From: Marcelo Tosatti Date: Wed, 11 Jun 2008 23:32:40 +0000 (-0300) Subject: KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend) X-Git-Tag: v2.6.26-rc8~3^2~8 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3094538739415a9225afd2a6c78cb0fe1c1f641b;p=linux-2.6 KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend) kvm_mmu_pte_write() does not handle 32-bit non-PAE large page backed guests properly. It will instantiate two 2MB sptes pointing to the same physical 2MB page when a guest large pte update is trapped. Instead of duplicating code to handle this, disallow directory level updates to happen through kvm_mmu_pte_write(), so the two 2MB sptes emulating one guest 4MB pte can be correctly created by the page fault handling path. 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 9628091c57..baa6503894 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -1581,11 +1581,13 @@ static void mmu_pte_write_new_pte(struct kvm_vcpu *vcpu, u64 *spte, const void *new) { - if ((sp->role.level != PT_PAGE_TABLE_LEVEL) - && !vcpu->arch.update_pte.largepage) { - ++vcpu->kvm->stat.mmu_pde_zapped; - return; - } + if (sp->role.level != PT_PAGE_TABLE_LEVEL) { + if (!vcpu->arch.update_pte.largepage || + sp->role.glevels == PT32_ROOT_LEVEL) { + ++vcpu->kvm->stat.mmu_pde_zapped; + return; + } + } ++vcpu->kvm->stat.mmu_pte_updated; if (sp->role.glevels == PT32_ROOT_LEVEL)