KVM: x86: move saving of arch.host_pkru to kvm_arch_vcpu_load in 5.4.y
Subsystems (4)
PATCH 1/1 KVM: x86: move saving of arch.host_pkru to kvm_arch_vcpu_load in 5.4.y
commit 37486135d3a7b03acc7755b63627a130437f066a upstream.
In 5.4.y only, vcpu->arch.host_pkru is being set on every run thru of vcpu_enter_guest, when it really only needs to be set on load. As a result, we're doing a rdpkru on supported CPUs on every iteration of vcpu_enter_guest even though the value never changes.
Mainline and 5.10.y already has host_pkru being initialized in kvm_arch_vcpu_load. This change is 5.4.y specific and moves host_pkru save to kvm_arch_vcpu_load.
Fixes 99e392a4979b ("KVM: x86: Fix pkru save/restore when guest CR4.PKE=0, move it to x86.c")
Cc [email protected] # 5.4.y
Cc Babu Moger <[email protected]>
Signed-off-by Jon Kohler <[email protected]>
--- arch/x86/kvm/x86.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
arch/x86/kvm/x86.c +3 -3
@@ -3507,6 +3507,9 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_x86_ops->vcpu_load (vcpu, cpu); +/* Save host pkru register if supported */ + vcpu->arch.host_pkru =read_pkru (); +/* Apply any externally detected TSC adjustments (due to suspend) */ if (unlikely (vcpu->arch.tsc_offset_adjustment)) {adjust_tsc_offset_host (vcpu, vcpu->arch.tsc_offset_adjustment);
@@ -8253,9 +8256,6 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)trace_kvm_entry (vcpu->vcpu_id);guest_enter_irqoff (); -/* Save host pkru register if supported */ - vcpu->arch.host_pkru =read_pkru (); -fpregs_assert_state_consistent ();if (test_thread_flag (TIF_NEED_FPU_LOAD ))switch_fpu_return ();
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2.30.1 (Apple Git-130)