Merge tag 'hyperv-fixes-signed-20240908' of...

Merge tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux

Pull hyperv fixes from Wei Liu:

 - Add a documentation overview of Confidential Computing VM support
   (Michael Kelley)

 - Use lapic timer in a TDX VM without paravisor (Dexuan Cui)

 - Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
   (Michael Kelley)

 - Fix a kexec crash due to VP assist page corruption (Anirudh
   Rayabharam)

 - Python3 compatibility fix for lsvmbus (Anthony Nandaa)

 - Misc fixes (Rachel Menge, Roman Kisel, zhang jiao, Hongbo Li)

* tag 'hyperv-fixes-signed-20240908' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux:
  hv: vmbus: Constify struct kobj_type and struct attribute_group
  tools: hv: rm .*.cmd when make clean
  x86/hyperv: fix kexec crash due to VP assist page corruption
  Drivers: hv: vmbus: Fix the misplaced function description
  tools: hv: lsvmbus: change shebang to use python3
  x86/hyperv: Set X86_FEATURE_TSC_KNOWN_FREQ when Hyper-V provides frequency
  Documentation: hyperv: Add overview of Confidential Computing VM support
  clocksource: hyper-v: Use lapic timer in a TDX VM without paravisor
  Drivers: hv: Remove deprecated hv_fcopy declarations

Documentation/virt/hyperv/index.rst

@@ -11,3 +11,4 @@ Hyper-V Enlightenments
    vmbus
    clocks
    vpci
+   coco

arch/x86/hyperv/hv_init.c

@@ -35,7 +35,6 @@
 #include <clocksource/hyperv_timer.h>
 #include <linux/highmem.h>
 
-int hyperv_init_cpuhp;
 u64 hv_current_partition_id = ~0ull;
 EXPORT_SYMBOL_GPL(hv_current_partition_id);
 
@@ -607,8 +606,6 @@ void __init hyperv_init(void)
 
 	register_syscore_ops(&hv_syscore_ops);
 
-	hyperv_init_cpuhp = cpuhp;
-
 	if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID)
 		hv_get_partition_id();
 
@@ -637,7 +634,7 @@ void __init hyperv_init(void)
 clean_guest_os_id:
 	wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
 	hv_ivm_msr_write(HV_X64_MSR_GUEST_OS_ID, 0);
-	cpuhp_remove_state(cpuhp);
+	cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE);
 free_ghcb_page:
 	free_percpu(hv_ghcb_pg);
 free_vp_assist_page:

arch/x86/include/asm/mshyperv.h

@@ -40,7 +40,6 @@ static inline unsigned char hv_get_nmi_reason(void)
 }
 
 #if IS_ENABLED(CONFIG_HYPERV)
-extern int hyperv_init_cpuhp;
 extern bool hyperv_paravisor_present;
 
 extern void *hv_hypercall_pg;

arch/x86/kernel/cpu/mshyperv.c

@@ -199,8 +199,8 @@ static void hv_machine_shutdown(void)
 	 * Call hv_cpu_die() on all the CPUs, otherwise later the hypervisor
 	 * corrupts the old VP Assist Pages and can crash the kexec kernel.
 	 */
-	if (kexec_in_progress && hyperv_init_cpuhp > 0)
-		cpuhp_remove_state(hyperv_init_cpuhp);
+	if (kexec_in_progress)
+		cpuhp_remove_state(CPUHP_AP_HYPERV_ONLINE);
 
 	/* The function calls stop_other_cpus(). */
 	native_machine_shutdown();
@@ -424,6 +424,7 @@ static void __init ms_hyperv_init_platform(void)
 	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
 		x86_platform.calibrate_tsc = hv_get_tsc_khz;
 		x86_platform.calibrate_cpu = hv_get_tsc_khz;
+		setup_force_cpu_cap(X86_FEATURE_TSC_KNOWN_FREQ);
 	}
 
 	if (ms_hyperv.priv_high & HV_ISOLATION) {
@@ -449,9 +450,23 @@ static void __init ms_hyperv_init_platform(void)
 			ms_hyperv.hints &= ~HV_X64_APIC_ACCESS_RECOMMENDED;
 
 			if (!ms_hyperv.paravisor_present) {
-				/* To be supported: more work is required.  */
+				/*
+				 * Mark the Hyper-V TSC page feature as disabled
+				 * in a TDX VM without paravisor so that the
+				 * Invariant TSC, which is a better clocksource
+				 * anyway, is used instead.
+				 */
 				ms_hyperv.features &= ~HV_MSR_REFERENCE_TSC_AVAILABLE;
 
+				/*
+				 * The Invariant TSC is expected to be available
+				 * in a TDX VM without paravisor, but if not,
+				 * print a warning message. The slower Hyper-V MSR-based
+				 * Ref Counter should end up being the clocksource.
+				 */
+				if (!(ms_hyperv.features & HV_ACCESS_TSC_INVARIANT))
+					pr_warn("Hyper-V: Invariant TSC is unavailable\n");
+
 				/* HV_MSR_CRASH_CTL is unsupported. */
 				ms_hyperv.misc_features &= ~HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE;
 

drivers/clocksource/hyperv_timer.c

@@ -137,7 +137,21 @@ static int hv_stimer_init(unsigned int cpu)
 	ce->name = "Hyper-V clockevent";
 	ce->features = CLOCK_EVT_FEAT_ONESHOT;
 	ce->cpumask = cpumask_of(cpu);
-	ce->rating = 1000;
+
+	/*
+	 * Lower the rating of the Hyper-V timer in a TDX VM without paravisor,
+	 * so the local APIC timer (lapic_clockevent) is the default timer in
+	 * such a VM. The Hyper-V timer is not preferred in such a VM because
+	 * it depends on the slow VM Reference Counter MSR (the Hyper-V TSC
+	 * page is not enbled in such a VM because the VM uses Invariant TSC
+	 * as a better clocksource and it's challenging to mark the Hyper-V
+	 * TSC page shared in very early boot).
+	 */
+	if (!ms_hyperv.paravisor_present && hv_isolation_type_tdx())
+		ce->rating = 90;
+	else
+		ce->rating = 1000;
+
 	ce->set_state_shutdown = hv_ce_shutdown;
 	ce->set_state_oneshot = hv_ce_set_oneshot;
 	ce->set_next_event = hv_ce_set_next_event;

drivers/hv/hv.c

@@ -342,9 +342,6 @@ int hv_synic_init(unsigned int cpu)
 	return 0;
 }
 
-/*
- * hv_synic_cleanup - Cleanup routine for hv_synic_init().
- */
 void hv_synic_disable_regs(unsigned int cpu)
 {
 	struct hv_per_cpu_context *hv_cpu =
@@ -436,6 +433,9 @@ static bool hv_synic_event_pending(void)
 	return pending;
 }
 
+/*
+ * hv_synic_cleanup - Cleanup routine for hv_synic_init().
+ */
 int hv_synic_cleanup(unsigned int cpu)
 {
 	struct vmbus_channel *channel, *sc;

drivers/hv/hyperv_vmbus.h

@@ -380,12 +380,6 @@ void hv_vss_deinit(void);
 int hv_vss_pre_suspend(void);
 int hv_vss_pre_resume(void);
 void hv_vss_onchannelcallback(void *context);
-
-int hv_fcopy_init(struct hv_util_service *srv);
-void hv_fcopy_deinit(void);
-int hv_fcopy_pre_suspend(void);
-int hv_fcopy_pre_resume(void);
-void hv_fcopy_onchannelcallback(void *context);
 void vmbus_initiate_unload(bool crash);
 
 static inline void hv_poll_channel(struct vmbus_channel *channel,

drivers/hv/vmbus_drv.c

@@ -1803,12 +1803,12 @@ static umode_t vmbus_chan_attr_is_visible(struct kobject *kobj,
 	return attr->mode;
 }
 
-static struct attribute_group vmbus_chan_group = {
+static const struct attribute_group vmbus_chan_group = {
 	.attrs = vmbus_chan_attrs,
 	.is_visible = vmbus_chan_attr_is_visible
 };
 
-static struct kobj_type vmbus_chan_ktype = {
+static const struct kobj_type vmbus_chan_ktype = {
 	.sysfs_ops = &vmbus_chan_sysfs_ops,
 	.release = vmbus_chan_release,
 };

tools/hv/Makefile

@@ -52,7 +52,7 @@ $(OUTPUT)hv_fcopy_uio_daemon: $(HV_FCOPY_UIO_DAEMON_IN)
 
 clean:
 	rm -f $(ALL_PROGRAMS)
-	find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete
+	find $(or $(OUTPUT),.) -name '*.o' -delete -o -name '\.*.d' -delete -o -name '\.*.cmd' -delete
 
 install: $(ALL_PROGRAMS)
 	install -d -m 755 $(DESTDIR)$(sbindir); \

tools/hv/lsvmbus

-#!/usr/bin/env python
+#!/usr/bin/env python3
 # SPDX-License-Identifier: GPL-2.0
 
 import os