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authorVitaly Kuznetsov <vkuznets@redhat.com>2018-01-24 14:23:33 +0100
committerThomas Gleixner <tglx@linutronix.de>2018-01-30 23:55:32 +0100
commit93286261de1b46339aa27cd4c639b21778f6cade (patch)
treeef94c61bab5e38bb42aee854d7babc4ece8c7de5 /arch/x86/include/uapi
parentx86/hyperv: Add a function to read both TSC and TSC page value simulateneously (diff)
downloadlinux-93286261de1b46339aa27cd4c639b21778f6cade.tar.xz
linux-93286261de1b46339aa27cd4c639b21778f6cade.zip
x86/hyperv: Reenlightenment notifications support
Hyper-V supports Live Migration notification. This is supposed to be used in conjunction with TSC emulation: when a VM is migrated to a host with different TSC frequency for some short period the host emulates the accesses to TSC and sends an interrupt to notify about the event. When the guest is done updating everything it can disable TSC emulation and everything will start working fast again. These notifications weren't required until now as Hyper-V guests are not supposed to use TSC as a clocksource: in Linux the TSC is even marked as unstable on boot. Guests normally use 'tsc page' clocksource and host updates its values on migrations automatically. Things change when with nested virtualization: even when the PV clocksources (kvm-clock or tsc page) are passed through to the nested guests the TSC frequency and frequency changes need to be know.. Hyper-V Top Level Functional Specification (as of v5.0b) wrongly specifies EAX:BIT(12) of CPUID:0x40000009 as the feature identification bit. The right one to check is EAX:BIT(13) of CPUID:0x40000003. I was assured that the fix in on the way. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Stephen Hemminger <sthemmin@microsoft.com> Cc: kvm@vger.kernel.org Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: "Michael Kelley (EOSG)" <Michael.H.Kelley@microsoft.com> Cc: Roman Kagan <rkagan@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: devel@linuxdriverproject.org Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Cathy Avery <cavery@redhat.com> Cc: Mohammed Gamal <mmorsy@redhat.com> Link: https://lkml.kernel.org/r/20180124132337.30138-4-vkuznets@redhat.com
Diffstat (limited to 'arch/x86/include/uapi')
-rw-r--r--arch/x86/include/uapi/asm/hyperv.h27
1 files changed, 27 insertions, 0 deletions
diff --git a/arch/x86/include/uapi/asm/hyperv.h b/arch/x86/include/uapi/asm/hyperv.h
index 1a5bfead93b4..197c2e6c7376 100644
--- a/arch/x86/include/uapi/asm/hyperv.h
+++ b/arch/x86/include/uapi/asm/hyperv.h
@@ -40,6 +40,9 @@
*/
#define HV_X64_ACCESS_FREQUENCY_MSRS (1 << 11)
+/* AccessReenlightenmentControls privilege */
+#define HV_X64_ACCESS_REENLIGHTENMENT BIT(13)
+
/*
* Basic SynIC MSRs (HV_X64_MSR_SCONTROL through HV_X64_MSR_EOM
* and HV_X64_MSR_SINT0 through HV_X64_MSR_SINT15) available
@@ -234,6 +237,30 @@
#define HV_X64_MSR_CRASH_PARAMS \
(1 + (HV_X64_MSR_CRASH_P4 - HV_X64_MSR_CRASH_P0))
+/* TSC emulation after migration */
+#define HV_X64_MSR_REENLIGHTENMENT_CONTROL 0x40000106
+
+struct hv_reenlightenment_control {
+ u64 vector:8;
+ u64 reserved1:8;
+ u64 enabled:1;
+ u64 reserved2:15;
+ u64 target_vp:32;
+};
+
+#define HV_X64_MSR_TSC_EMULATION_CONTROL 0x40000107
+#define HV_X64_MSR_TSC_EMULATION_STATUS 0x40000108
+
+struct hv_tsc_emulation_control {
+ u64 enabled:1;
+ u64 reserved:63;
+};
+
+struct hv_tsc_emulation_status {
+ u64 inprogress:1;
+ u64 reserved:63;
+};
+
#define HV_X64_MSR_HYPERCALL_ENABLE 0x00000001
#define HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_SHIFT 12
#define HV_X64_MSR_HYPERCALL_PAGE_ADDRESS_MASK \