[PATCH v2 5/6] KVM: x86: Unconditionally set l1tf_flush_l1d during vCPU load
From: Sean Christopherson <seanjc@google.com>
Date: 2024-05-22 01:40:26
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-mips, linux-riscv, lkml, loongarch
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Always set l1tf_flush_l1d during kvm_arch_vcpu_load() instead of setting it only when the vCPU is being scheduled back in. The flag is processed only when VM-Enter is imminent, and KVM obviously needs to load the vCPU before VM-Enter, so attempting to precisely set l1tf_flush_l1d provides no meaningful value. I.e. the flag _will_ be set either way, it's simply a matter of when. Signed-off-by: Sean Christopherson <seanjc@google.com> --- arch/x86/kvm/x86.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 59aa772af755..60fea297f91f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c@@ -5006,12 +5006,11 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) { struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); - if (vcpu->scheduled_out) { - vcpu->arch.l1tf_flush_l1d = true; - if (pmu->version && unlikely(pmu->event_count)) { - pmu->need_cleanup = true; - kvm_make_request(KVM_REQ_PMU, vcpu); - } + vcpu->arch.l1tf_flush_l1d = true; + + if (vcpu->scheduled_out && pmu->version && pmu->event_count) { + pmu->need_cleanup = true; + kvm_make_request(KVM_REQ_PMU, vcpu); } /* Address WBINVD may be executed by guest */
--
2.45.0.215.g3402c0e53f-goog