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[RFC v2 PATCH 06/13] KVM: Register/unregister memfd backed memslot
From: |
Chao Peng |
Subject: |
[RFC v2 PATCH 06/13] KVM: Register/unregister memfd backed memslot |
Date: |
Fri, 19 Nov 2021 21:47:32 +0800 |
Signed-off-by: Yu Zhang <yu.c.zhang@linux.intel.com>
Signed-off-by: Chao Peng <chao.p.peng@linux.intel.com>
---
virt/kvm/kvm_main.c | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 271cef8d1cd0..b8673490d301 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1426,7 +1426,7 @@ static void update_memslots(struct kvm_memslots *slots,
static int check_memory_region_flags(struct kvm *kvm,
const struct kvm_userspace_memory_region_ext *mem)
{
- u32 valid_flags = 0;
+ u32 valid_flags = KVM_MEM_FD;
if (!kvm->dirty_log_unsupported)
valid_flags |= KVM_MEM_LOG_DIRTY_PAGES;
@@ -1604,10 +1604,20 @@ static int kvm_set_memslot(struct kvm *kvm,
kvm_copy_memslots(slots, __kvm_memslots(kvm, as_id));
}
+ if (mem->flags & KVM_MEM_FD && change == KVM_MR_CREATE) {
+ r = kvm_memfd_register(kvm, mem, new);
+ if (r)
+ goto out_slots;
+ }
+
r = kvm_arch_prepare_memory_region(kvm, new, mem, change);
if (r)
goto out_slots;
+ if (mem->flags & KVM_MEM_FD && (r || change == KVM_MR_DELETE)) {
+ kvm_memfd_unregister(kvm, new);
+ }
+
update_memslots(slots, new, change);
slots = install_new_memslots(kvm, as_id, slots);
@@ -1683,10 +1693,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
return -EINVAL;
if (mem->guest_phys_addr & (PAGE_SIZE - 1))
return -EINVAL;
- /* We can read the guest memory with __xxx_user() later on. */
if ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
- (mem->userspace_addr != untagged_addr(mem->userspace_addr)) ||
- !access_ok((void __user *)(unsigned long)mem->userspace_addr,
+ (mem->userspace_addr != untagged_addr(mem->userspace_addr)))
+ return -EINVAL;
+ /* We can read the guest memory with __xxx_user() later on. */
+ if (!(mem->flags & KVM_MEM_FD) &&
+ !access_ok((void __user *)(unsigned long)mem->userspace_addr,
mem->memory_size))
return -EINVAL;
if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
@@ -1727,6 +1739,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
new.dirty_bitmap = NULL;
memset(&new.arch, 0, sizeof(new.arch));
} else { /* Modify an existing slot. */
+ /* Private memslots are immutable, they can only be deleted. */
+ if (mem->flags & KVM_MEM_FD && mem->private_fd >= 0)
+ return -EINVAL;
if ((new.userspace_addr != old.userspace_addr) ||
(new.npages != old.npages) ||
((new.flags ^ old.flags) & KVM_MEM_READONLY))
--
2.17.1
- Re: [RFC v2 PATCH 01/13] mm/shmem: Introduce F_SEAL_GUEST, (continued)
- [RFC v2 PATCH 02/13] KVM: Add KVM_EXIT_MEMORY_ERROR exit, Chao Peng, 2021/11/19
- [RFC v2 PATCH 03/13] KVM: Extend kvm_userspace_memory_region to support fd based memslot, Chao Peng, 2021/11/19
- [RFC v2 PATCH 04/13] KVM: Add fd-based memslot data structure and utils, Chao Peng, 2021/11/19
- [RFC v2 PATCH 05/13] KVM: Implement fd-based memory using new memfd interfaces, Chao Peng, 2021/11/19
- [RFC v2 PATCH 06/13] KVM: Register/unregister memfd backed memslot,
Chao Peng <=
- [RFC v2 PATCH 07/13] KVM: Handle page fault for fd based memslot, Chao Peng, 2021/11/19
- [RFC v2 PATCH 08/13] KVM: Rename hva memory invalidation code to cover fd-based offset, Chao Peng, 2021/11/19
- [RFC v2 PATCH 09/13] KVM: Introduce kvm_memfd_invalidate_range, Chao Peng, 2021/11/19
- [RFC v2 PATCH 10/13] KVM: Match inode for invalidation of fd-based slot, Chao Peng, 2021/11/19
- [RFC v2 PATCH 11/13] KVM: Add kvm_map_gfn_range, Chao Peng, 2021/11/19