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| author |   Vitaly Kuznetsov <vkuznets@redhat.com> | 2018-10-08 21:28:08 +0200 |
|---|---|---|
| committer |   Paolo Bonzini <pbonzini@redhat.com> | 2018-10-17 00:30:04 +0200 |
| commit | 14c07ad89f4d728a468caaea6a769c018c2b8dd6 (patch) | |
| tree | ccb089dc2bd41e92d0f0e7adf3891a34f57a325e /arch/x86/include/asm/kvm_host.h | |
| parent | x86/kvm/mmu.c: add kvm_mmu parameter to kvm_mmu_free_roots() (diff) | |
| download | linux-dev-14c07ad89f4d728a468caaea6a769c018c2b8dd6.tar.xz linux-dev-14c07ad89f4d728a468caaea6a769c018c2b8dd6.zip | |
x86/kvm/mmu: introduce guest_mmu
When EPT is used for nested guest we need to re-init MMU as shadow
EPT MMU (nested_ept_init_mmu_context() does that). When we return back
from L2 to L1 kvm_mmu_reset_context() in nested_vmx_load_cr3() resets
MMU back to normal TDP mode. Add a special 'guest_mmu' so we can use
separate root caches; the improved hit rate is not very important for
single vCPU performance, but it avoids contention on the mmu_lock for
many vCPUs.
On the nested CPUID benchmark, with 16 vCPUs, an L2->L1->L2 vmexit
goes from 42k to 26k cycles.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Reviewed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/include/asm/kvm_host.h')
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 586ef144e564..7448d0b744c9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -548,6 +548,9 @@ struct kvm_vcpu_arch { /* Non-nested MMU for L1 */ struct kvm_mmu root_mmu; + /* L1 MMU when running nested */ + struct kvm_mmu guest_mmu; + /* * Paging state of an L2 guest (used for nested npt) * |