search for: kvm_memslot

From: Hongyong Zang <zanghongyong at huawei.com> Vhost-net uses its own vhost_memory, which results from user space (qemu) info, to translate GPA to HVA. Since kernel's kvm structure already maintains the address relationship in its member *kvm_memslots*, these patches use kernel's kvm_memslots directly without the need of initialization and maintenance of vhost_memory. Hongyong Zang (2): kvm: Introduce get_kvm_from_task vhost-net: Use kvm_memslots for address translation drivers/vhost/vhost.c | 53 +++++++++++++++++-------------...

From: Hongyong Zang <zanghongyong at huawei.com> Vhost-net uses its own vhost_memory, which results from user space (qemu) info, to translate GPA to HVA. Since kernel's kvm structure already maintains the address relationship in its member *kvm_memslots*, these patches use kernel's kvm_memslots directly without the need of initialization and maintenance of vhost_memory. Hongyong Zang (2): kvm: Introduce get_kvm_from_task vhost-net: Use kvm_memslots for address translation drivers/vhost/vhost.c | 53 +++++++++++++++++-------------...

...eal_time_set_preempted in atomic context (neither in sched_out notifier nor in vcpu_put() after preempt_disable)). __copy_to_user in kvm_write_guest_offset_cached schedules and locks up the host. kvm->srcu (or kvm->slots_lock) is also not taken and kvm_write_guest_offset_cached needs to call kvm_memslots which requires it. This I think is why postcopy live migration locks up with current upstream, and it doesn't seem related to userfaultfd at all (initially I suspected the vmf conversion but it wasn't that) and in theory it can happen with heavy swapping or page migration too. Just the p...

...eal_time_set_preempted in atomic context (neither in sched_out notifier nor in vcpu_put() after preempt_disable)). __copy_to_user in kvm_write_guest_offset_cached schedules and locks up the host. kvm->srcu (or kvm->slots_lock) is also not taken and kvm_write_guest_offset_cached needs to call kvm_memslots which requires it. This I think is why postcopy live migration locks up with current upstream, and it doesn't seem related to userfaultfd at all (initially I suspected the vmf conversion but it wasn't that) and in theory it can happen with heavy swapping or page migration too. Just the p...

...6,7 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn); bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn); unsigned long kvm_host_page_size(struct kvm_vcpu *vcpu, gfn_t gfn); void mark_page_dirty(struct kvm *kvm, gfn_t gfn); +gfn_t kvm_get_max_gfn(struct kvm *kvm); struct kvm_memslots *kvm_vcpu_memslots(struct kvm_vcpu *vcpu); struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn); diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 4d965913d347..8c4bccf33c8c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1347,6 +1347,30 @@ s...

...o introduce something like kvm_write_guest_XXX_atomic and use them instead of kvm_write_guest_offset_cached. within pagefault_disable()/enable(), we can not call __copy_to_user I think. > kvm->srcu (or kvm->slots_lock) is also not taken and > kvm_write_guest_offset_cached needs to call kvm_memslots which > requires it. > let me check the details later. thanks for pointing it out. > This I think is why postcopy live migration locks up with current > upstream, and it doesn't seem related to userfaultfd at all (initially > I suspected the vmf conversion but it wasn't tha...

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

change from v6: fix typos and remove uncessary comments. change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3:

...n their GFN, * so binary search could be used to lookup GFN. @@ -1011,6 +1022,8 @@ int __kvm_set_memory_region(struct kvm *kvm, if (kvm_create_dirty_bitmap(&new) < 0) goto out_free; } + if (kvm_init_mroe_bitmap(&new) < 0) + goto out_free; slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) @@ -1264,13 +1277,23 @@ static bool memslot_is_readonly(struct kvm_memory_slot *slot) return slot->flags & KVM_MEM_READONLY; } +static bool gfn_is_readonly(struct kvm_memory_slot *slot, gfn_t gfn) +{ +#ifdef CONFIG_KVM_MROE + return test_bit(gfn - slot->...

...n their GFN, * so binary search could be used to lookup GFN. @@ -1011,6 +1022,8 @@ int __kvm_set_memory_region(struct kvm *kvm, if (kvm_create_dirty_bitmap(&new) < 0) goto out_free; } + if (kvm_init_mroe_bitmap(&new) < 0) + goto out_free; slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL); if (!slots) @@ -1264,13 +1277,23 @@ static bool memslot_is_readonly(struct kvm_memory_slot *slot) return slot->flags & KVM_MEM_READONLY; } +static bool gfn_is_readonly(struct kvm_memory_slot *slot, gfn_t gfn) +{ +#ifdef CONFIG_KVM_MROE + return test_bit(gfn - slot->...

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

change from v5: spilt x86/kvm patch into guest/host part. introduce kvm_write_guest_offset_cached. fix some typos. rebase patch onto 4.9.2 change from v4: spilt x86 kvm vcpu preempted check into two patches. add documentation patch. add x86 vcpu preempted check patch under xen add s390 vcpu preempted check patch change from v3: add x86 vcpu preempted check patch change from v2: no code

Here is change log from V3 To V4: - Fixing spelling/grammar mistakes suggested by Randy Dunlap - Changing the hypercall interface to be able to process multiple pages per one hypercall also suggested by Randy Dunlap. It turns out that this will save lots of vmexist/memory slot flushes when protecting many pages. [PATCH RFC V4 1/3] KVM: X86: Memory ROE documentation [PATCH RFC V4 2/3] KVM:

Hi, This is my first set of patches that works as I would expect, and the third revision I sent to mailing lists. Following up with my previous discussions about kernel rootkit mitigation via placing R/O protection on critical data structure, static data, privileged registers with static content. These patches present the first part where it is only possible to place these protections on memory

Hi, This is my first set of patches that works as I would expect, and the third revision I sent to mailing lists. Following up with my previous discussions about kernel rootkit mitigation via placing R/O protection on critical data structure, static data, privileged registers with static content. These patches present the first part where it is only possible to place these protections on memory

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VMs (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VMs (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VM-s (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place

The KVM introspection subsystem provides a facility for applications running on the host or in a separate VM, to control the execution of other VM-s (pause, resume, shutdown), query the state of the vCPUs (GPRs, MSRs etc.), alter the page access bits in the shadow page tables (only for the hardware backed ones, eg. Intel's EPT) and receive notifications when events of interest have taken place