linux-kernel - [PATCH v4 5/7] x86/irq: Count Hyper-V reenlightenment interrupts

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180124132337.30138-6-vkuznets@redhat.com>
Date:   Wed, 24 Jan 2018 14:23:35 +0100
From:   Vitaly Kuznetsov <vkuznets@...hat.com>
To:     kvm@...r.kernel.org, x86@...nel.org
Cc:     Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        "K. Y. Srinivasan" <kys@...rosoft.com>,
        Haiyang Zhang <haiyangz@...rosoft.com>,
        Stephen Hemminger <sthemmin@...rosoft.com>,
        "Michael Kelley (EOSG)" <Michael.H.Kelley@...rosoft.com>,
        Andy Lutomirski <luto@...nel.org>,
        Mohammed Gamal <mmorsy@...hat.com>,
        Cathy Avery <cavery@...hat.com>,
        Roman Kagan <rkagan@...tuozzo.com>,
        linux-kernel@...r.kernel.org, devel@...uxdriverproject.org
Subject: [PATCH v4 5/7] x86/irq: Count Hyper-V reenlightenment interrupts

Hyper-V reenlightenment interrupts arrive when the VM is migrated, we're
not supposed to see many of them. However, it may be important to know
that the event has happened in case we have L2 nested guests.

Signed-off-by: Vitaly Kuznetsov <vkuznets@...hat.com>
Reviewed-by: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/hyperv/hv_init.c      | 2 ++
 arch/x86/include/asm/hardirq.h | 3 +++
 arch/x86/kernel/irq.c          | 9 +++++++++
 3 files changed, 14 insertions(+)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index e4377e2f2a10..a3adece392f1 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -147,6 +147,8 @@ __visible void __irq_entry hyperv_reenlightenment_intr(struct pt_regs *regs)
 {
 	entering_ack_irq();
 
+	inc_irq_stat(irq_hv_reenlightenment_count);
+
 	schedule_delayed_work(&hv_reenlightenment_work, HZ/10);
 
 	exiting_irq();
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 51cc979dd364..7c341a74ec8c 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -38,6 +38,9 @@ typedef struct {
 #if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
 	unsigned int irq_hv_callback_count;
 #endif
+#if IS_ENABLED(CONFIG_HYPERV)
+	unsigned int irq_hv_reenlightenment_count;
+#endif
 } ____cacheline_aligned irq_cpustat_t;
 
 DECLARE_PER_CPU_SHARED_ALIGNED(irq_cpustat_t, irq_stat);
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 68e1867cca80..45fb4d2565f8 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -141,6 +141,15 @@ int arch_show_interrupts(struct seq_file *p, int prec)
 				   irq_stats(j)->irq_hv_callback_count);
 		seq_puts(p, "  Hypervisor callback interrupts\n");
 	}
+#endif
+#if IS_ENABLED(CONFIG_HYPERV)
+	if (test_bit(HYPERV_REENLIGHTENMENT_VECTOR, system_vectors)) {
+		seq_printf(p, "%*s: ", prec, "HRE");
+		for_each_online_cpu(j)
+			seq_printf(p, "%10u ",
+				   irq_stats(j)->irq_hv_reenlightenment_count);
+		seq_puts(p, "  Hyper-V reenlightenment interrupts\n");
+	}
 #endif
 	seq_printf(p, "%*s: %10u\n", prec, "ERR", atomic_read(&irq_err_count));
 #if defined(CONFIG_X86_IO_APIC)
-- 
2.14.3