From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Date: Sat, 24 May 2014 08:21:58 +0000 Subject: [PATCH 4/7] KVM: PPC: Book3S HV: Fix dirty map for hugepages Message-Id: <1400919721-14264-5-git-send-email-paulus@samba.org> List-Id: References: <1400919721-14264-1-git-send-email-paulus@samba.org> In-Reply-To: <1400919721-14264-1-git-send-email-paulus@samba.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alexander Graf Cc: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org From: Alexey Kardashevskiy The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty. In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index f32896f..d605dc24 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1053,6 +1053,7 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) { struct revmap_entry *rev = kvm->arch.revmap; unsigned long head, i, j; + unsigned long n; unsigned long *hptep; int ret = 0; @@ -1095,7 +1096,10 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) rev[i].guest_rpte |= HPTE_R_C; note_hpte_modification(kvm, &rev[i]); } - ret = 1; + n = hpte_page_size(hptep[0], hptep[1]); + n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (n > ret) + ret = n; } hptep[0] &= ~HPTE_V_HVLOCK; } while ((i = j) != head); @@ -1125,15 +1129,17 @@ static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long *map) { - unsigned long i; + unsigned long i, j; unsigned long *rmapp; struct kvm_vcpu *vcpu; preempt_disable(); rmapp = memslot->arch.rmap; for (i = 0; i < memslot->npages; ++i) { - if (kvm_test_clear_dirty(kvm, rmapp) && map) - __set_bit_le(i, map); + int ret = kvm_test_clear_dirty(kvm, rmapp); + if (ret && map) + for (j = i - (i % ret); ret; ++j, --ret) + __set_bit_le(j, map); ++rmapp; } -- 2.0.0.rc2 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Mackerras Subject: [PATCH 4/7] KVM: PPC: Book3S HV: Fix dirty map for hugepages Date: Sat, 24 May 2014 18:21:58 +1000 Message-ID: <1400919721-14264-5-git-send-email-paulus@samba.org> References: <1400919721-14264-1-git-send-email-paulus@samba.org> Cc: kvm-ppc@vger.kernel.org, kvm@vger.kernel.org To: Alexander Graf Return-path: In-Reply-To: <1400919721-14264-1-git-send-email-paulus@samba.org> Sender: kvm-ppc-owner@vger.kernel.org List-Id: kvm.vger.kernel.org From: Alexey Kardashevskiy The dirty map that we construct for the KVM_GET_DIRTY_LOG ioctl has one bit per system page (4K/64K). Currently, we only set one bit in the map for each HPT entry with the Change bit set, even if the HPT is for a large page (e.g., 16MB). Userspace then considers only the first system page dirty, though in fact the guest may have modified anywhere in the large page. To fix this, we make kvm_test_clear_dirty() return the actual number of pages that are dirty. In kvmppc_hv_get_dirty_log() we then set that many bits in the dirty map. Signed-off-by: Alexey Kardashevskiy Signed-off-by: Paul Mackerras --- arch/powerpc/kvm/book3s_64_mmu_hv.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c index f32896f..d605dc24 100644 --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c @@ -1053,6 +1053,7 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) { struct revmap_entry *rev = kvm->arch.revmap; unsigned long head, i, j; + unsigned long n; unsigned long *hptep; int ret = 0; @@ -1095,7 +1096,10 @@ static int kvm_test_clear_dirty(struct kvm *kvm, unsigned long *rmapp) rev[i].guest_rpte |= HPTE_R_C; note_hpte_modification(kvm, &rev[i]); } - ret = 1; + n = hpte_page_size(hptep[0], hptep[1]); + n = (n + PAGE_SIZE - 1) >> PAGE_SHIFT; + if (n > ret) + ret = n; } hptep[0] &= ~HPTE_V_HVLOCK; } while ((i = j) != head); @@ -1125,15 +1129,17 @@ static void harvest_vpa_dirty(struct kvmppc_vpa *vpa, long kvmppc_hv_get_dirty_log(struct kvm *kvm, struct kvm_memory_slot *memslot, unsigned long *map) { - unsigned long i; + unsigned long i, j; unsigned long *rmapp; struct kvm_vcpu *vcpu; preempt_disable(); rmapp = memslot->arch.rmap; for (i = 0; i < memslot->npages; ++i) { - if (kvm_test_clear_dirty(kvm, rmapp) && map) - __set_bit_le(i, map); + int ret = kvm_test_clear_dirty(kvm, rmapp); + if (ret && map) + for (j = i - (i % ret); ret; ++j, --ret) + __set_bit_le(j, map); ++rmapp; } -- 2.0.0.rc2