diff options
Diffstat (limited to 'pkg/sentry/platform/kvm/context.go')
| -rw-r--r-- | pkg/sentry/platform/kvm/context.go | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/pkg/sentry/platform/kvm/context.go b/pkg/sentry/platform/kvm/context.go index fd04a2c47..c9bfbc136 100644 --- a/pkg/sentry/platform/kvm/context.go +++ b/pkg/sentry/platform/kvm/context.go @@ -15,8 +15,6 @@ package kvm import ( - "sync/atomic" - "gvisor.googlesource.com/gvisor/pkg/sentry/arch" "gvisor.googlesource.com/gvisor/pkg/sentry/platform" "gvisor.googlesource.com/gvisor/pkg/sentry/platform/interrupt" @@ -54,10 +52,18 @@ func (c *context) Switch(as platform.AddressSpace, ac arch.Context, _ int32) (*a return nil, usermem.NoAccess, platform.ErrContextInterrupt } + // Set the active address space. + // + // This must be done prior to the call to Touch below. If the address + // space is invalidated between this line and the call below, we will + // flag on entry anyways. When the active address space below is + // cleared, it indicates that we don't need an explicit interrupt and + // that the flush can occur naturally on the next user entry. + cpu.active.set(localAS) + // Mark the address space as dirty. flags := ring0.Flags(0) - dirty := localAS.Touch(cpu) - if v := atomic.SwapUint32(dirty, 1); v == 0 { + if localAS.Touch(cpu) { flags |= ring0.FlagFlush } if ac.FullRestore() { @@ -67,6 +73,9 @@ func (c *context) Switch(as platform.AddressSpace, ac arch.Context, _ int32) (*a // Take the blue pill. si, at, err := cpu.SwitchToUser(regs, fp, localAS.pageTables, flags) + // Clear the address space. + cpu.active.set(nil) + // Release resources. c.machine.Put(cpu) |