summaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/mshyperv.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-09-02 03:25:20 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2021-09-02 03:25:20 +0200
commitc07f191907e7d7e04034a2b9657a6bbf1355c60a (patch)
tree93940e9c54eeb8121f7bce5e89e652ec7bc6c6f7 /arch/x86/kernel/cpu/mshyperv.c
parentMerge tag 'dt-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc (diff)
parenthv_utils: Set the maximum packet size for VSS driver to the length of the rec... (diff)
downloadlinux-c07f191907e7d7e04034a2b9657a6bbf1355c60a.tar.xz
linux-c07f191907e7d7e04034a2b9657a6bbf1355c60a.zip
Merge tag 'hyperv-next-signed-20210831' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu: - make Hyper-V code arch-agnostic (Michael Kelley) - fix sched_clock behaviour on Hyper-V (Ani Sinha) - fix a fault when Linux runs as the root partition on MSHV (Praveen Kumar) - fix VSS driver (Vitaly Kuznetsov) - cleanup (Sonia Sharma) * tag 'hyperv-next-signed-20210831' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: hv_utils: Set the maximum packet size for VSS driver to the length of the receive buffer Drivers: hv: Enable Hyper-V code to be built on ARM64 arm64: efi: Export screen_info arm64: hyperv: Initialize hypervisor on boot arm64: hyperv: Add panic handler arm64: hyperv: Add Hyper-V hypercall and register access utilities x86/hyperv: fix root partition faults when writing to VP assist page MSR hv: hyperv.h: Remove unused inline functions drivers: hv: Decouple Hyper-V clock/timer code from VMbus drivers x86/hyperv: add comment describing TSC_INVARIANT_CONTROL MSR setting bit 0 Drivers: hv: Move Hyper-V misc functionality to arch-neutral code Drivers: hv: Add arch independent default functions for some Hyper-V handlers Drivers: hv: Make portions of Hyper-V init code be arch neutral x86/hyperv: fix for unwanted manipulation of sched_clock when TSC marked unstable asm-generic/hyperv: Add missing #include of nmi.h
Diffstat (limited to 'arch/x86/kernel/cpu/mshyperv.c')
-rw-r--r--arch/x86/kernel/cpu/mshyperv.c38
1 files changed, 16 insertions, 22 deletions
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index c890d67a64ad..e095c28d27ae 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -17,7 +17,6 @@
#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/i8253.h>
-#include <linux/panic_notifier.h>
#include <linux/random.h>
#include <asm/processor.h>
#include <asm/hypervisor.h>
@@ -36,10 +35,7 @@
/* Is Linux running as the root partition? */
bool hv_root_partition;
-EXPORT_SYMBOL_GPL(hv_root_partition);
-
struct ms_hyperv_info ms_hyperv;
-EXPORT_SYMBOL_GPL(ms_hyperv);
#if IS_ENABLED(CONFIG_HYPERV)
static void (*vmbus_handler)(void);
@@ -65,14 +61,12 @@ void hv_setup_vmbus_handler(void (*handler)(void))
{
vmbus_handler = handler;
}
-EXPORT_SYMBOL_GPL(hv_setup_vmbus_handler);
void hv_remove_vmbus_handler(void)
{
/* We have no way to deallocate the interrupt gate */
vmbus_handler = NULL;
}
-EXPORT_SYMBOL_GPL(hv_remove_vmbus_handler);
/*
* Routines to do per-architecture handling of stimer0
@@ -107,25 +101,21 @@ void hv_setup_kexec_handler(void (*handler)(void))
{
hv_kexec_handler = handler;
}
-EXPORT_SYMBOL_GPL(hv_setup_kexec_handler);
void hv_remove_kexec_handler(void)
{
hv_kexec_handler = NULL;
}
-EXPORT_SYMBOL_GPL(hv_remove_kexec_handler);
void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs))
{
hv_crash_handler = handler;
}
-EXPORT_SYMBOL_GPL(hv_setup_crash_handler);
void hv_remove_crash_handler(void)
{
hv_crash_handler = NULL;
}
-EXPORT_SYMBOL_GPL(hv_remove_crash_handler);
#ifdef CONFIG_KEXEC_CORE
static void hv_machine_shutdown(void)
@@ -335,16 +325,6 @@ static void __init ms_hyperv_init_platform(void)
ms_hyperv.nested_features);
}
- /*
- * Hyper-V expects to get crash register data or kmsg when
- * crash enlightment is available and system crashes. Set
- * crash_kexec_post_notifiers to be true to make sure that
- * calling crash enlightment interface before running kdump
- * kernel.
- */
- if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
- crash_kexec_post_notifiers = true;
-
#ifdef CONFIG_X86_LOCAL_APIC
if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
@@ -373,10 +353,17 @@ static void __init ms_hyperv_init_platform(void)
machine_ops.crash_shutdown = hv_machine_crash_shutdown;
#endif
if (ms_hyperv.features & HV_ACCESS_TSC_INVARIANT) {
+ /*
+ * Writing to synthetic MSR 0x40000118 updates/changes the
+ * guest visible CPUIDs. Setting bit 0 of this MSR enables
+ * guests to report invariant TSC feature through CPUID
+ * instruction, CPUID 0x800000007/EDX, bit 8. See code in
+ * early_init_intel() where this bit is examined. The
+ * setting of this MSR bit should happen before init_intel()
+ * is called.
+ */
wrmsrl(HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x1);
setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);
- } else {
- mark_tsc_unstable("running on Hyper-V");
}
/*
@@ -437,6 +424,13 @@ static void __init ms_hyperv_init_platform(void)
/* Register Hyper-V specific clocksource */
hv_init_clocksource();
#endif
+ /*
+ * TSC should be marked as unstable only after Hyper-V
+ * clocksource has been initialized. This ensures that the
+ * stability of the sched_clock is not altered.
+ */
+ if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
+ mark_tsc_unstable("running on Hyper-V");
}
static bool __init ms_hyperv_x2apic_available(void)