On 2014-01-22 17:29, Paolo Bonzini wrote:
> After KVM commit 8a3caa6d74597c2a083f7c87f866891a0b12540b, kvm-kmod
> is broken in weird ways (for me it breaks every other time kvm is
> loaded, but only with ept=0...).
>
> The reason is that, after this commit, empty_zero_page is expected
> to be page-aligned, but the kvm-kmod compatibility shim isn't.
> empty_zero_page has been exported since v2.6.25:
>
> commit 8232fd625217dc641ed05dd238a8bb5c82828082
> Author: Theodore Ts'o <tytso@xxxxxxx>
> Date: Mon Nov 26 20:42:19 2007 +0100
>
> x86: export the symbol empty_zero_page on the 32-bit x86 architecture
>
> The latest KVM driver wants to use the empty_zero_page symbol, and it's
> not exported in 32-bit x86 (although it is exported by x86_64, s390, and
> uml architectures).
>
> Signed-off-by: "Theodore Ts'o" <tytso@xxxxxxx>
> Cc: tglx@xxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: kvm-devel@xxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
>
> so the compatibility shim should probably just be dropped.
>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
>
> ---
>
>
> diff --git a/external-module-compat-comm.h b/external-module-compat-comm.h
> index 34fb320..580aa9f 100644
> --- a/external-module-compat-comm.h
> +++ b/external-module-compat-comm.h
> @@ -180,18 +180,6 @@ void kvm_smp_send_reschedule(int cpu);
>
> #endif
>
> -/* empty_zero_page isn't exported in all kernels */
> -#include <asm/pgtable.h>
> -
> -#define empty_zero_page kvm_empty_zero_page
> -
> -static char empty_zero_page[PAGE_SIZE];
> -
> -static inline void blahblah(void)
> -{
> - (void)empty_zero_page[0];
> -}
> -
> /* __mmdrop() is not exported before 2.6.25 */
> #include <linux/sched.h>
>
>
Thanks, applied.
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SES-DE
Corporate Competence Center Embedded Linux
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