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 for Android: free password hash cracker in your pocket
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:	Sun, 19 Feb 2012 21:22:55 -0500
From:	Eric B Munson <emunson@...bm.net>
To:	avi@...hat.com
Cc:	Eric B Munson <emunson@...bm.net>, mingo@...hat.com, hpa@...or.com,
	ryanh@...ux.vnet.ibm.com, aliguori@...ibm.com, mtosatti@...hat.com,
	kvm@...r.kernel.org, linux-arch@...r.kernel.org, x86@...nel.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH 2/4 V15] Add functions to check if the host has stopped the vm

When a host stops or suspends a VM it will set a flag to show this.  The
watchdog will use these functions to determine if a softlockup is real, or the
result of a suspended VM.

Signed-off-by: Eric B Munson <emunson@...bm.net>
asm-generic changes Acked-by: Arnd Bergmann <arnd@...db.de>
Cc: mingo@...hat.com
Cc: hpa@...or.com
Cc: ryanh@...ux.vnet.ibm.com
Cc: aliguori@...ibm.com
Cc: mtosatti@...hat.com
Cc: kvm@...r.kernel.org
Cc: linux-arch@...r.kernel.org
Cc: x86@...nel.org
Cc: linux-kernel@...r.kernel.org
---
Changes from V11:
 Re-add the missing asm-generic stub for check_and_clear_guest_stopped()
Changes from V6:
 Use __this_cpu_and when clearing the PVCLOCK_GUEST_STOPPED flag
Changes from V5:
 Collapse generic stubs into this patch
 check_and_clear_guest_stopped() takes no args and uses __get_cpu_var()
 Include individual definitions in ia64, s390, and powerpc

 arch/ia64/include/asm/kvm_para.h    |    5 +++++
 arch/powerpc/include/asm/kvm_para.h |    5 +++++
 arch/s390/include/asm/kvm_para.h    |    5 +++++
 arch/x86/include/asm/kvm_para.h     |    8 ++++++++
 arch/x86/kernel/kvmclock.c          |   21 +++++++++++++++++++++
 include/asm-generic/kvm_para.h      |   14 ++++++++++++++
 6 files changed, 58 insertions(+), 0 deletions(-)
 create mode 100644 include/asm-generic/kvm_para.h

diff --git a/arch/ia64/include/asm/kvm_para.h b/arch/ia64/include/asm/kvm_para.h
index 1588aee..2019cb9 100644
--- a/arch/ia64/include/asm/kvm_para.h
+++ b/arch/ia64/include/asm/kvm_para.h
@@ -26,6 +26,11 @@ static inline unsigned int kvm_arch_para_features(void)
 	return 0;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+	return false;
+}
+
 #endif
 
 #endif
diff --git a/arch/powerpc/include/asm/kvm_para.h b/arch/powerpc/include/asm/kvm_para.h
index 7b754e7..c18916b 100644
--- a/arch/powerpc/include/asm/kvm_para.h
+++ b/arch/powerpc/include/asm/kvm_para.h
@@ -206,6 +206,11 @@ static inline unsigned int kvm_arch_para_features(void)
 	return r;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+	return false;
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* __POWERPC_KVM_PARA_H__ */
diff --git a/arch/s390/include/asm/kvm_para.h b/arch/s390/include/asm/kvm_para.h
index 6964db2..a988329 100644
--- a/arch/s390/include/asm/kvm_para.h
+++ b/arch/s390/include/asm/kvm_para.h
@@ -149,6 +149,11 @@ static inline unsigned int kvm_arch_para_features(void)
 	return 0;
 }
 
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+	return false;
+}
+
 #endif
 
 #endif /* __S390_KVM_PARA_H */
diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h
index 734c376..99c4bbe 100644
--- a/arch/x86/include/asm/kvm_para.h
+++ b/arch/x86/include/asm/kvm_para.h
@@ -95,6 +95,14 @@ struct kvm_vcpu_pv_apf_data {
 extern void kvmclock_init(void);
 extern int kvm_register_clock(char *txt);
 
+#ifdef CONFIG_KVM_CLOCK
+bool kvm_check_and_clear_guest_paused(void);
+#else
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+	return false;
+}
+#endif /* CONFIG_KVMCLOCK */
 
 /* This instruction is vmcall.  On non-VT architectures, it will generate a
  * trap that we will then rewrite to the appropriate instruction.
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index ca4e735..8562f77 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -22,6 +22,7 @@
 #include <asm/msr.h>
 #include <asm/apic.h>
 #include <linux/percpu.h>
+#include <linux/hardirq.h>
 
 #include <asm/x86_init.h>
 #include <asm/reboot.h>
@@ -114,6 +115,26 @@ static void kvm_get_preset_lpj(void)
 	preset_lpj = lpj;
 }
 
+bool kvm_check_and_clear_guest_paused(void)
+{
+	bool ret = false;
+	struct pvclock_vcpu_time_info *src;
+
+	/*
+	 * per_cpu() is safe here because this function is only called from
+	 * timer functions where preemption is already disabled.
+	 */
+	WARN_ON(!in_atomic());
+	src = &__get_cpu_var(hv_clock);
+	if ((src->flags & PVCLOCK_GUEST_STOPPED) != 0) {
+		__this_cpu_and(hv_clock.flags, ~PVCLOCK_GUEST_STOPPED);
+		ret = true;
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(kvm_check_and_clear_guest_paused);
+
 static struct clocksource kvm_clock = {
 	.name = "kvm-clock",
 	.read = kvm_clock_get_cycles,
diff --git a/include/asm-generic/kvm_para.h b/include/asm-generic/kvm_para.h
new file mode 100644
index 0000000..05ef7e7
--- /dev/null
+++ b/include/asm-generic/kvm_para.h
@@ -0,0 +1,14 @@
+#ifndef _ASM_GENERIC_KVM_PARA_H
+#define _ASM_GENERIC_KVM_PARA_H
+
+
+/*
+ * This function is used by architectures that support kvm to avoid issuing
+ * false soft lockup messages.
+ */
+static inline bool kvm_check_and_clear_guest_paused(void)
+{
+	return false;
+}
+
+#endif
-- 
1.7.5.4

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists