summaryrefslogtreecommitdiffhomepage
path: root/pkg/ring0
diff options
context:
space:
mode:
authorAndrei Vagin <avagin@google.com>2021-04-30 23:03:38 -0700
committergVisor bot <gvisor-bot@google.com>2021-04-30 23:07:15 -0700
commitcde8e8b7a905ce53fe72a1a71b86e9ef352bbc3a (patch)
treeda490778e2ed80b9f92a14066d69bf5e8410a758 /pkg/ring0
parent6fb8c01bb488e22c741a307e030b61c512dcd34f (diff)
kvm: prefault a root table page before switching into a user address space
The root table physical page has to be mapped to not fault in iret or sysret after switching into a user address space. sysret and iret are in the upper half that is global and so page tables of lower levels are already mapped. Fixes #5742 PiperOrigin-RevId: 371458644
Diffstat (limited to 'pkg/ring0')
-rw-r--r--pkg/ring0/pagetables/pagetables.go9
1 files changed, 9 insertions, 0 deletions
diff --git a/pkg/ring0/pagetables/pagetables.go b/pkg/ring0/pagetables/pagetables.go
index 3f17fba49..9dac53c80 100644
--- a/pkg/ring0/pagetables/pagetables.go
+++ b/pkg/ring0/pagetables/pagetables.go
@@ -322,3 +322,12 @@ func (p *PageTables) Lookup(addr hostarch.Addr, findFirst bool) (virtual hostarc
func (p *PageTables) MarkReadOnlyShared() {
p.readOnlyShared = true
}
+
+// PrefaultRootTable touches the root table page to be sure that its physical
+// pages are mapped.
+//
+//go:nosplit
+//go:noinline
+func (p *PageTables) PrefaultRootTable() PTE {
+ return p.root[0]
+}