Commit 960b3991 authored by Marcelo Tosatti's avatar Marcelo Tosatti Committed by Avi Kivity
Browse files

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: default avatarMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 1336028b
...@@ -2173,8 +2173,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, ...@@ -2173,8 +2173,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
int r; int r;
struct kvm_pv_mmu_op_buffer buffer; struct kvm_pv_mmu_op_buffer buffer;
down_read(&current->mm->mmap_sem);
buffer.ptr = buffer.buf; buffer.ptr = buffer.buf;
buffer.len = min_t(unsigned long, bytes, sizeof buffer.buf); buffer.len = min_t(unsigned long, bytes, sizeof buffer.buf);
buffer.processed = 0; buffer.processed = 0;
...@@ -2194,7 +2192,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes, ...@@ -2194,7 +2192,6 @@ int kvm_pv_mmu_op(struct kvm_vcpu *vcpu, unsigned long bytes,
r = 1; r = 1;
out: out:
*ret = buffer.processed; *ret = buffer.processed;
up_read(&current->mm->mmap_sem);
return r; return r;
} }
......
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