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-rw-r--r--arch/x86/include/asm/kvm_host.h3
-rw-r--r--arch/x86/kvm/mmu/mmu.c2
-rw-r--r--arch/x86/kvm/vmx/nested.c2
-rw-r--r--arch/x86/kvm/vmx/vmx.c20
-rw-r--r--arch/x86/kvm/x86.c6
-rw-r--r--arch/x86/kvm/x86.h14
6 files changed, 24 insertions, 23 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 692ec922945f..103af57e1060 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1055,9 +1055,6 @@ struct kvm_vcpu_arch {
/* be preempted when it's in kernel-mode(cpl=0) */
bool preempted_in_kernel;
- /* Flush the L1 Data cache for L1TF mitigation on VMENTER */
- bool l1tf_flush_l1d;
-
/* Host CPU on which VM-entry was most recently attempted */
int last_vmentry_cpu;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 667d66cf76d5..a81637a98019 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -4859,7 +4859,7 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code,
*/
BUILD_BUG_ON(lower_32_bits(PFERR_SYNTHETIC_MASK));
- vcpu->arch.l1tf_flush_l1d = true;
+ kvm_request_l1tf_flush_l1d();
if (!flags) {
trace_kvm_page_fault(vcpu, fault_address, error_code);
diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c
index 76271962cb70..256b51fc8c10 100644
--- a/arch/x86/kvm/vmx/nested.c
+++ b/arch/x86/kvm/vmx/nested.c
@@ -3880,7 +3880,7 @@ static int nested_vmx_run(struct kvm_vcpu *vcpu, bool launch)
goto vmentry_failed;
/* Hide L1D cache contents from the nested guest. */
- vmx->vcpu.arch.l1tf_flush_l1d = true;
+ kvm_request_l1tf_flush_l1d();
/*
* Must happen outside of nested_vmx_enter_non_root_mode() as it will
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 59d3f2671177..634f591d253e 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -395,26 +395,16 @@ static noinstr void vmx_l1d_flush(struct kvm_vcpu *vcpu)
* 'always'
*/
if (static_branch_likely(&vmx_l1d_flush_cond)) {
- bool flush_l1d;
-
/*
- * Clear the per-vcpu flush bit, it gets set again if the vCPU
+ * Clear the per-cpu flush bit, it gets set again if the vCPU
* is reloaded, i.e. if the vCPU is scheduled out or if KVM
* exits to userspace, or if KVM reaches one of the unsafe
- * VMEXIT handlers, e.g. if KVM calls into the emulator.
- */
- flush_l1d = vcpu->arch.l1tf_flush_l1d;
- vcpu->arch.l1tf_flush_l1d = false;
-
- /*
- * Clear the per-cpu flush bit, it gets set again from
- * the interrupt handlers.
+ * VMEXIT handlers, e.g. if KVM calls into the emulator,
+ * or from the interrupt handlers.
*/
- flush_l1d |= kvm_get_cpu_l1tf_flush_l1d();
- kvm_clear_cpu_l1tf_flush_l1d();
-
- if (!flush_l1d)
+ if (!kvm_get_cpu_l1tf_flush_l1d())
return;
+ kvm_clear_cpu_l1tf_flush_l1d();
}
vcpu->stat.l1d_flush++;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index be737d9645b9..6af37204bd97 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -5156,7 +5156,7 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
- vcpu->arch.l1tf_flush_l1d = true;
+ kvm_request_l1tf_flush_l1d();
if (vcpu->scheduled_out && pmu->version && pmu->event_count) {
pmu->need_cleanup = true;
@@ -7966,7 +7966,7 @@ int kvm_write_guest_virt_system(struct kvm_vcpu *vcpu, gva_t addr, void *val,
unsigned int bytes, struct x86_exception *exception)
{
/* kvm_write_guest_virt_system can pull in tons of pages. */
- vcpu->arch.l1tf_flush_l1d = true;
+ kvm_request_l1tf_flush_l1d();
return kvm_write_guest_virt_helper(addr, val, bytes, vcpu,
PFERR_WRITE_MASK, exception);
@@ -9374,7 +9374,7 @@ int x86_emulate_instruction(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
return handle_emulation_failure(vcpu, emulation_type);
}
- vcpu->arch.l1tf_flush_l1d = true;
+ kvm_request_l1tf_flush_l1d();
if (!(emulation_type & EMULTYPE_NO_DECODE)) {
kvm_clear_exception_queue(vcpu);
diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index f3dc77f006f9..cd67ccbb747f 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -420,6 +420,20 @@ static inline bool kvm_check_has_quirk(struct kvm *kvm, u64 quirk)
return !(kvm->arch.disabled_quirks & quirk);
}
+static __always_inline void kvm_request_l1tf_flush_l1d(void)
+{
+#if IS_ENABLED(CONFIG_CPU_MITIGATIONS) && IS_ENABLED(CONFIG_KVM_INTEL)
+ /*
+ * Use a raw write to set the per-CPU flag, as KVM will ensure a flush
+ * even if preemption is currently enabled.. If the current vCPU task
+ * is migrated to a different CPU (or userspace runs the vCPU on a
+ * different task) before the next VM-Entry, then kvm_arch_vcpu_load()
+ * will request a flush on the new CPU.
+ */
+ raw_cpu_write(irq_stat.kvm_cpu_l1tf_flush_l1d, 1);
+#endif
+}
+
void kvm_inject_realmode_interrupt(struct kvm_vcpu *vcpu, int irq, int inc_eip);
u64 get_kvmclock_ns(struct kvm *kvm);