From 5a48a622718cbd2d26d449f38ba40a2b5f7212cf Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Tue, 11 Apr 2017 02:49:21 -0700 Subject: x86/kvm: virt_xxx memory barriers instead of mandatory barriers MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit virt_xxx memory barriers are implemented trivially using the low-level __smp_xxx macros, __smp_xxx is equal to a compiler barrier for strong TSO memory model, however, mandatory barriers will unconditional add memory barriers, this patch replaces the rmb() in kvm_steal_clock() by virt_rmb(). Cc: Paolo Bonzini Cc: Radim Krčmář Signed-off-by: Wanpeng Li Reviewed-by: Paolo Bonzini Signed-off-by: Radim Krčmář --- arch/x86/kernel/kvm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index 14f65a5f938e..da5c09789984 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -396,9 +396,9 @@ static u64 kvm_steal_clock(int cpu) src = &per_cpu(steal_time, cpu); do { version = src->version; - rmb(); + virt_rmb(); steal = src->steal; - rmb(); + virt_rmb(); } while ((version & 1) || (version != src->version)); return steal; -- cgit v1.2.3