x86/fpu: Fix get_xsave_addr() behavior under virtualization

KVM uses the get_xsave_addr() function in a different fashion from
the native kernel, in that the 'xsave' parameter belongs to guest vcpu,
not the currently running task.

But 'xsave' is replaced with current task's (host) xsave structure, so
get_xsave_addr() will incorrectly return the bad xsave address to KVM.

Fix it so that the passed in 'xsave' address is used - as intended
originally.

Signed-off-by: Huaitong Han <huaitong.han@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: <stable@vger.kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave.hansen@intel.com
Link: http://lkml.kernel.org/r/1446800423-21622-1-git-send-email-huaitong.han@intel.com
[ Tidied up the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Huaitong Han 2015-11-06 17:00:23 +08:00 committed by Ingo Molnar
parent ab6b529475
commit a05917b6ba
1 changed files with 0 additions and 1 deletions

View File

@ -694,7 +694,6 @@ void *get_xsave_addr(struct xregs_state *xsave, int xstate_feature)
if (!boot_cpu_has(X86_FEATURE_XSAVE))
return NULL;
xsave = &current->thread.fpu.state.xsave;
/*
* We should not ever be requesting features that we
* have not enabled. Remember that pcntxt_mask is