search for: kvm_mem_readonly

...; } -void kvm_mmu_slot_remove_write_access(struct kvm *kvm, +static bool slot_rmap_apply_protection(struct kvm *kvm, + struct kvm_rmap_head *rmap_head, + void *data) +{ + struct kvm_write_access_data *d = (struct kvm_write_access_data *) data; + bool prot_mask = !(d->memslot->flags & KVM_MEM_READONLY); + + return __rmap_write_protect(kvm, rmap_head, prot_mask, d); +} + +void kvm_mmu_slot_apply_write_access(struct kvm *kvm, struct kvm_memory_slot *memslot) { bool flush; + struct kvm_write_access_data data = { + .i = 0, + .memslot = memslot, + }; spin_lock(&kvm->mmu_loc...

...; } -void kvm_mmu_slot_remove_write_access(struct kvm *kvm, +static bool slot_rmap_apply_protection(struct kvm *kvm, + struct kvm_rmap_head *rmap_head, + void *data) +{ + struct kvm_write_access_data *d = (struct kvm_write_access_data *) data; + bool prot_mask = !(d->memslot->flags & KVM_MEM_READONLY); + + return __rmap_write_protect(kvm, rmap_head, prot_mask, d); +} + +void kvm_mmu_slot_apply_write_access(struct kvm *kvm, struct kvm_memory_slot *memslot) { bool flush; + struct kvm_write_access_data data = { + .i = 0, + .memslot = memslot, + }; spin_lock(&kvm->mmu_loc...

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

...t room for the user space app using kvm to decide the rightful policy for handling ROE violations. The way it works by KVM_EXIT_MMIO error to user space, keeping all the architectural details hidden away from user space. A last note is that I didn't create this from scratch, instead I extended KVM_MEM_READONLY implementation to also allow R/O per page instead R/O per whole slot which is already done in kernel space.

...rt/kvm/kvm_main.c index 4d965913d347..8c4bccf33c8c 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1347,6 +1347,30 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, return kvm_set_memory_region(kvm, mem); } +gfn_t kvm_get_max_gfn(struct kvm *kvm) +{ + u32 skip_mask = KVM_MEM_READONLY | KVM_MEMSLOT_INVALID; + struct kvm_memory_slot *memslot; + struct kvm_memslots *slots; + gfn_t max_gfn = 0; + int idx; + + idx = srcu_read_lock(&kvm->srcu); + spin_lock(&kvm->mmu_lock); + + slots = kvm_memslots(kvm); + kvm_for_each_memslot(memslot, slots) + if (memslot->id < K...

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:

...ecide the rightful policy >> for handling ROE violations. The way it works by KVM_EXIT_MMIO error to user >> space, keeping all the architectural details hidden away from user space. >> >> A last note is that I didn't create this from scratch, instead I extended >> KVM_MEM_READONLY implementation to also allow R/O per page instead >> R/O per whole slot which is already done in kernel space. > > But then you still have to also do something about virtio code in QEMU > that might write to those pages, right? Probably yes, still I haven't fully planned that ye...

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