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authorHollis Blanchard <hollisb@us.ibm.com>2008-05-21 18:22:54 -0500
committerAvi Kivity <avi@qumranet.com>2008-06-06 21:22:33 +0300
commit905fa4b9d6e2c9fd1c9ad84e3abe83021f498f53 (patch)
treed26440a247f76a7f0b440973621bf2ca764e6697 /arch/powerpc/kvm
parent52435b7c7a29f7dd7947c8c204494d7f52f14813 (diff)
KVM: ppc: Use a read lock around MMU operations, and release it on error
gfn_to_page() and kvm_release_page_clean() are called from other contexts with mmap_sem locked only for reading. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'arch/powerpc/kvm')
-rw-r--r--arch/powerpc/kvm/44x_tlb.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c
index aa649c7db99b..1c48d6164bd5 100644
--- a/arch/powerpc/kvm/44x_tlb.c
+++ b/arch/powerpc/kvm/44x_tlb.c
@@ -142,18 +142,19 @@ void kvmppc_mmu_map(struct kvm_vcpu *vcpu, u64 gvaddr, gfn_t gfn, u64 asid,
stlbe = &vcpu->arch.shadow_tlb[victim];
/* Get reference to new page. */
- down_write(&current->mm->mmap_sem);
+ down_read(&current->mm->mmap_sem);
new_page = gfn_to_page(vcpu->kvm, gfn);
if (is_error_page(new_page)) {
printk(KERN_ERR "Couldn't get guest page!\n");
kvm_release_page_clean(new_page);
+ up_read(&current->mm->mmap_sem);
return;
}
hpaddr = page_to_phys(new_page);
/* Drop reference to old page. */
kvmppc_44x_shadow_release(vcpu, victim);
- up_write(&current->mm->mmap_sem);
+ up_read(&current->mm->mmap_sem);
vcpu->arch.shadow_pages[victim] = new_page;