From c066fafc595eef5ae3c83ae3a8305956b8c3ef15 Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Tue, 14 Aug 2018 20:37:45 +1000 Subject: [PATCH 1/2] KVM: PPC: Book3S HV: Use correct pagesize in kvm_unmap_radix() Since commit e641a317830b ("KVM: PPC: Book3S HV: Unify dirty page map between HPT and radix", 2017-10-26), kvm_unmap_radix() computes the number of PAGE_SIZEd pages being unmapped and passes it to kvmppc_update_dirty_map(), which expects to be passed the page size instead. Consequently it will only mark one system page dirty even when a large page (for example a THP page) is being unmapped. The consequence of this is that part of the THP page might not get copied during live migration, resulting in memory corruption for the guest. This fixes it by computing and passing the page size in kvm_unmap_radix(). Cc: stable@vger.kernel.org # v4.15+ Fixes: e641a317830b (KVM: PPC: Book3S HV: Unify dirty page map between HPT and radix) Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu_radix.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_radix.c b/arch/powerpc/kvm/book3s_64_mmu_radix.c index 176f911ee983..7efc42538ccf 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_radix.c +++ b/arch/powerpc/kvm/book3s_64_mmu_radix.c @@ -738,10 +738,10 @@ int kvm_unmap_radix(struct kvm *kvm, struct kvm_memory_slot *memslot, gpa, shift); kvmppc_radix_tlbie_page(kvm, gpa, shift); if ((old & _PAGE_DIRTY) && memslot->dirty_bitmap) { - unsigned long npages = 1; + unsigned long psize = PAGE_SIZE; if (shift) - npages = 1ul << (shift - PAGE_SHIFT); - kvmppc_update_dirty_map(memslot, gfn, npages); + psize = 1ul << shift; + kvmppc_update_dirty_map(memslot, gfn, psize); } } return 0; From 46dec40fb741f00f1864580130779aeeaf24fb3d Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Mon, 20 Aug 2018 16:05:45 +1000 Subject: [PATCH 2/2] KVM: PPC: Book3S HV: Don't truncate HPTE index in xlate function This fixes a bug which causes guest virtual addresses to get translated to guest real addresses incorrectly when the guest is using the HPT MMU and has more than 256GB of RAM, or more specifically has a HPT larger than 2GB. This has showed up in testing as a failure of the host to emulate doorbell instructions correctly on POWER9 for HPT guests with more than 256GB of RAM. The bug is that the HPTE index in kvmppc_mmu_book3s_64_hv_xlate() is stored as an int, and in forming the HPTE address, the index gets shifted left 4 bits as an int before being signed-extended to 64 bits. The simple fix is to make the variable a long int, matching the return type of kvmppc_hv_find_lock_hpte(), which is what calculates the index. Fixes: 697d3899dcb4 ("KVM: PPC: Implement MMIO emulation support for Book3S HV guests") Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index 7f3a8cf5d66f..4c08f42f6406 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -359,7 +359,7 @@ static int kvmppc_mmu_book3s_64_hv_xlate(struct kvm_vcpu *vcpu, gva_t eaddr, unsigned long pp, key; unsigned long v, orig_v, gr; __be64 *hptep; - int index; + long int index; int virtmode = vcpu->arch.shregs.msr & (data ? MSR_DR : MSR_IR); if (kvm_is_radix(vcpu->kvm))