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-rw-r--r--virt/kvm/Kconfig1
-rw-r--r--virt/kvm/guest_memfd.c75
-rw-r--r--virt/kvm/kvm_main.c4
3 files changed, 52 insertions, 28 deletions
diff --git a/virt/kvm/Kconfig b/virt/kvm/Kconfig
index 0227e13cd8dd..5f0015c5dd95 100644
--- a/virt/kvm/Kconfig
+++ b/virt/kvm/Kconfig
@@ -113,6 +113,7 @@ config KVM_GENERIC_MEMORY_ATTRIBUTES
bool
config KVM_GUEST_MEMFD
+ depends on KVM_GENERIC_MMU_NOTIFIER
select XARRAY_MULTI
bool
diff --git a/virt/kvm/guest_memfd.c b/virt/kvm/guest_memfd.c
index 94bafd6c558c..fbca8c0972da 100644
--- a/virt/kvm/guest_memfd.c
+++ b/virt/kvm/guest_memfd.c
@@ -102,8 +102,17 @@ static struct folio *kvm_gmem_get_folio(struct inode *inode, pgoff_t index)
return filemap_grab_folio(inode->i_mapping, index);
}
-static void kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t start,
- pgoff_t end)
+static enum kvm_gfn_range_filter kvm_gmem_get_invalidate_filter(struct inode *inode)
+{
+ if ((u64)inode->i_private & GUEST_MEMFD_FLAG_INIT_SHARED)
+ return KVM_FILTER_SHARED;
+
+ return KVM_FILTER_PRIVATE;
+}
+
+static void __kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t start,
+ pgoff_t end,
+ enum kvm_gfn_range_filter attr_filter)
{
bool flush = false, found_memslot = false;
struct kvm_memory_slot *slot;
@@ -118,8 +127,7 @@ static void kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t start,
.end = slot->base_gfn + min(pgoff + slot->npages, end) - pgoff,
.slot = slot,
.may_block = true,
- /* guest memfd is relevant to only private mappings. */
- .attr_filter = KVM_FILTER_PRIVATE,
+ .attr_filter = attr_filter,
};
if (!found_memslot) {
@@ -139,8 +147,21 @@ static void kvm_gmem_invalidate_begin(struct kvm_gmem *gmem, pgoff_t start,
KVM_MMU_UNLOCK(kvm);
}
-static void kvm_gmem_invalidate_end(struct kvm_gmem *gmem, pgoff_t start,
- pgoff_t end)
+static void kvm_gmem_invalidate_begin(struct inode *inode, pgoff_t start,
+ pgoff_t end)
+{
+ struct list_head *gmem_list = &inode->i_mapping->i_private_list;
+ enum kvm_gfn_range_filter attr_filter;
+ struct kvm_gmem *gmem;
+
+ attr_filter = kvm_gmem_get_invalidate_filter(inode);
+
+ list_for_each_entry(gmem, gmem_list, entry)
+ __kvm_gmem_invalidate_begin(gmem, start, end, attr_filter);
+}
+
+static void __kvm_gmem_invalidate_end(struct kvm_gmem *gmem, pgoff_t start,
+ pgoff_t end)
{
struct kvm *kvm = gmem->kvm;
@@ -151,12 +172,20 @@ static void kvm_gmem_invalidate_end(struct kvm_gmem *gmem, pgoff_t start,
}
}
-static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
+static void kvm_gmem_invalidate_end(struct inode *inode, pgoff_t start,
+ pgoff_t end)
{
struct list_head *gmem_list = &inode->i_mapping->i_private_list;
+ struct kvm_gmem *gmem;
+
+ list_for_each_entry(gmem, gmem_list, entry)
+ __kvm_gmem_invalidate_end(gmem, start, end);
+}
+
+static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
+{
pgoff_t start = offset >> PAGE_SHIFT;
pgoff_t end = (offset + len) >> PAGE_SHIFT;
- struct kvm_gmem *gmem;
/*
* Bindings must be stable across invalidation to ensure the start+end
@@ -164,13 +193,11 @@ static long kvm_gmem_punch_hole(struct inode *inode, loff_t offset, loff_t len)
*/
filemap_invalidate_lock(inode->i_mapping);
- list_for_each_entry(gmem, gmem_list, entry)
- kvm_gmem_invalidate_begin(gmem, start, end);
+ kvm_gmem_invalidate_begin(inode, start, end);
truncate_inode_pages_range(inode->i_mapping, offset, offset + len - 1);
- list_for_each_entry(gmem, gmem_list, entry)
- kvm_gmem_invalidate_end(gmem, start, end);
+ kvm_gmem_invalidate_end(inode, start, end);
filemap_invalidate_unlock(inode->i_mapping);
@@ -280,8 +307,9 @@ static int kvm_gmem_release(struct inode *inode, struct file *file)
* Zap all SPTEs pointed at by this file. Do not free the backing
* memory, as its lifetime is associated with the inode, not the file.
*/
- kvm_gmem_invalidate_begin(gmem, 0, -1ul);
- kvm_gmem_invalidate_end(gmem, 0, -1ul);
+ __kvm_gmem_invalidate_begin(gmem, 0, -1ul,
+ kvm_gmem_get_invalidate_filter(inode));
+ __kvm_gmem_invalidate_end(gmem, 0, -1ul);
list_del(&gmem->entry);
@@ -328,6 +356,9 @@ static vm_fault_t kvm_gmem_fault_user_mapping(struct vm_fault *vmf)
if (((loff_t)vmf->pgoff << PAGE_SHIFT) >= i_size_read(inode))
return VM_FAULT_SIGBUS;
+ if (!((u64)inode->i_private & GUEST_MEMFD_FLAG_INIT_SHARED))
+ return VM_FAULT_SIGBUS;
+
folio = kvm_gmem_get_folio(inode, vmf->pgoff);
if (IS_ERR(folio)) {
int err = PTR_ERR(folio);
@@ -400,8 +431,6 @@ static int kvm_gmem_migrate_folio(struct address_space *mapping,
static int kvm_gmem_error_folio(struct address_space *mapping, struct folio *folio)
{
- struct list_head *gmem_list = &mapping->i_private_list;
- struct kvm_gmem *gmem;
pgoff_t start, end;
filemap_invalidate_lock_shared(mapping);
@@ -409,8 +438,7 @@ static int kvm_gmem_error_folio(struct address_space *mapping, struct folio *fol
start = folio->index;
end = start + folio_nr_pages(folio);
- list_for_each_entry(gmem, gmem_list, entry)
- kvm_gmem_invalidate_begin(gmem, start, end);
+ kvm_gmem_invalidate_begin(mapping->host, start, end);
/*
* Do not truncate the range, what action is taken in response to the
@@ -421,8 +449,7 @@ static int kvm_gmem_error_folio(struct address_space *mapping, struct folio *fol
* error to userspace.
*/
- list_for_each_entry(gmem, gmem_list, entry)
- kvm_gmem_invalidate_end(gmem, start, end);
+ kvm_gmem_invalidate_end(mapping->host, start, end);
filemap_invalidate_unlock_shared(mapping);
@@ -458,7 +485,7 @@ static const struct inode_operations kvm_gmem_iops = {
.setattr = kvm_gmem_setattr,
};
-bool __weak kvm_arch_supports_gmem_mmap(struct kvm *kvm)
+bool __weak kvm_arch_supports_gmem_init_shared(struct kvm *kvm)
{
return true;
}
@@ -522,12 +549,8 @@ int kvm_gmem_create(struct kvm *kvm, struct kvm_create_guest_memfd *args)
{
loff_t size = args->size;
u64 flags = args->flags;
- u64 valid_flags = 0;
-
- if (kvm_arch_supports_gmem_mmap(kvm))
- valid_flags |= GUEST_MEMFD_FLAG_MMAP;
- if (flags & ~valid_flags)
+ if (flags & ~kvm_gmem_get_supported_flags(kvm))
return -EINVAL;
if (size <= 0 || !PAGE_ALIGNED(size))
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 226faeaa8e56..b7a0ae2a7b20 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4928,8 +4928,8 @@ static int kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
#ifdef CONFIG_KVM_GUEST_MEMFD
case KVM_CAP_GUEST_MEMFD:
return 1;
- case KVM_CAP_GUEST_MEMFD_MMAP:
- return !kvm || kvm_arch_supports_gmem_mmap(kvm);
+ case KVM_CAP_GUEST_MEMFD_FLAGS:
+ return kvm_gmem_get_supported_flags(kvm);
#endif
default:
break;
generated by cgit (git 2.34.1) at 2025-10-19 07:44:28 +0000