linux/arch/x86/kvm
Avi Kivity aa67f6096c KVM: VMX: Fix ds/es corruption on i386 with preemption
Commit b2da15ac26 ("KVM: VMX: Optimize %ds, %es reload") broke i386
in the following scenario:

  vcpu_load
  ...
  vmx_save_host_state
  vmx_vcpu_run
  (ds.rpl, es.rpl cleared by hardware)

  interrupt
    push ds, es  # pushes bad ds, es
    schedule
      vmx_vcpu_put
        vmx_load_host_state
          reload ds, es (with __USER_DS)
    pop ds, es  # of other thread's stack
    iret
  # other thread runs
  interrupt
    push ds, es
    schedule  # back in vcpu thread
    pop ds, es  # now with rpl=0
    iret
  ...
  vcpu_put
  resume_userspace
  iret  # clears ds, es due to mismatched rpl

(instead of resume_userspace, we might return with SYSEXIT and then
take an exception; when the exception IRETs we end up with cleared
ds, es)

Fix by avoiding the optimization on i386 and reloading ds, es on the
lightweight exit path.

Reported-by: Chris Clayron <chris2553@googlemail.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2012-08-01 20:23:57 -03:00
..
cpuid.c KVM: VMX: Implement PCID/INVPCID for guests with EPT 2012-07-12 13:07:34 +03:00
cpuid.h KVM: VMX: Implement PCID/INVPCID for guests with EPT 2012-07-12 13:07:34 +03:00
emulate.c KVM: x86 emulator: implement LTR 2012-07-09 14:19:05 +03:00
i8254.c KVM: x86: Run PIT work in own kthread 2012-04-27 19:40:29 -03:00
i8254.h KVM: x86: Run PIT work in own kthread 2012-04-27 19:40:29 -03:00
i8259.c KVM: PIC: call ack notifiers for irqs that are dropped form irr 2012-07-26 12:19:06 +03:00
irq.c KVM: fix typo in copyright notice 2010-10-24 10:53:14 +02:00
irq.h KVM: Intelligent device lookup on I/O bus 2011-09-25 19:17:59 +03:00
Kconfig KVM: Introduce direct MSI message injection for in-kernel irqchips 2012-04-24 15:59:47 +03:00
kvm_cache_regs.h KVM: MMU: Do not unconditionally read PDPTE from guest memory 2011-09-25 19:18:01 +03:00
kvm_timer.h KVM: emulate lapic tsc deadline timer for guest 2011-10-05 15:34:56 +02:00
lapic.c KVM: host side for eoi optimization 2012-06-25 12:40:55 +03:00
lapic.h KVM: host side for eoi optimization 2012-06-25 12:40:55 +03:00
Makefile KVM: Expose a version 2 architectural PMU to a guests 2011-12-27 11:24:29 +02:00
mmu_audit.c KVM: MMU: Improve iteration through sptes from rmap 2012-04-08 16:08:27 +03:00
mmu.c KVM updates for the 3.6 merge window 2012-07-24 12:01:20 -07:00
mmu.h KVM: MMU: mmio page fault support 2011-07-24 11:50:40 +03:00
mmutrace.h KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint 2012-07-11 16:51:22 +03:00
paging_tmpl.h KVM: MMU: fix kvm_mmu_pagetable_walk tracepoint 2012-07-11 16:51:22 +03:00
pmu.c perf/x86: Rename Intel specific macros 2012-07-05 21:19:39 +02:00
svm.c KVM: VMX: Implement PCID/INVPCID for guests with EPT 2012-07-12 13:07:34 +03:00
timer.c KVM: x86: Simplify kvm timer handler 2011-12-27 11:17:05 +02:00
trace.h KVM updates for the 3.6 merge window 2012-07-24 12:01:20 -07:00
tss.h KVM: x86: hardware task switching support 2008-04-27 12:00:39 +03:00
vmx.c KVM: VMX: Fix ds/es corruption on i386 with preemption 2012-08-01 20:23:57 -03:00
x86.c KVM: x86: apply kvmclock offset to guest wall clock time 2012-08-01 17:23:50 -03:00
x86.h KVM: x86: add paging gcc optimization 2012-04-08 14:03:13 +03:00