[PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics

Nuno Das Neves posted 3 patches 1 week, 3 days ago
[PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
Posted by Nuno Das Neves 1 week, 3 days ago
Introduce a debugfs interface to expose root and child partition stats
when running with mshv_root.

Create a debugfs directory "mshv" containing 'stats' files organized by
type and id. A stats file contains a number of counters depending on
its type. e.g. an excerpt from a VP stats file:

TotalRunTime                  : 1997602722
HypervisorRunTime             : 649671371
RemoteNodeRunTime             : 0
NormalizedRunTime             : 1997602721
IdealCpu                      : 0
HypercallsCount               : 1708169
HypercallsTime                : 111914774
PageInvalidationsCount        : 0
PageInvalidationsTime         : 0

On a root partition with some active child partitions, the entire
directory structure may look like:

mshv/
  stats             # hypervisor stats
  lp/               # logical processors
    0/              # LP id
      stats         # LP 0 stats
    1/
    2/
    3/
  partition/        # partition stats
    1/              # root partition id
      stats         # root partition stats
      vp/           # root virtual processors
        0/          # root VP id
          stats     # root VP 0 stats
        1/
        2/
        3/
    42/             # child partition id
      stats         # child partition stats
      vp/           # child VPs
        0/          # child VP id
          stats     # child VP 0 stats
        1/
    43/
    55/

On L1VH, some stats are not present as it does not own the hardware
like the root partition does:
- The hypervisor and lp stats are not present
- L1VH's partition directory is named "self" because it can't get its
  own id
- Some of L1VH's partition and VP stats fields are not populated, because
  it can't map its own HV_STATS_AREA_PARENT page.

Co-developed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Signed-off-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
Co-developed-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Signed-off-by: Praveen K Paladugu <prapal@linux.microsoft.com>
Co-developed-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Signed-off-by: Mukesh Rathor <mrathor@linux.microsoft.com>
Co-developed-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com>
Signed-off-by: Purna Pavan Chandra Aekkaladevi <paekkaladevi@linux.microsoft.com>
Co-developed-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Jinank Jain <jinankjain@microsoft.com>
Signed-off-by: Nuno Das Neves <nunodasneves@linux.microsoft.com>
Reviewed-by: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com>
---
 drivers/hv/Makefile         |    1 +
 drivers/hv/mshv_debugfs.c   | 1122 +++++++++++++++++++++++++++++++++++
 drivers/hv/mshv_root.h      |   34 ++
 drivers/hv/mshv_root_main.c |   32 +-
 4 files changed, 1185 insertions(+), 4 deletions(-)
 create mode 100644 drivers/hv/mshv_debugfs.c

diff --git a/drivers/hv/Makefile b/drivers/hv/Makefile
index 58b8d07639f3..36278c936914 100644
--- a/drivers/hv/Makefile
+++ b/drivers/hv/Makefile
@@ -15,6 +15,7 @@ hv_vmbus-$(CONFIG_HYPERV_TESTING)	+= hv_debugfs.o
 hv_utils-y := hv_util.o hv_kvp.o hv_snapshot.o hv_utils_transport.o
 mshv_root-y := mshv_root_main.o mshv_synic.o mshv_eventfd.o mshv_irq.o \
 	       mshv_root_hv_call.o mshv_portid_table.o
+mshv_root-$(CONFIG_DEBUG_FS) += mshv_debugfs.o
 mshv_vtl-y := mshv_vtl_main.o
 
 # Code that must be built-in
diff --git a/drivers/hv/mshv_debugfs.c b/drivers/hv/mshv_debugfs.c
new file mode 100644
index 000000000000..581018690a27
--- /dev/null
+++ b/drivers/hv/mshv_debugfs.c
@@ -0,0 +1,1122 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025, Microsoft Corporation.
+ *
+ * The /sys/kernel/debug/mshv directory contents.
+ * Contains various statistics data, provided by the hypervisor.
+ *
+ * Authors: Microsoft Linux virtualization team
+ */
+
+#include <linux/debugfs.h>
+#include <linux/stringify.h>
+#include <asm/mshyperv.h>
+#include <linux/slab.h>
+
+#include "mshv.h"
+#include "mshv_root.h"
+
+#define U32_BUF_SZ 11
+#define U64_BUF_SZ 21
+
+static struct dentry *mshv_debugfs;
+static struct dentry *mshv_debugfs_partition;
+static struct dentry *mshv_debugfs_lp;
+
+static u64 mshv_lps_count;
+
+static bool is_l1vh_parent(u64 partition_id)
+{
+	return hv_l1vh_partition() && (partition_id == HV_PARTITION_ID_SELF);
+}
+
+static int lp_stats_show(struct seq_file *m, void *v)
+{
+	const struct hv_stats_page *stats = m->private;
+
+#define LP_SEQ_PRINTF(cnt)		\
+	seq_printf(m, "%-29s: %llu\n", __stringify(cnt), stats->lp_cntrs[Lp##cnt])
+
+	LP_SEQ_PRINTF(GlobalTime);
+	LP_SEQ_PRINTF(TotalRunTime);
+	LP_SEQ_PRINTF(HypervisorRunTime);
+	LP_SEQ_PRINTF(HardwareInterrupts);
+	LP_SEQ_PRINTF(ContextSwitches);
+	LP_SEQ_PRINTF(InterProcessorInterrupts);
+	LP_SEQ_PRINTF(SchedulerInterrupts);
+	LP_SEQ_PRINTF(TimerInterrupts);
+	LP_SEQ_PRINTF(InterProcessorInterruptsSent);
+	LP_SEQ_PRINTF(ProcessorHalts);
+	LP_SEQ_PRINTF(MonitorTransitionCost);
+	LP_SEQ_PRINTF(ContextSwitchTime);
+	LP_SEQ_PRINTF(C1TransitionsCount);
+	LP_SEQ_PRINTF(C1RunTime);
+	LP_SEQ_PRINTF(C2TransitionsCount);
+	LP_SEQ_PRINTF(C2RunTime);
+	LP_SEQ_PRINTF(C3TransitionsCount);
+	LP_SEQ_PRINTF(C3RunTime);
+	LP_SEQ_PRINTF(RootVpIndex);
+	LP_SEQ_PRINTF(IdleSequenceNumber);
+	LP_SEQ_PRINTF(GlobalTscCount);
+	LP_SEQ_PRINTF(ActiveTscCount);
+	LP_SEQ_PRINTF(IdleAccumulation);
+	LP_SEQ_PRINTF(ReferenceCycleCount0);
+	LP_SEQ_PRINTF(ActualCycleCount0);
+	LP_SEQ_PRINTF(ReferenceCycleCount1);
+	LP_SEQ_PRINTF(ActualCycleCount1);
+	LP_SEQ_PRINTF(ProximityDomainId);
+	LP_SEQ_PRINTF(PostedInterruptNotifications);
+	LP_SEQ_PRINTF(BranchPredictorFlushes);
+#if IS_ENABLED(CONFIG_X86_64)
+	LP_SEQ_PRINTF(L1DataCacheFlushes);
+	LP_SEQ_PRINTF(ImmediateL1DataCacheFlushes);
+	LP_SEQ_PRINTF(MbFlushes);
+	LP_SEQ_PRINTF(CounterRefreshSequenceNumber);
+	LP_SEQ_PRINTF(CounterRefreshReferenceTime);
+	LP_SEQ_PRINTF(IdleAccumulationSnapshot);
+	LP_SEQ_PRINTF(ActiveTscCountSnapshot);
+	LP_SEQ_PRINTF(HwpRequestContextSwitches);
+	LP_SEQ_PRINTF(Placeholder1);
+	LP_SEQ_PRINTF(Placeholder2);
+	LP_SEQ_PRINTF(Placeholder3);
+	LP_SEQ_PRINTF(Placeholder4);
+	LP_SEQ_PRINTF(Placeholder5);
+	LP_SEQ_PRINTF(Placeholder6);
+	LP_SEQ_PRINTF(Placeholder7);
+	LP_SEQ_PRINTF(Placeholder8);
+	LP_SEQ_PRINTF(Placeholder9);
+	LP_SEQ_PRINTF(Placeholder10);
+	LP_SEQ_PRINTF(ReserveGroupId);
+	LP_SEQ_PRINTF(RunningPriority);
+	LP_SEQ_PRINTF(PerfmonInterruptCount);
+#elif IS_ENABLED(CONFIG_ARM64)
+	LP_SEQ_PRINTF(CounterRefreshSequenceNumber);
+	LP_SEQ_PRINTF(CounterRefreshReferenceTime);
+	LP_SEQ_PRINTF(IdleAccumulationSnapshot);
+	LP_SEQ_PRINTF(ActiveTscCountSnapshot);
+	LP_SEQ_PRINTF(HwpRequestContextSwitches);
+	LP_SEQ_PRINTF(Placeholder2);
+	LP_SEQ_PRINTF(Placeholder3);
+	LP_SEQ_PRINTF(Placeholder4);
+	LP_SEQ_PRINTF(Placeholder5);
+	LP_SEQ_PRINTF(Placeholder6);
+	LP_SEQ_PRINTF(Placeholder7);
+	LP_SEQ_PRINTF(Placeholder8);
+	LP_SEQ_PRINTF(Placeholder9);
+	LP_SEQ_PRINTF(SchLocalRunListSize);
+	LP_SEQ_PRINTF(ReserveGroupId);
+	LP_SEQ_PRINTF(RunningPriority);
+#endif
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(lp_stats);
+
+static void mshv_lp_stats_unmap(u32 lp_index, void *stats_page_addr)
+{
+	union hv_stats_object_identity identity = {
+		.lp.lp_index = lp_index,
+		.lp.stats_area_type = HV_STATS_AREA_SELF,
+	};
+	int err;
+
+	err = hv_unmap_stats_page(HV_STATS_OBJECT_LOGICAL_PROCESSOR,
+				  stats_page_addr, &identity);
+	if (err)
+		pr_err("%s: failed to unmap logical processor %u stats, err: %d\n",
+		       __func__, lp_index, err);
+}
+
+static void __init *mshv_lp_stats_map(u32 lp_index)
+{
+	union hv_stats_object_identity identity = {
+		.lp.lp_index = lp_index,
+		.lp.stats_area_type = HV_STATS_AREA_SELF,
+	};
+	void *stats;
+	int err;
+
+	err = hv_map_stats_page(HV_STATS_OBJECT_LOGICAL_PROCESSOR, &identity,
+				&stats);
+	if (err) {
+		pr_err("%s: failed to map logical processor %u stats, err: %d\n",
+		       __func__, lp_index, err);
+		return ERR_PTR(err);
+	}
+
+	return stats;
+}
+
+static void __init *lp_debugfs_stats_create(u32 lp_index, struct dentry *parent)
+{
+	struct dentry *dentry;
+	void *stats;
+
+	stats = mshv_lp_stats_map(lp_index);
+	if (IS_ERR(stats))
+		return stats;
+
+	dentry = debugfs_create_file("stats", 0400, parent,
+				     stats, &lp_stats_fops);
+	if (IS_ERR(dentry)) {
+		mshv_lp_stats_unmap(lp_index, stats);
+		return dentry;
+	}
+	return stats;
+}
+
+static int __init lp_debugfs_create(u32 lp_index, struct dentry *parent)
+{
+	struct dentry *idx;
+	char lp_idx_str[U32_BUF_SZ];
+	void *stats;
+	int err;
+
+	sprintf(lp_idx_str, "%u", lp_index);
+
+	idx = debugfs_create_dir(lp_idx_str, parent);
+	if (IS_ERR(idx))
+		return PTR_ERR(idx);
+
+	stats = lp_debugfs_stats_create(lp_index, idx);
+	if (IS_ERR(stats)) {
+		err = PTR_ERR(stats);
+		goto remove_debugfs_lp_idx;
+	}
+
+	return 0;
+
+remove_debugfs_lp_idx:
+	debugfs_remove_recursive(idx);
+	return err;
+}
+
+static void mshv_debugfs_lp_remove(void)
+{
+	int lp_index;
+
+	debugfs_remove_recursive(mshv_debugfs_lp);
+
+	for (lp_index = 0; lp_index < mshv_lps_count; lp_index++)
+		mshv_lp_stats_unmap(lp_index, NULL);
+}
+
+static int __init mshv_debugfs_lp_create(struct dentry *parent)
+{
+	struct dentry *lp_dir;
+	int err, lp_index;
+
+	lp_dir = debugfs_create_dir("lp", parent);
+	if (IS_ERR(lp_dir))
+		return PTR_ERR(lp_dir);
+
+	for (lp_index = 0; lp_index < mshv_lps_count; lp_index++) {
+		err = lp_debugfs_create(lp_index, lp_dir);
+		if (err)
+			goto remove_debugfs_lps;
+	}
+
+	mshv_debugfs_lp = lp_dir;
+
+	return 0;
+
+remove_debugfs_lps:
+	for (lp_index -= 1; lp_index >= 0; lp_index--)
+		mshv_lp_stats_unmap(lp_index, NULL);
+	debugfs_remove_recursive(lp_dir);
+	return err;
+}
+
+static int vp_stats_show(struct seq_file *m, void *v)
+{
+	const struct hv_stats_page **pstats = m->private;
+
+#define VP_SEQ_PRINTF(cnt)				 \
+do {								 \
+	if (pstats[HV_STATS_AREA_SELF]->vp_cntrs[Vp##cnt]) \
+		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
+			pstats[HV_STATS_AREA_SELF]->vp_cntrs[Vp##cnt]); \
+	else \
+		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
+			pstats[HV_STATS_AREA_PARENT]->vp_cntrs[Vp##cnt]); \
+} while (0)
+
+	VP_SEQ_PRINTF(TotalRunTime);
+	VP_SEQ_PRINTF(HypervisorRunTime);
+	VP_SEQ_PRINTF(RemoteNodeRunTime);
+	VP_SEQ_PRINTF(NormalizedRunTime);
+	VP_SEQ_PRINTF(IdealCpu);
+	VP_SEQ_PRINTF(HypercallsCount);
+	VP_SEQ_PRINTF(HypercallsTime);
+#if IS_ENABLED(CONFIG_X86_64)
+	VP_SEQ_PRINTF(PageInvalidationsCount);
+	VP_SEQ_PRINTF(PageInvalidationsTime);
+	VP_SEQ_PRINTF(ControlRegisterAccessesCount);
+	VP_SEQ_PRINTF(ControlRegisterAccessesTime);
+	VP_SEQ_PRINTF(IoInstructionsCount);
+	VP_SEQ_PRINTF(IoInstructionsTime);
+	VP_SEQ_PRINTF(HltInstructionsCount);
+	VP_SEQ_PRINTF(HltInstructionsTime);
+	VP_SEQ_PRINTF(MwaitInstructionsCount);
+	VP_SEQ_PRINTF(MwaitInstructionsTime);
+	VP_SEQ_PRINTF(CpuidInstructionsCount);
+	VP_SEQ_PRINTF(CpuidInstructionsTime);
+	VP_SEQ_PRINTF(MsrAccessesCount);
+	VP_SEQ_PRINTF(MsrAccessesTime);
+	VP_SEQ_PRINTF(OtherInterceptsCount);
+	VP_SEQ_PRINTF(OtherInterceptsTime);
+	VP_SEQ_PRINTF(ExternalInterruptsCount);
+	VP_SEQ_PRINTF(ExternalInterruptsTime);
+	VP_SEQ_PRINTF(PendingInterruptsCount);
+	VP_SEQ_PRINTF(PendingInterruptsTime);
+	VP_SEQ_PRINTF(EmulatedInstructionsCount);
+	VP_SEQ_PRINTF(EmulatedInstructionsTime);
+	VP_SEQ_PRINTF(DebugRegisterAccessesCount);
+	VP_SEQ_PRINTF(DebugRegisterAccessesTime);
+	VP_SEQ_PRINTF(PageFaultInterceptsCount);
+	VP_SEQ_PRINTF(PageFaultInterceptsTime);
+	VP_SEQ_PRINTF(GuestPageTableMaps);
+	VP_SEQ_PRINTF(LargePageTlbFills);
+	VP_SEQ_PRINTF(SmallPageTlbFills);
+	VP_SEQ_PRINTF(ReflectedGuestPageFaults);
+	VP_SEQ_PRINTF(ApicMmioAccesses);
+	VP_SEQ_PRINTF(IoInterceptMessages);
+	VP_SEQ_PRINTF(MemoryInterceptMessages);
+	VP_SEQ_PRINTF(ApicEoiAccesses);
+	VP_SEQ_PRINTF(OtherMessages);
+	VP_SEQ_PRINTF(PageTableAllocations);
+	VP_SEQ_PRINTF(LogicalProcessorMigrations);
+	VP_SEQ_PRINTF(AddressSpaceEvictions);
+	VP_SEQ_PRINTF(AddressSpaceSwitches);
+	VP_SEQ_PRINTF(AddressDomainFlushes);
+	VP_SEQ_PRINTF(AddressSpaceFlushes);
+	VP_SEQ_PRINTF(GlobalGvaRangeFlushes);
+	VP_SEQ_PRINTF(LocalGvaRangeFlushes);
+	VP_SEQ_PRINTF(PageTableEvictions);
+	VP_SEQ_PRINTF(PageTableReclamations);
+	VP_SEQ_PRINTF(PageTableResets);
+	VP_SEQ_PRINTF(PageTableValidations);
+	VP_SEQ_PRINTF(ApicTprAccesses);
+	VP_SEQ_PRINTF(PageTableWriteIntercepts);
+	VP_SEQ_PRINTF(SyntheticInterrupts);
+	VP_SEQ_PRINTF(VirtualInterrupts);
+	VP_SEQ_PRINTF(ApicIpisSent);
+	VP_SEQ_PRINTF(ApicSelfIpisSent);
+	VP_SEQ_PRINTF(GpaSpaceHypercalls);
+	VP_SEQ_PRINTF(LogicalProcessorHypercalls);
+	VP_SEQ_PRINTF(LongSpinWaitHypercalls);
+	VP_SEQ_PRINTF(OtherHypercalls);
+	VP_SEQ_PRINTF(SyntheticInterruptHypercalls);
+	VP_SEQ_PRINTF(VirtualInterruptHypercalls);
+	VP_SEQ_PRINTF(VirtualMmuHypercalls);
+	VP_SEQ_PRINTF(VirtualProcessorHypercalls);
+	VP_SEQ_PRINTF(HardwareInterrupts);
+	VP_SEQ_PRINTF(NestedPageFaultInterceptsCount);
+	VP_SEQ_PRINTF(NestedPageFaultInterceptsTime);
+	VP_SEQ_PRINTF(PageScans);
+	VP_SEQ_PRINTF(LogicalProcessorDispatches);
+	VP_SEQ_PRINTF(WaitingForCpuTime);
+	VP_SEQ_PRINTF(ExtendedHypercalls);
+	VP_SEQ_PRINTF(ExtendedHypercallInterceptMessages);
+	VP_SEQ_PRINTF(MbecNestedPageTableSwitches);
+	VP_SEQ_PRINTF(OtherReflectedGuestExceptions);
+	VP_SEQ_PRINTF(GlobalIoTlbFlushes);
+	VP_SEQ_PRINTF(GlobalIoTlbFlushCost);
+	VP_SEQ_PRINTF(LocalIoTlbFlushes);
+	VP_SEQ_PRINTF(LocalIoTlbFlushCost);
+	VP_SEQ_PRINTF(HypercallsForwardedCount);
+	VP_SEQ_PRINTF(HypercallsForwardingTime);
+	VP_SEQ_PRINTF(PageInvalidationsForwardedCount);
+	VP_SEQ_PRINTF(PageInvalidationsForwardingTime);
+	VP_SEQ_PRINTF(ControlRegisterAccessesForwardedCount);
+	VP_SEQ_PRINTF(ControlRegisterAccessesForwardingTime);
+	VP_SEQ_PRINTF(IoInstructionsForwardedCount);
+	VP_SEQ_PRINTF(IoInstructionsForwardingTime);
+	VP_SEQ_PRINTF(HltInstructionsForwardedCount);
+	VP_SEQ_PRINTF(HltInstructionsForwardingTime);
+	VP_SEQ_PRINTF(MwaitInstructionsForwardedCount);
+	VP_SEQ_PRINTF(MwaitInstructionsForwardingTime);
+	VP_SEQ_PRINTF(CpuidInstructionsForwardedCount);
+	VP_SEQ_PRINTF(CpuidInstructionsForwardingTime);
+	VP_SEQ_PRINTF(MsrAccessesForwardedCount);
+	VP_SEQ_PRINTF(MsrAccessesForwardingTime);
+	VP_SEQ_PRINTF(OtherInterceptsForwardedCount);
+	VP_SEQ_PRINTF(OtherInterceptsForwardingTime);
+	VP_SEQ_PRINTF(ExternalInterruptsForwardedCount);
+	VP_SEQ_PRINTF(ExternalInterruptsForwardingTime);
+	VP_SEQ_PRINTF(PendingInterruptsForwardedCount);
+	VP_SEQ_PRINTF(PendingInterruptsForwardingTime);
+	VP_SEQ_PRINTF(EmulatedInstructionsForwardedCount);
+	VP_SEQ_PRINTF(EmulatedInstructionsForwardingTime);
+	VP_SEQ_PRINTF(DebugRegisterAccessesForwardedCount);
+	VP_SEQ_PRINTF(DebugRegisterAccessesForwardingTime);
+	VP_SEQ_PRINTF(PageFaultInterceptsForwardedCount);
+	VP_SEQ_PRINTF(PageFaultInterceptsForwardingTime);
+	VP_SEQ_PRINTF(VmclearEmulationCount);
+	VP_SEQ_PRINTF(VmclearEmulationTime);
+	VP_SEQ_PRINTF(VmptrldEmulationCount);
+	VP_SEQ_PRINTF(VmptrldEmulationTime);
+	VP_SEQ_PRINTF(VmptrstEmulationCount);
+	VP_SEQ_PRINTF(VmptrstEmulationTime);
+	VP_SEQ_PRINTF(VmreadEmulationCount);
+	VP_SEQ_PRINTF(VmreadEmulationTime);
+	VP_SEQ_PRINTF(VmwriteEmulationCount);
+	VP_SEQ_PRINTF(VmwriteEmulationTime);
+	VP_SEQ_PRINTF(VmxoffEmulationCount);
+	VP_SEQ_PRINTF(VmxoffEmulationTime);
+	VP_SEQ_PRINTF(VmxonEmulationCount);
+	VP_SEQ_PRINTF(VmxonEmulationTime);
+	VP_SEQ_PRINTF(NestedVMEntriesCount);
+	VP_SEQ_PRINTF(NestedVMEntriesTime);
+	VP_SEQ_PRINTF(NestedSLATSoftPageFaultsCount);
+	VP_SEQ_PRINTF(NestedSLATSoftPageFaultsTime);
+	VP_SEQ_PRINTF(NestedSLATHardPageFaultsCount);
+	VP_SEQ_PRINTF(NestedSLATHardPageFaultsTime);
+	VP_SEQ_PRINTF(InvEptAllContextEmulationCount);
+	VP_SEQ_PRINTF(InvEptAllContextEmulationTime);
+	VP_SEQ_PRINTF(InvEptSingleContextEmulationCount);
+	VP_SEQ_PRINTF(InvEptSingleContextEmulationTime);
+	VP_SEQ_PRINTF(InvVpidAllContextEmulationCount);
+	VP_SEQ_PRINTF(InvVpidAllContextEmulationTime);
+	VP_SEQ_PRINTF(InvVpidSingleContextEmulationCount);
+	VP_SEQ_PRINTF(InvVpidSingleContextEmulationTime);
+	VP_SEQ_PRINTF(InvVpidSingleAddressEmulationCount);
+	VP_SEQ_PRINTF(InvVpidSingleAddressEmulationTime);
+	VP_SEQ_PRINTF(NestedTlbPageTableReclamations);
+	VP_SEQ_PRINTF(NestedTlbPageTableEvictions);
+	VP_SEQ_PRINTF(FlushGuestPhysicalAddressSpaceHypercalls);
+	VP_SEQ_PRINTF(FlushGuestPhysicalAddressListHypercalls);
+	VP_SEQ_PRINTF(PostedInterruptNotifications);
+	VP_SEQ_PRINTF(PostedInterruptScans);
+	VP_SEQ_PRINTF(TotalCoreRunTime);
+	VP_SEQ_PRINTF(MaximumRunTime);
+	VP_SEQ_PRINTF(HwpRequestContextSwitches);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket0);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket1);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket2);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket3);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket4);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket5);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket6);
+	VP_SEQ_PRINTF(VmloadEmulationCount);
+	VP_SEQ_PRINTF(VmloadEmulationTime);
+	VP_SEQ_PRINTF(VmsaveEmulationCount);
+	VP_SEQ_PRINTF(VmsaveEmulationTime);
+	VP_SEQ_PRINTF(GifInstructionEmulationCount);
+	VP_SEQ_PRINTF(GifInstructionEmulationTime);
+	VP_SEQ_PRINTF(EmulatedErrataSvmInstructions);
+	VP_SEQ_PRINTF(Placeholder1);
+	VP_SEQ_PRINTF(Placeholder2);
+	VP_SEQ_PRINTF(Placeholder3);
+	VP_SEQ_PRINTF(Placeholder4);
+	VP_SEQ_PRINTF(Placeholder5);
+	VP_SEQ_PRINTF(Placeholder6);
+	VP_SEQ_PRINTF(Placeholder7);
+	VP_SEQ_PRINTF(Placeholder8);
+	VP_SEQ_PRINTF(Placeholder9);
+	VP_SEQ_PRINTF(Placeholder10);
+	VP_SEQ_PRINTF(SchedulingPriority);
+	VP_SEQ_PRINTF(RdpmcInstructionsCount);
+	VP_SEQ_PRINTF(RdpmcInstructionsTime);
+	VP_SEQ_PRINTF(PerfmonPmuMsrAccessesCount);
+	VP_SEQ_PRINTF(PerfmonLbrMsrAccessesCount);
+	VP_SEQ_PRINTF(PerfmonIptMsrAccessesCount);
+	VP_SEQ_PRINTF(PerfmonInterruptCount);
+	VP_SEQ_PRINTF(Vtl1DispatchCount);
+	VP_SEQ_PRINTF(Vtl2DispatchCount);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket0);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket1);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket2);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket3);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket4);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket5);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket6);
+	VP_SEQ_PRINTF(Vtl1RunTime);
+	VP_SEQ_PRINTF(Vtl2RunTime);
+	VP_SEQ_PRINTF(IommuHypercalls);
+	VP_SEQ_PRINTF(CpuGroupHypercalls);
+	VP_SEQ_PRINTF(VsmHypercalls);
+	VP_SEQ_PRINTF(EventLogHypercalls);
+	VP_SEQ_PRINTF(DeviceDomainHypercalls);
+	VP_SEQ_PRINTF(DepositHypercalls);
+	VP_SEQ_PRINTF(SvmHypercalls);
+	VP_SEQ_PRINTF(BusLockAcquisitionCount);
+#elif IS_ENABLED(CONFIG_ARM64)
+	VP_SEQ_PRINTF(SysRegAccessesCount);
+	VP_SEQ_PRINTF(SysRegAccessesTime);
+	VP_SEQ_PRINTF(SmcInstructionsCount);
+	VP_SEQ_PRINTF(SmcInstructionsTime);
+	VP_SEQ_PRINTF(OtherInterceptsCount);
+	VP_SEQ_PRINTF(OtherInterceptsTime);
+	VP_SEQ_PRINTF(ExternalInterruptsCount);
+	VP_SEQ_PRINTF(ExternalInterruptsTime);
+	VP_SEQ_PRINTF(PendingInterruptsCount);
+	VP_SEQ_PRINTF(PendingInterruptsTime);
+	VP_SEQ_PRINTF(GuestPageTableMaps);
+	VP_SEQ_PRINTF(LargePageTlbFills);
+	VP_SEQ_PRINTF(SmallPageTlbFills);
+	VP_SEQ_PRINTF(ReflectedGuestPageFaults);
+	VP_SEQ_PRINTF(MemoryInterceptMessages);
+	VP_SEQ_PRINTF(OtherMessages);
+	VP_SEQ_PRINTF(LogicalProcessorMigrations);
+	VP_SEQ_PRINTF(AddressDomainFlushes);
+	VP_SEQ_PRINTF(AddressSpaceFlushes);
+	VP_SEQ_PRINTF(SyntheticInterrupts);
+	VP_SEQ_PRINTF(VirtualInterrupts);
+	VP_SEQ_PRINTF(ApicSelfIpisSent);
+	VP_SEQ_PRINTF(GpaSpaceHypercalls);
+	VP_SEQ_PRINTF(LogicalProcessorHypercalls);
+	VP_SEQ_PRINTF(LongSpinWaitHypercalls);
+	VP_SEQ_PRINTF(OtherHypercalls);
+	VP_SEQ_PRINTF(SyntheticInterruptHypercalls);
+	VP_SEQ_PRINTF(VirtualInterruptHypercalls);
+	VP_SEQ_PRINTF(VirtualMmuHypercalls);
+	VP_SEQ_PRINTF(VirtualProcessorHypercalls);
+	VP_SEQ_PRINTF(HardwareInterrupts);
+	VP_SEQ_PRINTF(NestedPageFaultInterceptsCount);
+	VP_SEQ_PRINTF(NestedPageFaultInterceptsTime);
+	VP_SEQ_PRINTF(LogicalProcessorDispatches);
+	VP_SEQ_PRINTF(WaitingForCpuTime);
+	VP_SEQ_PRINTF(ExtendedHypercalls);
+	VP_SEQ_PRINTF(ExtendedHypercallInterceptMessages);
+	VP_SEQ_PRINTF(MbecNestedPageTableSwitches);
+	VP_SEQ_PRINTF(OtherReflectedGuestExceptions);
+	VP_SEQ_PRINTF(GlobalIoTlbFlushes);
+	VP_SEQ_PRINTF(GlobalIoTlbFlushCost);
+	VP_SEQ_PRINTF(LocalIoTlbFlushes);
+	VP_SEQ_PRINTF(LocalIoTlbFlushCost);
+	VP_SEQ_PRINTF(FlushGuestPhysicalAddressSpaceHypercalls);
+	VP_SEQ_PRINTF(FlushGuestPhysicalAddressListHypercalls);
+	VP_SEQ_PRINTF(PostedInterruptNotifications);
+	VP_SEQ_PRINTF(PostedInterruptScans);
+	VP_SEQ_PRINTF(TotalCoreRunTime);
+	VP_SEQ_PRINTF(MaximumRunTime);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket0);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket1);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket2);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket3);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket4);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket5);
+	VP_SEQ_PRINTF(WaitingForCpuTimeBucket6);
+	VP_SEQ_PRINTF(HwpRequestContextSwitches);
+	VP_SEQ_PRINTF(Placeholder2);
+	VP_SEQ_PRINTF(Placeholder3);
+	VP_SEQ_PRINTF(Placeholder4);
+	VP_SEQ_PRINTF(Placeholder5);
+	VP_SEQ_PRINTF(Placeholder6);
+	VP_SEQ_PRINTF(Placeholder7);
+	VP_SEQ_PRINTF(Placeholder8);
+	VP_SEQ_PRINTF(ContentionTime);
+	VP_SEQ_PRINTF(WakeUpTime);
+	VP_SEQ_PRINTF(SchedulingPriority);
+	VP_SEQ_PRINTF(Vtl1DispatchCount);
+	VP_SEQ_PRINTF(Vtl2DispatchCount);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket0);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket1);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket2);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket3);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket4);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket5);
+	VP_SEQ_PRINTF(Vtl2DispatchBucket6);
+	VP_SEQ_PRINTF(Vtl1RunTime);
+	VP_SEQ_PRINTF(Vtl2RunTime);
+	VP_SEQ_PRINTF(IommuHypercalls);
+	VP_SEQ_PRINTF(CpuGroupHypercalls);
+	VP_SEQ_PRINTF(VsmHypercalls);
+	VP_SEQ_PRINTF(EventLogHypercalls);
+	VP_SEQ_PRINTF(DeviceDomainHypercalls);
+	VP_SEQ_PRINTF(DepositHypercalls);
+	VP_SEQ_PRINTF(SvmHypercalls);
+#endif
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(vp_stats);
+
+static void mshv_vp_stats_unmap(u64 partition_id, u32 vp_index, void *stats_page_addr,
+				enum hv_stats_area_type stats_area_type)
+{
+	union hv_stats_object_identity identity = {
+		.vp.partition_id = partition_id,
+		.vp.vp_index = vp_index,
+		.vp.stats_area_type = stats_area_type,
+	};
+	int err;
+
+	err = hv_unmap_stats_page(HV_STATS_OBJECT_VP, stats_page_addr, &identity);
+	if (err)
+		pr_err("%s: failed to unmap partition %llu vp %u %s stats, err: %d\n",
+		       __func__, partition_id, vp_index,
+		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
+		       err);
+}
+
+static void *mshv_vp_stats_map(u64 partition_id, u32 vp_index,
+			       enum hv_stats_area_type stats_area_type)
+{
+	union hv_stats_object_identity identity = {
+		.vp.partition_id = partition_id,
+		.vp.vp_index = vp_index,
+		.vp.stats_area_type = stats_area_type,
+	};
+	void *stats;
+	int err;
+
+	err = hv_map_stats_page(HV_STATS_OBJECT_VP, &identity, &stats);
+	if (err) {
+		pr_err("%s: failed to map partition %llu vp %u %s stats, err: %d\n",
+		       __func__, partition_id, vp_index,
+		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
+		       err);
+		return ERR_PTR(err);
+	}
+	return stats;
+}
+
+static int vp_debugfs_stats_create(u64 partition_id, u32 vp_index,
+				   struct dentry **vp_stats_ptr,
+				   struct dentry *parent)
+{
+	struct dentry *dentry;
+	struct hv_stats_page **pstats;
+	int err;
+
+	pstats = kcalloc(2, sizeof(struct hv_stats_page *), GFP_KERNEL_ACCOUNT);
+	if (!pstats)
+		return -ENOMEM;
+
+	pstats[HV_STATS_AREA_SELF] = mshv_vp_stats_map(partition_id, vp_index,
+						       HV_STATS_AREA_SELF);
+	if (IS_ERR(pstats[HV_STATS_AREA_SELF])) {
+		err = PTR_ERR(pstats[HV_STATS_AREA_SELF]);
+		goto cleanup;
+	}
+
+	/*
+	 * L1VH partition cannot access its vp stats in parent area.
+	 */
+	if (is_l1vh_parent(partition_id)) {
+		pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
+	} else {
+		pstats[HV_STATS_AREA_PARENT] = mshv_vp_stats_map(
+			partition_id, vp_index, HV_STATS_AREA_PARENT);
+		if (IS_ERR(pstats[HV_STATS_AREA_PARENT])) {
+			err = PTR_ERR(pstats[HV_STATS_AREA_PARENT]);
+			goto unmap_self;
+		}
+		if (!pstats[HV_STATS_AREA_PARENT])
+			pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
+	}
+
+	dentry = debugfs_create_file("stats", 0400, parent,
+				     pstats, &vp_stats_fops);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		goto unmap_vp_stats;
+	}
+
+	*vp_stats_ptr = dentry;
+	return 0;
+
+unmap_vp_stats:
+	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF])
+		mshv_vp_stats_unmap(partition_id, vp_index, pstats[HV_STATS_AREA_PARENT],
+				    HV_STATS_AREA_PARENT);
+unmap_self:
+	mshv_vp_stats_unmap(partition_id, vp_index, pstats[HV_STATS_AREA_SELF],
+			    HV_STATS_AREA_SELF);
+cleanup:
+	kfree(pstats);
+	return err;
+}
+
+static void vp_debugfs_remove(u64 partition_id, u32 vp_index,
+			      struct dentry *vp_stats)
+{
+	struct hv_stats_page **pstats = NULL;
+	void *stats;
+
+	pstats = vp_stats->d_inode->i_private;
+	debugfs_remove_recursive(vp_stats->d_parent);
+	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF]) {
+		stats = pstats[HV_STATS_AREA_PARENT];
+		mshv_vp_stats_unmap(partition_id, vp_index, stats,
+				    HV_STATS_AREA_PARENT);
+	}
+
+	stats = pstats[HV_STATS_AREA_SELF];
+	mshv_vp_stats_unmap(partition_id, vp_index, stats, HV_STATS_AREA_SELF);
+
+	kfree(pstats);
+}
+
+static int vp_debugfs_create(u64 partition_id, u32 vp_index,
+			     struct dentry **vp_stats_ptr,
+			     struct dentry *parent)
+{
+	struct dentry *vp_idx_dir;
+	char vp_idx_str[U32_BUF_SZ];
+	int err;
+
+	sprintf(vp_idx_str, "%u", vp_index);
+
+	vp_idx_dir = debugfs_create_dir(vp_idx_str, parent);
+	if (IS_ERR(vp_idx_dir))
+		return PTR_ERR(vp_idx_dir);
+
+	err = vp_debugfs_stats_create(partition_id, vp_index, vp_stats_ptr,
+				      vp_idx_dir);
+	if (err)
+		goto remove_debugfs_vp_idx;
+
+	return 0;
+
+remove_debugfs_vp_idx:
+	debugfs_remove_recursive(vp_idx_dir);
+	return err;
+}
+
+static int partition_stats_show(struct seq_file *m, void *v)
+{
+	const struct hv_stats_page **pstats = m->private;
+
+#define PARTITION_SEQ_PRINTF(cnt)				 \
+do {								 \
+	if (pstats[HV_STATS_AREA_SELF]->pt_cntrs[Partition##cnt]) \
+		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
+			pstats[HV_STATS_AREA_SELF]->pt_cntrs[Partition##cnt]); \
+	else \
+		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
+			pstats[HV_STATS_AREA_PARENT]->pt_cntrs[Partition##cnt]); \
+} while (0)
+
+	PARTITION_SEQ_PRINTF(VirtualProcessors);
+	PARTITION_SEQ_PRINTF(TlbSize);
+	PARTITION_SEQ_PRINTF(AddressSpaces);
+	PARTITION_SEQ_PRINTF(DepositedPages);
+	PARTITION_SEQ_PRINTF(GpaPages);
+	PARTITION_SEQ_PRINTF(GpaSpaceModifications);
+	PARTITION_SEQ_PRINTF(VirtualTlbFlushEntires);
+	PARTITION_SEQ_PRINTF(RecommendedTlbSize);
+	PARTITION_SEQ_PRINTF(GpaPages4K);
+	PARTITION_SEQ_PRINTF(GpaPages2M);
+	PARTITION_SEQ_PRINTF(GpaPages1G);
+	PARTITION_SEQ_PRINTF(GpaPages512G);
+	PARTITION_SEQ_PRINTF(DevicePages4K);
+	PARTITION_SEQ_PRINTF(DevicePages2M);
+	PARTITION_SEQ_PRINTF(DevicePages1G);
+	PARTITION_SEQ_PRINTF(DevicePages512G);
+	PARTITION_SEQ_PRINTF(AttachedDevices);
+	PARTITION_SEQ_PRINTF(DeviceInterruptMappings);
+	PARTITION_SEQ_PRINTF(IoTlbFlushes);
+	PARTITION_SEQ_PRINTF(IoTlbFlushCost);
+	PARTITION_SEQ_PRINTF(DeviceInterruptErrors);
+	PARTITION_SEQ_PRINTF(DeviceDmaErrors);
+	PARTITION_SEQ_PRINTF(DeviceInterruptThrottleEvents);
+	PARTITION_SEQ_PRINTF(SkippedTimerTicks);
+	PARTITION_SEQ_PRINTF(PartitionId);
+#if IS_ENABLED(CONFIG_X86_64)
+	PARTITION_SEQ_PRINTF(NestedTlbSize);
+	PARTITION_SEQ_PRINTF(RecommendedNestedTlbSize);
+	PARTITION_SEQ_PRINTF(NestedTlbFreeListSize);
+	PARTITION_SEQ_PRINTF(NestedTlbTrimmedPages);
+	PARTITION_SEQ_PRINTF(PagesShattered);
+	PARTITION_SEQ_PRINTF(PagesRecombined);
+	PARTITION_SEQ_PRINTF(HwpRequestValue);
+#elif IS_ENABLED(CONFIG_ARM64)
+	PARTITION_SEQ_PRINTF(HwpRequestValue);
+#endif
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(partition_stats);
+
+static void mshv_partition_stats_unmap(u64 partition_id, void *stats_page_addr,
+				       enum hv_stats_area_type stats_area_type)
+{
+	union hv_stats_object_identity identity = {
+		.partition.partition_id = partition_id,
+		.partition.stats_area_type = stats_area_type,
+	};
+	int err;
+
+	err = hv_unmap_stats_page(HV_STATS_OBJECT_PARTITION, stats_page_addr,
+				  &identity);
+	if (err) {
+		pr_err("%s: failed to unmap partition %lld %s stats, err: %d\n",
+		       __func__, partition_id,
+		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
+		       err);
+	}
+}
+
+static void *mshv_partition_stats_map(u64 partition_id,
+				      enum hv_stats_area_type stats_area_type)
+{
+	union hv_stats_object_identity identity = {
+		.partition.partition_id = partition_id,
+		.partition.stats_area_type = stats_area_type,
+	};
+	void *stats;
+	int err;
+
+	err = hv_map_stats_page(HV_STATS_OBJECT_PARTITION, &identity, &stats);
+	if (err) {
+		pr_err("%s: failed to map partition %lld %s stats, err: %d\n",
+		       __func__, partition_id,
+		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
+		       err);
+		return ERR_PTR(err);
+	}
+	return stats;
+}
+
+static int mshv_debugfs_partition_stats_create(u64 partition_id,
+					    struct dentry **partition_stats_ptr,
+					    struct dentry *parent)
+{
+	struct dentry *dentry;
+	struct hv_stats_page **pstats;
+	int err;
+
+	pstats = kcalloc(2, sizeof(struct hv_stats_page *), GFP_KERNEL_ACCOUNT);
+	if (!pstats)
+		return -ENOMEM;
+
+	pstats[HV_STATS_AREA_SELF] = mshv_partition_stats_map(partition_id,
+							      HV_STATS_AREA_SELF);
+	if (IS_ERR(pstats[HV_STATS_AREA_SELF])) {
+		err = PTR_ERR(pstats[HV_STATS_AREA_SELF]);
+		goto cleanup;
+	}
+
+	/*
+	 * L1VH partition cannot access its partition stats in parent area.
+	 */
+	if (is_l1vh_parent(partition_id)) {
+		pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
+	} else {
+		pstats[HV_STATS_AREA_PARENT] = mshv_partition_stats_map(partition_id,
+									HV_STATS_AREA_PARENT);
+		if (IS_ERR(pstats[HV_STATS_AREA_PARENT])) {
+			err = PTR_ERR(pstats[HV_STATS_AREA_PARENT]);
+			goto unmap_self;
+		}
+		if (!pstats[HV_STATS_AREA_PARENT])
+			pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
+	}
+
+	dentry = debugfs_create_file("stats", 0400, parent,
+				     pstats, &partition_stats_fops);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		goto unmap_partition_stats;
+	}
+
+	*partition_stats_ptr = dentry;
+	return 0;
+
+unmap_partition_stats:
+	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF])
+		mshv_partition_stats_unmap(partition_id, pstats[HV_STATS_AREA_PARENT],
+					   HV_STATS_AREA_PARENT);
+unmap_self:
+	mshv_partition_stats_unmap(partition_id, pstats[HV_STATS_AREA_SELF],
+				   HV_STATS_AREA_SELF);
+cleanup:
+	kfree(pstats);
+	return err;
+}
+
+static void partition_debugfs_remove(u64 partition_id, struct dentry *dentry)
+{
+	struct hv_stats_page **pstats = NULL;
+	void *stats;
+
+	pstats = dentry->d_inode->i_private;
+
+	debugfs_remove_recursive(dentry->d_parent);
+
+	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF]) {
+		stats = pstats[HV_STATS_AREA_PARENT];
+		mshv_partition_stats_unmap(partition_id, stats, HV_STATS_AREA_PARENT);
+	}
+
+	stats = pstats[HV_STATS_AREA_SELF];
+	mshv_partition_stats_unmap(partition_id, stats, HV_STATS_AREA_SELF);
+
+	kfree(pstats);
+}
+
+static int partition_debugfs_create(u64 partition_id,
+				    struct dentry **vp_dir_ptr,
+				    struct dentry **partition_stats_ptr,
+				    struct dentry *parent)
+{
+	char part_id_str[U64_BUF_SZ];
+	struct dentry *part_id_dir, *vp_dir;
+	int err;
+
+	if (is_l1vh_parent(partition_id))
+		sprintf(part_id_str, "self");
+	else
+		sprintf(part_id_str, "%llu", partition_id);
+
+	part_id_dir = debugfs_create_dir(part_id_str, parent);
+	if (IS_ERR(part_id_dir))
+		return PTR_ERR(part_id_dir);
+
+	vp_dir = debugfs_create_dir("vp", part_id_dir);
+	if (IS_ERR(vp_dir)) {
+		err = PTR_ERR(vp_dir);
+		goto remove_debugfs_partition_id;
+	}
+
+	err = mshv_debugfs_partition_stats_create(partition_id,
+						  partition_stats_ptr,
+						  part_id_dir);
+	if (err)
+		goto remove_debugfs_partition_id;
+
+	*vp_dir_ptr = vp_dir;
+
+	return 0;
+
+remove_debugfs_partition_id:
+	debugfs_remove_recursive(part_id_dir);
+	return err;
+}
+
+static void mshv_debugfs_parent_partition_remove(void)
+{
+	int idx;
+
+	for_each_online_cpu(idx)
+		vp_debugfs_remove(hv_current_partition_id, idx, NULL);
+
+	partition_debugfs_remove(hv_current_partition_id, NULL);
+}
+
+static int __init mshv_debugfs_parent_partition_create(void)
+{
+	struct dentry *partition_stats, *vp_dir;
+	int err, idx, i;
+
+	mshv_debugfs_partition = debugfs_create_dir("partition",
+						     mshv_debugfs);
+	if (IS_ERR(mshv_debugfs_partition))
+		return PTR_ERR(mshv_debugfs_partition);
+
+	err = partition_debugfs_create(hv_current_partition_id,
+				       &vp_dir,
+				       &partition_stats,
+				       mshv_debugfs_partition);
+	if (err)
+		goto remove_debugfs_partition;
+
+	for_each_online_cpu(idx) {
+		struct dentry *vp_stats;
+
+		err = vp_debugfs_create(hv_current_partition_id,
+					hv_vp_index[idx],
+					&vp_stats,
+					vp_dir);
+		if (err)
+			goto remove_debugfs_partition_vp;
+	}
+
+	return 0;
+
+remove_debugfs_partition_vp:
+	for_each_online_cpu(i) {
+		if (i >= idx)
+			break;
+		vp_debugfs_remove(hv_current_partition_id, i, NULL);
+	}
+	partition_debugfs_remove(hv_current_partition_id, NULL);
+remove_debugfs_partition:
+	debugfs_remove_recursive(mshv_debugfs_partition);
+	return err;
+}
+
+static int hv_stats_show(struct seq_file *m, void *v)
+{
+	const struct hv_stats_page *stats = m->private;
+
+#define HV_SEQ_PRINTF(cnt)		\
+	seq_printf(m, "%-25s: %llu\n", __stringify(cnt), stats->hv_cntrs[Hv##cnt])
+
+	HV_SEQ_PRINTF(LogicalProcessors);
+	HV_SEQ_PRINTF(Partitions);
+	HV_SEQ_PRINTF(TotalPages);
+	HV_SEQ_PRINTF(VirtualProcessors);
+	HV_SEQ_PRINTF(MonitoredNotifications);
+	HV_SEQ_PRINTF(ModernStandbyEntries);
+	HV_SEQ_PRINTF(PlatformIdleTransitions);
+	HV_SEQ_PRINTF(HypervisorStartupCost);
+	HV_SEQ_PRINTF(IOSpacePages);
+	HV_SEQ_PRINTF(NonEssentialPagesForDump);
+	HV_SEQ_PRINTF(SubsumedPages);
+
+	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(hv_stats);
+
+static void mshv_hv_stats_unmap(void)
+{
+	union hv_stats_object_identity identity = {
+		.hv.stats_area_type = HV_STATS_AREA_SELF,
+	};
+	int err;
+
+	err = hv_unmap_stats_page(HV_STATS_OBJECT_HYPERVISOR, NULL, &identity);
+	if (err)
+		pr_err("%s: failed to unmap hypervisor stats: %d\n",
+		       __func__, err);
+}
+
+static void * __init mshv_hv_stats_map(void)
+{
+	union hv_stats_object_identity identity = {
+		.hv.stats_area_type = HV_STATS_AREA_SELF,
+	};
+	void *stats;
+	int err;
+
+	err = hv_map_stats_page(HV_STATS_OBJECT_HYPERVISOR, &identity, &stats);
+	if (err) {
+		pr_err("%s: failed to map hypervisor stats: %d\n",
+		       __func__, err);
+		return ERR_PTR(err);
+	}
+	return stats;
+}
+
+static int __init mshv_debugfs_hv_stats_create(struct dentry *parent)
+{
+	struct dentry *dentry;
+	u64 *stats;
+	int err;
+
+	stats = mshv_hv_stats_map();
+	if (IS_ERR(stats))
+		return PTR_ERR(stats);
+
+	dentry = debugfs_create_file("stats", 0400, parent,
+				     stats, &hv_stats_fops);
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		pr_err("%s: failed to create hypervisor stats dentry: %d\n",
+		       __func__, err);
+		goto unmap_hv_stats;
+	}
+
+	mshv_lps_count = stats[HvLogicalProcessors];
+
+	return 0;
+
+unmap_hv_stats:
+	mshv_hv_stats_unmap();
+	return err;
+}
+
+int mshv_debugfs_vp_create(struct mshv_vp *vp)
+{
+	struct mshv_partition *p = vp->vp_partition;
+	int err;
+
+	if (!mshv_debugfs)
+		return 0;
+
+	err = vp_debugfs_create(p->pt_id, vp->vp_index,
+				&vp->vp_debugfs_stats_dentry,
+				p->pt_debugfs_vp_dentry);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+void mshv_debugfs_vp_remove(struct mshv_vp *vp)
+{
+	if (!mshv_debugfs)
+		return;
+
+	vp_debugfs_remove(vp->vp_partition->pt_id, vp->vp_index,
+			  vp->vp_debugfs_stats_dentry);
+}
+
+int mshv_debugfs_partition_create(struct mshv_partition *partition)
+{
+	int err;
+
+	if (!mshv_debugfs)
+		return 0;
+
+	err = partition_debugfs_create(partition->pt_id,
+				       &partition->pt_debugfs_vp_dentry,
+				       &partition->pt_debugfs_stats_dentry,
+				       mshv_debugfs_partition);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+void mshv_debugfs_partition_remove(struct mshv_partition *partition)
+{
+	if (!mshv_debugfs)
+		return;
+
+	partition_debugfs_remove(partition->pt_id,
+				 partition->pt_debugfs_stats_dentry);
+}
+
+int __init mshv_debugfs_init(void)
+{
+	int err;
+
+	mshv_debugfs = debugfs_create_dir("mshv", NULL);
+	if (IS_ERR(mshv_debugfs)) {
+		pr_err("%s: failed to create debugfs directory\n", __func__);
+		return PTR_ERR(mshv_debugfs);
+	}
+
+	if (hv_root_partition()) {
+		err = mshv_debugfs_hv_stats_create(mshv_debugfs);
+		if (err)
+			goto remove_mshv_dir;
+
+		err = mshv_debugfs_lp_create(mshv_debugfs);
+		if (err)
+			goto unmap_hv_stats;
+	}
+
+	err = mshv_debugfs_parent_partition_create();
+	if (err)
+		goto unmap_lp_stats;
+
+	return 0;
+
+unmap_lp_stats:
+	if (hv_root_partition())
+		mshv_debugfs_lp_remove();
+unmap_hv_stats:
+	if (hv_root_partition())
+		mshv_hv_stats_unmap();
+remove_mshv_dir:
+	debugfs_remove_recursive(mshv_debugfs);
+	return err;
+}
+
+void mshv_debugfs_exit(void)
+{
+	mshv_debugfs_parent_partition_remove();
+
+	if (hv_root_partition()) {
+		mshv_debugfs_lp_remove();
+		mshv_hv_stats_unmap();
+	}
+
+	debugfs_remove_recursive(mshv_debugfs);
+}
diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h
index 3eb815011b46..1f1b1984449b 100644
--- a/drivers/hv/mshv_root.h
+++ b/drivers/hv/mshv_root.h
@@ -51,6 +51,9 @@ struct mshv_vp {
 		unsigned int kicked_by_hv;
 		wait_queue_head_t vp_suspend_queue;
 	} run;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+	struct dentry *vp_debugfs_stats_dentry;
+#endif
 };
 
 #define vp_fmt(fmt) "p%lluvp%u: " fmt
@@ -128,6 +131,10 @@ struct mshv_partition {
 	u64 isolation_type;
 	bool import_completed;
 	bool pt_initialized;
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+	struct dentry *pt_debugfs_stats_dentry;
+	struct dentry *pt_debugfs_vp_dentry;
+#endif
 };
 
 #define pt_fmt(fmt) "p%llu: " fmt
@@ -308,6 +315,33 @@ int hv_call_modify_spa_host_access(u64 partition_id, struct page **pages,
 int hv_call_get_partition_property_ex(u64 partition_id, u64 property_code, u64 arg,
 				      void *property_value, size_t property_value_sz);
 
+#if IS_ENABLED(CONFIG_DEBUG_FS)
+int __init mshv_debugfs_init(void);
+void mshv_debugfs_exit(void);
+
+int mshv_debugfs_partition_create(struct mshv_partition *partition);
+void mshv_debugfs_partition_remove(struct mshv_partition *partition);
+int mshv_debugfs_vp_create(struct mshv_vp *vp);
+void mshv_debugfs_vp_remove(struct mshv_vp *vp);
+#else
+static inline int __init mshv_debugfs_init(void)
+{
+	return 0;
+}
+static inline void mshv_debugfs_exit(void) { }
+
+static inline int mshv_debugfs_partition_create(struct mshv_partition *partition)
+{
+	return 0;
+}
+static inline void mshv_debugfs_partition_remove(struct mshv_partition *partition) { }
+static inline int mshv_debugfs_vp_create(struct mshv_vp *vp)
+{
+	return 0;
+}
+static inline void mshv_debugfs_vp_remove(struct mshv_vp *vp) { }
+#endif
+
 extern struct mshv_root mshv_root;
 extern enum hv_scheduler_type hv_scheduler_type;
 extern u8 * __percpu *hv_synic_eventring_tail;
diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
index 19006b788e85..152fcd9b45e6 100644
--- a/drivers/hv/mshv_root_main.c
+++ b/drivers/hv/mshv_root_main.c
@@ -982,6 +982,10 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
 	if (hv_scheduler_type == HV_SCHEDULER_TYPE_ROOT)
 		memcpy(vp->vp_stats_pages, stats_pages, sizeof(stats_pages));
 
+	ret = mshv_debugfs_vp_create(vp);
+	if (ret)
+		goto put_partition;
+
 	/*
 	 * Keep anon_inode_getfd last: it installs fd in the file struct and
 	 * thus makes the state accessible in user space.
@@ -989,7 +993,7 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
 	ret = anon_inode_getfd("mshv_vp", &mshv_vp_fops, vp,
 			       O_RDWR | O_CLOEXEC);
 	if (ret < 0)
-		goto put_partition;
+		goto remove_debugfs_vp;
 
 	/* already exclusive with the partition mutex for all ioctls */
 	partition->pt_vp_count++;
@@ -997,6 +1001,8 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
 
 	return ret;
 
+remove_debugfs_vp:
+	mshv_debugfs_vp_remove(vp);
 put_partition:
 	mshv_partition_put(partition);
 free_vp:
@@ -1556,13 +1562,18 @@ mshv_partition_ioctl_initialize(struct mshv_partition *partition)
 
 	ret = hv_call_initialize_partition(partition->pt_id);
 	if (ret)
-		goto withdraw_mem;
+		return ret;
+
+	ret = mshv_debugfs_partition_create(partition);
+	if (ret)
+		goto finalize_partition;
 
 	partition->pt_initialized = true;
 
 	return 0;
 
-withdraw_mem:
+finalize_partition:
+	hv_call_finalize_partition(partition->pt_id);
 	hv_call_withdraw_memory(U64_MAX, NUMA_NO_NODE, partition->pt_id);
 
 	return ret;
@@ -1741,6 +1752,8 @@ static void destroy_partition(struct mshv_partition *partition)
 			if (!vp)
 				continue;
 
+			mshv_debugfs_vp_remove(vp);
+
 			if (hv_scheduler_type == HV_SCHEDULER_TYPE_ROOT)
 				mshv_vp_stats_unmap(partition->pt_id, vp->vp_index,
 						    (void **)vp->vp_stats_pages);
@@ -1775,6 +1788,8 @@ static void destroy_partition(struct mshv_partition *partition)
 			partition->pt_vp_array[i] = NULL;
 		}
 
+		mshv_debugfs_partition_remove(partition);
+
 		/* Deallocates and unmaps everything including vcpus, GPA mappings etc */
 		hv_call_finalize_partition(partition->pt_id);
 
@@ -2351,10 +2366,14 @@ static int __init mshv_parent_partition_init(void)
 
 	mshv_init_vmm_caps(dev);
 
-	ret = mshv_irqfd_wq_init();
+	ret = mshv_debugfs_init();
 	if (ret)
 		goto exit_partition;
 
+	ret = mshv_irqfd_wq_init();
+	if (ret)
+		goto exit_debugfs;
+
 	spin_lock_init(&mshv_root.pt_ht_lock);
 	hash_init(mshv_root.pt_htable);
 
@@ -2362,6 +2381,10 @@ static int __init mshv_parent_partition_init(void)
 
 	return 0;
 
+destroy_irqds_wq:
+	mshv_irqfd_wq_cleanup();
+exit_debugfs:
+	mshv_debugfs_exit();
 exit_partition:
 	if (hv_root_partition())
 		mshv_root_partition_exit();
@@ -2378,6 +2401,7 @@ static void __exit mshv_parent_partition_exit(void)
 {
 	hv_setup_mshv_handler(NULL);
 	mshv_port_table_fini();
+	mshv_debugfs_exit();
 	misc_deregister(&mshv_dev);
 	mshv_irqfd_wq_cleanup();
 	if (hv_root_partition())
-- 
2.34.1
Re: [PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
Posted by kernel test robot 1 week, 1 day ago
Hi Nuno,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20251205]
[cannot apply to linus/master v6.18 v6.18-rc7 v6.18-rc6 v6.18]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Nuno-Das-Neves/mshv-Ignore-second-stats-page-map-result-failure/20251206-033756
base:   next-20251205
patch link:    https://lore.kernel.org/r/1764961122-31679-4-git-send-email-nunodasneves%40linux.microsoft.com
patch subject: [PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
config: x86_64-randconfig-076-20251208 (https://download.01.org/0day-ci/archive/20251208/202512081314.ULBIWb1d-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251208/202512081314.ULBIWb1d-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512081314.ULBIWb1d-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/hv/mshv_root_main.c:2369:1: warning: unused label 'destroy_irqds_wq' [-Wunused-label]
    2369 | destroy_irqds_wq:
         | ^~~~~~~~~~~~~~~~~
   1 warning generated.


vim +/destroy_irqds_wq +2369 drivers/hv/mshv_root_main.c

  2299	
  2300	static int __init mshv_parent_partition_init(void)
  2301	{
  2302		int ret;
  2303		struct device *dev;
  2304		union hv_hypervisor_version_info version_info;
  2305	
  2306		if (!hv_parent_partition() || is_kdump_kernel())
  2307			return -ENODEV;
  2308	
  2309		if (hv_get_hypervisor_version(&version_info))
  2310			return -ENODEV;
  2311	
  2312		ret = misc_register(&mshv_dev);
  2313		if (ret)
  2314			return ret;
  2315	
  2316		dev = mshv_dev.this_device;
  2317	
  2318		if (version_info.build_number < MSHV_HV_MIN_VERSION ||
  2319		    version_info.build_number > MSHV_HV_MAX_VERSION) {
  2320			dev_err(dev, "Running on unvalidated Hyper-V version\n");
  2321			dev_err(dev, "Versions: current: %u  min: %u  max: %u\n",
  2322				version_info.build_number, MSHV_HV_MIN_VERSION,
  2323				MSHV_HV_MAX_VERSION);
  2324		}
  2325	
  2326		mshv_root.synic_pages = alloc_percpu(struct hv_synic_pages);
  2327		if (!mshv_root.synic_pages) {
  2328			dev_err(dev, "Failed to allocate percpu synic page\n");
  2329			ret = -ENOMEM;
  2330			goto device_deregister;
  2331		}
  2332	
  2333		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mshv_synic",
  2334					mshv_synic_init,
  2335					mshv_synic_cleanup);
  2336		if (ret < 0) {
  2337			dev_err(dev, "Failed to setup cpu hotplug state: %i\n", ret);
  2338			goto free_synic_pages;
  2339		}
  2340	
  2341		mshv_cpuhp_online = ret;
  2342	
  2343		ret = mshv_retrieve_scheduler_type(dev);
  2344		if (ret)
  2345			goto remove_cpu_state;
  2346	
  2347		if (hv_root_partition())
  2348			ret = mshv_root_partition_init(dev);
  2349		if (ret)
  2350			goto remove_cpu_state;
  2351	
  2352		mshv_init_vmm_caps(dev);
  2353	
  2354		ret = mshv_debugfs_init();
  2355		if (ret)
  2356			goto exit_partition;
  2357	
  2358		ret = mshv_irqfd_wq_init();
  2359		if (ret)
  2360			goto exit_debugfs;
  2361	
  2362		spin_lock_init(&mshv_root.pt_ht_lock);
  2363		hash_init(mshv_root.pt_htable);
  2364	
  2365		hv_setup_mshv_handler(mshv_isr);
  2366	
  2367		return 0;
  2368	
> 2369	destroy_irqds_wq:
  2370		mshv_irqfd_wq_cleanup();
  2371	exit_debugfs:
  2372		mshv_debugfs_exit();
  2373	exit_partition:
  2374		if (hv_root_partition())
  2375			mshv_root_partition_exit();
  2376	remove_cpu_state:
  2377		cpuhp_remove_state(mshv_cpuhp_online);
  2378	free_synic_pages:
  2379		free_percpu(mshv_root.synic_pages);
  2380	device_deregister:
  2381		misc_deregister(&mshv_dev);
  2382		return ret;
  2383	}
  2384	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
Posted by kernel test robot 1 week, 1 day ago
Hi Nuno,

kernel test robot noticed the following build warnings:

[auto build test WARNING on next-20251205]
[cannot apply to linus/master v6.18 v6.18-rc7 v6.18-rc6 v6.18]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Nuno-Das-Neves/mshv-Ignore-second-stats-page-map-result-failure/20251206-033756
base:   next-20251205
patch link:    https://lore.kernel.org/r/1764961122-31679-4-git-send-email-nunodasneves%40linux.microsoft.com
patch subject: [PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
config: x86_64-randconfig-002-20251208 (https://download.01.org/0day-ci/archive/20251208/202512081050.0AW9Ecvg-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.4.0-5) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251208/202512081050.0AW9Ecvg-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202512081050.0AW9Ecvg-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/hv/mshv_root_main.c: In function 'mshv_parent_partition_init':
>> drivers/hv/mshv_root_main.c:2369:1: warning: label 'destroy_irqds_wq' defined but not used [-Wunused-label]
    2369 | destroy_irqds_wq:
         | ^~~~~~~~~~~~~~~~


vim +/destroy_irqds_wq +2369 drivers/hv/mshv_root_main.c

  2299	
  2300	static int __init mshv_parent_partition_init(void)
  2301	{
  2302		int ret;
  2303		struct device *dev;
  2304		union hv_hypervisor_version_info version_info;
  2305	
  2306		if (!hv_parent_partition() || is_kdump_kernel())
  2307			return -ENODEV;
  2308	
  2309		if (hv_get_hypervisor_version(&version_info))
  2310			return -ENODEV;
  2311	
  2312		ret = misc_register(&mshv_dev);
  2313		if (ret)
  2314			return ret;
  2315	
  2316		dev = mshv_dev.this_device;
  2317	
  2318		if (version_info.build_number < MSHV_HV_MIN_VERSION ||
  2319		    version_info.build_number > MSHV_HV_MAX_VERSION) {
  2320			dev_err(dev, "Running on unvalidated Hyper-V version\n");
  2321			dev_err(dev, "Versions: current: %u  min: %u  max: %u\n",
  2322				version_info.build_number, MSHV_HV_MIN_VERSION,
  2323				MSHV_HV_MAX_VERSION);
  2324		}
  2325	
  2326		mshv_root.synic_pages = alloc_percpu(struct hv_synic_pages);
  2327		if (!mshv_root.synic_pages) {
  2328			dev_err(dev, "Failed to allocate percpu synic page\n");
  2329			ret = -ENOMEM;
  2330			goto device_deregister;
  2331		}
  2332	
  2333		ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "mshv_synic",
  2334					mshv_synic_init,
  2335					mshv_synic_cleanup);
  2336		if (ret < 0) {
  2337			dev_err(dev, "Failed to setup cpu hotplug state: %i\n", ret);
  2338			goto free_synic_pages;
  2339		}
  2340	
  2341		mshv_cpuhp_online = ret;
  2342	
  2343		ret = mshv_retrieve_scheduler_type(dev);
  2344		if (ret)
  2345			goto remove_cpu_state;
  2346	
  2347		if (hv_root_partition())
  2348			ret = mshv_root_partition_init(dev);
  2349		if (ret)
  2350			goto remove_cpu_state;
  2351	
  2352		mshv_init_vmm_caps(dev);
  2353	
  2354		ret = mshv_debugfs_init();
  2355		if (ret)
  2356			goto exit_partition;
  2357	
  2358		ret = mshv_irqfd_wq_init();
  2359		if (ret)
  2360			goto exit_debugfs;
  2361	
  2362		spin_lock_init(&mshv_root.pt_ht_lock);
  2363		hash_init(mshv_root.pt_htable);
  2364	
  2365		hv_setup_mshv_handler(mshv_isr);
  2366	
  2367		return 0;
  2368	
> 2369	destroy_irqds_wq:
  2370		mshv_irqfd_wq_cleanup();
  2371	exit_debugfs:
  2372		mshv_debugfs_exit();
  2373	exit_partition:
  2374		if (hv_root_partition())
  2375			mshv_root_partition_exit();
  2376	remove_cpu_state:
  2377		cpuhp_remove_state(mshv_cpuhp_online);
  2378	free_synic_pages:
  2379		free_percpu(mshv_root.synic_pages);
  2380	device_deregister:
  2381		misc_deregister(&mshv_dev);
  2382		return ret;
  2383	}
  2384	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v2 3/3] mshv: Add debugfs to view hypervisor statistics
Posted by Stanislav Kinsburskii 1 week, 3 days ago
On Fri, Dec 05, 2025 at 10:58:42AM -0800, Nuno Das Neves wrote:
> Introduce a debugfs interface to expose root and child partition stats
> when running with mshv_root.
> 
> Create a debugfs directory "mshv" containing 'stats' files organized by
> type and id. A stats file contains a number of counters depending on
> its type. e.g. an excerpt from a VP stats file:
> 
> TotalRunTime                  : 1997602722
> HypervisorRunTime             : 649671371
> RemoteNodeRunTime             : 0
> NormalizedRunTime             : 1997602721
> IdealCpu                      : 0
> HypercallsCount               : 1708169
> HypercallsTime                : 111914774
> PageInvalidationsCount        : 0
> PageInvalidationsTime         : 0
> 
> On a root partition with some active child partitions, the entire
> directory structure may look like:
> 
> mshv/
>   stats             # hypervisor stats
>   lp/               # logical processors
>     0/              # LP id
>       stats         # LP 0 stats
>     1/
>     2/
>     3/
>   partition/        # partition stats
>     1/              # root partition id
>       stats         # root partition stats
>       vp/           # root virtual processors
>         0/          # root VP id
>           stats     # root VP 0 stats
>         1/
>         2/
>         3/
>     42/             # child partition id
>       stats         # child partition stats
>       vp/           # child VPs
>         0/          # child VP id
>           stats     # child VP 0 stats
>         1/
>     43/
>     55/
> 
> On L1VH, some stats are not present as it does not own the hardware
> like the root partition does:
> - The hypervisor and lp stats are not present
> - L1VH's partition directory is named "self" because it can't get its
>   own id
> - Some of L1VH's partition and VP stats fields are not populated, because
>   it can't map its own HV_STATS_AREA_PARENT page.
> 

<snip>

> +static void __init *lp_debugfs_stats_create(u32 lp_index, struct dentry *parent)

It would be better to return struct hv_stats_page from this (and other
functions).

> +{
> +	struct dentry *dentry;
> +	void *stats;
> +
> +	stats = mshv_lp_stats_map(lp_index);
> +	if (IS_ERR(stats))
> +		return stats;
> +
> +	dentry = debugfs_create_file("stats", 0400, parent,
> +				     stats, &lp_stats_fops);
> +	if (IS_ERR(dentry)) {
> +		mshv_lp_stats_unmap(lp_index, stats);
> +		return dentry;

This is sloppy as it returns struct dentry instead of struct
hv_stats_page and using void here simply sweeps the problem under the
carpet which otherwise the compiler would catch.
How about using ERR_CAST instead as it will make this behavior explicit?

> +	}
> +	return stats;
> +}
> +
> +static int __init lp_debugfs_create(u32 lp_index, struct dentry *parent)
> +{
> +	struct dentry *idx;
> +	char lp_idx_str[U32_BUF_SZ];
> +	void *stats;
> +	int err;
> +
> +	sprintf(lp_idx_str, "%u", lp_index);
> +
> +	idx = debugfs_create_dir(lp_idx_str, parent);
> +	if (IS_ERR(idx))
> +		return PTR_ERR(idx);
> +
> +	stats = lp_debugfs_stats_create(lp_index, idx);
> +	if (IS_ERR(stats)) {
> +		err = PTR_ERR(stats);
> +		goto remove_debugfs_lp_idx;
> +	}
> +
> +	return 0;
> +
> +remove_debugfs_lp_idx:
> +	debugfs_remove_recursive(idx);
> +	return err;
> +}
> +
> +static void mshv_debugfs_lp_remove(void)
> +{
> +	int lp_index;
> +
> +	debugfs_remove_recursive(mshv_debugfs_lp);
> +
> +	for (lp_index = 0; lp_index < mshv_lps_count; lp_index++)
> +		mshv_lp_stats_unmap(lp_index, NULL);
> +}
> +
> +static int __init mshv_debugfs_lp_create(struct dentry *parent)
> +{
> +	struct dentry *lp_dir;
> +	int err, lp_index;
> +
> +	lp_dir = debugfs_create_dir("lp", parent);
> +	if (IS_ERR(lp_dir))
> +		return PTR_ERR(lp_dir);
> +
> +	for (lp_index = 0; lp_index < mshv_lps_count; lp_index++) {
> +		err = lp_debugfs_create(lp_index, lp_dir);
> +		if (err)
> +			goto remove_debugfs_lps;
> +	}
> +
> +	mshv_debugfs_lp = lp_dir;
> +
> +	return 0;
> +
> +remove_debugfs_lps:
> +	for (lp_index -= 1; lp_index >= 0; lp_index--)
> +		mshv_lp_stats_unmap(lp_index, NULL);
> +	debugfs_remove_recursive(lp_dir);
> +	return err;
> +}
> +
> +static int vp_stats_show(struct seq_file *m, void *v)
> +{
> +	const struct hv_stats_page **pstats = m->private;
> +
> +#define VP_SEQ_PRINTF(cnt)				 \
> +do {								 \
> +	if (pstats[HV_STATS_AREA_SELF]->vp_cntrs[Vp##cnt]) \
> +		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
> +			pstats[HV_STATS_AREA_SELF]->vp_cntrs[Vp##cnt]); \
> +	else \
> +		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
> +			pstats[HV_STATS_AREA_PARENT]->vp_cntrs[Vp##cnt]); \
> +} while (0)
> +
> +	VP_SEQ_PRINTF(TotalRunTime);
> +	VP_SEQ_PRINTF(HypervisorRunTime);
> +	VP_SEQ_PRINTF(RemoteNodeRunTime);
> +	VP_SEQ_PRINTF(NormalizedRunTime);
> +	VP_SEQ_PRINTF(IdealCpu);
> +	VP_SEQ_PRINTF(HypercallsCount);
> +	VP_SEQ_PRINTF(HypercallsTime);
> +#if IS_ENABLED(CONFIG_X86_64)
> +	VP_SEQ_PRINTF(PageInvalidationsCount);
> +	VP_SEQ_PRINTF(PageInvalidationsTime);
> +	VP_SEQ_PRINTF(ControlRegisterAccessesCount);
> +	VP_SEQ_PRINTF(ControlRegisterAccessesTime);
> +	VP_SEQ_PRINTF(IoInstructionsCount);
> +	VP_SEQ_PRINTF(IoInstructionsTime);
> +	VP_SEQ_PRINTF(HltInstructionsCount);
> +	VP_SEQ_PRINTF(HltInstructionsTime);
> +	VP_SEQ_PRINTF(MwaitInstructionsCount);
> +	VP_SEQ_PRINTF(MwaitInstructionsTime);
> +	VP_SEQ_PRINTF(CpuidInstructionsCount);
> +	VP_SEQ_PRINTF(CpuidInstructionsTime);
> +	VP_SEQ_PRINTF(MsrAccessesCount);
> +	VP_SEQ_PRINTF(MsrAccessesTime);
> +	VP_SEQ_PRINTF(OtherInterceptsCount);
> +	VP_SEQ_PRINTF(OtherInterceptsTime);
> +	VP_SEQ_PRINTF(ExternalInterruptsCount);
> +	VP_SEQ_PRINTF(ExternalInterruptsTime);
> +	VP_SEQ_PRINTF(PendingInterruptsCount);
> +	VP_SEQ_PRINTF(PendingInterruptsTime);
> +	VP_SEQ_PRINTF(EmulatedInstructionsCount);
> +	VP_SEQ_PRINTF(EmulatedInstructionsTime);
> +	VP_SEQ_PRINTF(DebugRegisterAccessesCount);
> +	VP_SEQ_PRINTF(DebugRegisterAccessesTime);
> +	VP_SEQ_PRINTF(PageFaultInterceptsCount);
> +	VP_SEQ_PRINTF(PageFaultInterceptsTime);
> +	VP_SEQ_PRINTF(GuestPageTableMaps);
> +	VP_SEQ_PRINTF(LargePageTlbFills);
> +	VP_SEQ_PRINTF(SmallPageTlbFills);
> +	VP_SEQ_PRINTF(ReflectedGuestPageFaults);
> +	VP_SEQ_PRINTF(ApicMmioAccesses);
> +	VP_SEQ_PRINTF(IoInterceptMessages);
> +	VP_SEQ_PRINTF(MemoryInterceptMessages);
> +	VP_SEQ_PRINTF(ApicEoiAccesses);
> +	VP_SEQ_PRINTF(OtherMessages);
> +	VP_SEQ_PRINTF(PageTableAllocations);
> +	VP_SEQ_PRINTF(LogicalProcessorMigrations);
> +	VP_SEQ_PRINTF(AddressSpaceEvictions);
> +	VP_SEQ_PRINTF(AddressSpaceSwitches);
> +	VP_SEQ_PRINTF(AddressDomainFlushes);
> +	VP_SEQ_PRINTF(AddressSpaceFlushes);
> +	VP_SEQ_PRINTF(GlobalGvaRangeFlushes);
> +	VP_SEQ_PRINTF(LocalGvaRangeFlushes);
> +	VP_SEQ_PRINTF(PageTableEvictions);
> +	VP_SEQ_PRINTF(PageTableReclamations);
> +	VP_SEQ_PRINTF(PageTableResets);
> +	VP_SEQ_PRINTF(PageTableValidations);
> +	VP_SEQ_PRINTF(ApicTprAccesses);
> +	VP_SEQ_PRINTF(PageTableWriteIntercepts);
> +	VP_SEQ_PRINTF(SyntheticInterrupts);
> +	VP_SEQ_PRINTF(VirtualInterrupts);
> +	VP_SEQ_PRINTF(ApicIpisSent);
> +	VP_SEQ_PRINTF(ApicSelfIpisSent);
> +	VP_SEQ_PRINTF(GpaSpaceHypercalls);
> +	VP_SEQ_PRINTF(LogicalProcessorHypercalls);
> +	VP_SEQ_PRINTF(LongSpinWaitHypercalls);
> +	VP_SEQ_PRINTF(OtherHypercalls);
> +	VP_SEQ_PRINTF(SyntheticInterruptHypercalls);
> +	VP_SEQ_PRINTF(VirtualInterruptHypercalls);
> +	VP_SEQ_PRINTF(VirtualMmuHypercalls);
> +	VP_SEQ_PRINTF(VirtualProcessorHypercalls);
> +	VP_SEQ_PRINTF(HardwareInterrupts);
> +	VP_SEQ_PRINTF(NestedPageFaultInterceptsCount);
> +	VP_SEQ_PRINTF(NestedPageFaultInterceptsTime);
> +	VP_SEQ_PRINTF(PageScans);
> +	VP_SEQ_PRINTF(LogicalProcessorDispatches);
> +	VP_SEQ_PRINTF(WaitingForCpuTime);
> +	VP_SEQ_PRINTF(ExtendedHypercalls);
> +	VP_SEQ_PRINTF(ExtendedHypercallInterceptMessages);
> +	VP_SEQ_PRINTF(MbecNestedPageTableSwitches);
> +	VP_SEQ_PRINTF(OtherReflectedGuestExceptions);
> +	VP_SEQ_PRINTF(GlobalIoTlbFlushes);
> +	VP_SEQ_PRINTF(GlobalIoTlbFlushCost);
> +	VP_SEQ_PRINTF(LocalIoTlbFlushes);
> +	VP_SEQ_PRINTF(LocalIoTlbFlushCost);
> +	VP_SEQ_PRINTF(HypercallsForwardedCount);
> +	VP_SEQ_PRINTF(HypercallsForwardingTime);
> +	VP_SEQ_PRINTF(PageInvalidationsForwardedCount);
> +	VP_SEQ_PRINTF(PageInvalidationsForwardingTime);
> +	VP_SEQ_PRINTF(ControlRegisterAccessesForwardedCount);
> +	VP_SEQ_PRINTF(ControlRegisterAccessesForwardingTime);
> +	VP_SEQ_PRINTF(IoInstructionsForwardedCount);
> +	VP_SEQ_PRINTF(IoInstructionsForwardingTime);
> +	VP_SEQ_PRINTF(HltInstructionsForwardedCount);
> +	VP_SEQ_PRINTF(HltInstructionsForwardingTime);
> +	VP_SEQ_PRINTF(MwaitInstructionsForwardedCount);
> +	VP_SEQ_PRINTF(MwaitInstructionsForwardingTime);
> +	VP_SEQ_PRINTF(CpuidInstructionsForwardedCount);
> +	VP_SEQ_PRINTF(CpuidInstructionsForwardingTime);
> +	VP_SEQ_PRINTF(MsrAccessesForwardedCount);
> +	VP_SEQ_PRINTF(MsrAccessesForwardingTime);
> +	VP_SEQ_PRINTF(OtherInterceptsForwardedCount);
> +	VP_SEQ_PRINTF(OtherInterceptsForwardingTime);
> +	VP_SEQ_PRINTF(ExternalInterruptsForwardedCount);
> +	VP_SEQ_PRINTF(ExternalInterruptsForwardingTime);
> +	VP_SEQ_PRINTF(PendingInterruptsForwardedCount);
> +	VP_SEQ_PRINTF(PendingInterruptsForwardingTime);
> +	VP_SEQ_PRINTF(EmulatedInstructionsForwardedCount);
> +	VP_SEQ_PRINTF(EmulatedInstructionsForwardingTime);
> +	VP_SEQ_PRINTF(DebugRegisterAccessesForwardedCount);
> +	VP_SEQ_PRINTF(DebugRegisterAccessesForwardingTime);
> +	VP_SEQ_PRINTF(PageFaultInterceptsForwardedCount);
> +	VP_SEQ_PRINTF(PageFaultInterceptsForwardingTime);
> +	VP_SEQ_PRINTF(VmclearEmulationCount);
> +	VP_SEQ_PRINTF(VmclearEmulationTime);
> +	VP_SEQ_PRINTF(VmptrldEmulationCount);
> +	VP_SEQ_PRINTF(VmptrldEmulationTime);
> +	VP_SEQ_PRINTF(VmptrstEmulationCount);
> +	VP_SEQ_PRINTF(VmptrstEmulationTime);
> +	VP_SEQ_PRINTF(VmreadEmulationCount);
> +	VP_SEQ_PRINTF(VmreadEmulationTime);
> +	VP_SEQ_PRINTF(VmwriteEmulationCount);
> +	VP_SEQ_PRINTF(VmwriteEmulationTime);
> +	VP_SEQ_PRINTF(VmxoffEmulationCount);
> +	VP_SEQ_PRINTF(VmxoffEmulationTime);
> +	VP_SEQ_PRINTF(VmxonEmulationCount);
> +	VP_SEQ_PRINTF(VmxonEmulationTime);
> +	VP_SEQ_PRINTF(NestedVMEntriesCount);
> +	VP_SEQ_PRINTF(NestedVMEntriesTime);
> +	VP_SEQ_PRINTF(NestedSLATSoftPageFaultsCount);
> +	VP_SEQ_PRINTF(NestedSLATSoftPageFaultsTime);
> +	VP_SEQ_PRINTF(NestedSLATHardPageFaultsCount);
> +	VP_SEQ_PRINTF(NestedSLATHardPageFaultsTime);
> +	VP_SEQ_PRINTF(InvEptAllContextEmulationCount);
> +	VP_SEQ_PRINTF(InvEptAllContextEmulationTime);
> +	VP_SEQ_PRINTF(InvEptSingleContextEmulationCount);
> +	VP_SEQ_PRINTF(InvEptSingleContextEmulationTime);
> +	VP_SEQ_PRINTF(InvVpidAllContextEmulationCount);
> +	VP_SEQ_PRINTF(InvVpidAllContextEmulationTime);
> +	VP_SEQ_PRINTF(InvVpidSingleContextEmulationCount);
> +	VP_SEQ_PRINTF(InvVpidSingleContextEmulationTime);
> +	VP_SEQ_PRINTF(InvVpidSingleAddressEmulationCount);
> +	VP_SEQ_PRINTF(InvVpidSingleAddressEmulationTime);
> +	VP_SEQ_PRINTF(NestedTlbPageTableReclamations);
> +	VP_SEQ_PRINTF(NestedTlbPageTableEvictions);
> +	VP_SEQ_PRINTF(FlushGuestPhysicalAddressSpaceHypercalls);
> +	VP_SEQ_PRINTF(FlushGuestPhysicalAddressListHypercalls);
> +	VP_SEQ_PRINTF(PostedInterruptNotifications);
> +	VP_SEQ_PRINTF(PostedInterruptScans);
> +	VP_SEQ_PRINTF(TotalCoreRunTime);
> +	VP_SEQ_PRINTF(MaximumRunTime);
> +	VP_SEQ_PRINTF(HwpRequestContextSwitches);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket0);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket1);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket2);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket3);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket4);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket5);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket6);
> +	VP_SEQ_PRINTF(VmloadEmulationCount);
> +	VP_SEQ_PRINTF(VmloadEmulationTime);
> +	VP_SEQ_PRINTF(VmsaveEmulationCount);
> +	VP_SEQ_PRINTF(VmsaveEmulationTime);
> +	VP_SEQ_PRINTF(GifInstructionEmulationCount);
> +	VP_SEQ_PRINTF(GifInstructionEmulationTime);
> +	VP_SEQ_PRINTF(EmulatedErrataSvmInstructions);
> +	VP_SEQ_PRINTF(Placeholder1);
> +	VP_SEQ_PRINTF(Placeholder2);
> +	VP_SEQ_PRINTF(Placeholder3);
> +	VP_SEQ_PRINTF(Placeholder4);
> +	VP_SEQ_PRINTF(Placeholder5);
> +	VP_SEQ_PRINTF(Placeholder6);
> +	VP_SEQ_PRINTF(Placeholder7);
> +	VP_SEQ_PRINTF(Placeholder8);
> +	VP_SEQ_PRINTF(Placeholder9);
> +	VP_SEQ_PRINTF(Placeholder10);
> +	VP_SEQ_PRINTF(SchedulingPriority);
> +	VP_SEQ_PRINTF(RdpmcInstructionsCount);
> +	VP_SEQ_PRINTF(RdpmcInstructionsTime);
> +	VP_SEQ_PRINTF(PerfmonPmuMsrAccessesCount);
> +	VP_SEQ_PRINTF(PerfmonLbrMsrAccessesCount);
> +	VP_SEQ_PRINTF(PerfmonIptMsrAccessesCount);
> +	VP_SEQ_PRINTF(PerfmonInterruptCount);
> +	VP_SEQ_PRINTF(Vtl1DispatchCount);
> +	VP_SEQ_PRINTF(Vtl2DispatchCount);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket0);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket1);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket2);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket3);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket4);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket5);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket6);
> +	VP_SEQ_PRINTF(Vtl1RunTime);
> +	VP_SEQ_PRINTF(Vtl2RunTime);
> +	VP_SEQ_PRINTF(IommuHypercalls);
> +	VP_SEQ_PRINTF(CpuGroupHypercalls);
> +	VP_SEQ_PRINTF(VsmHypercalls);
> +	VP_SEQ_PRINTF(EventLogHypercalls);
> +	VP_SEQ_PRINTF(DeviceDomainHypercalls);
> +	VP_SEQ_PRINTF(DepositHypercalls);
> +	VP_SEQ_PRINTF(SvmHypercalls);
> +	VP_SEQ_PRINTF(BusLockAcquisitionCount);
> +#elif IS_ENABLED(CONFIG_ARM64)
> +	VP_SEQ_PRINTF(SysRegAccessesCount);
> +	VP_SEQ_PRINTF(SysRegAccessesTime);
> +	VP_SEQ_PRINTF(SmcInstructionsCount);
> +	VP_SEQ_PRINTF(SmcInstructionsTime);
> +	VP_SEQ_PRINTF(OtherInterceptsCount);
> +	VP_SEQ_PRINTF(OtherInterceptsTime);
> +	VP_SEQ_PRINTF(ExternalInterruptsCount);
> +	VP_SEQ_PRINTF(ExternalInterruptsTime);
> +	VP_SEQ_PRINTF(PendingInterruptsCount);
> +	VP_SEQ_PRINTF(PendingInterruptsTime);
> +	VP_SEQ_PRINTF(GuestPageTableMaps);
> +	VP_SEQ_PRINTF(LargePageTlbFills);
> +	VP_SEQ_PRINTF(SmallPageTlbFills);
> +	VP_SEQ_PRINTF(ReflectedGuestPageFaults);
> +	VP_SEQ_PRINTF(MemoryInterceptMessages);
> +	VP_SEQ_PRINTF(OtherMessages);
> +	VP_SEQ_PRINTF(LogicalProcessorMigrations);
> +	VP_SEQ_PRINTF(AddressDomainFlushes);
> +	VP_SEQ_PRINTF(AddressSpaceFlushes);
> +	VP_SEQ_PRINTF(SyntheticInterrupts);
> +	VP_SEQ_PRINTF(VirtualInterrupts);
> +	VP_SEQ_PRINTF(ApicSelfIpisSent);
> +	VP_SEQ_PRINTF(GpaSpaceHypercalls);
> +	VP_SEQ_PRINTF(LogicalProcessorHypercalls);
> +	VP_SEQ_PRINTF(LongSpinWaitHypercalls);
> +	VP_SEQ_PRINTF(OtherHypercalls);
> +	VP_SEQ_PRINTF(SyntheticInterruptHypercalls);
> +	VP_SEQ_PRINTF(VirtualInterruptHypercalls);
> +	VP_SEQ_PRINTF(VirtualMmuHypercalls);
> +	VP_SEQ_PRINTF(VirtualProcessorHypercalls);
> +	VP_SEQ_PRINTF(HardwareInterrupts);
> +	VP_SEQ_PRINTF(NestedPageFaultInterceptsCount);
> +	VP_SEQ_PRINTF(NestedPageFaultInterceptsTime);
> +	VP_SEQ_PRINTF(LogicalProcessorDispatches);
> +	VP_SEQ_PRINTF(WaitingForCpuTime);
> +	VP_SEQ_PRINTF(ExtendedHypercalls);
> +	VP_SEQ_PRINTF(ExtendedHypercallInterceptMessages);
> +	VP_SEQ_PRINTF(MbecNestedPageTableSwitches);
> +	VP_SEQ_PRINTF(OtherReflectedGuestExceptions);
> +	VP_SEQ_PRINTF(GlobalIoTlbFlushes);
> +	VP_SEQ_PRINTF(GlobalIoTlbFlushCost);
> +	VP_SEQ_PRINTF(LocalIoTlbFlushes);
> +	VP_SEQ_PRINTF(LocalIoTlbFlushCost);
> +	VP_SEQ_PRINTF(FlushGuestPhysicalAddressSpaceHypercalls);
> +	VP_SEQ_PRINTF(FlushGuestPhysicalAddressListHypercalls);
> +	VP_SEQ_PRINTF(PostedInterruptNotifications);
> +	VP_SEQ_PRINTF(PostedInterruptScans);
> +	VP_SEQ_PRINTF(TotalCoreRunTime);
> +	VP_SEQ_PRINTF(MaximumRunTime);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket0);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket1);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket2);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket3);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket4);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket5);
> +	VP_SEQ_PRINTF(WaitingForCpuTimeBucket6);
> +	VP_SEQ_PRINTF(HwpRequestContextSwitches);
> +	VP_SEQ_PRINTF(Placeholder2);
> +	VP_SEQ_PRINTF(Placeholder3);
> +	VP_SEQ_PRINTF(Placeholder4);
> +	VP_SEQ_PRINTF(Placeholder5);
> +	VP_SEQ_PRINTF(Placeholder6);
> +	VP_SEQ_PRINTF(Placeholder7);
> +	VP_SEQ_PRINTF(Placeholder8);
> +	VP_SEQ_PRINTF(ContentionTime);
> +	VP_SEQ_PRINTF(WakeUpTime);
> +	VP_SEQ_PRINTF(SchedulingPriority);
> +	VP_SEQ_PRINTF(Vtl1DispatchCount);
> +	VP_SEQ_PRINTF(Vtl2DispatchCount);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket0);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket1);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket2);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket3);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket4);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket5);
> +	VP_SEQ_PRINTF(Vtl2DispatchBucket6);
> +	VP_SEQ_PRINTF(Vtl1RunTime);
> +	VP_SEQ_PRINTF(Vtl2RunTime);
> +	VP_SEQ_PRINTF(IommuHypercalls);
> +	VP_SEQ_PRINTF(CpuGroupHypercalls);
> +	VP_SEQ_PRINTF(VsmHypercalls);
> +	VP_SEQ_PRINTF(EventLogHypercalls);
> +	VP_SEQ_PRINTF(DeviceDomainHypercalls);
> +	VP_SEQ_PRINTF(DepositHypercalls);
> +	VP_SEQ_PRINTF(SvmHypercalls);
> +#endif
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(vp_stats);
> +
> +static void mshv_vp_stats_unmap(u64 partition_id, u32 vp_index, void *stats_page_addr,
> +				enum hv_stats_area_type stats_area_type)
> +{
> +	union hv_stats_object_identity identity = {
> +		.vp.partition_id = partition_id,
> +		.vp.vp_index = vp_index,
> +		.vp.stats_area_type = stats_area_type,
> +	};
> +	int err;
> +
> +	err = hv_unmap_stats_page(HV_STATS_OBJECT_VP, stats_page_addr, &identity);
> +	if (err)
> +		pr_err("%s: failed to unmap partition %llu vp %u %s stats, err: %d\n",
> +		       __func__, partition_id, vp_index,
> +		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
> +		       err);
> +}
> +
> +static void *mshv_vp_stats_map(u64 partition_id, u32 vp_index,
> +			       enum hv_stats_area_type stats_area_type)
> +{
> +	union hv_stats_object_identity identity = {
> +		.vp.partition_id = partition_id,
> +		.vp.vp_index = vp_index,
> +		.vp.stats_area_type = stats_area_type,
> +	};
> +	void *stats;
> +	int err;
> +
> +	err = hv_map_stats_page(HV_STATS_OBJECT_VP, &identity, &stats);
> +	if (err) {
> +		pr_err("%s: failed to map partition %llu vp %u %s stats, err: %d\n",
> +		       __func__, partition_id, vp_index,
> +		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
> +		       err);
> +		return ERR_PTR(err);
> +	}
> +	return stats;
> +}
> +
> +static int vp_debugfs_stats_create(u64 partition_id, u32 vp_index,
> +				   struct dentry **vp_stats_ptr,
> +				   struct dentry *parent)
> +{
> +	struct dentry *dentry;
> +	struct hv_stats_page **pstats;
> +	int err;
> +
> +	pstats = kcalloc(2, sizeof(struct hv_stats_page *), GFP_KERNEL_ACCOUNT);
> +	if (!pstats)
> +		return -ENOMEM;
> +
> +	pstats[HV_STATS_AREA_SELF] = mshv_vp_stats_map(partition_id, vp_index,
> +						       HV_STATS_AREA_SELF);
> +	if (IS_ERR(pstats[HV_STATS_AREA_SELF])) {
> +		err = PTR_ERR(pstats[HV_STATS_AREA_SELF]);
> +		goto cleanup;
> +	}
> +
> +	/*
> +	 * L1VH partition cannot access its vp stats in parent area.
> +	 */
> +	if (is_l1vh_parent(partition_id)) {
> +		pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
> +	} else {
> +		pstats[HV_STATS_AREA_PARENT] = mshv_vp_stats_map(
> +			partition_id, vp_index, HV_STATS_AREA_PARENT);
> +		if (IS_ERR(pstats[HV_STATS_AREA_PARENT])) {
> +			err = PTR_ERR(pstats[HV_STATS_AREA_PARENT]);
> +			goto unmap_self;
> +		}
> +		if (!pstats[HV_STATS_AREA_PARENT])
> +			pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
> +	}
> +
> +	dentry = debugfs_create_file("stats", 0400, parent,
> +				     pstats, &vp_stats_fops);
> +	if (IS_ERR(dentry)) {
> +		err = PTR_ERR(dentry);
> +		goto unmap_vp_stats;
> +	}
> +
> +	*vp_stats_ptr = dentry;
> +	return 0;
> +
> +unmap_vp_stats:
> +	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF])
> +		mshv_vp_stats_unmap(partition_id, vp_index, pstats[HV_STATS_AREA_PARENT],
> +				    HV_STATS_AREA_PARENT);
> +unmap_self:
> +	mshv_vp_stats_unmap(partition_id, vp_index, pstats[HV_STATS_AREA_SELF],
> +			    HV_STATS_AREA_SELF);
> +cleanup:
> +	kfree(pstats);
> +	return err;
> +}
> +
> +static void vp_debugfs_remove(u64 partition_id, u32 vp_index,
> +			      struct dentry *vp_stats)
> +{
> +	struct hv_stats_page **pstats = NULL;
> +	void *stats;
> +
> +	pstats = vp_stats->d_inode->i_private;
> +	debugfs_remove_recursive(vp_stats->d_parent);
> +	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF]) {
> +		stats = pstats[HV_STATS_AREA_PARENT];
> +		mshv_vp_stats_unmap(partition_id, vp_index, stats,
> +				    HV_STATS_AREA_PARENT);
> +	}
> +
> +	stats = pstats[HV_STATS_AREA_SELF];
> +	mshv_vp_stats_unmap(partition_id, vp_index, stats, HV_STATS_AREA_SELF);
> +
> +	kfree(pstats);
> +}
> +
> +static int vp_debugfs_create(u64 partition_id, u32 vp_index,
> +			     struct dentry **vp_stats_ptr,
> +			     struct dentry *parent)
> +{
> +	struct dentry *vp_idx_dir;
> +	char vp_idx_str[U32_BUF_SZ];
> +	int err;
> +
> +	sprintf(vp_idx_str, "%u", vp_index);
> +
> +	vp_idx_dir = debugfs_create_dir(vp_idx_str, parent);
> +	if (IS_ERR(vp_idx_dir))
> +		return PTR_ERR(vp_idx_dir);
> +
> +	err = vp_debugfs_stats_create(partition_id, vp_index, vp_stats_ptr,
> +				      vp_idx_dir);
> +	if (err)
> +		goto remove_debugfs_vp_idx;
> +
> +	return 0;
> +
> +remove_debugfs_vp_idx:
> +	debugfs_remove_recursive(vp_idx_dir);
> +	return err;
> +}
> +
> +static int partition_stats_show(struct seq_file *m, void *v)
> +{
> +	const struct hv_stats_page **pstats = m->private;
> +
> +#define PARTITION_SEQ_PRINTF(cnt)				 \
> +do {								 \
> +	if (pstats[HV_STATS_AREA_SELF]->pt_cntrs[Partition##cnt]) \
> +		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
> +			pstats[HV_STATS_AREA_SELF]->pt_cntrs[Partition##cnt]); \
> +	else \
> +		seq_printf(m, "%-30s: %llu\n", __stringify(cnt), \
> +			pstats[HV_STATS_AREA_PARENT]->pt_cntrs[Partition##cnt]); \
> +} while (0)
> +
> +	PARTITION_SEQ_PRINTF(VirtualProcessors);
> +	PARTITION_SEQ_PRINTF(TlbSize);
> +	PARTITION_SEQ_PRINTF(AddressSpaces);
> +	PARTITION_SEQ_PRINTF(DepositedPages);
> +	PARTITION_SEQ_PRINTF(GpaPages);
> +	PARTITION_SEQ_PRINTF(GpaSpaceModifications);
> +	PARTITION_SEQ_PRINTF(VirtualTlbFlushEntires);
> +	PARTITION_SEQ_PRINTF(RecommendedTlbSize);
> +	PARTITION_SEQ_PRINTF(GpaPages4K);
> +	PARTITION_SEQ_PRINTF(GpaPages2M);
> +	PARTITION_SEQ_PRINTF(GpaPages1G);
> +	PARTITION_SEQ_PRINTF(GpaPages512G);
> +	PARTITION_SEQ_PRINTF(DevicePages4K);
> +	PARTITION_SEQ_PRINTF(DevicePages2M);
> +	PARTITION_SEQ_PRINTF(DevicePages1G);
> +	PARTITION_SEQ_PRINTF(DevicePages512G);
> +	PARTITION_SEQ_PRINTF(AttachedDevices);
> +	PARTITION_SEQ_PRINTF(DeviceInterruptMappings);
> +	PARTITION_SEQ_PRINTF(IoTlbFlushes);
> +	PARTITION_SEQ_PRINTF(IoTlbFlushCost);
> +	PARTITION_SEQ_PRINTF(DeviceInterruptErrors);
> +	PARTITION_SEQ_PRINTF(DeviceDmaErrors);
> +	PARTITION_SEQ_PRINTF(DeviceInterruptThrottleEvents);
> +	PARTITION_SEQ_PRINTF(SkippedTimerTicks);
> +	PARTITION_SEQ_PRINTF(PartitionId);
> +#if IS_ENABLED(CONFIG_X86_64)
> +	PARTITION_SEQ_PRINTF(NestedTlbSize);
> +	PARTITION_SEQ_PRINTF(RecommendedNestedTlbSize);
> +	PARTITION_SEQ_PRINTF(NestedTlbFreeListSize);
> +	PARTITION_SEQ_PRINTF(NestedTlbTrimmedPages);
> +	PARTITION_SEQ_PRINTF(PagesShattered);
> +	PARTITION_SEQ_PRINTF(PagesRecombined);
> +	PARTITION_SEQ_PRINTF(HwpRequestValue);
> +#elif IS_ENABLED(CONFIG_ARM64)
> +	PARTITION_SEQ_PRINTF(HwpRequestValue);
> +#endif
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(partition_stats);
> +
> +static void mshv_partition_stats_unmap(u64 partition_id, void *stats_page_addr,
> +				       enum hv_stats_area_type stats_area_type)
> +{
> +	union hv_stats_object_identity identity = {
> +		.partition.partition_id = partition_id,
> +		.partition.stats_area_type = stats_area_type,
> +	};
> +	int err;
> +
> +	err = hv_unmap_stats_page(HV_STATS_OBJECT_PARTITION, stats_page_addr,
> +				  &identity);
> +	if (err) {

nit: redundant curly brackets

> +		pr_err("%s: failed to unmap partition %lld %s stats, err: %d\n",
> +		       __func__, partition_id,
> +		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
> +		       err);
> +	}
> +}
> +
> +static void *mshv_partition_stats_map(u64 partition_id,
> +				      enum hv_stats_area_type stats_area_type)
> +{
> +	union hv_stats_object_identity identity = {
> +		.partition.partition_id = partition_id,
> +		.partition.stats_area_type = stats_area_type,
> +	};
> +	void *stats;
> +	int err;
> +
> +	err = hv_map_stats_page(HV_STATS_OBJECT_PARTITION, &identity, &stats);
> +	if (err) {
> +		pr_err("%s: failed to map partition %lld %s stats, err: %d\n",
> +		       __func__, partition_id,
> +		       (stats_area_type == HV_STATS_AREA_SELF) ? "self" : "parent",
> +		       err);
> +		return ERR_PTR(err);
> +	}
> +	return stats;
> +}
> +
> +static int mshv_debugfs_partition_stats_create(u64 partition_id,
> +					    struct dentry **partition_stats_ptr,
> +					    struct dentry *parent)
> +{
> +	struct dentry *dentry;
> +	struct hv_stats_page **pstats;
> +	int err;
> +
> +	pstats = kcalloc(2, sizeof(struct hv_stats_page *), GFP_KERNEL_ACCOUNT);
> +	if (!pstats)
> +		return -ENOMEM;
> +
> +	pstats[HV_STATS_AREA_SELF] = mshv_partition_stats_map(partition_id,
> +							      HV_STATS_AREA_SELF);
> +	if (IS_ERR(pstats[HV_STATS_AREA_SELF])) {
> +		err = PTR_ERR(pstats[HV_STATS_AREA_SELF]);
> +		goto cleanup;
> +	}
> +
> +	/*
> +	 * L1VH partition cannot access its partition stats in parent area.
> +	 */
> +	if (is_l1vh_parent(partition_id)) {
> +		pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
> +	} else {
> +		pstats[HV_STATS_AREA_PARENT] = mshv_partition_stats_map(partition_id,
> +									HV_STATS_AREA_PARENT);
> +		if (IS_ERR(pstats[HV_STATS_AREA_PARENT])) {
> +			err = PTR_ERR(pstats[HV_STATS_AREA_PARENT]);
> +			goto unmap_self;
> +		}
> +		if (!pstats[HV_STATS_AREA_PARENT])
> +			pstats[HV_STATS_AREA_PARENT] = pstats[HV_STATS_AREA_SELF];
> +	}
> +
> +	dentry = debugfs_create_file("stats", 0400, parent,
> +				     pstats, &partition_stats_fops);
> +	if (IS_ERR(dentry)) {
> +		err = PTR_ERR(dentry);
> +		goto unmap_partition_stats;
> +	}
> +
> +	*partition_stats_ptr = dentry;
> +	return 0;
> +
> +unmap_partition_stats:
> +	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF])
> +		mshv_partition_stats_unmap(partition_id, pstats[HV_STATS_AREA_PARENT],
> +					   HV_STATS_AREA_PARENT);
> +unmap_self:
> +	mshv_partition_stats_unmap(partition_id, pstats[HV_STATS_AREA_SELF],
> +				   HV_STATS_AREA_SELF);
> +cleanup:
> +	kfree(pstats);
> +	return err;
> +}
> +
> +static void partition_debugfs_remove(u64 partition_id, struct dentry *dentry)
> +{
> +	struct hv_stats_page **pstats = NULL;
> +	void *stats;

nit: stats variable looks redundant

> +
> +	pstats = dentry->d_inode->i_private;
> +
> +	debugfs_remove_recursive(dentry->d_parent);
> +
> +	if (pstats[HV_STATS_AREA_PARENT] != pstats[HV_STATS_AREA_SELF]) {
> +		stats = pstats[HV_STATS_AREA_PARENT];
> +		mshv_partition_stats_unmap(partition_id, stats, HV_STATS_AREA_PARENT);
> +	}
> +
> +	stats = pstats[HV_STATS_AREA_SELF];
> +	mshv_partition_stats_unmap(partition_id, stats, HV_STATS_AREA_SELF);
> +
> +	kfree(pstats);
> +}
> +
> +static int partition_debugfs_create(u64 partition_id,
> +				    struct dentry **vp_dir_ptr,
> +				    struct dentry **partition_stats_ptr,
> +				    struct dentry *parent)
> +{
> +	char part_id_str[U64_BUF_SZ];
> +	struct dentry *part_id_dir, *vp_dir;
> +	int err;
> +
> +	if (is_l1vh_parent(partition_id))
> +		sprintf(part_id_str, "self");
> +	else
> +		sprintf(part_id_str, "%llu", partition_id);
> +
> +	part_id_dir = debugfs_create_dir(part_id_str, parent);
> +	if (IS_ERR(part_id_dir))
> +		return PTR_ERR(part_id_dir);
> +
> +	vp_dir = debugfs_create_dir("vp", part_id_dir);
> +	if (IS_ERR(vp_dir)) {
> +		err = PTR_ERR(vp_dir);
> +		goto remove_debugfs_partition_id;
> +	}
> +
> +	err = mshv_debugfs_partition_stats_create(partition_id,
> +						  partition_stats_ptr,
> +						  part_id_dir);
> +	if (err)
> +		goto remove_debugfs_partition_id;
> +
> +	*vp_dir_ptr = vp_dir;
> +
> +	return 0;
> +
> +remove_debugfs_partition_id:
> +	debugfs_remove_recursive(part_id_dir);
> +	return err;
> +}
> +
> +static void mshv_debugfs_parent_partition_remove(void)
> +{
> +	int idx;
> +
> +	for_each_online_cpu(idx)
> +		vp_debugfs_remove(hv_current_partition_id, idx, NULL);
> +
> +	partition_debugfs_remove(hv_current_partition_id, NULL);
> +}
> +
> +static int __init mshv_debugfs_parent_partition_create(void)
> +{
> +	struct dentry *partition_stats, *vp_dir;
> +	int err, idx, i;
> +
> +	mshv_debugfs_partition = debugfs_create_dir("partition",
> +						     mshv_debugfs);
> +	if (IS_ERR(mshv_debugfs_partition))
> +		return PTR_ERR(mshv_debugfs_partition);
> +
> +	err = partition_debugfs_create(hv_current_partition_id,
> +				       &vp_dir,
> +				       &partition_stats,
> +				       mshv_debugfs_partition);
> +	if (err)
> +		goto remove_debugfs_partition;
> +
> +	for_each_online_cpu(idx) {
> +		struct dentry *vp_stats;
> +
> +		err = vp_debugfs_create(hv_current_partition_id,
> +					hv_vp_index[idx],
> +					&vp_stats,
> +					vp_dir);
> +		if (err)
> +			goto remove_debugfs_partition_vp;
> +	}
> +
> +	return 0;
> +
> +remove_debugfs_partition_vp:
> +	for_each_online_cpu(i) {
> +		if (i >= idx)
> +			break;
> +		vp_debugfs_remove(hv_current_partition_id, i, NULL);
> +	}
> +	partition_debugfs_remove(hv_current_partition_id, NULL);
> +remove_debugfs_partition:
> +	debugfs_remove_recursive(mshv_debugfs_partition);
> +	return err;
> +}
> +
> +static int hv_stats_show(struct seq_file *m, void *v)
> +{
> +	const struct hv_stats_page *stats = m->private;
> +
> +#define HV_SEQ_PRINTF(cnt)		\
> +	seq_printf(m, "%-25s: %llu\n", __stringify(cnt), stats->hv_cntrs[Hv##cnt])
> +
> +	HV_SEQ_PRINTF(LogicalProcessors);
> +	HV_SEQ_PRINTF(Partitions);
> +	HV_SEQ_PRINTF(TotalPages);
> +	HV_SEQ_PRINTF(VirtualProcessors);
> +	HV_SEQ_PRINTF(MonitoredNotifications);
> +	HV_SEQ_PRINTF(ModernStandbyEntries);
> +	HV_SEQ_PRINTF(PlatformIdleTransitions);
> +	HV_SEQ_PRINTF(HypervisorStartupCost);
> +	HV_SEQ_PRINTF(IOSpacePages);
> +	HV_SEQ_PRINTF(NonEssentialPagesForDump);
> +	HV_SEQ_PRINTF(SubsumedPages);
> +
> +	return 0;
> +}
> +DEFINE_SHOW_ATTRIBUTE(hv_stats);
> +
> +static void mshv_hv_stats_unmap(void)
> +{
> +	union hv_stats_object_identity identity = {
> +		.hv.stats_area_type = HV_STATS_AREA_SELF,
> +	};
> +	int err;
> +
> +	err = hv_unmap_stats_page(HV_STATS_OBJECT_HYPERVISOR, NULL, &identity);
> +	if (err)
> +		pr_err("%s: failed to unmap hypervisor stats: %d\n",
> +		       __func__, err);
> +}
> +
> +static void * __init mshv_hv_stats_map(void)
> +{
> +	union hv_stats_object_identity identity = {
> +		.hv.stats_area_type = HV_STATS_AREA_SELF,
> +	};
> +	void *stats;
> +	int err;
> +
> +	err = hv_map_stats_page(HV_STATS_OBJECT_HYPERVISOR, &identity, &stats);
> +	if (err) {
> +		pr_err("%s: failed to map hypervisor stats: %d\n",
> +		       __func__, err);
> +		return ERR_PTR(err);
> +	}
> +	return stats;
> +}
> +
> +static int __init mshv_debugfs_hv_stats_create(struct dentry *parent)
> +{
> +	struct dentry *dentry;
> +	u64 *stats;
> +	int err;
> +
> +	stats = mshv_hv_stats_map();
> +	if (IS_ERR(stats))
> +		return PTR_ERR(stats);
> +
> +	dentry = debugfs_create_file("stats", 0400, parent,
> +				     stats, &hv_stats_fops);
> +	if (IS_ERR(dentry)) {
> +		err = PTR_ERR(dentry);
> +		pr_err("%s: failed to create hypervisor stats dentry: %d\n",
> +		       __func__, err);
> +		goto unmap_hv_stats;
> +	}
> +
> +	mshv_lps_count = stats[HvLogicalProcessors];
> +
> +	return 0;
> +
> +unmap_hv_stats:
> +	mshv_hv_stats_unmap();
> +	return err;
> +}
> +
> +int mshv_debugfs_vp_create(struct mshv_vp *vp)
> +{
> +	struct mshv_partition *p = vp->vp_partition;
> +	int err;

nit: redundant variable

> +
> +	if (!mshv_debugfs)
> +		return 0;
> +
> +	err = vp_debugfs_create(p->pt_id, vp->vp_index,
> +				&vp->vp_debugfs_stats_dentry,
> +				p->pt_debugfs_vp_dentry);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +void mshv_debugfs_vp_remove(struct mshv_vp *vp)
> +{
> +	if (!mshv_debugfs)
> +		return;
> +
> +	vp_debugfs_remove(vp->vp_partition->pt_id, vp->vp_index,
> +			  vp->vp_debugfs_stats_dentry);
> +}
> +
> +int mshv_debugfs_partition_create(struct mshv_partition *partition)
> +{
> +	int err;
> +
> +	if (!mshv_debugfs)
> +		return 0;
> +
> +	err = partition_debugfs_create(partition->pt_id,
> +				       &partition->pt_debugfs_vp_dentry,
> +				       &partition->pt_debugfs_stats_dentry,
> +				       mshv_debugfs_partition);
> +	if (err)
> +		return err;
> +
> +	return 0;
> +}
> +
> +void mshv_debugfs_partition_remove(struct mshv_partition *partition)
> +{
> +	if (!mshv_debugfs)
> +		return;
> +
> +	partition_debugfs_remove(partition->pt_id,
> +				 partition->pt_debugfs_stats_dentry);
> +}
> +
> +int __init mshv_debugfs_init(void)
> +{
> +	int err;
> +
> +	mshv_debugfs = debugfs_create_dir("mshv", NULL);
> +	if (IS_ERR(mshv_debugfs)) {
> +		pr_err("%s: failed to create debugfs directory\n", __func__);
> +		return PTR_ERR(mshv_debugfs);
> +	}
> +
> +	if (hv_root_partition()) {
> +		err = mshv_debugfs_hv_stats_create(mshv_debugfs);
> +		if (err)
> +			goto remove_mshv_dir;
> +
> +		err = mshv_debugfs_lp_create(mshv_debugfs);
> +		if (err)
> +			goto unmap_hv_stats;
> +	}
> +
> +	err = mshv_debugfs_parent_partition_create();
> +	if (err)
> +		goto unmap_lp_stats;
> +
> +	return 0;
> +
> +unmap_lp_stats:
> +	if (hv_root_partition())
> +		mshv_debugfs_lp_remove();
> +unmap_hv_stats:
> +	if (hv_root_partition())
> +		mshv_hv_stats_unmap();
> +remove_mshv_dir:
> +	debugfs_remove_recursive(mshv_debugfs);
> +	return err;
> +}
> +
> +void mshv_debugfs_exit(void)
> +{
> +	mshv_debugfs_parent_partition_remove();
> +
> +	if (hv_root_partition()) {
> +		mshv_debugfs_lp_remove();
> +		mshv_hv_stats_unmap();
> +	}
> +
> +	debugfs_remove_recursive(mshv_debugfs);
> +}
> diff --git a/drivers/hv/mshv_root.h b/drivers/hv/mshv_root.h
> index 3eb815011b46..1f1b1984449b 100644
> --- a/drivers/hv/mshv_root.h
> +++ b/drivers/hv/mshv_root.h
> @@ -51,6 +51,9 @@ struct mshv_vp {
>  		unsigned int kicked_by_hv;
>  		wait_queue_head_t vp_suspend_queue;
>  	} run;
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +	struct dentry *vp_debugfs_stats_dentry;

nit: the name could be shorter like vp_stats_dentry, for example

> +#endif
>  };
>  
>  #define vp_fmt(fmt) "p%lluvp%u: " fmt
> @@ -128,6 +131,10 @@ struct mshv_partition {
>  	u64 isolation_type;
>  	bool import_completed;
>  	bool pt_initialized;
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +	struct dentry *pt_debugfs_stats_dentry;
> +	struct dentry *pt_debugfs_vp_dentry;

same here

> +#endif
>  };
>  
>  #define pt_fmt(fmt) "p%llu: " fmt
> @@ -308,6 +315,33 @@ int hv_call_modify_spa_host_access(u64 partition_id, struct page **pages,
>  int hv_call_get_partition_property_ex(u64 partition_id, u64 property_code, u64 arg,
>  				      void *property_value, size_t property_value_sz);
>  
> +#if IS_ENABLED(CONFIG_DEBUG_FS)
> +int __init mshv_debugfs_init(void);
> +void mshv_debugfs_exit(void);
> +
> +int mshv_debugfs_partition_create(struct mshv_partition *partition);
> +void mshv_debugfs_partition_remove(struct mshv_partition *partition);
> +int mshv_debugfs_vp_create(struct mshv_vp *vp);
> +void mshv_debugfs_vp_remove(struct mshv_vp *vp);
> +#else
> +static inline int __init mshv_debugfs_init(void)
> +{
> +	return 0;
> +}
> +static inline void mshv_debugfs_exit(void) { }
> +
> +static inline int mshv_debugfs_partition_create(struct mshv_partition *partition)
> +{
> +	return 0;
> +}
> +static inline void mshv_debugfs_partition_remove(struct mshv_partition *partition) { }
> +static inline int mshv_debugfs_vp_create(struct mshv_vp *vp)
> +{
> +	return 0;
> +}
> +static inline void mshv_debugfs_vp_remove(struct mshv_vp *vp) { }
> +#endif
> +
>  extern struct mshv_root mshv_root;
>  extern enum hv_scheduler_type hv_scheduler_type;
>  extern u8 * __percpu *hv_synic_eventring_tail;
> diff --git a/drivers/hv/mshv_root_main.c b/drivers/hv/mshv_root_main.c
> index 19006b788e85..152fcd9b45e6 100644
> --- a/drivers/hv/mshv_root_main.c
> +++ b/drivers/hv/mshv_root_main.c
> @@ -982,6 +982,10 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
>  	if (hv_scheduler_type == HV_SCHEDULER_TYPE_ROOT)
>  		memcpy(vp->vp_stats_pages, stats_pages, sizeof(stats_pages));
>  
> +	ret = mshv_debugfs_vp_create(vp);
> +	if (ret)
> +		goto put_partition;
> +
>  	/*
>  	 * Keep anon_inode_getfd last: it installs fd in the file struct and
>  	 * thus makes the state accessible in user space.
> @@ -989,7 +993,7 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
>  	ret = anon_inode_getfd("mshv_vp", &mshv_vp_fops, vp,
>  			       O_RDWR | O_CLOEXEC);
>  	if (ret < 0)
> -		goto put_partition;
> +		goto remove_debugfs_vp;
>  
>  	/* already exclusive with the partition mutex for all ioctls */
>  	partition->pt_vp_count++;
> @@ -997,6 +1001,8 @@ mshv_partition_ioctl_create_vp(struct mshv_partition *partition,
>  
>  	return ret;
>  
> +remove_debugfs_vp:
> +	mshv_debugfs_vp_remove(vp);
>  put_partition:
>  	mshv_partition_put(partition);
>  free_vp:
> @@ -1556,13 +1562,18 @@ mshv_partition_ioctl_initialize(struct mshv_partition *partition)
>  
>  	ret = hv_call_initialize_partition(partition->pt_id);
>  	if (ret)
> -		goto withdraw_mem;

Looks like the behavior changed here. Could you explain?


> +		return ret;
> +
> +	ret = mshv_debugfs_partition_create(partition);
> +	if (ret)
> +		goto finalize_partition;
>  
>  	partition->pt_initialized = true;
>  
>  	return 0;
>  
> -withdraw_mem:
> +finalize_partition:
> +	hv_call_finalize_partition(partition->pt_id);
>  	hv_call_withdraw_memory(U64_MAX, NUMA_NO_NODE, partition->pt_id);
>  
>  	return ret;
> @@ -1741,6 +1752,8 @@ static void destroy_partition(struct mshv_partition *partition)
>  			if (!vp)
>  				continue;
>  
> +			mshv_debugfs_vp_remove(vp);
> +
>  			if (hv_scheduler_type == HV_SCHEDULER_TYPE_ROOT)
>  				mshv_vp_stats_unmap(partition->pt_id, vp->vp_index,
>  						    (void **)vp->vp_stats_pages);
> @@ -1775,6 +1788,8 @@ static void destroy_partition(struct mshv_partition *partition)
>  			partition->pt_vp_array[i] = NULL;
>  		}
>  
> +		mshv_debugfs_partition_remove(partition);
> +
>  		/* Deallocates and unmaps everything including vcpus, GPA mappings etc */
>  		hv_call_finalize_partition(partition->pt_id);
>  
> @@ -2351,10 +2366,14 @@ static int __init mshv_parent_partition_init(void)
>  
>  	mshv_init_vmm_caps(dev);
>  
> -	ret = mshv_irqfd_wq_init();
> +	ret = mshv_debugfs_init();
>  	if (ret)
>  		goto exit_partition;
>  
> +	ret = mshv_irqfd_wq_init();
> +	if (ret)
> +		goto exit_debugfs;
> +
>  	spin_lock_init(&mshv_root.pt_ht_lock);
>  	hash_init(mshv_root.pt_htable);
>  
> @@ -2362,6 +2381,10 @@ static int __init mshv_parent_partition_init(void)
>  
>  	return 0;
>  
> +destroy_irqds_wq:

Where is this label used?

Thanks,
Stanislav

> +	mshv_irqfd_wq_cleanup();
> +exit_debugfs:
> +	mshv_debugfs_exit();
>  exit_partition:
>  	if (hv_root_partition())
>  		mshv_root_partition_exit();
> @@ -2378,6 +2401,7 @@ static void __exit mshv_parent_partition_exit(void)
>  {
>  	hv_setup_mshv_handler(NULL);
>  	mshv_port_table_fini();
> +	mshv_debugfs_exit();
>  	misc_deregister(&mshv_dev);
>  	mshv_irqfd_wq_cleanup();
>  	if (hv_root_partition())
> -- 
> 2.34.1