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| author | Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> | 2013-05-31 08:36:20 +0800 |
|---|---|---|
| committer | Gleb Natapov <gleb@redhat.com> | 2013-06-05 12:32:00 +0300 |
| commit | 758ccc89b83cc15d575204091c1a1fec306245cb (patch) | |
| tree | af66f3ed31cf6acec53394efe4eeabca1c815312 /arch/x86 | |
| parent | 6ea34c9b78c10289846db0abeebd6b84d5aca084 (diff) | |
| download | linux-758ccc89b83cc15d575204091c1a1fec306245cb.tar.gz linux-758ccc89b83cc15d575204091c1a1fec306245cb.tar.bz2 linux-758ccc89b83cc15d575204091c1a1fec306245cb.zip | |
KVM: x86: drop calling kvm_mmu_zap_all in emulator_fix_hypercall
Quote Gleb's mail:
| Back then kvm->lock protected memslot access so code like:
|
| mutex_lock(&vcpu->kvm->lock);
| kvm_mmu_zap_all(vcpu->kvm);
| mutex_unlock(&vcpu->kvm->lock);
|
| which is what 7aa81cc0 does was enough to guaranty that no vcpu will
| run while code is patched. This is no longer the case and
| mutex_lock(&vcpu->kvm->lock); is gone from that code path long time ago,
| so now kvm_mmu_zap_all() there is useless and the code is incorrect.
So we drop it and it will be fixed later
Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/x86.c | 7 |
1 files changed, 0 insertions, 7 deletions
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 8d28810a5f88..6739b1d4ce7c 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -5523,13 +5523,6 @@ static int emulator_fix_hypercall(struct x86_emulate_ctxt *ctxt) char instruction[3]; unsigned long rip = kvm_rip_read(vcpu); - /* - * Blow out the MMU to ensure that no other VCPU has an active mapping - * to ensure that the updated hypercall appears atomically across all - * VCPUs. - */ - kvm_mmu_zap_all(vcpu->kvm); - kvm_x86_ops->patch_hypercall(vcpu, instruction); return emulator_write_emulated(ctxt, rip, instruction, 3, NULL); |