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authorLinus Torvalds <torvalds@linux-foundation.org>2008-06-24 18:09:06 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-06-24 18:09:06 -0700
commit919c0d14ae93073a3957c018a6d86ceb1e2e454b (patch)
treeb654cfcee21adaf4842447e4fe21f74aa956bcca /include/asm-x86/pvclock-abi.h
parentde08341a0ef747d607542af3ae441b286f503e35 (diff)
parent6b1ed9086592fd4b066daae222751bb6757ca5eb (diff)
Merge branch 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
* 'kvm-updates-2.6.26' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: KVM: Remove now unused structs from kvm_para.h x86: KVM guest: Use the paravirt clocksource structs and functions KVM: Make kvm host use the paravirt clocksource structs x86: Make xen use the paravirt clocksource structs and functions x86: Add structs and functions for paravirt clocksource KVM: VMX: Fix host msr corruption with preemption enabled KVM: ioapic: fix lost interrupt when changing a device's irq KVM: MMU: Fix oops on guest userspace access to guest pagetable KVM: MMU: large page update_pte issue with non-PAE 32-bit guests (resend) KVM: MMU: Fix rmap_write_protect() hugepage iteration bug KVM: close timer injection race window in __vcpu_run KVM: Fix race between timer migration and vcpu migration
Diffstat (limited to 'include/asm-x86/pvclock-abi.h')
-rw-r--r--include/asm-x86/pvclock-abi.h42
1 files changed, 42 insertions, 0 deletions
diff --git a/include/asm-x86/pvclock-abi.h b/include/asm-x86/pvclock-abi.h
new file mode 100644
index 000000000000..6857f840b243
--- /dev/null
+++ b/include/asm-x86/pvclock-abi.h
@@ -0,0 +1,42 @@
+#ifndef _ASM_X86_PVCLOCK_ABI_H_
+#define _ASM_X86_PVCLOCK_ABI_H_
+#ifndef __ASSEMBLY__
+
+/*
+ * These structs MUST NOT be changed.
+ * They are the ABI between hypervisor and guest OS.
+ * Both Xen and KVM are using this.
+ *
+ * pvclock_vcpu_time_info holds the system time and the tsc timestamp
+ * of the last update. So the guest can use the tsc delta to get a
+ * more precise system time. There is one per virtual cpu.
+ *
+ * pvclock_wall_clock references the point in time when the system
+ * time was zero (usually boot time), thus the guest calculates the
+ * current wall clock by adding the system time.
+ *
+ * Protocol for the "version" fields is: hypervisor raises it (making
+ * it uneven) before it starts updating the fields and raises it again
+ * (making it even) when it is done. Thus the guest can make sure the
+ * time values it got are consistent by checking the version before
+ * and after reading them.
+ */
+
+struct pvclock_vcpu_time_info {
+ u32 version;
+ u32 pad0;
+ u64 tsc_timestamp;
+ u64 system_time;
+ u32 tsc_to_system_mul;
+ s8 tsc_shift;
+ u8 pad[3];
+} __attribute__((__packed__)); /* 32 bytes */
+
+struct pvclock_wall_clock {
+ u32 version;
+ u32 sec;
+ u32 nsec;
+} __attribute__((__packed__));
+
+#endif /* __ASSEMBLY__ */
+#endif /* _ASM_X86_PVCLOCK_ABI_H_ */