From 960b3991698872f68f09d51f4c2794ad484fe1fd Mon Sep 17 00:00:00 2001 From: Marcelo Tosatti Date: Wed, 16 Apr 2008 17:19:06 -0300 Subject: [PATCH] KVM: MMU: kvm_pv_mmu_op should not take mmap_sem kvm_pv_mmu_op should not take mmap_sem. All gfn_to_page() callers down in the MMU processing will take it if necessary, so as it is it can deadlock. Apparently a leftover from the days before slots_lock. Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- arch/x86/kvm/mmu.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 078a7f1ac34c..2ad6f5481671 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2173,8 +2173,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, int r; struct kvm_pv_mmu_op_buffer buffer; - down_read(¤t->mm->mmap_sem); - buffer.ptr = buffer.buf; buffer.len = min_t(unsigned long, bytes, sizeof buffer.buf); buffer.processed = 0; @@ -2194,7 +2192,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, r = 1; out: *ret = buffer.processed; - up_read(¤t->mm->mmap_sem); return r; } -- 2.20.1