From: Hollis Blanchard Date: Wed, 21 May 2008 23:22:54 +0000 (-0500) Subject: KVM: ppc: Use a read lock around MMU operations, and release it on error X-Git-Tag: v2.6.26-rc6~11^2~7 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=905fa4b9d6e2c9fd1c9ad84e3abe83021f498f53;p=linux-2.6-omap-h63xx.git 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 Signed-off-by: Avi Kivity --- diff --git a/arch/powerpc/kvm/44x_tlb.c b/arch/powerpc/kvm/44x_tlb.c index aa649c7db99..1c48d6164bd 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(¤t->mm->mmap_sem); + down_read(¤t->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(¤t->mm->mmap_sem); return; } hpaddr = page_to_phys(new_page); /* Drop reference to old page. */ kvmppc_44x_shadow_release(vcpu, victim); - up_write(¤t->mm->mmap_sem); + up_read(¤t->mm->mmap_sem); vcpu->arch.shadow_pages[victim] = new_page;