[PATCH 4.14 087/104] x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d

From: Greg Kroah-Hartman
Date: Tue Aug 14 2018 - 13:37:46 EST


4.14-stable review patch. If anyone has any objections, please let me know.

------------------

From: Nicolai Stange <nstange@xxxxxxx>

commit ffcba43ff66c7dab34ec700debd491d2a4d319b4 upstream

The last missing piece to having vmx_l1d_flush() take interrupts after
VMEXIT into account is to set the kvm_cpu_l1tf_flush_l1d per-cpu flag on
irq entry.

Issue calls to kvm_set_cpu_l1tf_flush_l1d() from entering_irq(),
ipi_entering_ack_irq(), smp_reschedule_interrupt() and
uv_bau_message_interrupt().

Suggested-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Nicolai Stange <nstange@xxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/x86/include/asm/apic.h | 3 +++
arch/x86/kernel/smp.c | 1 +
arch/x86/platform/uv/tlb_uv.c | 1 +
3 files changed, 5 insertions(+)

--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -10,6 +10,7 @@
#include <asm/fixmap.h>
#include <asm/mpspec.h>
#include <asm/msr.h>
+#include <asm/hardirq.h>

#define ARCH_APICTIMER_STOPS_ON_C3 1

@@ -626,6 +627,7 @@ extern void irq_exit(void);
static inline void entering_irq(void)
{
irq_enter();
+ kvm_set_cpu_l1tf_flush_l1d();
}

static inline void entering_ack_irq(void)
@@ -638,6 +640,7 @@ static inline void ipi_entering_ack_irq(
{
irq_enter();
ack_APIC_irq();
+ kvm_set_cpu_l1tf_flush_l1d();
}

static inline void exiting_irq(void)
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -261,6 +261,7 @@ __visible void __irq_entry smp_reschedul
{
ack_APIC_irq();
inc_irq_stat(irq_resched_count);
+ kvm_set_cpu_l1tf_flush_l1d();

if (trace_resched_ipi_enabled()) {
/*
--- a/arch/x86/platform/uv/tlb_uv.c
+++ b/arch/x86/platform/uv/tlb_uv.c
@@ -1285,6 +1285,7 @@ void uv_bau_message_interrupt(struct pt_
struct msg_desc msgdesc;

ack_APIC_irq();
+ kvm_set_cpu_l1tf_flush_l1d();
time_start = get_cycles();

bcp = &per_cpu(bau_control, smp_processor_id());