch/x86/kernel/fpu/core.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c
index 9c475e2efd4d..c55013fc82ab 100644
--- a/arch/x86/kernel/fpu/core.c
+++ b/arch/x86/kernel/fpu/core.c

@@ -16,6 +16,7 @@
 
 #include <linux/hardirq.h>
 #include <linux/pkeys.h>
+#include <linux/vmalloc.h>
 
 #include "context.h"
 #include "internal.h"

-- 
2.33.0