From: Marcelo Tosatti Date: Mon, 17 Mar 2008 13:08:18 +0000 (-0300) Subject: KVM: MMU: handle page removal with shadow mapping X-Git-Tag: v2.6.25-rc7~3^2~2 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=15aaa819e20cb183f26392ed8ea16020630ef142;p=linux-2.6-omap-h63xx.git KVM: MMU: handle page removal with shadow mapping Do not assume that a shadow mapping will always point to the same host frame number. Fixes crash with madvise(MADV_DONTNEED). [avi: move after first printk(), add another printk()] Signed-off-by: Marcelo Tosatti Signed-off-by: Avi Kivity --- diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index e49c4d433c0..4ba85d95bd2 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -892,14 +892,25 @@ static void mmu_set_spte(struct kvm_vcpu *vcpu, u64 *shadow_pte, int *ptwrite, gfn_t gfn, struct page *page) { u64 spte; - int was_rmapped = is_rmap_pte(*shadow_pte); + int was_rmapped = 0; int was_writeble = is_writeble_pte(*shadow_pte); + hfn_t host_pfn = (*shadow_pte & PT64_BASE_ADDR_MASK) >> PAGE_SHIFT; pgprintk("%s: spte %llx access %x write_fault %d" " user_fault %d gfn %lx\n", __FUNCTION__, *shadow_pte, pt_access, write_fault, user_fault, gfn); + if (is_rmap_pte(*shadow_pte)) { + if (host_pfn != page_to_pfn(page)) { + pgprintk("hfn old %lx new %lx\n", + host_pfn, page_to_pfn(page)); + rmap_remove(vcpu->kvm, shadow_pte); + } + else + was_rmapped = 1; + } + /* * We don't set the accessed bit, since we sometimes want to see * whether the guest actually used the pte (in order to detect