diff options
Diffstat (limited to 'pkg/sentry/platform/kvm/address_space.go')
| -rw-r--r-- | pkg/sentry/platform/kvm/address_space.go | 24 |
1 files changed, 18 insertions, 6 deletions
diff --git a/pkg/sentry/platform/kvm/address_space.go b/pkg/sentry/platform/kvm/address_space.go index c2f4559a0..f74c98dd0 100644 --- a/pkg/sentry/platform/kvm/address_space.go +++ b/pkg/sentry/platform/kvm/address_space.go @@ -102,11 +102,18 @@ func (as *addressSpace) mapHost(addr usermem.Addr, m hostMapEntry, at usermem.Ac // important; if the pagetable mappings were installed before // ensuring the physical pages were available, then some other // thread could theoretically access them. - prev := as.pageTables.Map(addr, length, pagetables.MapOpts{ - AccessType: at, - User: true, - }, physical) - inv = inv || prev + // + // Due to the way KVM's shadow paging implementation works, + // modifications to the page tables while in host mode may not + // be trapped, leading to the shadow pages being out of sync. + // Therefore, we need to ensure that we are in guest mode for + // page table modifications. See the call to bluepill, below. + as.machine.retryInGuest(func() { + inv = as.pageTables.Map(addr, length, pagetables.MapOpts{ + AccessType: at, + User: true, + }, physical) || inv + }) m.addr += length m.length -= length addr += usermem.Addr(length) @@ -214,7 +221,12 @@ func (as *addressSpace) Unmap(addr usermem.Addr, length uint64) { as.mu.Lock() defer as.mu.Unlock() - if prev := as.pageTables.Unmap(addr, uintptr(length)); prev { + // See above re: retryInGuest. + var prev bool + as.machine.retryInGuest(func() { + prev = as.pageTables.Unmap(addr, uintptr(length)) || prev + }) + if prev { as.invalidate() as.files.DeleteMapping(usermem.AddrRange{ Start: addr, |