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* [PATCH v12 0/7] KVM statistics data fd-based binary interface
@ 2021-06-18 22:27 Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 1/7] KVM: stats: Separate generic stats from architecture specific ones Jing Zhang
                   ` (6 more replies)
  0 siblings, 7 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

This patchset provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
In this patchset, every statistics data are treated to have some
attributes as below:
  * architecture dependent or generic
  * VM statistics data or VCPU statistics data
  * type: cumulative, instantaneous, peak
  * unit: none for simple counter, nanosecond, microsecond,
    millisecond, second, Byte, KiByte, MiByte, GiByte, Clock Cycles
Since no lock/synchronization is used, the consistency between all
the statistics data is not guaranteed. That means not all statistics
data are read out at the exact same time, since the statistics data
are still being updated by KVM subsystems while they are read out.

---

* v11 -> v12
  - Revised the structure kvm_stats_header and corresponding code by
    Paolo's suggestion. Move the id string out of header.
  - Define stats header and stats descriptors as const.
  - Update some comments by Greg's review.

* v10 -> v11
  - Rebase to kvm/queue, commit f1b832550832
    (KVM: x86/mmu: Fix TDP MMU page table level)
  - Separate binary stats implementation commit
  - Use flexible length array member field in API structure instead of
    zero-length array member field
  - Move major binary stats reading function in a separate source file
  - Move stats id string into vm/vcpu structures
  - Add some detailed comments and update commit messages
  - Addressed some other review comments from Greg K.H. and Paolo.

* v9 -> v10
  - Relocate vcpu stat in vcpu's slab's usercopy region
  - Fix test issue for capability checking
  - Update commit message to explain why/how we need to add this new
    API for KVM statistics

* v8 -> v9
  - Rebase to commit 8331a2bc0898
    (KVM: X86: Introduce KVM_HC_MAP_GPA_RANGE hypercall)
  - Reduce code duplication between binary and debugfs interface
  - Add field "offset" in stats descriptor to let us define stats
    descriptors in any order (not necessary in the order of stats
    defined in vm/vcpu stats structures)
  - Add static check to make sure the number of stats descriptors
    is the same as the number of stats defined in vm/vcpu stats
    structures
  - Fix missing/mismatched stats descriptor definition caused by
    rebase

* v7 -> v8
  - Rebase to kvm/queue, commit c1dc20e254b4 ("KVM: switch per-VM
  stats to u64")
  - Revise code to reflect the per-VM stats type from ulong to u64
  - Addressed some other nits

* v6 -> v7
  - Improve file descriptor allocation function by Krish suggestion
  - Use "generic stats" instead of "common stats" as Krish suggested
  - Addressed some other nits from Krish and David Matlack

* v5 -> v6
  - Use designated initializers for STATS_DESC
  - Change KVM_STATS_SCALE... to KVM_STATS_BASE...
  - Use a common function for kvm_[vm|vcpu]_stats_read
  - Fix some documentation errors/missings
  - Use TEST_ASSERT in selftest
  - Use a common function for [vm|vcpu]_stats_test in selftest

* v4 -> v5
  - Rebase to kvm/queue, commit a4345a7cecfb ("Merge tag
    'kvmarm-fixes-5.13-1'")
  - Change maximum stats name length to 48
  - Replace VM_STATS_COMMON/VCPU_STATS_COMMON macros with stats
    descriptor definition macros.
  - Fixed some errors/warnings reported by checkpatch.pl

* v3 -> v4
  - Rebase to kvm/queue, commit 9f242010c3b4 ("KVM: avoid "deadlock"
    between install_new_memslots and MMU notifier")
  - Use C-stype comments in the whole patch
  - Fix wrong count for x86 VCPU stats descriptors
  - Fix KVM stats data size counting and validity check in selftest

* v2 -> v3
  - Rebase to kvm/queue, commit edf408f5257b ("KVM: avoid "deadlock"
    between install_new_memslots and MMU notifier")
  - Resolve some nitpicks about format

* v1 -> v2
  - Use ARRAY_SIZE to count the number of stats descriptors
  - Fix missing `size` field initialization in macro STATS_DESC

[1] https://lore.kernel.org/kvm/20210402224359.2297157-1-jingzhangos@google.com
[2] https://lore.kernel.org/kvm/20210415151741.1607806-1-jingzhangos@google.com
[3] https://lore.kernel.org/kvm/20210423181727.596466-1-jingzhangos@google.com
[4] https://lore.kernel.org/kvm/20210429203740.1935629-1-jingzhangos@google.com
[5] https://lore.kernel.org/kvm/20210517145314.157626-1-jingzhangos@google.com
[6] https://lore.kernel.org/kvm/20210524151828.4113777-1-jingzhangos@google.com
[7] https://lore.kernel.org/kvm/20210603211426.790093-1-jingzhangos@google.com
[8] https://lore.kernel.org/kvm/20210611124624.1404010-1-jingzhangos@google.com
[9] https://lore.kernel.org/kvm/20210614212155.1670777-1-jingzhangos@google.com
[10] https://lore.kernel.org/kvm/20210617044146.2667540-1-jingzhangos@google.com
[11] https://lore.kernel.org/kvm/20210618044819.3690166-1-jingzhangos@google.com

---

Jing Zhang (7):
  KVM: stats: Separate generic stats from architecture specific ones
  KVM: stats: Add fd-based API to read binary stats data
  KVM: stats: Support binary stats retrieval for a VM
  KVM: stats: Support binary stats retrieval for a VCPU
  KVM: stats: Add documentation for binary statistics interface
  KVM: selftests: Add selftest for KVM statistics data binary interface
  KVM: stats: Remove code duplication for binary and debugfs stats

 Documentation/virt/kvm/api.rst                | 198 ++++++++++++++-
 arch/arm64/include/asm/kvm_host.h             |   9 +-
 arch/arm64/kvm/Makefile                       |   2 +-
 arch/arm64/kvm/guest.c                        |  48 ++--
 arch/mips/include/asm/kvm_host.h              |   9 +-
 arch/mips/kvm/Makefile                        |   2 +-
 arch/mips/kvm/mips.c                          |  90 ++++---
 arch/powerpc/include/asm/kvm_host.h           |   9 +-
 arch/powerpc/kvm/Makefile                     |   2 +-
 arch/powerpc/kvm/book3s.c                     |  91 ++++---
 arch/powerpc/kvm/book3s_hv.c                  |  12 +-
 arch/powerpc/kvm/book3s_pr.c                  |   2 +-
 arch/powerpc/kvm/book3s_pr_papr.c             |   2 +-
 arch/powerpc/kvm/booke.c                      |  76 ++++--
 arch/s390/include/asm/kvm_host.h              |   9 +-
 arch/s390/kvm/Makefile                        |   3 +-
 arch/s390/kvm/kvm-s390.c                      | 232 +++++++++--------
 arch/x86/include/asm/kvm_host.h               |   9 +-
 arch/x86/kvm/Makefile                         |   2 +-
 arch/x86/kvm/x86.c                            | 109 ++++----
 include/linux/kvm_host.h                      | 182 ++++++++++++--
 include/linux/kvm_types.h                     |  14 ++
 include/uapi/linux/kvm.h                      |  73 ++++++
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   3 +
 .../testing/selftests/kvm/include/kvm_util.h  |   3 +
 .../selftests/kvm/kvm_binary_stats_test.c     | 234 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/kvm_util.c    |  12 +
 virt/kvm/binary_stats.c                       | 144 +++++++++++
 virt/kvm/kvm_main.c                           | 218 +++++++++++++---
 30 files changed, 1443 insertions(+), 357 deletions(-)
 create mode 100644 tools/testing/selftests/kvm/kvm_binary_stats_test.c
 create mode 100644 virt/kvm/binary_stats.c


base-commit: f1b8325508327a302f1d5cd8a4bf51e2c9c72fa9
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply	[flat|nested] 16+ messages in thread

* [PATCH v12 1/7] KVM: stats: Separate generic stats from architecture specific ones
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data Jing Zhang
                   ` (5 subsequent siblings)
  6 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

Put all generic statistics in a separate structure to ease
statistics handling for the incoming new statistics API.
Generic KVM stats are those collected in architecture
independent code or those supported by all architectures.

No functional change intended.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 arch/arm64/include/asm/kvm_host.h   |  9 ++-------
 arch/arm64/kvm/guest.c              | 12 ++++++------
 arch/mips/include/asm/kvm_host.h    |  9 ++-------
 arch/mips/kvm/mips.c                | 12 ++++++------
 arch/powerpc/include/asm/kvm_host.h |  9 ++-------
 arch/powerpc/kvm/book3s.c           | 12 ++++++------
 arch/powerpc/kvm/book3s_hv.c        | 12 ++++++------
 arch/powerpc/kvm/book3s_pr.c        |  2 +-
 arch/powerpc/kvm/book3s_pr_papr.c   |  2 +-
 arch/powerpc/kvm/booke.c            | 14 +++++++-------
 arch/s390/include/asm/kvm_host.h    |  9 ++-------
 arch/s390/kvm/kvm-s390.c            | 12 ++++++------
 arch/x86/include/asm/kvm_host.h     |  9 ++-------
 arch/x86/kvm/x86.c                  | 14 +++++++-------
 include/linux/kvm_host.h            |  9 +++++++--
 include/linux/kvm_types.h           | 12 ++++++++++++
 virt/kvm/kvm_main.c                 | 14 +++++++-------
 17 files changed, 82 insertions(+), 90 deletions(-)

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index d56f365b38a8..5a2c82f63baa 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -556,16 +556,11 @@ static inline bool __vcpu_write_sys_reg_to_cpu(u64 val, int reg)
 }
 
 struct kvm_vm_stat {
-	u64 remote_tlb_flush;
+	struct kvm_vm_stat_generic generic;
 };
 
 struct kvm_vcpu_stat {
-	u64 halt_successful_poll;
-	u64 halt_attempted_poll;
-	u64 halt_poll_success_ns;
-	u64 halt_poll_fail_ns;
-	u64 halt_poll_invalid;
-	u64 halt_wakeup;
+	struct kvm_vcpu_stat_generic generic;
 	u64 hvc_exit_stat;
 	u64 wfe_exit_stat;
 	u64 wfi_exit_stat;
diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 5cb4a1cd5603..4962331d01e6 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -29,18 +29,18 @@
 #include "trace.h"
 
 struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
 	VCPU_STAT("hvc_exit_stat", hvc_exit_stat),
 	VCPU_STAT("wfe_exit_stat", wfe_exit_stat),
 	VCPU_STAT("wfi_exit_stat", wfi_exit_stat),
 	VCPU_STAT("mmio_exit_user", mmio_exit_user),
 	VCPU_STAT("mmio_exit_kernel", mmio_exit_kernel),
 	VCPU_STAT("exits", exits),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
 	{ NULL }
 };
 
diff --git a/arch/mips/include/asm/kvm_host.h b/arch/mips/include/asm/kvm_host.h
index 4245c082095f..696f6b009377 100644
--- a/arch/mips/include/asm/kvm_host.h
+++ b/arch/mips/include/asm/kvm_host.h
@@ -109,10 +109,11 @@ static inline bool kvm_is_error_hva(unsigned long addr)
 }
 
 struct kvm_vm_stat {
-	u64 remote_tlb_flush;
+	struct kvm_vm_stat_generic generic;
 };
 
 struct kvm_vcpu_stat {
+	struct kvm_vcpu_stat_generic generic;
 	u64 wait_exits;
 	u64 cache_exits;
 	u64 signal_exits;
@@ -142,12 +143,6 @@ struct kvm_vcpu_stat {
 #ifdef CONFIG_CPU_LOONGSON64
 	u64 vz_cpucfg_exits;
 #endif
-	u64 halt_successful_poll;
-	u64 halt_attempted_poll;
-	u64 halt_poll_success_ns;
-	u64 halt_poll_fail_ns;
-	u64 halt_poll_invalid;
-	u64 halt_wakeup;
 };
 
 struct kvm_arch_memory_slot {
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 4d4af97dcc88..ff205b35719b 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -68,12 +68,12 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 #ifdef CONFIG_CPU_LOONGSON64
 	VCPU_STAT("vz_cpucfg", vz_cpucfg_exits),
 #endif
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
 	{NULL}
 };
 
diff --git a/arch/powerpc/include/asm/kvm_host.h b/arch/powerpc/include/asm/kvm_host.h
index ae3d4af61b66..80cfe4f42894 100644
--- a/arch/powerpc/include/asm/kvm_host.h
+++ b/arch/powerpc/include/asm/kvm_host.h
@@ -81,12 +81,13 @@ struct kvmppc_book3s_shadow_vcpu;
 struct kvm_nested_guest;
 
 struct kvm_vm_stat {
-	u64 remote_tlb_flush;
+	struct kvm_vm_stat_generic generic;
 	u64 num_2M_pages;
 	u64 num_1G_pages;
 };
 
 struct kvm_vcpu_stat {
+	struct kvm_vcpu_stat_generic generic;
 	u64 sum_exits;
 	u64 mmio_exits;
 	u64 signal_exits;
@@ -102,14 +103,8 @@ struct kvm_vcpu_stat {
 	u64 emulated_inst_exits;
 	u64 dec_exits;
 	u64 ext_intr_exits;
-	u64 halt_poll_success_ns;
-	u64 halt_poll_fail_ns;
 	u64 halt_wait_ns;
-	u64 halt_successful_poll;
-	u64 halt_attempted_poll;
 	u64 halt_successful_wait;
-	u64 halt_poll_invalid;
-	u64 halt_wakeup;
 	u64 dbell_exits;
 	u64 gdbell_exits;
 	u64 ld;
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 2b691f4d1f26..92cdb4175945 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -47,14 +47,14 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("dec", dec_exits),
 	VCPU_STAT("ext_intr", ext_intr_exits),
 	VCPU_STAT("queue_intr", queue_intr),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
 	VCPU_STAT("halt_wait_ns", halt_wait_ns),
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
 	VCPU_STAT("halt_successful_wait", halt_successful_wait),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
 	VCPU_STAT("pf_storage", pf_storage),
 	VCPU_STAT("sp_storage", sp_storage),
 	VCPU_STAT("pf_instruc", pf_instruc),
diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 7360350e66ff..b3506c35a46b 100644
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -236,7 +236,7 @@ static void kvmppc_fast_vcpu_kick_hv(struct kvm_vcpu *vcpu)
 
 	waitp = kvm_arch_vcpu_get_wait(vcpu);
 	if (rcuwait_wake_up(waitp))
-		++vcpu->stat.halt_wakeup;
+		++vcpu->stat.generic.halt_wakeup;
 
 	cpu = READ_ONCE(vcpu->arch.thread_cpu);
 	if (cpu >= 0 && kvmppc_ipi_thread(cpu))
@@ -3925,7 +3925,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 	cur = start_poll = ktime_get();
 	if (vc->halt_poll_ns) {
 		ktime_t stop = ktime_add_ns(start_poll, vc->halt_poll_ns);
-		++vc->runner->stat.halt_attempted_poll;
+		++vc->runner->stat.generic.halt_attempted_poll;
 
 		vc->vcore_state = VCORE_POLLING;
 		spin_unlock(&vc->lock);
@@ -3942,7 +3942,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 		vc->vcore_state = VCORE_INACTIVE;
 
 		if (!do_sleep) {
-			++vc->runner->stat.halt_successful_poll;
+			++vc->runner->stat.generic.halt_successful_poll;
 			goto out;
 		}
 	}
@@ -3954,7 +3954,7 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 		do_sleep = 0;
 		/* If we polled, count this as a successful poll */
 		if (vc->halt_poll_ns)
-			++vc->runner->stat.halt_successful_poll;
+			++vc->runner->stat.generic.halt_successful_poll;
 		goto out;
 	}
 
@@ -3981,13 +3981,13 @@ static void kvmppc_vcore_blocked(struct kvmppc_vcore *vc)
 			ktime_to_ns(cur) - ktime_to_ns(start_wait);
 		/* Attribute failed poll time */
 		if (vc->halt_poll_ns)
-			vc->runner->stat.halt_poll_fail_ns +=
+			vc->runner->stat.generic.halt_poll_fail_ns +=
 				ktime_to_ns(start_wait) -
 				ktime_to_ns(start_poll);
 	} else {
 		/* Attribute successful poll time */
 		if (vc->halt_poll_ns)
-			vc->runner->stat.halt_poll_success_ns +=
+			vc->runner->stat.generic.halt_poll_success_ns +=
 				ktime_to_ns(cur) -
 				ktime_to_ns(start_poll);
 	}
diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c
index d7733b07f489..71bcb0140461 100644
--- a/arch/powerpc/kvm/book3s_pr.c
+++ b/arch/powerpc/kvm/book3s_pr.c
@@ -493,7 +493,7 @@ static void kvmppc_set_msr_pr(struct kvm_vcpu *vcpu, u64 msr)
 		if (!vcpu->arch.pending_exceptions) {
 			kvm_vcpu_block(vcpu);
 			kvm_clear_request(KVM_REQ_UNHALT, vcpu);
-			vcpu->stat.halt_wakeup++;
+			vcpu->stat.generic.halt_wakeup++;
 
 			/* Unset POW bit after we woke up */
 			msr &= ~MSR_POW;
diff --git a/arch/powerpc/kvm/book3s_pr_papr.c b/arch/powerpc/kvm/book3s_pr_papr.c
index 031c8015864a..ac14239f3424 100644
--- a/arch/powerpc/kvm/book3s_pr_papr.c
+++ b/arch/powerpc/kvm/book3s_pr_papr.c
@@ -378,7 +378,7 @@ int kvmppc_h_pr(struct kvm_vcpu *vcpu, unsigned long cmd)
 		kvmppc_set_msr_fast(vcpu, kvmppc_get_msr(vcpu) | MSR_EE);
 		kvm_vcpu_block(vcpu);
 		kvm_clear_request(KVM_REQ_UNHALT, vcpu);
-		vcpu->stat.halt_wakeup++;
+		vcpu->stat.generic.halt_wakeup++;
 		return EMULATE_DONE;
 	case H_LOGICAL_CI_LOAD:
 		return kvmppc_h_pr_logical_ci_load(vcpu);
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 7d5fe43f85c4..80d3b39aa7ac 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -49,15 +49,15 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("inst_emu", emulated_inst_exits),
 	VCPU_STAT("dec", dec_exits),
 	VCPU_STAT("ext_intr", ext_intr_exits),
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
 	VCPU_STAT("doorbell", dbell_exits),
 	VCPU_STAT("guest doorbell", gdbell_exits),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
-	VM_STAT("remote_tlb_flush", remote_tlb_flush),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
+	VM_STAT_GENERIC("remote_tlb_flush", remote_tlb_flush),
 	{ NULL }
 };
 
diff --git a/arch/s390/include/asm/kvm_host.h b/arch/s390/include/asm/kvm_host.h
index 8925f3969478..9b4473f76e56 100644
--- a/arch/s390/include/asm/kvm_host.h
+++ b/arch/s390/include/asm/kvm_host.h
@@ -361,6 +361,7 @@ struct sie_page {
 };
 
 struct kvm_vcpu_stat {
+	struct kvm_vcpu_stat_generic generic;
 	u64 exit_userspace;
 	u64 exit_null;
 	u64 exit_external_request;
@@ -370,13 +371,7 @@ struct kvm_vcpu_stat {
 	u64 exit_validity;
 	u64 exit_instruction;
 	u64 exit_pei;
-	u64 halt_successful_poll;
-	u64 halt_attempted_poll;
-	u64 halt_poll_invalid;
 	u64 halt_no_poll_steal;
-	u64 halt_wakeup;
-	u64 halt_poll_success_ns;
-	u64 halt_poll_fail_ns;
 	u64 instruction_lctl;
 	u64 instruction_lctlg;
 	u64 instruction_stctl;
@@ -755,12 +750,12 @@ struct kvm_vcpu_arch {
 };
 
 struct kvm_vm_stat {
+	struct kvm_vm_stat_generic generic;
 	u64 inject_io;
 	u64 inject_float_mchk;
 	u64 inject_pfault_done;
 	u64 inject_service_signal;
 	u64 inject_virtio;
-	u64 remote_tlb_flush;
 };
 
 struct kvm_arch_memory_slot {
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 1296fc10f80c..e8bc7cd06794 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -72,13 +72,13 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("exit_program_interruption", exit_program_interruption),
 	VCPU_STAT("exit_instr_and_program_int", exit_instr_and_program),
 	VCPU_STAT("exit_operation_exception", exit_operation_exception),
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
 	VCPU_STAT("halt_no_poll_steal", halt_no_poll_steal),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
 	VCPU_STAT("instruction_lctlg", instruction_lctlg),
 	VCPU_STAT("instruction_lctl", instruction_lctl),
 	VCPU_STAT("instruction_stctl", instruction_stctl),
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index e11d64aa0bcd..408051552121 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1160,6 +1160,7 @@ struct kvm_arch {
 };
 
 struct kvm_vm_stat {
+	struct kvm_vm_stat_generic generic;
 	u64 mmu_shadow_zapped;
 	u64 mmu_pte_write;
 	u64 mmu_pde_zapped;
@@ -1167,13 +1168,13 @@ struct kvm_vm_stat {
 	u64 mmu_recycled;
 	u64 mmu_cache_miss;
 	u64 mmu_unsync;
-	u64 remote_tlb_flush;
 	u64 lpages;
 	u64 nx_lpage_splits;
 	u64 max_mmu_page_hash_collisions;
 };
 
 struct kvm_vcpu_stat {
+	struct kvm_vcpu_stat_generic generic;
 	u64 pf_fixed;
 	u64 pf_guest;
 	u64 tlb_flush;
@@ -1187,10 +1188,6 @@ struct kvm_vcpu_stat {
 	u64 nmi_window_exits;
 	u64 l1d_flush;
 	u64 halt_exits;
-	u64 halt_successful_poll;
-	u64 halt_attempted_poll;
-	u64 halt_poll_invalid;
-	u64 halt_wakeup;
 	u64 request_irq_exits;
 	u64 irq_exits;
 	u64 host_state_reload;
@@ -1201,8 +1198,6 @@ struct kvm_vcpu_stat {
 	u64 irq_injections;
 	u64 nmi_injections;
 	u64 req_event;
-	u64 halt_poll_success_ns;
-	u64 halt_poll_fail_ns;
 	u64 nested_run;
 	u64 directed_yield_attempted;
 	u64 directed_yield_successful;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8b898ec8d349..157212157aee 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -235,10 +235,10 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("irq_window", irq_window_exits),
 	VCPU_STAT("nmi_window", nmi_window_exits),
 	VCPU_STAT("halt_exits", halt_exits),
-	VCPU_STAT("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_wakeup", halt_wakeup),
+	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
+	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
+	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
+	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
 	VCPU_STAT("hypercalls", hypercalls),
 	VCPU_STAT("request_irq", request_irq_exits),
 	VCPU_STAT("irq_exits", irq_exits),
@@ -250,8 +250,8 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("nmi_injections", nmi_injections),
 	VCPU_STAT("req_event", req_event),
 	VCPU_STAT("l1d_flush", l1d_flush),
-	VCPU_STAT("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT("halt_poll_fail_ns", halt_poll_fail_ns),
+	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
+	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
 	VCPU_STAT("nested_run", nested_run),
 	VCPU_STAT("directed_yield_attempted", directed_yield_attempted),
 	VCPU_STAT("directed_yield_successful", directed_yield_successful),
@@ -263,7 +263,7 @@ struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VM_STAT("mmu_recycled", mmu_recycled),
 	VM_STAT("mmu_cache_miss", mmu_cache_miss),
 	VM_STAT("mmu_unsync", mmu_unsync),
-	VM_STAT("remote_tlb_flush", remote_tlb_flush),
+	VM_STAT_GENERIC("remote_tlb_flush", remote_tlb_flush),
 	VM_STAT("largepages", lpages, .mode = 0444),
 	VM_STAT("nx_largepages_splitted", nx_lpage_splits, .mode = 0444),
 	VM_STAT("max_mmu_page_hash_collisions", max_mmu_page_hash_collisions),
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 37cbb56ccd09..5a31e0696360 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1275,10 +1275,15 @@ struct kvm_stats_debugfs_item {
 #define KVM_DBGFS_GET_MODE(dbgfs_item)                                         \
 	((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
 
-#define VM_STAT(n, x, ...) 							\
+#define VM_STAT(n, x, ...)						       \
 	{ n, offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__ }
-#define VCPU_STAT(n, x, ...)							\
+#define VCPU_STAT(n, x, ...)						       \
 	{ n, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__ }
+#define VM_STAT_GENERIC(n, x, ...)					       \
+	{ n, offsetof(struct kvm, stat.generic.x), KVM_STAT_VM, ## __VA_ARGS__ }
+#define VCPU_STAT_GENERIC(n, x, ...)					       \
+	{ n, offsetof(struct kvm_vcpu, stat.generic.x),			       \
+	  KVM_STAT_VCPU, ## __VA_ARGS__ }
 
 extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index a7580f69dda0..48db778291b7 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -76,5 +76,17 @@ struct kvm_mmu_memory_cache {
 };
 #endif
 
+struct kvm_vm_stat_generic {
+	u64 remote_tlb_flush;
+};
+
+struct kvm_vcpu_stat_generic {
+	u64 halt_successful_poll;
+	u64 halt_attempted_poll;
+	u64 halt_poll_invalid;
+	u64 halt_wakeup;
+	u64 halt_poll_success_ns;
+	u64 halt_poll_fail_ns;
+};
 
 #endif /* __KVM_TYPES_H__ */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index ed4d1581d502..cec986487b30 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -332,7 +332,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm)
 	 */
 	if (!kvm_arch_flush_remote_tlb(kvm)
 	    || kvm_make_all_cpus_request(kvm, KVM_REQ_TLB_FLUSH))
-		++kvm->stat.remote_tlb_flush;
+		++kvm->stat.generic.remote_tlb_flush;
 	cmpxchg(&kvm->tlbs_dirty, dirty_count, 0);
 }
 EXPORT_SYMBOL_GPL(kvm_flush_remote_tlbs);
@@ -3029,9 +3029,9 @@ static inline void
 update_halt_poll_stats(struct kvm_vcpu *vcpu, u64 poll_ns, bool waited)
 {
 	if (waited)
-		vcpu->stat.halt_poll_fail_ns += poll_ns;
+		vcpu->stat.generic.halt_poll_fail_ns += poll_ns;
 	else
-		vcpu->stat.halt_poll_success_ns += poll_ns;
+		vcpu->stat.generic.halt_poll_success_ns += poll_ns;
 }
 
 /*
@@ -3049,16 +3049,16 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
 	if (vcpu->halt_poll_ns && !kvm_arch_no_poll(vcpu)) {
 		ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
 
-		++vcpu->stat.halt_attempted_poll;
+		++vcpu->stat.generic.halt_attempted_poll;
 		do {
 			/*
 			 * This sets KVM_REQ_UNHALT if an interrupt
 			 * arrives.
 			 */
 			if (kvm_vcpu_check_block(vcpu) < 0) {
-				++vcpu->stat.halt_successful_poll;
+				++vcpu->stat.generic.halt_successful_poll;
 				if (!vcpu_valid_wakeup(vcpu))
-					++vcpu->stat.halt_poll_invalid;
+					++vcpu->stat.generic.halt_poll_invalid;
 				goto out;
 			}
 			poll_end = cur = ktime_get();
@@ -3115,7 +3115,7 @@ bool kvm_vcpu_wake_up(struct kvm_vcpu *vcpu)
 	waitp = kvm_arch_vcpu_get_wait(vcpu);
 	if (rcuwait_wake_up(waitp)) {
 		WRITE_ONCE(vcpu->ready, true);
-		++vcpu->stat.halt_wakeup;
+		++vcpu->stat.generic.halt_wakeup;
 		return true;
 	}
 
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 1/7] KVM: stats: Separate generic stats from architecture specific ones Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-21 16:54   ` Paolo Bonzini
  2021-06-18 22:27 ` [PATCH v12 3/7] KVM: stats: Support binary stats retrieval for a VM Jing Zhang
                   ` (4 subsequent siblings)
  6 siblings, 1 reply; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

This commit defines the API for userspace and prepare the common
functionalities to support per VM/VCPU binary stats data readings.

The KVM stats now is only accessible by debugfs, which has some
shortcomings this change series are supposed to fix:
1. The current debugfs stats solution in KVM could be disabled
   when kernel Lockdown mode is enabled, which is a potential
   rick for production.
2. The current debugfs stats solution in KVM is organized as "one
   stats per file", it is good for debugging, but not efficient
   for production.
3. The stats read/clear in current debugfs solution in KVM are
   protected by the global kvm_lock.

Besides that, there are some other benefits with this change:
1. All KVM VM/VCPU stats can be read out in a bulk by one copy
   to userspace.
2. A schema is used to describe KVM statistics. From userspace's
   perspective, the KVM statistics are self-describing.
3. With the fd-based solution, a separate telemetry would be able
   to read KVM stats in a less privileged environment.
4. After the initial setup by reading in stats descriptors, a
   telemetry only needs to read the stats data itself, no more
   parsing or setup is needed.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 arch/arm64/kvm/Makefile   |   2 +-
 arch/mips/kvm/Makefile    |   2 +-
 arch/powerpc/kvm/Makefile |   2 +-
 arch/s390/kvm/Makefile    |   3 +-
 arch/x86/kvm/Makefile     |   2 +-
 include/linux/kvm_host.h  | 151 ++++++++++++++++++++++++++++++++++++++
 include/uapi/linux/kvm.h  |  73 ++++++++++++++++++
 virt/kvm/binary_stats.c   | 144 ++++++++++++++++++++++++++++++++++++
 8 files changed, 374 insertions(+), 5 deletions(-)
 create mode 100644 virt/kvm/binary_stats.c

diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile
index 589921392cb1..989bb5dad2c8 100644
--- a/arch/arm64/kvm/Makefile
+++ b/arch/arm64/kvm/Makefile
@@ -11,7 +11,7 @@ obj-$(CONFIG_KVM) += kvm.o
 obj-$(CONFIG_KVM) += hyp/
 
 kvm-y := $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o $(KVM)/eventfd.o \
-	 $(KVM)/vfio.o $(KVM)/irqchip.o \
+	 $(KVM)/vfio.o $(KVM)/irqchip.o $(KVM)/binary_stats.o \
 	 arm.o mmu.o mmio.o psci.o perf.o hypercalls.o pvtime.o \
 	 inject_fault.o va_layout.o handle_exit.o \
 	 guest.o debug.o reset.o sys_regs.o \
diff --git a/arch/mips/kvm/Makefile b/arch/mips/kvm/Makefile
index 30cc060857c7..c67250a956b8 100644
--- a/arch/mips/kvm/Makefile
+++ b/arch/mips/kvm/Makefile
@@ -2,7 +2,7 @@
 # Makefile for KVM support for MIPS
 #
 
-common-objs-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o eventfd.o)
+common-objs-y = $(addprefix ../../../virt/kvm/, kvm_main.o coalesced_mmio.o eventfd.o binary_stats.o)
 
 EXTRA_CFLAGS += -Ivirt/kvm -Iarch/mips/kvm
 
diff --git a/arch/powerpc/kvm/Makefile b/arch/powerpc/kvm/Makefile
index 2bfeaa13befb..b347d043b932 100644
--- a/arch/powerpc/kvm/Makefile
+++ b/arch/powerpc/kvm/Makefile
@@ -6,7 +6,7 @@
 ccflags-y := -Ivirt/kvm -Iarch/powerpc/kvm
 KVM := ../../../virt/kvm
 
-common-objs-y = $(KVM)/kvm_main.o $(KVM)/eventfd.o
+common-objs-y = $(KVM)/kvm_main.o $(KVM)/eventfd.o $(KVM)/binary_stats.o
 common-objs-$(CONFIG_KVM_VFIO) += $(KVM)/vfio.o
 common-objs-$(CONFIG_KVM_MMIO) += $(KVM)/coalesced_mmio.o
 
diff --git a/arch/s390/kvm/Makefile b/arch/s390/kvm/Makefile
index 12decca22e7c..b3aaadc60ead 100644
--- a/arch/s390/kvm/Makefile
+++ b/arch/s390/kvm/Makefile
@@ -4,7 +4,8 @@
 # Copyright IBM Corp. 2008
 
 KVM := ../../../virt/kvm
-common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o  $(KVM)/async_pf.o $(KVM)/irqchip.o $(KVM)/vfio.o
+common-objs = $(KVM)/kvm_main.o $(KVM)/eventfd.o  $(KVM)/async_pf.o \
+	      $(KVM)/irqchip.o $(KVM)/vfio.o $(KVM)/binary_stats.o
 
 ccflags-y := -Ivirt/kvm -Iarch/s390/kvm
 
diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
index 83331376b779..75dfd27b6e8a 100644
--- a/arch/x86/kvm/Makefile
+++ b/arch/x86/kvm/Makefile
@@ -11,7 +11,7 @@ KVM := ../../../virt/kvm
 
 kvm-y			+= $(KVM)/kvm_main.o $(KVM)/coalesced_mmio.o \
 				$(KVM)/eventfd.o $(KVM)/irqchip.o $(KVM)/vfio.o \
-				$(KVM)/dirty_ring.o
+				$(KVM)/dirty_ring.o $(KVM)/binary_stats.o
 kvm-$(CONFIG_KVM_ASYNC_PF)	+= $(KVM)/async_pf.o
 
 kvm-y			+= x86.o emulate.o i8259.o irq.o lapic.o \
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 5a31e0696360..30434be38858 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1272,6 +1272,12 @@ struct kvm_stats_debugfs_item {
 	int mode;
 };
 
+#define KVM_STATS_NAME_SIZE     48
+struct _kvm_stats_desc {
+	struct kvm_stats_desc desc;
+	char name[KVM_STATS_NAME_SIZE];
+};
+
 #define KVM_DBGFS_GET_MODE(dbgfs_item)                                         \
 	((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
 
@@ -1285,8 +1291,153 @@ struct kvm_stats_debugfs_item {
 	{ n, offsetof(struct kvm_vcpu, stat.generic.x),			       \
 	  KVM_STAT_VCPU, ## __VA_ARGS__ }
 
+#define STATS_DESC_COMMON(type, unit, base, exp)			       \
+	.flags = type | unit | base |					       \
+		 BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) |	       \
+		 BUILD_BUG_ON_ZERO(unit & ~KVM_STATS_UNIT_MASK) |	       \
+		 BUILD_BUG_ON_ZERO(base & ~KVM_STATS_BASE_MASK),	       \
+	.exponent = exp,						       \
+	.size = 1
+
+#define VM_GENERIC_STATS_DESC(stat, type, unit, base, exp)		       \
+	{								       \
+		{							       \
+			STATS_DESC_COMMON(type, unit, base, exp),	       \
+			.offset = offsetof(struct kvm_vm_stat, generic.stat)   \
+		},							       \
+		.name = #stat,						       \
+	}
+#define VCPU_GENERIC_STATS_DESC(stat, type, unit, base, exp)		       \
+	{								       \
+		{							       \
+			STATS_DESC_COMMON(type, unit, base, exp),	       \
+			.offset = offsetof(struct kvm_vcpu_stat, generic.stat) \
+		},							       \
+		.name = #stat,						       \
+	}
+#define VM_STATS_DESC(stat, type, unit, base, exp)			       \
+	{								       \
+		{							       \
+			STATS_DESC_COMMON(type, unit, base, exp),	       \
+			.offset = offsetof(struct kvm_vm_stat, stat)	       \
+		},							       \
+		.name = #stat,						       \
+	}
+#define VCPU_STATS_DESC(stat, type, unit, base, exp)			       \
+	{								       \
+		{							       \
+			STATS_DESC_COMMON(type, unit, base, exp),	       \
+			.offset = offsetof(struct kvm_vcpu_stat, stat)	       \
+		},							       \
+		.name = #stat,						       \
+	}
+/* SCOPE: VM, VM_GENERIC, VCPU, VCPU_GENERIC */
+#define STATS_DESC(SCOPE, stat, type, unit, base, exp)			       \
+	SCOPE##_STATS_DESC(stat, type, unit, base, exp)
+
+#define STATS_DESC_CUMULATIVE(SCOPE, name, unit, base, exponent)	       \
+	STATS_DESC(SCOPE, name, KVM_STATS_TYPE_CUMULATIVE, unit, base, exponent)
+#define STATS_DESC_INSTANT(SCOPE, name, unit, base, exponent)		       \
+	STATS_DESC(SCOPE, name, KVM_STATS_TYPE_INSTANT, unit, base, exponent)
+#define STATS_DESC_PEAK(SCOPE, name, unit, base, exponent)		       \
+	STATS_DESC(SCOPE, name, KVM_STATS_TYPE_PEAK, unit, base, exponent)
+
+/* Cumulative read/write counter */
+#define STATS_DESC_COUNTER(SCOPE, name)					       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_NONE,		       \
+		KVM_STATS_BASE_POW10, 0)
+/* Instantaneous read only counter */
+#define STATS_DESC_ICOUNTER(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_NONE,		       \
+		KVM_STATS_BASE_POW10, 0)
+/* Instantaneous read/write counter */
+#define STATS_DESC_PCOUNTER(SCOPE, name)				       \
+	STATS_DESC_PEAK(SCOPE, name, KVM_STATS_UNIT_NONE,		       \
+		KVM_STATS_BASE_POW10, 0)
+
+/* Cumulative clock cycles */
+#define STATS_DESC_CYCLE(SCOPE, name)					       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_CYCLES,	       \
+		KVM_STATS_BASE_POW10, 0)
+/* Instantaneous clock cycles */
+#define STATS_DESC_ICYCLE(SCOPE, name)					       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_CYCLES,		       \
+		KVM_STATS_BASE_POW10, 0)
+
+/* Cumulative memory size in Byte */
+#define STATS_DESC_SIZE_BYTE(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_BYTES,	       \
+		KVM_STATS_BASE_POW2, 0)
+/* Cumulative memory size in KiByte */
+#define STATS_DESC_SIZE_KBYTE(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_BYTES,	       \
+		KVM_STATS_BASE_POW2, 10)
+/* Cumulative memory size in MiByte */
+#define STATS_DESC_SIZE_MBYTE(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_BYTES,	       \
+		KVM_STATS_BASE_POW2, 20)
+/* Cumulative memory size in GiByte */
+#define STATS_DESC_SIZE_GBYTE(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_BYTES,	       \
+		KVM_STATS_BASE_POW2, 30)
+
+/* Instantaneous memory size in Byte */
+#define STATS_DESC_ISIZE_BYTE(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BYTES,		       \
+		KVM_STATS_BASE_POW2, 0)
+/* Instantaneous memory size in KiByte */
+#define STATS_DESC_ISIZE_KBYTE(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BYTES,		       \
+		KVM_STATS_BASE_POW2, 10)
+/* Instantaneous memory size in MiByte */
+#define STATS_DESC_ISIZE_MBYTE(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BYTES,		       \
+		KVM_STATS_BASE_POW2, 20)
+/* Instantaneous memory size in GiByte */
+#define STATS_DESC_ISIZE_GBYTE(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_BYTES,		       \
+		KVM_STATS_BASE_POW2, 30)
+
+/* Cumulative time in second */
+#define STATS_DESC_TIME_SEC(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,	       \
+		KVM_STATS_BASE_POW10, 0)
+/* Cumulative time in millisecond */
+#define STATS_DESC_TIME_MSEC(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,	       \
+		KVM_STATS_BASE_POW10, -3)
+/* Cumulative time in microsecond */
+#define STATS_DESC_TIME_USEC(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,	       \
+		KVM_STATS_BASE_POW10, -6)
+/* Cumulative time in nanosecond */
+#define STATS_DESC_TIME_NSEC(SCOPE, name)				       \
+	STATS_DESC_CUMULATIVE(SCOPE, name, KVM_STATS_UNIT_SECONDS,	       \
+		KVM_STATS_BASE_POW10, -9)
+
+/* Instantaneous time in second */
+#define STATS_DESC_ITIME_SEC(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_SECONDS,		       \
+		KVM_STATS_BASE_POW10, 0)
+/* Instantaneous time in millisecond */
+#define STATS_DESC_ITIME_MSEC(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_SECONDS,		       \
+		KVM_STATS_BASE_POW10, -3)
+/* Instantaneous time in microsecond */
+#define STATS_DESC_ITIME_USEC(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_SECONDS,		       \
+		KVM_STATS_BASE_POW10, -6)
+/* Instantaneous time in nanosecond */
+#define STATS_DESC_ITIME_NSEC(SCOPE, name)				       \
+	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_SECONDS,		       \
+		KVM_STATS_BASE_POW10, -9)
+
 extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
+ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
+		       const struct _kvm_stats_desc *desc,
+		       void *stats, size_t size_stats,
+		       char __user *user_buffer, size_t size, loff_t *offset);
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 9febe1412f7a..703b44316fd4 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -1086,6 +1086,7 @@ struct kvm_ppc_resize_hpt {
 #define KVM_CAP_HYPERV_ENFORCE_CPUID 199
 #define KVM_CAP_SREGS2 200
 #define KVM_CAP_EXIT_HYPERCALL 201
+#define KVM_CAP_BINARY_STATS_FD 202
 
 #ifdef KVM_CAP_IRQ_ROUTING
 
@@ -1905,4 +1906,76 @@ struct kvm_dirty_gfn {
 #define KVM_BUS_LOCK_DETECTION_OFF             (1 << 0)
 #define KVM_BUS_LOCK_DETECTION_EXIT            (1 << 1)
 
+/**
+ * struct kvm_stats_header - Header of per vm/vcpu binary statistics data.
+ * @flags: Some extra information for header, always 0 for now.
+ * @name_size: The size in bytes of the memory which contains statistics
+ *             name string including trailing '\0'. The memory is allocated
+ *             at the send of statistics descriptor.
+ * @num_desc: The number of statistics the vm or vcpu has.
+ * @id_offset: The offset of the vm/vcpu stats' id string in the file pointed
+ *             by vm/vcpu stats fd.
+ * @desc_offset: The offset of the vm/vcpu stats' descriptor block in the file
+ *               pointd by vm/vcpu stats fd.
+ * @data_offset: The offset of the vm/vcpu stats' data block in the file
+ *               pointed by vm/vcpu stats fd.
+ *
+ * This is the header userspace needs to read from stats fd before any other
+ * readings. It is used by userspace to discover all the information about the
+ * vm/vcpu's binary statistics.
+ * Userspace reads this header from the start of the vm/vcpu's stats fd.
+ */
+struct kvm_stats_header {
+	__u32 flags;
+	__u32 name_size;
+	__u32 num_desc;
+	__u32 id_offset;
+	__u32 desc_offset;
+	__u32 data_offset;
+};
+
+#define KVM_STATS_TYPE_SHIFT		0
+#define KVM_STATS_TYPE_MASK		(0xF << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_CUMULATIVE	(0x0 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_INSTANT		(0x1 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_PEAK		(0x2 << KVM_STATS_TYPE_SHIFT)
+#define KVM_STATS_TYPE_MAX		KVM_STATS_TYPE_PEAK
+
+#define KVM_STATS_UNIT_SHIFT		4
+#define KVM_STATS_UNIT_MASK		(0xF << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_NONE		(0x0 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_BYTES		(0x1 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_SECONDS		(0x2 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_CYCLES		(0x3 << KVM_STATS_UNIT_SHIFT)
+#define KVM_STATS_UNIT_MAX		KVM_STATS_UNIT_CYCLES
+
+#define KVM_STATS_BASE_SHIFT		8
+#define KVM_STATS_BASE_MASK		(0xF << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_POW10		(0x0 << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_POW2		(0x1 << KVM_STATS_BASE_SHIFT)
+#define KVM_STATS_BASE_MAX		KVM_STATS_BASE_POW2
+
+/**
+ * struct kvm_stats_desc - Descriptor of a KVM statistics.
+ * @flags: Annotations of the stats, like type, unit, etc.
+ * @exponent: Used together with @flags to determine the unit.
+ * @size: The number of data items for this stats.
+ *        Every data item is of type __u64.
+ * @offset: The offset of the stats to the start of stat structure in
+ *          struture kvm or kvm_vcpu.
+ * @unused: Unused field for future usage. Always 0 for now.
+ * @name: The name string for the stats. Its size is indicated by the
+ *        &kvm_stats_header->name_size.
+ */
+struct kvm_stats_desc {
+	__u32 flags;
+	__s16 exponent;
+	__u16 size;
+	__u32 offset;
+	__u32 unused;
+	char name[];
+};
+
+#define KVM_GET_STATS_FD  _IO(KVMIO,  0xce)
+
 #endif /* __LINUX_KVM_H */
diff --git a/virt/kvm/binary_stats.c b/virt/kvm/binary_stats.c
new file mode 100644
index 000000000000..fbc148a0e6c9
--- /dev/null
+++ b/virt/kvm/binary_stats.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * KVM binary statistics interface implementation
+ *
+ * Copyright 2021 Google LLC
+ */
+
+#include <linux/kvm_host.h>
+#include <linux/kvm.h>
+#include <linux/errno.h>
+#include <linux/uaccess.h>
+
+/**
+ * kvm_stats_read() - Common vm/vcpu stats read function to userspace.
+ * @id: identification string of the stats
+ * @header: stats header for a vm or a vcpu
+ * @desc: start address of an array of stats descriptors for a vm or a vcpu
+ * @stats: start address of stats data block for a vm or a vcpu
+ * @size_stats: the size of stats data block pointed by @stats
+ * @user_buffer: start address of userspace buffer
+ * @size: requested read size from userspace
+ * @offset: the start position from which the content will be read for the
+ *          corresponding vm or vcp file descriptor
+ *
+ * The file content of a vm/vcpu file descriptor is now defined as below:
+ * +-------------+
+ * |   Header    |
+ * +-------------+
+ * |  id string  |
+ * +-------------+
+ * | Descriptors |
+ * +-------------+
+ * | Stats Data  |
+ * +-------------+
+ * Although this function allows userspace to read any amount of data (as long
+ * as in the limit) from any position, the typical usage would follow below
+ * steps:
+ * 1. Read header from offset 0. Get the offset of descriptors and stats data
+ *    and some other necessary information. This is a one-time work for the
+ *    lifecycle of the corresponding vm/vcpu stats fd.
+ * 2. Read id string from its offset. This is a one-time work for the lifecycle
+ *    of the corresponding vm/vcpu stats fd.
+ * 3. Read descriptors from its offset and discover all the stats by parsing
+ *    descriptors. This is a one-time work for the lifecycle of the
+ *    corresponding vm/vcpu stats fd.
+ * 4. Periodically read stats data from its offset using pread.
+ *
+ * Return: the number of bytes that has been successfully read
+ */
+ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
+		       const struct _kvm_stats_desc *desc,
+		       void *stats, size_t size_stats,
+		       char __user *user_buffer, size_t size, loff_t *offset)
+{
+	ssize_t len;
+	ssize_t copylen;
+	ssize_t remain = size;
+	size_t size_desc;
+	size_t size_header;
+	void *src;
+	loff_t pos = *offset;
+	char __user *dest = user_buffer;
+
+	size_header = sizeof(*header);
+	size_desc = header->num_desc * sizeof(*desc);
+
+	len = KVM_STATS_NAME_SIZE + size_header + size_desc + size_stats - pos;
+	len = min(len, remain);
+	if (len <= 0)
+		return 0;
+	remain = len;
+
+	/*
+	 * Copy kvm stats header.
+	 * The header is the first block of content userspace usually read out.
+	 * The pos is 0 and the copylen and remain would be the size of header.
+	 * The copy of the header would be skipped if offset is larger than the
+	 * size of header. That usually happens when userspace reads stats
+	 * descriptors and stats data.
+	 */
+	copylen = size_header - pos;
+	copylen = min(copylen, remain);
+	if (copylen > 0) {
+		src = (void *)header + pos;
+		if (copy_to_user(dest, src, copylen))
+			return -EFAULT;
+		remain -= copylen;
+		pos += copylen;
+		dest += copylen;
+	}
+
+	/*
+	 * Copy kvm stats header id string.
+	 * The id string is unique for every vm/vcpu, which is stored in kvm
+	 * and kvm_vcpu structure.
+	 * The id string is part of the stat header from the perspective of
+	 * userspace, it is usually read out together with previous constant
+	 * header part and could be skipped for later descriptors and stats
+	 * data readings.
+	 */
+	copylen = size_header + KVM_STATS_NAME_SIZE - pos;
+	copylen = min(copylen, remain);
+	if (copylen > 0) {
+		src = id + pos - size_header;
+		if (copy_to_user(dest, src, copylen))
+			return -EFAULT;
+		remain -= copylen;
+		pos += copylen;
+		dest += copylen;
+	}
+
+	/*
+	 * Copy kvm stats descriptors.
+	 * The descriptors copy would be skipped in the typical case that
+	 * userspace periodically read stats data, since the pos would be
+	 * greater than the end address of descriptors
+	 * (header->header.desc_offset + size_desc) causing copylen <= 0.
+	 */
+	copylen = header->desc_offset + size_desc - pos;
+	copylen = min(copylen, remain);
+	if (copylen > 0) {
+		src = (void *)desc + pos - header->desc_offset;
+		if (copy_to_user(dest, src, copylen))
+			return -EFAULT;
+		remain -= copylen;
+		pos += copylen;
+		dest += copylen;
+	}
+
+	/* Copy kvm stats values */
+	copylen = header->data_offset + size_stats - pos;
+	copylen = min(copylen, remain);
+	if (copylen > 0) {
+		src = stats + pos - header->data_offset;
+		if (copy_to_user(dest, src, copylen))
+			return -EFAULT;
+		remain -= copylen;
+		pos += copylen;
+		dest += copylen;
+	}
+
+	*offset = pos;
+	return len;
+}
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 3/7] KVM: stats: Support binary stats retrieval for a VM
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 1/7] KVM: stats: Separate generic stats from architecture specific ones Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU Jing Zhang
                   ` (3 subsequent siblings)
  6 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

Add a VM ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VM stats header,
descriptors and data.
Define VM statistics descriptors and header for all architectures.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 arch/arm64/kvm/guest.c    | 15 ++++++++++++++
 arch/mips/kvm/mips.c      | 15 ++++++++++++++
 arch/powerpc/kvm/book3s.c | 17 ++++++++++++++++
 arch/powerpc/kvm/booke.c  | 17 ++++++++++++++++
 arch/s390/kvm/kvm-s390.c  | 20 ++++++++++++++++++
 arch/x86/kvm/x86.c        | 25 +++++++++++++++++++++++
 include/linux/kvm_host.h  |  7 ++++++-
 include/linux/kvm_types.h |  2 ++
 virt/kvm/kvm_main.c       | 43 +++++++++++++++++++++++++++++++++++++++
 9 files changed, 160 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index 4962331d01e6..b2bc01245900 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -28,6 +28,21 @@
 
 #include "trace.h"
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS()
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset =  sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
 	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index ff205b35719b..4478ae689a1e 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -38,6 +38,21 @@
 #define VECTORSPACING 0x100	/* for EI/VI mode */
 #endif
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS()
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("wait", wait_exits),
 	VCPU_STAT("cache", cache_exits),
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 92cdb4175945..6a4ccebf4d35 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -38,6 +38,23 @@
 
 /* #define EXIT_DEBUG */
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS(),
+	STATS_DESC_ICOUNTER(VM, num_2M_pages),
+	STATS_DESC_ICOUNTER(VM, num_1G_pages)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("exits", sum_exits),
 	VCPU_STAT("mmio", mmio_exits),
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 80d3b39aa7ac..9a2624bec6fc 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -36,6 +36,23 @@
 
 unsigned long kvmppc_booke_handlers;
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS(),
+	STATS_DESC_ICOUNTER(VM, num_2M_pages),
+	STATS_DESC_ICOUNTER(VM, num_1G_pages)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("mmio", mmio_exits),
 	VCPU_STAT("sig", signal_exits),
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index e8bc7cd06794..ced9c0474dd8 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -58,6 +58,26 @@
 #define VCPU_IRQS_MAX_BUF (sizeof(struct kvm_s390_irq) * \
 			   (KVM_MAX_VCPUS + LOCAL_IRQS))
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS(),
+	STATS_DESC_COUNTER(VM, inject_io),
+	STATS_DESC_COUNTER(VM, inject_float_mchk),
+	STATS_DESC_COUNTER(VM, inject_pfault_done),
+	STATS_DESC_COUNTER(VM, inject_service_signal),
+	STATS_DESC_COUNTER(VM, inject_virtio)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("userspace_handled", exit_userspace),
 	VCPU_STAT("exit_null", exit_null),
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 157212157aee..8e3329e99a15 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -223,6 +223,31 @@ EXPORT_SYMBOL_GPL(host_xss);
 u64 __read_mostly supported_xss;
 EXPORT_SYMBOL_GPL(supported_xss);
 
+const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
+	KVM_GENERIC_VM_STATS(),
+	STATS_DESC_COUNTER(VM, mmu_shadow_zapped),
+	STATS_DESC_COUNTER(VM, mmu_pte_write),
+	STATS_DESC_COUNTER(VM, mmu_pde_zapped),
+	STATS_DESC_COUNTER(VM, mmu_flooded),
+	STATS_DESC_COUNTER(VM, mmu_recycled),
+	STATS_DESC_COUNTER(VM, mmu_cache_miss),
+	STATS_DESC_ICOUNTER(VM, mmu_unsync),
+	STATS_DESC_ICOUNTER(VM, lpages),
+	STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
+	STATS_DESC_ICOUNTER(VM, max_mmu_page_hash_collisions)
+};
+static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
+		sizeof(struct kvm_vm_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vm_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vm_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vm_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("pf_fixed", pf_fixed),
 	VCPU_STAT("pf_guest", pf_guest),
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 30434be38858..1b3a8ccea485 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -599,6 +599,7 @@ struct kvm {
 #ifdef CONFIG_HAVE_KVM_PM_NOTIFIER
 	struct notifier_block pm_notifier;
 #endif
+	char stats_id[KVM_STATS_NAME_SIZE];
 };
 
 #define kvm_err(fmt, ...) \
@@ -1272,7 +1273,6 @@ struct kvm_stats_debugfs_item {
 	int mode;
 };
 
-#define KVM_STATS_NAME_SIZE     48
 struct _kvm_stats_desc {
 	struct kvm_stats_desc desc;
 	char name[KVM_STATS_NAME_SIZE];
@@ -1432,12 +1432,17 @@ struct _kvm_stats_desc {
 	STATS_DESC_INSTANT(SCOPE, name, KVM_STATS_UNIT_SECONDS,		       \
 		KVM_STATS_BASE_POW10, -9)
 
+#define KVM_GENERIC_VM_STATS()						       \
+	STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
+
 extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
 ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
 		       const struct _kvm_stats_desc *desc,
 		       void *stats, size_t size_stats,
 		       char __user *user_buffer, size_t size, loff_t *offset);
+extern const struct kvm_stats_header kvm_vm_stats_header;
+extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
diff --git a/include/linux/kvm_types.h b/include/linux/kvm_types.h
index 48db778291b7..ed6a985c5680 100644
--- a/include/linux/kvm_types.h
+++ b/include/linux/kvm_types.h
@@ -89,4 +89,6 @@ struct kvm_vcpu_stat_generic {
 	u64 halt_poll_fail_ns;
 };
 
+#define KVM_STATS_NAME_SIZE	48
+
 #endif /* __KVM_TYPES_H__ */
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cec986487b30..cf0d487272b9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -4055,6 +4055,46 @@ static int kvm_vm_ioctl_enable_cap_generic(struct kvm *kvm,
 	}
 }
 
+static ssize_t kvm_vm_stats_read(struct file *file, char __user *user_buffer,
+			      size_t size, loff_t *offset)
+{
+	struct kvm *kvm = file->private_data;
+
+	return kvm_stats_read(kvm->stats_id, &kvm_vm_stats_header,
+				&kvm_vm_stats_desc[0], &kvm->stat,
+				sizeof(kvm->stat), user_buffer, size, offset);
+}
+
+static const struct file_operations kvm_vm_stats_fops = {
+	.read = kvm_vm_stats_read,
+	.llseek = noop_llseek,
+};
+
+static int kvm_vm_ioctl_get_stats_fd(struct kvm *kvm)
+{
+	int fd;
+	struct file *file;
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+	file = anon_inode_getfile("kvm-vm-stats",
+			&kvm_vm_stats_fops, kvm, O_RDONLY);
+	if (IS_ERR(file)) {
+		put_unused_fd(fd);
+		return PTR_ERR(file);
+	}
+	file->f_mode |= FMODE_PREAD;
+	fd_install(fd, file);
+
+	/* Fill the stats id string */
+	snprintf(kvm->stats_id, sizeof(kvm->stats_id),
+			"kvm-%d", task_pid_nr(current));
+
+	return fd;
+}
+
 static long kvm_vm_ioctl(struct file *filp,
 			   unsigned int ioctl, unsigned long arg)
 {
@@ -4237,6 +4277,9 @@ static long kvm_vm_ioctl(struct file *filp,
 	case KVM_RESET_DIRTY_RINGS:
 		r = kvm_vm_ioctl_reset_dirty_pages(kvm);
 		break;
+	case KVM_GET_STATS_FD:
+		r = kvm_vm_ioctl_get_stats_fd(kvm);
+		break;
 	default:
 		r = kvm_arch_vm_ioctl(filp, ioctl, arg);
 	}
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
                   ` (2 preceding siblings ...)
  2021-06-18 22:27 ` [PATCH v12 3/7] KVM: stats: Support binary stats retrieval for a VM Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-21 16:46   ` Paolo Bonzini
  2021-06-18 22:27 ` [PATCH v12 5/7] KVM: stats: Add documentation for binary statistics interface Jing Zhang
                   ` (2 subsequent siblings)
  6 siblings, 1 reply; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

Add a VCPU ioctl to get a statistics file descriptor by which a read
functionality is provided for userspace to read out VCPU stats header,
descriptors and data.
Define VCPU statistics descriptors and header for all architectures.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 arch/arm64/kvm/guest.c    |  21 ++++++++
 arch/mips/kvm/mips.c      |  44 ++++++++++++++++
 arch/powerpc/kvm/book3s.c |  45 ++++++++++++++++
 arch/powerpc/kvm/booke.c  |  38 ++++++++++++++
 arch/s390/kvm/kvm-s390.c  | 108 ++++++++++++++++++++++++++++++++++++++
 arch/x86/kvm/x86.c        |  41 +++++++++++++++
 include/linux/kvm_host.h  |  13 ++++-
 virt/kvm/kvm_main.c       |  57 ++++++++++++++++++--
 8 files changed, 362 insertions(+), 5 deletions(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index b2bc01245900..ce8b53b3c5c8 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -43,6 +43,27 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, hvc_exit_stat),
+	STATS_DESC_COUNTER(VCPU, wfe_exit_stat),
+	STATS_DESC_COUNTER(VCPU, wfi_exit_stat),
+	STATS_DESC_COUNTER(VCPU, mmio_exit_user),
+	STATS_DESC_COUNTER(VCPU, mmio_exit_kernel),
+	STATS_DESC_COUNTER(VCPU, exits)
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
 	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index 4478ae689a1e..a048111fd6ec 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -53,6 +53,50 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, wait_exits),
+	STATS_DESC_COUNTER(VCPU, cache_exits),
+	STATS_DESC_COUNTER(VCPU, signal_exits),
+	STATS_DESC_COUNTER(VCPU, int_exits),
+	STATS_DESC_COUNTER(VCPU, cop_unusable_exits),
+	STATS_DESC_COUNTER(VCPU, tlbmod_exits),
+	STATS_DESC_COUNTER(VCPU, tlbmiss_ld_exits),
+	STATS_DESC_COUNTER(VCPU, tlbmiss_st_exits),
+	STATS_DESC_COUNTER(VCPU, addrerr_st_exits),
+	STATS_DESC_COUNTER(VCPU, addrerr_ld_exits),
+	STATS_DESC_COUNTER(VCPU, syscall_exits),
+	STATS_DESC_COUNTER(VCPU, resvd_inst_exits),
+	STATS_DESC_COUNTER(VCPU, break_inst_exits),
+	STATS_DESC_COUNTER(VCPU, trap_inst_exits),
+	STATS_DESC_COUNTER(VCPU, msa_fpe_exits),
+	STATS_DESC_COUNTER(VCPU, fpe_exits),
+	STATS_DESC_COUNTER(VCPU, msa_disabled_exits),
+	STATS_DESC_COUNTER(VCPU, flush_dcache_exits),
+	STATS_DESC_COUNTER(VCPU, vz_gpsi_exits),
+	STATS_DESC_COUNTER(VCPU, vz_gsfc_exits),
+	STATS_DESC_COUNTER(VCPU, vz_hc_exits),
+	STATS_DESC_COUNTER(VCPU, vz_grr_exits),
+	STATS_DESC_COUNTER(VCPU, vz_gva_exits),
+	STATS_DESC_COUNTER(VCPU, vz_ghfc_exits),
+	STATS_DESC_COUNTER(VCPU, vz_gpa_exits),
+	STATS_DESC_COUNTER(VCPU, vz_resvd_exits),
+#ifdef CONFIG_CPU_LOONGSON64
+	STATS_DESC_COUNTER(VCPU, vz_cpucfg_exits),
+#endif
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("wait", wait_exits),
 	VCPU_STAT("cache", cache_exits),
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 6a4ccebf4d35..5a258779baa2 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -55,6 +55,51 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, sum_exits),
+	STATS_DESC_COUNTER(VCPU, mmio_exits),
+	STATS_DESC_COUNTER(VCPU, signal_exits),
+	STATS_DESC_COUNTER(VCPU, light_exits),
+	STATS_DESC_COUNTER(VCPU, itlb_real_miss_exits),
+	STATS_DESC_COUNTER(VCPU, itlb_virt_miss_exits),
+	STATS_DESC_COUNTER(VCPU, dtlb_real_miss_exits),
+	STATS_DESC_COUNTER(VCPU, dtlb_virt_miss_exits),
+	STATS_DESC_COUNTER(VCPU, syscall_exits),
+	STATS_DESC_COUNTER(VCPU, isi_exits),
+	STATS_DESC_COUNTER(VCPU, dsi_exits),
+	STATS_DESC_COUNTER(VCPU, emulated_inst_exits),
+	STATS_DESC_COUNTER(VCPU, dec_exits),
+	STATS_DESC_COUNTER(VCPU, ext_intr_exits),
+	STATS_DESC_TIME_NSEC(VCPU, halt_wait_ns),
+	STATS_DESC_COUNTER(VCPU, halt_successful_wait),
+	STATS_DESC_COUNTER(VCPU, dbell_exits),
+	STATS_DESC_COUNTER(VCPU, gdbell_exits),
+	STATS_DESC_COUNTER(VCPU, ld),
+	STATS_DESC_COUNTER(VCPU, st),
+	STATS_DESC_COUNTER(VCPU, pf_storage),
+	STATS_DESC_COUNTER(VCPU, pf_instruc),
+	STATS_DESC_COUNTER(VCPU, sp_storage),
+	STATS_DESC_COUNTER(VCPU, sp_instruc),
+	STATS_DESC_COUNTER(VCPU, queue_intr),
+	STATS_DESC_COUNTER(VCPU, ld_slow),
+	STATS_DESC_COUNTER(VCPU, st_slow),
+	STATS_DESC_COUNTER(VCPU, pthru_all),
+	STATS_DESC_COUNTER(VCPU, pthru_host),
+	STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("exits", sum_exits),
 	VCPU_STAT("mmio", mmio_exits),
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index 9a2624bec6fc..ae2289fb4425 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -53,6 +53,44 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, sum_exits),
+	STATS_DESC_COUNTER(VCPU, mmio_exits),
+	STATS_DESC_COUNTER(VCPU, signal_exits),
+	STATS_DESC_COUNTER(VCPU, light_exits),
+	STATS_DESC_COUNTER(VCPU, itlb_real_miss_exits),
+	STATS_DESC_COUNTER(VCPU, itlb_virt_miss_exits),
+	STATS_DESC_COUNTER(VCPU, dtlb_real_miss_exits),
+	STATS_DESC_COUNTER(VCPU, dtlb_virt_miss_exits),
+	STATS_DESC_COUNTER(VCPU, syscall_exits),
+	STATS_DESC_COUNTER(VCPU, isi_exits),
+	STATS_DESC_COUNTER(VCPU, dsi_exits),
+	STATS_DESC_COUNTER(VCPU, emulated_inst_exits),
+	STATS_DESC_COUNTER(VCPU, dec_exits),
+	STATS_DESC_COUNTER(VCPU, ext_intr_exits),
+	STATS_DESC_TIME_NSEC(VCPU, halt_wait_ns),
+	STATS_DESC_COUNTER(VCPU, halt_successful_wait),
+	STATS_DESC_COUNTER(VCPU, dbell_exits),
+	STATS_DESC_COUNTER(VCPU, gdbell_exits),
+	STATS_DESC_COUNTER(VCPU, ld),
+	STATS_DESC_COUNTER(VCPU, st),
+	STATS_DESC_COUNTER(VCPU, pthru_all),
+	STATS_DESC_COUNTER(VCPU, pthru_host),
+	STATS_DESC_COUNTER(VCPU, pthru_bad_aff)
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("mmio", mmio_exits),
 	VCPU_STAT("sig", signal_exits),
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index ced9c0474dd8..47b5023c43d0 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -78,6 +78,114 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, exit_userspace),
+	STATS_DESC_COUNTER(VCPU, exit_null),
+	STATS_DESC_COUNTER(VCPU, exit_external_request),
+	STATS_DESC_COUNTER(VCPU, exit_io_request),
+	STATS_DESC_COUNTER(VCPU, exit_external_interrupt),
+	STATS_DESC_COUNTER(VCPU, exit_stop_request),
+	STATS_DESC_COUNTER(VCPU, exit_validity),
+	STATS_DESC_COUNTER(VCPU, exit_instruction),
+	STATS_DESC_COUNTER(VCPU, exit_pei),
+	STATS_DESC_COUNTER(VCPU, halt_no_poll_steal),
+	STATS_DESC_COUNTER(VCPU, instruction_lctl),
+	STATS_DESC_COUNTER(VCPU, instruction_lctlg),
+	STATS_DESC_COUNTER(VCPU, instruction_stctl),
+	STATS_DESC_COUNTER(VCPU, instruction_stctg),
+	STATS_DESC_COUNTER(VCPU, exit_program_interruption),
+	STATS_DESC_COUNTER(VCPU, exit_instr_and_program),
+	STATS_DESC_COUNTER(VCPU, exit_operation_exception),
+	STATS_DESC_COUNTER(VCPU, deliver_ckc),
+	STATS_DESC_COUNTER(VCPU, deliver_cputm),
+	STATS_DESC_COUNTER(VCPU, deliver_external_call),
+	STATS_DESC_COUNTER(VCPU, deliver_emergency_signal),
+	STATS_DESC_COUNTER(VCPU, deliver_service_signal),
+	STATS_DESC_COUNTER(VCPU, deliver_virtio),
+	STATS_DESC_COUNTER(VCPU, deliver_stop_signal),
+	STATS_DESC_COUNTER(VCPU, deliver_prefix_signal),
+	STATS_DESC_COUNTER(VCPU, deliver_restart_signal),
+	STATS_DESC_COUNTER(VCPU, deliver_program),
+	STATS_DESC_COUNTER(VCPU, deliver_io),
+	STATS_DESC_COUNTER(VCPU, deliver_machine_check),
+	STATS_DESC_COUNTER(VCPU, exit_wait_state),
+	STATS_DESC_COUNTER(VCPU, inject_ckc),
+	STATS_DESC_COUNTER(VCPU, inject_cputm),
+	STATS_DESC_COUNTER(VCPU, inject_external_call),
+	STATS_DESC_COUNTER(VCPU, inject_emergency_signal),
+	STATS_DESC_COUNTER(VCPU, inject_mchk),
+	STATS_DESC_COUNTER(VCPU, inject_pfault_init),
+	STATS_DESC_COUNTER(VCPU, inject_program),
+	STATS_DESC_COUNTER(VCPU, inject_restart),
+	STATS_DESC_COUNTER(VCPU, inject_set_prefix),
+	STATS_DESC_COUNTER(VCPU, inject_stop_signal),
+	STATS_DESC_COUNTER(VCPU, instruction_epsw),
+	STATS_DESC_COUNTER(VCPU, instruction_gs),
+	STATS_DESC_COUNTER(VCPU, instruction_io_other),
+	STATS_DESC_COUNTER(VCPU, instruction_lpsw),
+	STATS_DESC_COUNTER(VCPU, instruction_lpswe),
+	STATS_DESC_COUNTER(VCPU, instruction_pfmf),
+	STATS_DESC_COUNTER(VCPU, instruction_ptff),
+	STATS_DESC_COUNTER(VCPU, instruction_sck),
+	STATS_DESC_COUNTER(VCPU, instruction_sckpf),
+	STATS_DESC_COUNTER(VCPU, instruction_stidp),
+	STATS_DESC_COUNTER(VCPU, instruction_spx),
+	STATS_DESC_COUNTER(VCPU, instruction_stpx),
+	STATS_DESC_COUNTER(VCPU, instruction_stap),
+	STATS_DESC_COUNTER(VCPU, instruction_iske),
+	STATS_DESC_COUNTER(VCPU, instruction_ri),
+	STATS_DESC_COUNTER(VCPU, instruction_rrbe),
+	STATS_DESC_COUNTER(VCPU, instruction_sske),
+	STATS_DESC_COUNTER(VCPU, instruction_ipte_interlock),
+	STATS_DESC_COUNTER(VCPU, instruction_stsi),
+	STATS_DESC_COUNTER(VCPU, instruction_stfl),
+	STATS_DESC_COUNTER(VCPU, instruction_tb),
+	STATS_DESC_COUNTER(VCPU, instruction_tpi),
+	STATS_DESC_COUNTER(VCPU, instruction_tprot),
+	STATS_DESC_COUNTER(VCPU, instruction_tsch),
+	STATS_DESC_COUNTER(VCPU, instruction_sie),
+	STATS_DESC_COUNTER(VCPU, instruction_essa),
+	STATS_DESC_COUNTER(VCPU, instruction_sthyi),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_sense),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_sense_running),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_external_call),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_emergency),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_cond_emergency),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_start),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_stop),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_stop_store_status),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_store_status),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_store_adtl_status),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_arch),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_prefix),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_restart),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_init_cpu_reset),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_cpu_reset),
+	STATS_DESC_COUNTER(VCPU, instruction_sigp_unknown),
+	STATS_DESC_COUNTER(VCPU, diagnose_10),
+	STATS_DESC_COUNTER(VCPU, diagnose_44),
+	STATS_DESC_COUNTER(VCPU, diagnose_9c),
+	STATS_DESC_COUNTER(VCPU, diagnose_9c_ignored),
+	STATS_DESC_COUNTER(VCPU, diagnose_9c_forward),
+	STATS_DESC_COUNTER(VCPU, diagnose_258),
+	STATS_DESC_COUNTER(VCPU, diagnose_308),
+	STATS_DESC_COUNTER(VCPU, diagnose_500),
+	STATS_DESC_COUNTER(VCPU, diagnose_other),
+	STATS_DESC_COUNTER(VCPU, pfault_sync)
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("userspace_handled", exit_userspace),
 	VCPU_STAT("exit_null", exit_null),
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8e3329e99a15..c87f7e17cd0d 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -248,6 +248,47 @@ const struct kvm_stats_header kvm_vm_stats_header = {
 		       sizeof(kvm_vm_stats_desc),
 };
 
+const struct _kvm_stats_desc kvm_vcpu_stats_desc[] = {
+	KVM_GENERIC_VCPU_STATS(),
+	STATS_DESC_COUNTER(VCPU, pf_fixed),
+	STATS_DESC_COUNTER(VCPU, pf_guest),
+	STATS_DESC_COUNTER(VCPU, tlb_flush),
+	STATS_DESC_COUNTER(VCPU, invlpg),
+	STATS_DESC_COUNTER(VCPU, exits),
+	STATS_DESC_COUNTER(VCPU, io_exits),
+	STATS_DESC_COUNTER(VCPU, mmio_exits),
+	STATS_DESC_COUNTER(VCPU, signal_exits),
+	STATS_DESC_COUNTER(VCPU, irq_window_exits),
+	STATS_DESC_COUNTER(VCPU, nmi_window_exits),
+	STATS_DESC_COUNTER(VCPU, l1d_flush),
+	STATS_DESC_COUNTER(VCPU, halt_exits),
+	STATS_DESC_COUNTER(VCPU, request_irq_exits),
+	STATS_DESC_COUNTER(VCPU, irq_exits),
+	STATS_DESC_COUNTER(VCPU, host_state_reload),
+	STATS_DESC_COUNTER(VCPU, fpu_reload),
+	STATS_DESC_COUNTER(VCPU, insn_emulation),
+	STATS_DESC_COUNTER(VCPU, insn_emulation_fail),
+	STATS_DESC_COUNTER(VCPU, hypercalls),
+	STATS_DESC_COUNTER(VCPU, irq_injections),
+	STATS_DESC_COUNTER(VCPU, nmi_injections),
+	STATS_DESC_COUNTER(VCPU, req_event),
+	STATS_DESC_COUNTER(VCPU, nested_run),
+	STATS_DESC_COUNTER(VCPU, directed_yield_attempted),
+	STATS_DESC_COUNTER(VCPU, directed_yield_successful),
+	STATS_DESC_ICOUNTER(VCPU, guest_mode)
+};
+static_assert(ARRAY_SIZE(kvm_vcpu_stats_desc) ==
+		sizeof(struct kvm_vcpu_stat) / sizeof(u64));
+
+const struct kvm_stats_header kvm_vcpu_stats_header = {
+	.name_size = KVM_STATS_NAME_SIZE,
+	.num_desc = ARRAY_SIZE(kvm_vcpu_stats_desc),
+	.id_offset = sizeof(struct kvm_stats_header),
+	.desc_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE,
+	.data_offset = sizeof(struct kvm_stats_header) + KVM_STATS_NAME_SIZE +
+		       sizeof(kvm_vcpu_stats_desc),
+};
+
 struct kvm_stats_debugfs_item debugfs_entries[] = {
 	VCPU_STAT("pf_fixed", pf_fixed),
 	VCPU_STAT("pf_guest", pf_guest),
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 1b3a8ccea485..d9bb7644ec6f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -305,7 +305,6 @@ struct kvm_vcpu {
 	struct pid __rcu *pid;
 	int sigset_active;
 	sigset_t sigset;
-	struct kvm_vcpu_stat stat;
 	unsigned int halt_poll_ns;
 	bool valid_wakeup;
 
@@ -342,7 +341,9 @@ struct kvm_vcpu {
 	bool preempted;
 	bool ready;
 	struct kvm_vcpu_arch arch;
+	struct kvm_vcpu_stat stat;
 	struct kvm_dirty_ring dirty_ring;
+	char stats_id[KVM_STATS_NAME_SIZE];
 };
 
 /* must be called with irqs disabled */
@@ -1435,6 +1436,14 @@ struct _kvm_stats_desc {
 #define KVM_GENERIC_VM_STATS()						       \
 	STATS_DESC_COUNTER(VM_GENERIC, remote_tlb_flush)
 
+#define KVM_GENERIC_VCPU_STATS()					       \
+	STATS_DESC_COUNTER(VCPU_GENERIC, halt_successful_poll),		       \
+	STATS_DESC_COUNTER(VCPU_GENERIC, halt_attempted_poll),		       \
+	STATS_DESC_COUNTER(VCPU_GENERIC, halt_poll_invalid),		       \
+	STATS_DESC_COUNTER(VCPU_GENERIC, halt_wakeup),			       \
+	STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_success_ns),	       \
+	STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
+
 extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
 ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
@@ -1443,6 +1452,8 @@ ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
 		       char __user *user_buffer, size_t size, loff_t *offset);
 extern const struct kvm_stats_header kvm_vm_stats_header;
 extern const struct _kvm_stats_desc kvm_vm_stats_desc[];
+extern const struct kvm_stats_header kvm_vcpu_stats_header;
+extern const struct _kvm_stats_desc kvm_vcpu_stats_desc[];
 
 #if defined(CONFIG_MMU_NOTIFIER) && defined(KVM_ARCH_WANT_MMU_NOTIFIER)
 static inline int mmu_notifier_retry(struct kvm *kvm, unsigned long mmu_seq)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index cf0d487272b9..5f9d566db1c4 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -3497,6 +3497,48 @@ static int kvm_vcpu_ioctl_set_sigmask(struct kvm_vcpu *vcpu, sigset_t *sigset)
 	return 0;
 }
 
+static ssize_t kvm_vcpu_stats_read(struct file *file, char __user *user_buffer,
+			      size_t size, loff_t *offset)
+{
+	struct kvm_vcpu *vcpu = file->private_data;
+
+	return kvm_stats_read(vcpu->stats_id, &kvm_vcpu_stats_header,
+			&kvm_vcpu_stats_desc[0], &vcpu->stat,
+			sizeof(vcpu->stat), user_buffer, size, offset);
+}
+
+static const struct file_operations kvm_vcpu_stats_fops = {
+	.read = kvm_vcpu_stats_read,
+	.llseek = noop_llseek,
+};
+
+static int kvm_vcpu_ioctl_get_stats_fd(struct kvm_vcpu *vcpu)
+{
+	int fd;
+	struct file *file;
+	char name[15 + ITOA_MAX_LEN + 1];
+
+	snprintf(name, sizeof(name), "kvm-vcpu-stats:%d", vcpu->vcpu_id);
+
+	fd = get_unused_fd_flags(O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+
+	file = anon_inode_getfile(name, &kvm_vcpu_stats_fops, vcpu, O_RDONLY);
+	if (IS_ERR(file)) {
+		put_unused_fd(fd);
+		return PTR_ERR(file);
+	}
+	file->f_mode |= FMODE_PREAD;
+	fd_install(fd, file);
+
+	/* Fill the stats id string for the vcpu */
+	snprintf(vcpu->stats_id, sizeof(vcpu->stats_id), "kvm-%d/vcpu-%d",
+					task_pid_nr(current), vcpu->vcpu_id);
+
+	return fd;
+}
+
 static long kvm_vcpu_ioctl(struct file *filp,
 			   unsigned int ioctl, unsigned long arg)
 {
@@ -3694,6 +3736,10 @@ static long kvm_vcpu_ioctl(struct file *filp,
 		r = kvm_arch_vcpu_ioctl_set_fpu(vcpu, fpu);
 		break;
 	}
+	case KVM_GET_STATS_FD: {
+		r = kvm_vcpu_ioctl_get_stats_fd(vcpu);
+		break;
+	}
 	default:
 		r = kvm_arch_vcpu_ioctl(filp, ioctl, arg);
 	}
@@ -3952,6 +3998,8 @@ static long kvm_vm_ioctl_check_extension_generic(struct kvm *kvm, long arg)
 #else
 		return 0;
 #endif
+	case KVM_CAP_BINARY_STATS_FD:
+		return 1;
 	default:
 		break;
 	}
@@ -5253,10 +5301,11 @@ int kvm_init(void *opaque, unsigned vcpu_size, unsigned vcpu_align,
 		vcpu_align = __alignof__(struct kvm_vcpu);
 	kvm_vcpu_cache =
 		kmem_cache_create_usercopy("kvm_vcpu", vcpu_size, vcpu_align,
-					   SLAB_ACCOUNT,
-					   offsetof(struct kvm_vcpu, arch),
-					   sizeof_field(struct kvm_vcpu, arch),
-					   NULL);
+				   SLAB_ACCOUNT,
+				   offsetof(struct kvm_vcpu, arch),
+				   sizeof_field(struct kvm_vcpu, arch)
+				   + sizeof_field(struct kvm_vcpu, stat),
+				   NULL);
 	if (!kvm_vcpu_cache) {
 		r = -ENOMEM;
 		goto out_free_3;
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 5/7] KVM: stats: Add documentation for binary statistics interface
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
                   ` (3 preceding siblings ...)
  2021-06-18 22:27 ` [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 6/7] KVM: selftests: Add selftest for KVM statistics data binary interface Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 7/7] KVM: stats: Remove code duplication for binary and debugfs stats Jing Zhang
  6 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

This new API provides a file descriptor for every VM and VCPU to read
KVM statistics data in binary format.
It is meant to provide a lightweight, flexible, scalable and efficient
lock-free solution for user space telemetry applications to pull the
statistics data periodically for large scale systems. The pulling
frequency could be as high as a few times per second.
The statistics descriptors are defined by KVM in kernel and can be
by userspace to discover VM/VCPU statistics during the one-time setup
stage.
The statistics data itself could be read out by userspace telemetry
periodically without any extra parsing or setup effort.
There are a few existed interface protocols and definitions, but no
one can fulfil all the requirements this interface implemented as
below:
1. During high frequency periodic stats reading, there should be no
   extra efforts except the stats data read itself.
2. Support stats annotation, like type (cumulative, instantaneous,
   peak, histogram, etc) and unit (counter, time, size, cycles, etc).
3. The stats data reading should be free of lock/synchronization. We
   don't care about the consistency between all the stats data. All
   stats data can not be read out at exactly the same time. We really
   care about the change or trend of the stats data. The lock-free
   solution is not just for efficiency and scalability, also for the
   stats data accuracy and usability. For example, in the situation
   that all the stats data readings are protected by a global lock,
   if one VCPU died somehow with that lock held, then all stats data
   reading would be blocked, then we have no way from stats data that
   which VCPU has died.
4. The stats data reading workload can be handed over to other
   unprivileged process.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 Documentation/virt/kvm/api.rst | 198 ++++++++++++++++++++++++++++++++-
 1 file changed, 197 insertions(+), 1 deletion(-)

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index e328caa35d6c..289ea7be696a 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -5034,7 +5034,6 @@ see KVM_XEN_VCPU_SET_ATTR above.
 The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used
 with the KVM_XEN_VCPU_GET_ATTR ioctl.
 
-
 4.131 KVM_GET_SREGS2
 ------------------
 
@@ -5081,6 +5080,195 @@ Writes special registers into the vcpu.
 See KVM_GET_SREGS2 for the data structures.
 This ioctl (when supported) replaces the KVM_SET_SREGS.
 
+4.133 KVM_GET_STATS_FD
+----------------------
+
+:Capability: KVM_CAP_STATS_BINARY_FD
+:Architectures: all
+:Type: vm ioctl, vcpu ioctl
+:Parameters: none
+:Returns: statistics file descriptor on success, < 0 on error
+
+Errors:
+
+  ======     ======================================================
+  ENOMEM     if the fd could not be created due to lack of memory
+  EMFILE     if the number of opened files exceeds the limit
+  ======     ======================================================
+
+The file descriptor can be used to read VM/vCPU statistics data in binary
+format. Please be aware that it is not guaranteed that the four blocks are
+adjacent, that's why offset fields are included in the Header. But the
+order of the four blocks are guaranteed and there is no overlap between any
+two blocks.
+And all four blocks are aligned with 64 bits in the file.
+The file data is organized into three blocks as below:
++-------------+
+|   Header    |
++-------------+
++-------------+
+|  id string  |
++-------------+
++-------------+
+| Descriptors |
++-------------+
++-------------+
+| Stats Data  |
++-------------+
+
+The Header block is always at the start of the file. It is only needed to be
+read one time for the lifetime of the file descriptor.
+It is in the form of ``struct kvm_stats_header`` as below::
+
+	struct kvm_stats_header {
+                __u32 flags;
+		__u32 name_size;
+		__u32 num_desc;
+                __u32 id_offset;
+		__u32 desc_offset;
+		__u32 data_offset;
+	};
+
+The ``flags`` field is not used at the moment. It is always read as 0.
+
+The ``name_size`` field is the size (in byte) of the statistics name string
+(including trailing '\0') appended to the end of every statistics descriptor.
+It also is the size of id string block.
+
+The ``num_desc`` field is the number of statistics.
+
+The ``id_offset`` field is the offset of the id string from the start of the
+file indicated by the file descriptor. It is a multiple of 8.
+
+The ``desc_offset`` field is the offset of the Descriptors block from the start
+of the file indicated by the file descriptor. It is a multiple of 8.
+
+The ``data_offset`` field is the offset of the Stats Data block from the start
+of the file indicated by the file descriptor. It is a multiple of 8.
+
+The id string is a '\0' terminated string which identifies the corresponding
+KVM statistics. For VM statistics, it is in the form of "kvm-{kvm pid}", like
+"kvm-12345". For VCPU statistics, it is in the form of
+"kvm-{kvm pid}/vcpu-{vcpu id}", like "kvm-12345/vcpu-12".
+The size of id string block is indicated by the ``name_size`` field in Header.
+
+The Descriptors block is only needed to be read once for the lifetime of the
+file descriptor. It is an array of ``struct kvm_stats_desc`` as shown in
+below code block::
+
+	#define KVM_STATS_TYPE_SHIFT		0
+	#define KVM_STATS_TYPE_MASK		(0xF << KVM_STATS_TYPE_SHIFT)
+	#define KVM_STATS_TYPE_CUMULATIVE	(0x0 << KVM_STATS_TYPE_SHIFT)
+	#define KVM_STATS_TYPE_INSTANT		(0x1 << KVM_STATS_TYPE_SHIFT)
+        #define KVM_STATS_TYPE_PEAK		(0x2 << KVM_STATS_TYPE_SHIFT)
+        #define KVM_STATS_TYPE_MAX		KVM_STATS_TYPE_PEAK
+
+	#define KVM_STATS_UNIT_SHIFT		4
+	#define KVM_STATS_UNIT_MASK		(0xF << KVM_STATS_UNIT_SHIFT)
+	#define KVM_STATS_UNIT_NONE		(0x0 << KVM_STATS_UNIT_SHIFT)
+	#define KVM_STATS_UNIT_BYTES		(0x1 << KVM_STATS_UNIT_SHIFT)
+	#define KVM_STATS_UNIT_SECONDS		(0x2 << KVM_STATS_UNIT_SHIFT)
+	#define KVM_STATS_UNIT_CYCLES		(0x3 << KVM_STATS_UNIT_SHIFT)
+	#define KVM_STATS_UNIT_MAX		KVM_STATS_UNIT_CYCLES
+
+	#define KVM_STATS_BASE_SHIFT		8
+	#define KVM_STATS_BASE_MASK		(0xF << KVM_STATS_BASE_SHIFT)
+	#define KVM_STATS_BASE_POW10		(0x0 << KVM_STATS_BASE_SHIFT)
+	#define KVM_STATS_BASE_POW2		(0x1 << KVM_STATS_BASE_SHIFT)
+	#define KVM_STATS_BASE_MAX		KVM_STATS_BASE_POW2
+
+	struct kvm_stats_desc {
+		__u32 flags;
+		__s16 exponent;
+		__u16 size;
+		__u32 offset;
+		__u32 unused;
+		char name[];
+	};
+
+The ``flags`` field contains the type and unit of the statistics data described
+by this descriptor. Its endianness is CPU native.
+The following flags are supported:
+
+Bits 0-3 of ``flags`` encode the type:
+  * ``KVM_STATS_TYPE_CUMULATIVE``
+    The statistics data is cumulative. The value of data can only be increased.
+    Most of the counters used in KVM are of this type.
+    The corresponding ``size`` field for this type is always 1.
+    All cumulative statistics data are read/write.
+  * ``KVM_STATS_TYPE_INSTANT``
+    The statistics data is instantaneous. Its value can be increased or
+    decreased. This type is usually used as a measurement of some resources,
+    like the number of dirty pages, the number of large pages, etc.
+    All instant statistics are read only.
+    The corresponding ``size`` field for this type is always 1.
+  * ``KVM_STATS_TYPE_PEAK``
+    The statistics data is peak, which is used as read/write instant statistics.
+    The corresponding ``size`` field for this type is always 1.
+
+Bits 4-7 of ``flags`` encode the unit:
+  * ``KVM_STATS_UNIT_NONE``
+    There is no unit for the value of statistics data. This usually means that
+    the value is a simple counter of an event.
+  * ``KVM_STATS_UNIT_BYTES``
+    It indicates that the statistics data is used to measure memory size, in the
+    unit of Byte, KiByte, MiByte, GiByte, etc. The unit of the data is
+    determined by the ``exponent`` field in the descriptor. The
+    ``KVM_STATS_BASE_POW2`` flag is valid in this case. The unit of the data is
+    determined by ``pow(2, exponent)``. For example, if value is 10,
+    ``exponent`` is 20, which means the unit of statistics data is MiByte, we
+    can get the statistics data in the unit of Byte by
+    ``value * pow(2, exponent) = 10 * pow(2, 20) = 10 MiByte`` which is
+    10 * 1024 * 1024 Bytes.
+  * ``KVM_STATS_UNIT_SECONDS``
+    It indicates that the statistics data is used to measure time/latency, in
+    the unit of nanosecond, microsecond, millisecond and second. The unit of the
+    data is determined by the ``exponent`` field in the descriptor. The
+    ``KVM_STATS_BASE_POW10`` flag is valid in this case. The unit of the data
+    is determined by ``pow(10, exponent)``. For example, if value is 2000000,
+    ``exponent`` is -6, which means the unit of statistics data is microsecond,
+    we can get the statistics data in the unit of second by
+    ``value * pow(10, exponent) = 2000000 * pow(10, -6) = 2 seconds``.
+  * ``KVM_STATS_UNIT_CYCLES``
+    It indicates that the statistics data is used to measure CPU clock cycles.
+    The ``KVM_STATS_BASE_POW10`` flag is valid in this case. For example, if
+    value is 200, ``exponent`` is 4, we can get the number of CPU clock cycles
+    by ``value * pow(10, exponent) = 200 * pow(10, 4) = 2000000``.
+
+Bits 8-11 of ``flags`` encode the base:
+  * ``KVM_STATS_BASE_POW10``
+    The scale is based on power of 10. It is used for measurement of time and
+    CPU clock cycles.
+  * ``KVM_STATS_BASE_POW2``
+    The scale is based on power of 2. It is used for measurement of memory size.
+
+The ``exponent`` field is the scale of corresponding statistics data. For
+example, if the unit is ``KVM_STATS_UNIT_BYTES``, the base is
+``KVM_STATS_BASE_POW2``, the ``exponent`` is 10, then we know that the real
+unit of the statistics data is KBytes a.k.a pow(2, 10) = 1024 bytes.
+If the unit is ``KVM_STATS_UNIT_SECONDS``, the base is ``KVM_STATS_BASE_POW10``,
+the ``exponent`` is -6, then we know that the real unit of the statistics data
+is microsecond a.k.a 1 second * pow(10, -6) = 1 microsecond.
+
+The ``size`` field is the number of values of this statistics data. Its
+value is usually 1 for most of simple statistics. 1 means it contains an
+unsigned 64bit data.
+
+The ``offset`` field is the offset from the start of Data Block to the start of
+the corresponding statistics data.
+
+The ``unused`` fields are reserved for future support for other types of
+statistics data, like log/linear histogram. Its current value is always 0.
+
+The ``name`` field is the name string of the statistics data. The name string
+starts at the end of ``struct kvm_stats_desc``.
+The maximum length (including trailing '\0') is indicated by ``name_size``
+in ``struct kvm_stats_header``.
+
+The Stats Data block contains an array of statistics data whose type is __u64.
+It would be read out by userspace periodically.
+The order of data value in Stats Data block is the same as the order of
+descriptors in Descriptors block.
 
 5. The kvm_run structure
 ========================
@@ -6969,3 +7157,11 @@ The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset
 of the result of KVM_CHECK_EXTENSION.  KVM will forward to userspace
 the hypercalls whose corresponding bit is in the argument, and return
 ENOSYS for the others.
+
+8.35 KVM_CAP_STATS_BINARY_FD
+----------------------------
+
+:Architectures: all
+
+This capability indicates the feature that userspace can create get a file
+descriptor for every VM and VCPU to read statistics data in binary format.
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 6/7] KVM: selftests: Add selftest for KVM statistics data binary interface
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
                   ` (4 preceding siblings ...)
  2021-06-18 22:27 ` [PATCH v12 5/7] KVM: stats: Add documentation for binary statistics interface Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  2021-06-18 22:27 ` [PATCH v12 7/7] KVM: stats: Remove code duplication for binary and debugfs stats Jing Zhang
  6 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

Add selftest to check KVM stats descriptors validity.

Reviewed-by: David Matlack <dmatlack@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Tested-by: Fuad Tabba <tabba@google.com> #arm64
Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 tools/testing/selftests/kvm/.gitignore        |   1 +
 tools/testing/selftests/kvm/Makefile          |   3 +
 .../testing/selftests/kvm/include/kvm_util.h  |   3 +
 .../selftests/kvm/kvm_binary_stats_test.c     | 234 ++++++++++++++++++
 tools/testing/selftests/kvm/lib/kvm_util.c    |  12 +
 5 files changed, 253 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/kvm_binary_stats_test.c

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index e0e14150744e..ebe81d67c738 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -46,3 +46,4 @@
 /memslot_perf_test
 /set_memory_region_test
 /steal_time
+/kvm_binary_stats_test
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 61e2accd080d..8e4eaf8cdc06 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -79,6 +79,7 @@ TEST_GEN_PROGS_x86_64 += memslot_modification_stress_test
 TEST_GEN_PROGS_x86_64 += memslot_perf_test
 TEST_GEN_PROGS_x86_64 += set_memory_region_test
 TEST_GEN_PROGS_x86_64 += steal_time
+TEST_GEN_PROGS_x86_64 += kvm_binary_stats_test
 
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list-sve
@@ -90,6 +91,7 @@ TEST_GEN_PROGS_aarch64 += kvm_create_max_vcpus
 TEST_GEN_PROGS_aarch64 += kvm_page_table_test
 TEST_GEN_PROGS_aarch64 += set_memory_region_test
 TEST_GEN_PROGS_aarch64 += steal_time
+TEST_GEN_PROGS_aarch64 += kvm_binary_stats_test
 
 TEST_GEN_PROGS_s390x = s390x/memop
 TEST_GEN_PROGS_s390x += s390x/resets
@@ -99,6 +101,7 @@ TEST_GEN_PROGS_s390x += dirty_log_test
 TEST_GEN_PROGS_s390x += kvm_create_max_vcpus
 TEST_GEN_PROGS_s390x += kvm_page_table_test
 TEST_GEN_PROGS_s390x += set_memory_region_test
+TEST_GEN_PROGS_s390x += kvm_binary_stats_test
 
 TEST_GEN_PROGS += $(TEST_GEN_PROGS_$(UNAME_M))
 LIBKVM += $(LIBKVM_$(UNAME_M))
diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h
index 35739567189e..558b450f3d7c 100644
--- a/tools/testing/selftests/kvm/include/kvm_util.h
+++ b/tools/testing/selftests/kvm/include/kvm_util.h
@@ -391,4 +391,7 @@ uint64_t get_ucall(struct kvm_vm *vm, uint32_t vcpu_id, struct ucall *uc);
 #define GUEST_ASSERT_4(_condition, arg1, arg2, arg3, arg4) \
 	__GUEST_ASSERT((_condition), 4, (arg1), (arg2), (arg3), (arg4))
 
+int vm_get_stats_fd(struct kvm_vm *vm);
+int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid);
+
 #endif /* SELFTEST_KVM_UTIL_H */
diff --git a/tools/testing/selftests/kvm/kvm_binary_stats_test.c b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
new file mode 100644
index 000000000000..8c2c6e2e2b36
--- /dev/null
+++ b/tools/testing/selftests/kvm/kvm_binary_stats_test.c
@@ -0,0 +1,234 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * kvm_binary_stats_test
+ *
+ * Copyright (C) 2021, Google LLC.
+ *
+ * Test the fd-based interface for KVM statistics.
+ */
+
+#define _GNU_SOURCE /* for program_invocation_short_name */
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "test_util.h"
+
+#include "kvm_util.h"
+#include "asm/kvm.h"
+#include "linux/kvm.h"
+
+static void stats_test(int stats_fd)
+{
+	ssize_t ret;
+	int i;
+	size_t size_desc;
+	size_t size_data = 0;
+	struct kvm_stats_header *header;
+	char *id;
+	struct kvm_stats_desc *stats_desc;
+	u64 *stats_data;
+	struct kvm_stats_desc *pdesc;
+
+	/* Read kvm stats header */
+	header = malloc(sizeof(*header));
+	TEST_ASSERT(header, "Allocate memory for stats header");
+
+	ret = read(stats_fd, header, sizeof(*header));
+	TEST_ASSERT(ret == sizeof(*header), "Read stats header");
+	size_desc = sizeof(*stats_desc) + header->name_size;
+
+	/* Read kvm stats id string */
+	id = malloc(header->name_size);
+	TEST_ASSERT(id, "Allocate memory for id string");
+	ret = read(stats_fd, id, header->name_size);
+	TEST_ASSERT(ret == header->name_size, "Read id string");
+
+	/* Check id string, that should start with "kvm" */
+	TEST_ASSERT(!strncmp(id, "kvm", 3) && strlen(id) < header->name_size,
+				"Invalid KVM stats type, id: %s", id);
+
+	/* Sanity check for other fields in header */
+	if (header->num_desc == 0) {
+		printf("No KVM stats defined!");
+		return;
+	}
+	/* Check overlap */
+	TEST_ASSERT(header->desc_offset > 0 && header->data_offset > 0
+			&& header->desc_offset >= sizeof(*header)
+			&& header->data_offset >= sizeof(*header),
+			"Invalid offset fields in header");
+	TEST_ASSERT(header->desc_offset > header->data_offset ||
+			(header->desc_offset + size_desc * header->num_desc <=
+							header->data_offset),
+			"Descriptor block is overlapped with data block");
+
+	/* Allocate memory for stats descriptors */
+	stats_desc = calloc(header->num_desc, size_desc);
+	TEST_ASSERT(stats_desc, "Allocate memory for stats descriptors");
+	/* Read kvm stats descriptors */
+	ret = pread(stats_fd, stats_desc,
+			size_desc * header->num_desc, header->desc_offset);
+	TEST_ASSERT(ret == size_desc * header->num_desc,
+			"Read KVM stats descriptors");
+
+	/* Sanity check for fields in descriptors */
+	for (i = 0; i < header->num_desc; ++i) {
+		pdesc = (void *)stats_desc + i * size_desc;
+		/* Check type,unit,base boundaries */
+		TEST_ASSERT((pdesc->flags & KVM_STATS_TYPE_MASK)
+				<= KVM_STATS_TYPE_MAX, "Unknown KVM stats type");
+		TEST_ASSERT((pdesc->flags & KVM_STATS_UNIT_MASK)
+				<= KVM_STATS_UNIT_MAX, "Unknown KVM stats unit");
+		TEST_ASSERT((pdesc->flags & KVM_STATS_BASE_MASK)
+				<= KVM_STATS_BASE_MAX, "Unknown KVM stats base");
+		/* Check exponent for stats unit
+		 * Exponent for counter should be greater than or equal to 0
+		 * Exponent for unit bytes should be greater than or equal to 0
+		 * Exponent for unit seconds should be less than or equal to 0
+		 * Exponent for unit clock cycles should be greater than or
+		 * equal to 0
+		 */
+		switch (pdesc->flags & KVM_STATS_UNIT_MASK) {
+		case KVM_STATS_UNIT_NONE:
+		case KVM_STATS_UNIT_BYTES:
+		case KVM_STATS_UNIT_CYCLES:
+			TEST_ASSERT(pdesc->exponent >= 0,
+					"Unsupported KVM stats unit");
+			break;
+		case KVM_STATS_UNIT_SECONDS:
+			TEST_ASSERT(pdesc->exponent <= 0,
+					"Unsupported KVM stats unit");
+			break;
+		}
+		/* Check name string */
+		TEST_ASSERT(strlen(pdesc->name) < header->name_size,
+				"KVM stats name(%s) too long", pdesc->name);
+		/* Check size field, which should not be zero */
+		TEST_ASSERT(pdesc->size, "KVM descriptor(%s) with size of 0",
+				pdesc->name);
+		size_data += pdesc->size * sizeof(*stats_data);
+	}
+	/* Check overlap */
+	TEST_ASSERT(header->data_offset >= header->desc_offset
+		|| header->data_offset + size_data <= header->desc_offset,
+		"Data block is overlapped with Descriptor block");
+	/* Check validity of all stats data size */
+	TEST_ASSERT(size_data >= header->num_desc * sizeof(*stats_data),
+			"Data size is not correct");
+	/* Check stats offset */
+	for (i = 0; i < header->num_desc; ++i) {
+		pdesc = (void *)stats_desc + i * size_desc;
+		TEST_ASSERT(pdesc->offset < size_data,
+			"Invalid offset (%u) for stats: %s",
+			pdesc->offset, pdesc->name);
+	}
+
+	/* Allocate memory for stats data */
+	stats_data = malloc(size_data);
+	TEST_ASSERT(stats_data, "Allocate memory for stats data");
+	/* Read kvm stats data as a bulk */
+	ret = pread(stats_fd, stats_data, size_data, header->data_offset);
+	TEST_ASSERT(ret == size_data, "Read KVM stats data");
+	/* Read kvm stats data one by one */
+	size_data = 0;
+	for (i = 0; i < header->num_desc; ++i) {
+		pdesc = (void *)stats_desc + i * size_desc;
+		ret = pread(stats_fd, stats_data,
+				pdesc->size * sizeof(*stats_data),
+				header->data_offset + size_data);
+		TEST_ASSERT(ret == pdesc->size * sizeof(*stats_data),
+				"Read data of KVM stats: %s", pdesc->name);
+		size_data += pdesc->size * sizeof(*stats_data);
+	}
+
+	free(stats_data);
+	free(stats_desc);
+	free(id);
+	free(header);
+}
+
+
+static void vm_stats_test(struct kvm_vm *vm)
+{
+	int stats_fd;
+
+	/* Get fd for VM stats */
+	stats_fd = vm_get_stats_fd(vm);
+	TEST_ASSERT(stats_fd >= 0, "Get VM stats fd");
+
+	stats_test(stats_fd);
+	close(stats_fd);
+	TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed");
+}
+
+static void vcpu_stats_test(struct kvm_vm *vm, int vcpu_id)
+{
+	int stats_fd;
+
+	/* Get fd for VCPU stats */
+	stats_fd = vcpu_get_stats_fd(vm, vcpu_id);
+	TEST_ASSERT(stats_fd >= 0, "Get VCPU stats fd");
+
+	stats_test(stats_fd);
+	close(stats_fd);
+	TEST_ASSERT(fcntl(stats_fd, F_GETFD) == -1, "Stats fd not freed");
+}
+
+#define DEFAULT_NUM_VM		4
+#define DEFAULT_NUM_VCPU	4
+
+/*
+ * Usage: kvm_bin_form_stats [#vm] [#vcpu]
+ * The first parameter #vm set the number of VMs being created.
+ * The second parameter #vcpu set the number of VCPUs being created.
+ * By default, DEFAULT_NUM_VM VM and DEFAULT_NUM_VCPU VCPU for the VM would be
+ * created for testing.
+ */
+
+int main(int argc, char *argv[])
+{
+	int max_vm = DEFAULT_NUM_VM, max_vcpu = DEFAULT_NUM_VCPU, ret, i, j;
+	struct kvm_vm **vms;
+
+	/* Get the number of VMs and VCPUs that would be created for testing. */
+	if (argc > 1) {
+		max_vm = strtol(argv[1], NULL, 0);
+		if (max_vm <= 0)
+			max_vm = DEFAULT_NUM_VM;
+	}
+	if (argc > 2) {
+		max_vcpu = strtol(argv[2], NULL, 0);
+		if (max_vcpu <= 0)
+			max_vcpu = DEFAULT_NUM_VCPU;
+	}
+
+	/* Check the extension for binary stats */
+	ret = kvm_check_cap(KVM_CAP_BINARY_STATS_FD);
+	TEST_ASSERT(ret > 0,
+			"Binary form statistics interface is not supported");
+
+	/* Create VMs and VCPUs */
+	vms = malloc(sizeof(vms[0]) * max_vm);
+	TEST_ASSERT(vms, "Allocate memory for storing VM pointers");
+	for (i = 0; i < max_vm; ++i) {
+		vms[i] = vm_create(VM_MODE_DEFAULT,
+				DEFAULT_GUEST_PHY_PAGES, O_RDWR);
+		for (j = 0; j < max_vcpu; ++j)
+			vm_vcpu_add(vms[i], j);
+	}
+
+	/* Check stats read for every VM and VCPU */
+	for (i = 0; i < max_vm; ++i) {
+		vm_stats_test(vms[i]);
+		for (j = 0; j < max_vcpu; ++j)
+			vcpu_stats_test(vms[i], j);
+	}
+
+	for (i = 0; i < max_vm; ++i)
+		kvm_vm_free(vms[i]);
+	free(vms);
+	return 0;
+}
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index a2b732cf96ea..9047a51227e6 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -2286,3 +2286,15 @@ unsigned int vm_calc_num_guest_pages(enum vm_guest_mode mode, size_t size)
 	n = DIV_ROUND_UP(size, vm_guest_mode_params[mode].page_size);
 	return vm_adjust_num_guest_pages(mode, n);
 }
+
+int vm_get_stats_fd(struct kvm_vm *vm)
+{
+	return ioctl(vm->fd, KVM_GET_STATS_FD, NULL);
+}
+
+int vcpu_get_stats_fd(struct kvm_vm *vm, uint32_t vcpuid)
+{
+	struct vcpu *vcpu = vcpu_find(vm, vcpuid);
+
+	return ioctl(vcpu->fd, KVM_GET_STATS_FD, NULL);
+}
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* [PATCH v12 7/7] KVM: stats: Remove code duplication for binary and debugfs stats
  2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
                   ` (5 preceding siblings ...)
  2021-06-18 22:27 ` [PATCH v12 6/7] KVM: selftests: Add selftest for KVM statistics data binary interface Jing Zhang
@ 2021-06-18 22:27 ` Jing Zhang
  6 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-18 22:27 UTC (permalink / raw)
  To: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Paolo Bonzini, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH
  Cc: Jing Zhang

To remove code duplication, use the binary stats descriptors for
debugfs interface for KVM stats. Then we only have one stats
definitions for both binary and debugfs interface.

Signed-off-by: Jing Zhang <jingzhangos@google.com>
---
 arch/arm64/kvm/guest.c    |  16 ------
 arch/mips/kvm/mips.c      |  39 --------------
 arch/powerpc/kvm/book3s.c |  33 ------------
 arch/powerpc/kvm/booke.c  |  25 ---------
 arch/s390/kvm/kvm-s390.c  | 108 --------------------------------------
 arch/x86/kvm/x86.c        |  49 +----------------
 include/linux/kvm_host.h  |  22 +-------
 virt/kvm/kvm_main.c       | 104 ++++++++++++++++++++++++++----------
 8 files changed, 78 insertions(+), 318 deletions(-)

diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c
index ce8b53b3c5c8..1512a8007a78 100644
--- a/arch/arm64/kvm/guest.c
+++ b/arch/arm64/kvm/guest.c
@@ -64,22 +64,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT("hvc_exit_stat", hvc_exit_stat),
-	VCPU_STAT("wfe_exit_stat", wfe_exit_stat),
-	VCPU_STAT("wfi_exit_stat", wfi_exit_stat),
-	VCPU_STAT("mmio_exit_user", mmio_exit_user),
-	VCPU_STAT("mmio_exit_kernel", mmio_exit_kernel),
-	VCPU_STAT("exits", exits),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	{ NULL }
-};
-
 static bool core_reg_offset_is_vreg(u64 off)
 {
 	return off >= KVM_REG_ARM_CORE_REG(fp_regs.vregs) &&
diff --git a/arch/mips/kvm/mips.c b/arch/mips/kvm/mips.c
index a048111fd6ec..af9dd029a4e1 100644
--- a/arch/mips/kvm/mips.c
+++ b/arch/mips/kvm/mips.c
@@ -97,45 +97,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("wait", wait_exits),
-	VCPU_STAT("cache", cache_exits),
-	VCPU_STAT("signal", signal_exits),
-	VCPU_STAT("interrupt", int_exits),
-	VCPU_STAT("cop_unusable", cop_unusable_exits),
-	VCPU_STAT("tlbmod", tlbmod_exits),
-	VCPU_STAT("tlbmiss_ld", tlbmiss_ld_exits),
-	VCPU_STAT("tlbmiss_st", tlbmiss_st_exits),
-	VCPU_STAT("addrerr_st", addrerr_st_exits),
-	VCPU_STAT("addrerr_ld", addrerr_ld_exits),
-	VCPU_STAT("syscall", syscall_exits),
-	VCPU_STAT("resvd_inst", resvd_inst_exits),
-	VCPU_STAT("break_inst", break_inst_exits),
-	VCPU_STAT("trap_inst", trap_inst_exits),
-	VCPU_STAT("msa_fpe", msa_fpe_exits),
-	VCPU_STAT("fpe", fpe_exits),
-	VCPU_STAT("msa_disabled", msa_disabled_exits),
-	VCPU_STAT("flush_dcache", flush_dcache_exits),
-	VCPU_STAT("vz_gpsi", vz_gpsi_exits),
-	VCPU_STAT("vz_gsfc", vz_gsfc_exits),
-	VCPU_STAT("vz_hc", vz_hc_exits),
-	VCPU_STAT("vz_grr", vz_grr_exits),
-	VCPU_STAT("vz_gva", vz_gva_exits),
-	VCPU_STAT("vz_ghfc", vz_ghfc_exits),
-	VCPU_STAT("vz_gpa", vz_gpa_exits),
-	VCPU_STAT("vz_resvd", vz_resvd_exits),
-#ifdef CONFIG_CPU_LOONGSON64
-	VCPU_STAT("vz_cpucfg", vz_cpucfg_exits),
-#endif
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	{NULL}
-};
-
 bool kvm_trace_guest_mode_change;
 
 int kvm_guest_mode_change_trace_reg(void)
diff --git a/arch/powerpc/kvm/book3s.c b/arch/powerpc/kvm/book3s.c
index 5a258779baa2..122468ce297d 100644
--- a/arch/powerpc/kvm/book3s.c
+++ b/arch/powerpc/kvm/book3s.c
@@ -100,39 +100,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("exits", sum_exits),
-	VCPU_STAT("mmio", mmio_exits),
-	VCPU_STAT("sig", signal_exits),
-	VCPU_STAT("sysc", syscall_exits),
-	VCPU_STAT("inst_emu", emulated_inst_exits),
-	VCPU_STAT("dec", dec_exits),
-	VCPU_STAT("ext_intr", ext_intr_exits),
-	VCPU_STAT("queue_intr", queue_intr),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	VCPU_STAT("halt_wait_ns", halt_wait_ns),
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT("halt_successful_wait", halt_successful_wait),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT("pf_storage", pf_storage),
-	VCPU_STAT("sp_storage", sp_storage),
-	VCPU_STAT("pf_instruc", pf_instruc),
-	VCPU_STAT("sp_instruc", sp_instruc),
-	VCPU_STAT("ld", ld),
-	VCPU_STAT("ld_slow", ld_slow),
-	VCPU_STAT("st", st),
-	VCPU_STAT("st_slow", st_slow),
-	VCPU_STAT("pthru_all", pthru_all),
-	VCPU_STAT("pthru_host", pthru_host),
-	VCPU_STAT("pthru_bad_aff", pthru_bad_aff),
-	VM_STAT("largepages_2M", num_2M_pages, .mode = 0444),
-	VM_STAT("largepages_1G", num_1G_pages, .mode = 0444),
-	{ NULL }
-};
-
 static inline void kvmppc_update_int_pending(struct kvm_vcpu *vcpu,
 			unsigned long pending_now, unsigned long old_pending)
 {
diff --git a/arch/powerpc/kvm/booke.c b/arch/powerpc/kvm/booke.c
index ae2289fb4425..551b30d84aee 100644
--- a/arch/powerpc/kvm/booke.c
+++ b/arch/powerpc/kvm/booke.c
@@ -91,31 +91,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("mmio", mmio_exits),
-	VCPU_STAT("sig", signal_exits),
-	VCPU_STAT("itlb_r", itlb_real_miss_exits),
-	VCPU_STAT("itlb_v", itlb_virt_miss_exits),
-	VCPU_STAT("dtlb_r", dtlb_real_miss_exits),
-	VCPU_STAT("dtlb_v", dtlb_virt_miss_exits),
-	VCPU_STAT("sysc", syscall_exits),
-	VCPU_STAT("isi", isi_exits),
-	VCPU_STAT("dsi", dsi_exits),
-	VCPU_STAT("inst_emu", emulated_inst_exits),
-	VCPU_STAT("dec", dec_exits),
-	VCPU_STAT("ext_intr", ext_intr_exits),
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT("doorbell", dbell_exits),
-	VCPU_STAT("guest doorbell", gdbell_exits),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	VM_STAT_GENERIC("remote_tlb_flush", remote_tlb_flush),
-	{ NULL }
-};
-
 /* TODO: use vcpu_printf() */
 void kvmppc_dump_vcpu(struct kvm_vcpu *vcpu)
 {
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 47b5023c43d0..1695f0ced5ba 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -186,114 +186,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("userspace_handled", exit_userspace),
-	VCPU_STAT("exit_null", exit_null),
-	VCPU_STAT("pfault_sync", pfault_sync),
-	VCPU_STAT("exit_validity", exit_validity),
-	VCPU_STAT("exit_stop_request", exit_stop_request),
-	VCPU_STAT("exit_external_request", exit_external_request),
-	VCPU_STAT("exit_io_request", exit_io_request),
-	VCPU_STAT("exit_external_interrupt", exit_external_interrupt),
-	VCPU_STAT("exit_instruction", exit_instruction),
-	VCPU_STAT("exit_pei", exit_pei),
-	VCPU_STAT("exit_program_interruption", exit_program_interruption),
-	VCPU_STAT("exit_instr_and_program_int", exit_instr_and_program),
-	VCPU_STAT("exit_operation_exception", exit_operation_exception),
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT("halt_no_poll_steal", halt_no_poll_steal),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	VCPU_STAT("instruction_lctlg", instruction_lctlg),
-	VCPU_STAT("instruction_lctl", instruction_lctl),
-	VCPU_STAT("instruction_stctl", instruction_stctl),
-	VCPU_STAT("instruction_stctg", instruction_stctg),
-	VCPU_STAT("deliver_ckc", deliver_ckc),
-	VCPU_STAT("deliver_cputm", deliver_cputm),
-	VCPU_STAT("deliver_emergency_signal", deliver_emergency_signal),
-	VCPU_STAT("deliver_external_call", deliver_external_call),
-	VCPU_STAT("deliver_service_signal", deliver_service_signal),
-	VCPU_STAT("deliver_virtio", deliver_virtio),
-	VCPU_STAT("deliver_stop_signal", deliver_stop_signal),
-	VCPU_STAT("deliver_prefix_signal", deliver_prefix_signal),
-	VCPU_STAT("deliver_restart_signal", deliver_restart_signal),
-	VCPU_STAT("deliver_program", deliver_program),
-	VCPU_STAT("deliver_io", deliver_io),
-	VCPU_STAT("deliver_machine_check", deliver_machine_check),
-	VCPU_STAT("exit_wait_state", exit_wait_state),
-	VCPU_STAT("inject_ckc", inject_ckc),
-	VCPU_STAT("inject_cputm", inject_cputm),
-	VCPU_STAT("inject_external_call", inject_external_call),
-	VM_STAT("inject_float_mchk", inject_float_mchk),
-	VCPU_STAT("inject_emergency_signal", inject_emergency_signal),
-	VM_STAT("inject_io", inject_io),
-	VCPU_STAT("inject_mchk", inject_mchk),
-	VM_STAT("inject_pfault_done", inject_pfault_done),
-	VCPU_STAT("inject_program", inject_program),
-	VCPU_STAT("inject_restart", inject_restart),
-	VM_STAT("inject_service_signal", inject_service_signal),
-	VCPU_STAT("inject_set_prefix", inject_set_prefix),
-	VCPU_STAT("inject_stop_signal", inject_stop_signal),
-	VCPU_STAT("inject_pfault_init", inject_pfault_init),
-	VM_STAT("inject_virtio", inject_virtio),
-	VCPU_STAT("instruction_epsw", instruction_epsw),
-	VCPU_STAT("instruction_gs", instruction_gs),
-	VCPU_STAT("instruction_io_other", instruction_io_other),
-	VCPU_STAT("instruction_lpsw", instruction_lpsw),
-	VCPU_STAT("instruction_lpswe", instruction_lpswe),
-	VCPU_STAT("instruction_pfmf", instruction_pfmf),
-	VCPU_STAT("instruction_ptff", instruction_ptff),
-	VCPU_STAT("instruction_stidp", instruction_stidp),
-	VCPU_STAT("instruction_sck", instruction_sck),
-	VCPU_STAT("instruction_sckpf", instruction_sckpf),
-	VCPU_STAT("instruction_spx", instruction_spx),
-	VCPU_STAT("instruction_stpx", instruction_stpx),
-	VCPU_STAT("instruction_stap", instruction_stap),
-	VCPU_STAT("instruction_iske", instruction_iske),
-	VCPU_STAT("instruction_ri", instruction_ri),
-	VCPU_STAT("instruction_rrbe", instruction_rrbe),
-	VCPU_STAT("instruction_sske", instruction_sske),
-	VCPU_STAT("instruction_ipte_interlock", instruction_ipte_interlock),
-	VCPU_STAT("instruction_essa", instruction_essa),
-	VCPU_STAT("instruction_stsi", instruction_stsi),
-	VCPU_STAT("instruction_stfl", instruction_stfl),
-	VCPU_STAT("instruction_tb", instruction_tb),
-	VCPU_STAT("instruction_tpi", instruction_tpi),
-	VCPU_STAT("instruction_tprot", instruction_tprot),
-	VCPU_STAT("instruction_tsch", instruction_tsch),
-	VCPU_STAT("instruction_sthyi", instruction_sthyi),
-	VCPU_STAT("instruction_sie", instruction_sie),
-	VCPU_STAT("instruction_sigp_sense", instruction_sigp_sense),
-	VCPU_STAT("instruction_sigp_sense_running", instruction_sigp_sense_running),
-	VCPU_STAT("instruction_sigp_external_call", instruction_sigp_external_call),
-	VCPU_STAT("instruction_sigp_emergency", instruction_sigp_emergency),
-	VCPU_STAT("instruction_sigp_cond_emergency", instruction_sigp_cond_emergency),
-	VCPU_STAT("instruction_sigp_start", instruction_sigp_start),
-	VCPU_STAT("instruction_sigp_stop", instruction_sigp_stop),
-	VCPU_STAT("instruction_sigp_stop_store_status", instruction_sigp_stop_store_status),
-	VCPU_STAT("instruction_sigp_store_status", instruction_sigp_store_status),
-	VCPU_STAT("instruction_sigp_store_adtl_status", instruction_sigp_store_adtl_status),
-	VCPU_STAT("instruction_sigp_set_arch", instruction_sigp_arch),
-	VCPU_STAT("instruction_sigp_set_prefix", instruction_sigp_prefix),
-	VCPU_STAT("instruction_sigp_restart", instruction_sigp_restart),
-	VCPU_STAT("instruction_sigp_cpu_reset", instruction_sigp_cpu_reset),
-	VCPU_STAT("instruction_sigp_init_cpu_reset", instruction_sigp_init_cpu_reset),
-	VCPU_STAT("instruction_sigp_unknown", instruction_sigp_unknown),
-	VCPU_STAT("instruction_diag_10", diagnose_10),
-	VCPU_STAT("instruction_diag_44", diagnose_44),
-	VCPU_STAT("instruction_diag_9c", diagnose_9c),
-	VCPU_STAT("diag_9c_ignored", diagnose_9c_ignored),
-	VCPU_STAT("diag_9c_forward", diagnose_9c_forward),
-	VCPU_STAT("instruction_diag_258", diagnose_258),
-	VCPU_STAT("instruction_diag_308", diagnose_308),
-	VCPU_STAT("instruction_diag_500", diagnose_500),
-	VCPU_STAT("instruction_diag_other", diagnose_other),
-	{ NULL }
-};
-
 /* allow nested virtualization in KVM (if enabled by user space) */
 static int nested;
 module_param(nested, int, S_IRUGO);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c87f7e17cd0d..f2dbb1649177 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -234,7 +234,7 @@ const struct _kvm_stats_desc kvm_vm_stats_desc[] = {
 	STATS_DESC_ICOUNTER(VM, mmu_unsync),
 	STATS_DESC_ICOUNTER(VM, lpages),
 	STATS_DESC_ICOUNTER(VM, nx_lpage_splits),
-	STATS_DESC_ICOUNTER(VM, max_mmu_page_hash_collisions)
+	STATS_DESC_PCOUNTER(VM, max_mmu_page_hash_collisions)
 };
 static_assert(ARRAY_SIZE(kvm_vm_stats_desc) ==
 		sizeof(struct kvm_vm_stat) / sizeof(u64));
@@ -289,53 +289,6 @@ const struct kvm_stats_header kvm_vcpu_stats_header = {
 		       sizeof(kvm_vcpu_stats_desc),
 };
 
-struct kvm_stats_debugfs_item debugfs_entries[] = {
-	VCPU_STAT("pf_fixed", pf_fixed),
-	VCPU_STAT("pf_guest", pf_guest),
-	VCPU_STAT("tlb_flush", tlb_flush),
-	VCPU_STAT("invlpg", invlpg),
-	VCPU_STAT("exits", exits),
-	VCPU_STAT("io_exits", io_exits),
-	VCPU_STAT("mmio_exits", mmio_exits),
-	VCPU_STAT("signal_exits", signal_exits),
-	VCPU_STAT("irq_window", irq_window_exits),
-	VCPU_STAT("nmi_window", nmi_window_exits),
-	VCPU_STAT("halt_exits", halt_exits),
-	VCPU_STAT_GENERIC("halt_successful_poll", halt_successful_poll),
-	VCPU_STAT_GENERIC("halt_attempted_poll", halt_attempted_poll),
-	VCPU_STAT_GENERIC("halt_poll_invalid", halt_poll_invalid),
-	VCPU_STAT_GENERIC("halt_wakeup", halt_wakeup),
-	VCPU_STAT("hypercalls", hypercalls),
-	VCPU_STAT("request_irq", request_irq_exits),
-	VCPU_STAT("irq_exits", irq_exits),
-	VCPU_STAT("host_state_reload", host_state_reload),
-	VCPU_STAT("fpu_reload", fpu_reload),
-	VCPU_STAT("insn_emulation", insn_emulation),
-	VCPU_STAT("insn_emulation_fail", insn_emulation_fail),
-	VCPU_STAT("irq_injections", irq_injections),
-	VCPU_STAT("nmi_injections", nmi_injections),
-	VCPU_STAT("req_event", req_event),
-	VCPU_STAT("l1d_flush", l1d_flush),
-	VCPU_STAT_GENERIC("halt_poll_success_ns", halt_poll_success_ns),
-	VCPU_STAT_GENERIC("halt_poll_fail_ns", halt_poll_fail_ns),
-	VCPU_STAT("nested_run", nested_run),
-	VCPU_STAT("directed_yield_attempted", directed_yield_attempted),
-	VCPU_STAT("directed_yield_successful", directed_yield_successful),
-	VCPU_STAT("guest_mode", guest_mode),
-	VM_STAT("mmu_shadow_zapped", mmu_shadow_zapped),
-	VM_STAT("mmu_pte_write", mmu_pte_write),
-	VM_STAT("mmu_pde_zapped", mmu_pde_zapped),
-	VM_STAT("mmu_flooded", mmu_flooded),
-	VM_STAT("mmu_recycled", mmu_recycled),
-	VM_STAT("mmu_cache_miss", mmu_cache_miss),
-	VM_STAT("mmu_unsync", mmu_unsync),
-	VM_STAT_GENERIC("remote_tlb_flush", remote_tlb_flush),
-	VM_STAT("largepages", lpages, .mode = 0444),
-	VM_STAT("nx_largepages_splitted", nx_lpage_splits, .mode = 0444),
-	VM_STAT("max_mmu_page_hash_collisions", max_mmu_page_hash_collisions),
-	{ NULL }
-};
-
 u64 __read_mostly host_xcr0;
 u64 __read_mostly supported_xcr0;
 EXPORT_SYMBOL_GPL(supported_xcr0);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index d9bb7644ec6f..48277d5b41ba 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1264,14 +1264,8 @@ enum kvm_stat_kind {
 
 struct kvm_stat_data {
 	struct kvm *kvm;
-	struct kvm_stats_debugfs_item *dbgfs_item;
-};
-
-struct kvm_stats_debugfs_item {
-	const char *name;
-	int offset;
+	const struct _kvm_stats_desc *desc;
 	enum kvm_stat_kind kind;
-	int mode;
 };
 
 struct _kvm_stats_desc {
@@ -1279,19 +1273,6 @@ struct _kvm_stats_desc {
 	char name[KVM_STATS_NAME_SIZE];
 };
 
-#define KVM_DBGFS_GET_MODE(dbgfs_item)                                         \
-	((dbgfs_item)->mode ? (dbgfs_item)->mode : 0644)
-
-#define VM_STAT(n, x, ...)						       \
-	{ n, offsetof(struct kvm, stat.x), KVM_STAT_VM, ## __VA_ARGS__ }
-#define VCPU_STAT(n, x, ...)						       \
-	{ n, offsetof(struct kvm_vcpu, stat.x), KVM_STAT_VCPU, ## __VA_ARGS__ }
-#define VM_STAT_GENERIC(n, x, ...)					       \
-	{ n, offsetof(struct kvm, stat.generic.x), KVM_STAT_VM, ## __VA_ARGS__ }
-#define VCPU_STAT_GENERIC(n, x, ...)					       \
-	{ n, offsetof(struct kvm_vcpu, stat.generic.x),			       \
-	  KVM_STAT_VCPU, ## __VA_ARGS__ }
-
 #define STATS_DESC_COMMON(type, unit, base, exp)			       \
 	.flags = type | unit | base |					       \
 		 BUILD_BUG_ON_ZERO(type & ~KVM_STATS_TYPE_MASK) |	       \
@@ -1444,7 +1425,6 @@ struct _kvm_stats_desc {
 	STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_success_ns),	       \
 	STATS_DESC_TIME_NSEC(VCPU_GENERIC, halt_poll_fail_ns)
 
-extern struct kvm_stats_debugfs_item debugfs_entries[];
 extern struct dentry *kvm_debugfs_dir;
 ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
 		       const struct _kvm_stats_desc *desc,
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 5f9d566db1c4..7a4d69c98822 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -115,7 +115,6 @@ static DEFINE_PER_CPU(struct kvm_vcpu *, kvm_running_vcpu);
 struct dentry *kvm_debugfs_dir;
 EXPORT_SYMBOL_GPL(kvm_debugfs_dir);
 
-static int kvm_debugfs_num_entries;
 static const struct file_operations stat_fops_per_vm;
 
 static long kvm_vcpu_ioctl(struct file *file, unsigned int ioctl,
@@ -860,9 +859,24 @@ static void kvm_free_memslots(struct kvm *kvm, struct kvm_memslots *slots)
 	kvfree(slots);
 }
 
+static umode_t kvm_stats_debugfs_mode(const struct _kvm_stats_desc *pdesc)
+{
+	switch (pdesc->desc.flags & KVM_STATS_TYPE_MASK) {
+	case KVM_STATS_TYPE_INSTANT:
+		return 0444;
+	case KVM_STATS_TYPE_CUMULATIVE:
+	case KVM_STATS_TYPE_PEAK:
+	default:
+		return 0644;
+	}
+}
+
+
 static void kvm_destroy_vm_debugfs(struct kvm *kvm)
 {
 	int i;
+	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
+				      kvm_vcpu_stats_header.num_desc;
 
 	if (!kvm->debugfs_dentry)
 		return;
@@ -880,7 +894,10 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 {
 	char dir_name[ITOA_MAX_LEN * 2];
 	struct kvm_stat_data *stat_data;
-	struct kvm_stats_debugfs_item *p;
+	const struct _kvm_stats_desc *pdesc;
+	int i;
+	int kvm_debugfs_num_entries = kvm_vm_stats_header.num_desc +
+				      kvm_vcpu_stats_header.num_desc;
 
 	if (!debugfs_initialized())
 		return 0;
@@ -894,15 +911,32 @@ static int kvm_create_vm_debugfs(struct kvm *kvm, int fd)
 	if (!kvm->debugfs_stat_data)
 		return -ENOMEM;
 
-	for (p = debugfs_entries; p->name; p++) {
+	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vm_stats_desc[i];
 		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
 		if (!stat_data)
 			return -ENOMEM;
 
 		stat_data->kvm = kvm;
-		stat_data->dbgfs_item = p;
-		kvm->debugfs_stat_data[p - debugfs_entries] = stat_data;
-		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
+		stat_data->desc = pdesc;
+		stat_data->kind = KVM_STAT_VM;
+		kvm->debugfs_stat_data[i] = stat_data;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				    kvm->debugfs_dentry, stat_data,
+				    &stat_fops_per_vm);
+	}
+
+	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vcpu_stats_desc[i];
+		stat_data = kzalloc(sizeof(*stat_data), GFP_KERNEL_ACCOUNT);
+		if (!stat_data)
+			return -ENOMEM;
+
+		stat_data->kvm = kvm;
+		stat_data->desc = pdesc;
+		stat_data->kind = KVM_STAT_VCPU;
+		kvm->debugfs_stat_data[i] = stat_data;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
 				    kvm->debugfs_dentry, stat_data,
 				    &stat_fops_per_vm);
 	}
@@ -4901,7 +4935,7 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file,
 		return -ENOENT;
 
 	if (simple_attr_open(inode, file, get,
-		    KVM_DBGFS_GET_MODE(stat_data->dbgfs_item) & 0222
+		    kvm_stats_debugfs_mode(stat_data->desc) & 0222
 		    ? set : NULL,
 		    fmt)) {
 		kvm_put_kvm(stat_data->kvm);
@@ -4924,14 +4958,14 @@ static int kvm_debugfs_release(struct inode *inode, struct file *file)
 
 static int kvm_get_stat_per_vm(struct kvm *kvm, size_t offset, u64 *val)
 {
-	*val = *(u64 *)((void *)kvm + offset);
+	*val = *(u64 *)((void *)(&kvm->stat) + offset);
 
 	return 0;
 }
 
 static int kvm_clear_stat_per_vm(struct kvm *kvm, size_t offset)
 {
-	*(u64 *)((void *)kvm + offset) = 0;
+	*(u64 *)((void *)(&kvm->stat) + offset) = 0;
 
 	return 0;
 }
@@ -4944,7 +4978,7 @@ static int kvm_get_stat_per_vcpu(struct kvm *kvm, size_t offset, u64 *val)
 	*val = 0;
 
 	kvm_for_each_vcpu(i, vcpu, kvm)
-		*val += *(u64 *)((void *)vcpu + offset);
+		*val += *(u64 *)((void *)(&vcpu->stat) + offset);
 
 	return 0;
 }
@@ -4955,7 +4989,7 @@ static int kvm_clear_stat_per_vcpu(struct kvm *kvm, size_t offset)
 	struct kvm_vcpu *vcpu;
 
 	kvm_for_each_vcpu(i, vcpu, kvm)
-		*(u64 *)((void *)vcpu + offset) = 0;
+		*(u64 *)((void *)(&vcpu->stat) + offset) = 0;
 
 	return 0;
 }
@@ -4965,14 +4999,14 @@ static int kvm_stat_data_get(void *data, u64 *val)
 	int r = -EFAULT;
 	struct kvm_stat_data *stat_data = (struct kvm_stat_data *)data;
 
-	switch (stat_data->dbgfs_item->kind) {
+	switch (stat_data->kind) {
 	case KVM_STAT_VM:
 		r = kvm_get_stat_per_vm(stat_data->kvm,
-					stat_data->dbgfs_item->offset, val);
+					stat_data->desc->desc.offset, val);
 		break;
 	case KVM_STAT_VCPU:
 		r = kvm_get_stat_per_vcpu(stat_data->kvm,
-					  stat_data->dbgfs_item->offset, val);
+					  stat_data->desc->desc.offset, val);
 		break;
 	}
 
@@ -4987,14 +5021,14 @@ static int kvm_stat_data_clear(void *data, u64 val)
 	if (val)
 		return -EINVAL;
 
-	switch (stat_data->dbgfs_item->kind) {
+	switch (stat_data->kind) {
 	case KVM_STAT_VM:
 		r = kvm_clear_stat_per_vm(stat_data->kvm,
-					  stat_data->dbgfs_item->offset);
+					  stat_data->desc->desc.offset);
 		break;
 	case KVM_STAT_VCPU:
 		r = kvm_clear_stat_per_vcpu(stat_data->kvm,
-					    stat_data->dbgfs_item->offset);
+					    stat_data->desc->desc.offset);
 		break;
 	}
 
@@ -5051,6 +5085,7 @@ static int vm_stat_clear(void *_offset, u64 val)
 }
 
 DEFINE_SIMPLE_ATTRIBUTE(vm_stat_fops, vm_stat_get, vm_stat_clear, "%llu\n");
+DEFINE_SIMPLE_ATTRIBUTE(vm_stat_readonly_fops, vm_stat_get, NULL, "%llu\n");
 
 static int vcpu_stat_get(void *_offset, u64 *val)
 {
@@ -5087,11 +5122,7 @@ static int vcpu_stat_clear(void *_offset, u64 val)
 
 DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_fops, vcpu_stat_get, vcpu_stat_clear,
 			"%llu\n");
-
-static const struct file_operations *stat_fops[] = {
-	[KVM_STAT_VCPU] = &vcpu_stat_fops,
-	[KVM_STAT_VM]   = &vm_stat_fops,
-};
+DEFINE_SIMPLE_ATTRIBUTE(vcpu_stat_readonly_fops, vcpu_stat_get, NULL, "%llu\n");
 
 static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
 {
@@ -5145,15 +5176,32 @@ static void kvm_uevent_notify_change(unsigned int type, struct kvm *kvm)
 
 static void kvm_init_debug(void)
 {
-	struct kvm_stats_debugfs_item *p;
+	const struct file_operations *fops;
+	const struct _kvm_stats_desc *pdesc;
+	int i;
 
 	kvm_debugfs_dir = debugfs_create_dir("kvm", NULL);
 
-	kvm_debugfs_num_entries = 0;
-	for (p = debugfs_entries; p->name; ++p, kvm_debugfs_num_entries++) {
-		debugfs_create_file(p->name, KVM_DBGFS_GET_MODE(p),
-				    kvm_debugfs_dir, (void *)(long)p->offset,
-				    stat_fops[p->kind]);
+	for (i = 0; i < kvm_vm_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vm_stats_desc[i];
+		if (kvm_stats_debugfs_mode(pdesc) & 0222)
+			fops = &vm_stat_fops;
+		else
+			fops = &vm_stat_readonly_fops;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				kvm_debugfs_dir,
+				(void *)(long)pdesc->desc.offset, fops);
+	}
+
+	for (i = 0; i < kvm_vcpu_stats_header.num_desc; ++i) {
+		pdesc = &kvm_vcpu_stats_desc[i];
+		if (kvm_stats_debugfs_mode(pdesc) & 0222)
+			fops = &vcpu_stat_fops;
+		else
+			fops = &vcpu_stat_readonly_fops;
+		debugfs_create_file(pdesc->name, kvm_stats_debugfs_mode(pdesc),
+				kvm_debugfs_dir,
+				(void *)(long)pdesc->desc.offset, fops);
 	}
 }
 
-- 
2.32.0.288.g62a8d224e6-goog


^ permalink raw reply related	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU
  2021-06-18 22:27 ` [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU Jing Zhang
@ 2021-06-21 16:46   ` Paolo Bonzini
  2021-06-21 17:42     ` Jing Zhang
  0 siblings, 1 reply; 16+ messages in thread
From: Paolo Bonzini @ 2021-06-21 16:46 UTC (permalink / raw)
  To: Jing Zhang, KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390,
	Linuxkselftest, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On 19/06/21 00:27, Jing Zhang wrote:
> +	struct kvm_vcpu_stat stat;
>   	struct kvm_dirty_ring dirty_ring;
> +	char stats_id[KVM_STATS_NAME_SIZE];

I think stats_id needs to be part of the usercopy region too.

You can also use

offsetofend(struct kvm_vcpu, stats_id) - offsetof(struct kvm_vcpu, arch)

to compute the size.

Paolo


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-18 22:27 ` [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data Jing Zhang
@ 2021-06-21 16:54   ` Paolo Bonzini
  2021-06-21 17:46     ` Jing Zhang
  0 siblings, 1 reply; 16+ messages in thread
From: Paolo Bonzini @ 2021-06-21 16:54 UTC (permalink / raw)
  To: Jing Zhang, KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390,
	Linuxkselftest, Marc Zyngier, James Morse, Julien Thierry,
	Suzuki K Poulose, Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On 19/06/21 00:27, Jing Zhang wrote:
> +/**
> + * kvm_stats_read() - Common vm/vcpu stats read function to userspace.

Common function to read from the binary statistics file descriptor.

> + * @id: identification string of the stats
> + * @header: stats header for a vm or a vcpu
> + * @desc: start address of an array of stats descriptors for a vm or a vcpu
> + * @stats: start address of stats data block for a vm or a vcpu
> + * @size_stats: the size of stats data block pointed by @stats
> + * @user_buffer: start address of userspace buffer
> + * @size: requested read size from userspace
> + * @offset: the start position from which the content will be read for the
> + *          corresponding vm or vcp file descriptor
> + *
> + * The file content of a vm/vcpu file descriptor is now defined as below:
> + * +-------------+
> + * |   Header    |
> + * +-------------+
> + * |  id string  |
> + * +-------------+
> + * | Descriptors |
> + * +-------------+
> + * | Stats Data  |
> + * +-------------+
> + * Although this function allows userspace to read any amount of data (as long
> + * as in the limit) from any position, the typical usage would follow below
> + * steps:
> + * 1. Read header from offset 0. Get the offset of descriptors and stats data
> + *    and some other necessary information. This is a one-time work for the
> + *    lifecycle of the corresponding vm/vcpu stats fd.
> + * 2. Read id string from its offset. This is a one-time work for the lifecycle
> + *    of the corresponding vm/vcpu stats fd.
> + * 3. Read descriptors from its offset and discover all the stats by parsing
> + *    descriptors. This is a one-time work for the lifecycle of the
> + *    corresponding vm/vcpu stats fd.
> + * 4. Periodically read stats data from its offset using pread.
> + *
> + * Return: the number of bytes that has been successfully read
> + */
> +ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> +		       const struct _kvm_stats_desc *desc,
> +		       void *stats, size_t size_stats,
> +		       char __user *user_buffer, size_t size, loff_t *offset)


You can replace the header argument with just the number of descriptors, 
and then construct the header in the "if" statement below that copies it 
to userspace:

const struct kvm_stats_header kvm_vm_stats_header = {
	.name_size = KVM_STATS_NAME_SIZE,
	.num_desc = num_desc,
	.id_offset = size_header,
	.desc_offset = size_header + KVM_STATS_NAME_SIZE,
	.data_offset = size_header + KVM_STATS_NAME_SIZE +
		       size_desc,
};

Of course size_header can be assigned with sizeof (struct kvm_stats_header).

This removes the definition of the header in each architecture.

Paolo

> +{
> +	ssize_t len;
> +	ssize_t copylen;
> +	ssize_t remain = size;
> +	size_t size_desc;
> +	size_t size_header;
> +	void *src;
> +	loff_t pos = *offset;
> +	char __user *dest = user_buffer;
> +
> +	size_header = sizeof(*header);
> +	size_desc = header->num_desc * sizeof(*desc);
> +
> +	len = KVM_STATS_NAME_SIZE + size_header + size_desc + size_stats - pos;
> +	len = min(len, remain);
> +	if (len <= 0)
> +		return 0;
> +	remain = len;
> +
> +	/*
> +	 * Copy kvm stats header.
> +	 * The header is the first block of content userspace usually read out.
> +	 * The pos is 0 and the copylen and remain would be the size of header.
> +	 * The copy of the header would be skipped if offset is larger than the
> +	 * size of header. That usually happens when userspace reads stats
> +	 * descriptors and stats data.
> +	 */
> +	copylen = size_header - pos;
> +	copylen = min(copylen, remain);
> +	if (copylen > 0) {
> +		src = (void *)header + pos;
> +		if (copy_to_user(dest, src, copylen))
> +			return -EFAULT;
> +		remain -= copylen;
> +		pos += copylen;
> +		dest += copylen;
> +	}
> +
> +	/*
> +	 * Copy kvm stats header id string.
> +	 * The id string is unique for every vm/vcpu, which is stored in kvm
> +	 * and kvm_vcpu structure.
> +	 * The id string is part of the stat header from the perspective of
> +	 * userspace, it is usually read out together with previous constant
> +	 * header part and could be skipped for later descriptors and stats
> +	 * data readings.
> +	 */
> +	copylen = size_header + KVM_STATS_NAME_SIZE - pos;

Should use header->id_offset instead of size_header here and in the 
computation of src.

> +	copylen = min(copylen, remain);
> +	if (copylen > 0) {
> +		src = id + pos - size_header;
> +		if (copy_to_user(dest, src, copylen))
> +			return -EFAULT;
> +		remain -= copylen;
> +		pos += copylen;
> +		dest += copylen;
> +	}
> +
> +	/*
> +	 * Copy kvm stats descriptors.
> +	 * The descriptors copy would be skipped in the typical case that
> +	 * userspace periodically read stats data, since the pos would be
> +	 * greater than the end address of descriptors
> +	 * (header->header.desc_offset + size_desc) causing copylen <= 0.
> +	 */
> +	copylen = header->desc_offset + size_desc - pos;
> +	copylen = min(copylen, remain);
> +	if (copylen > 0) {
> +		src = (void *)desc + pos - header->desc_offset;
> +		if (copy_to_user(dest, src, copylen))
> +			return -EFAULT;
> +		remain -= copylen;
> +		pos += copylen;
> +		dest += copylen;
> +	}
> +
> +	/* Copy kvm stats values */
> +	copylen = header->data_offset + size_stats - pos;
> +	copylen = min(copylen, remain);
> +	if (copylen > 0) {
> +		src = stats + pos - header->data_offset;
> +		if (copy_to_user(dest, src, copylen))
> +			return -EFAULT;
> +		remain -= copylen;
> +		pos += copylen;
> +		dest += copylen;
> +	}
> +
> +	*offset = pos;
> +	return len;
> +}


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU
  2021-06-21 16:46   ` Paolo Bonzini
@ 2021-06-21 17:42     ` Jing Zhang
  0 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-21 17:42 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On Mon, Jun 21, 2021 at 11:46 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 19/06/21 00:27, Jing Zhang wrote:
> > +     struct kvm_vcpu_stat stat;
> >       struct kvm_dirty_ring dirty_ring;
> > +     char stats_id[KVM_STATS_NAME_SIZE];
>
> I think stats_id needs to be part of the usercopy region too.
>
> You can also use
>
> offsetofend(struct kvm_vcpu, stats_id) - offsetof(struct kvm_vcpu, arch)
>
> to compute the size.
Sure! Will do.
>
> Paolo
>

Thanks,
Jing

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-21 16:54   ` Paolo Bonzini
@ 2021-06-21 17:46     ` Jing Zhang
  2021-06-21 22:45       ` Paolo Bonzini
  0 siblings, 1 reply; 16+ messages in thread
From: Jing Zhang @ 2021-06-21 17:46 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On Mon, Jun 21, 2021 at 11:54 AM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 19/06/21 00:27, Jing Zhang wrote:
> > +/**
> > + * kvm_stats_read() - Common vm/vcpu stats read function to userspace.
>
> Common function to read from the binary statistics file descriptor.
>
> > + * @id: identification string of the stats
> > + * @header: stats header for a vm or a vcpu
> > + * @desc: start address of an array of stats descriptors for a vm or a vcpu
> > + * @stats: start address of stats data block for a vm or a vcpu
> > + * @size_stats: the size of stats data block pointed by @stats
> > + * @user_buffer: start address of userspace buffer
> > + * @size: requested read size from userspace
> > + * @offset: the start position from which the content will be read for the
> > + *          corresponding vm or vcp file descriptor
> > + *
> > + * The file content of a vm/vcpu file descriptor is now defined as below:
> > + * +-------------+
> > + * |   Header    |
> > + * +-------------+
> > + * |  id string  |
> > + * +-------------+
> > + * | Descriptors |
> > + * +-------------+
> > + * | Stats Data  |
> > + * +-------------+
> > + * Although this function allows userspace to read any amount of data (as long
> > + * as in the limit) from any position, the typical usage would follow below
> > + * steps:
> > + * 1. Read header from offset 0. Get the offset of descriptors and stats data
> > + *    and some other necessary information. This is a one-time work for the
> > + *    lifecycle of the corresponding vm/vcpu stats fd.
> > + * 2. Read id string from its offset. This is a one-time work for the lifecycle
> > + *    of the corresponding vm/vcpu stats fd.
> > + * 3. Read descriptors from its offset and discover all the stats by parsing
> > + *    descriptors. This is a one-time work for the lifecycle of the
> > + *    corresponding vm/vcpu stats fd.
> > + * 4. Periodically read stats data from its offset using pread.
> > + *
> > + * Return: the number of bytes that has been successfully read
> > + */
> > +ssize_t kvm_stats_read(char *id, const struct kvm_stats_header *header,
> > +                    const struct _kvm_stats_desc *desc,
> > +                    void *stats, size_t size_stats,
> > +                    char __user *user_buffer, size_t size, loff_t *offset)
>
>
> You can replace the header argument with just the number of descriptors,
> and then construct the header in the "if" statement below that copies it
> to userspace:
>
> const struct kvm_stats_header kvm_vm_stats_header = {
>         .name_size = KVM_STATS_NAME_SIZE,
>         .num_desc = num_desc,
The problem is how we calculate the number of descriptors, which needs the
size of the descriptor array for each architecture.
Define another global variable to export the size of descriptor array?
>         .id_offset = size_header,
>         .desc_offset = size_header + KVM_STATS_NAME_SIZE,
>         .data_offset = size_header + KVM_STATS_NAME_SIZE +
>                        size_desc,
> };
>
> Of course size_header can be assigned with sizeof (struct kvm_stats_header).
>
> This removes the definition of the header in each architecture.
>
> Paolo
>
> > +{
> > +     ssize_t len;
> > +     ssize_t copylen;
> > +     ssize_t remain = size;
> > +     size_t size_desc;
> > +     size_t size_header;
> > +     void *src;
> > +     loff_t pos = *offset;
> > +     char __user *dest = user_buffer;
> > +
> > +     size_header = sizeof(*header);
> > +     size_desc = header->num_desc * sizeof(*desc);
> > +
> > +     len = KVM_STATS_NAME_SIZE + size_header + size_desc + size_stats - pos;
> > +     len = min(len, remain);
> > +     if (len <= 0)
> > +             return 0;
> > +     remain = len;
> > +
> > +     /*
> > +      * Copy kvm stats header.
> > +      * The header is the first block of content userspace usually read out.
> > +      * The pos is 0 and the copylen and remain would be the size of header.
> > +      * The copy of the header would be skipped if offset is larger than the
> > +      * size of header. That usually happens when userspace reads stats
> > +      * descriptors and stats data.
> > +      */
> > +     copylen = size_header - pos;
> > +     copylen = min(copylen, remain);
> > +     if (copylen > 0) {
> > +             src = (void *)header + pos;
> > +             if (copy_to_user(dest, src, copylen))
> > +                     return -EFAULT;
> > +             remain -= copylen;
> > +             pos += copylen;
> > +             dest += copylen;
> > +     }
> > +
> > +     /*
> > +      * Copy kvm stats header id string.
> > +      * The id string is unique for every vm/vcpu, which is stored in kvm
> > +      * and kvm_vcpu structure.
> > +      * The id string is part of the stat header from the perspective of
> > +      * userspace, it is usually read out together with previous constant
> > +      * header part and could be skipped for later descriptors and stats
> > +      * data readings.
> > +      */
> > +     copylen = size_header + KVM_STATS_NAME_SIZE - pos;
>
> Should use header->id_offset instead of size_header here and in the
> computation of src.
>
> > +     copylen = min(copylen, remain);
> > +     if (copylen > 0) {
> > +             src = id + pos - size_header;
> > +             if (copy_to_user(dest, src, copylen))
> > +                     return -EFAULT;
> > +             remain -= copylen;
> > +             pos += copylen;
> > +             dest += copylen;
> > +     }
> > +
> > +     /*
> > +      * Copy kvm stats descriptors.
> > +      * The descriptors copy would be skipped in the typical case that
> > +      * userspace periodically read stats data, since the pos would be
> > +      * greater than the end address of descriptors
> > +      * (header->header.desc_offset + size_desc) causing copylen <= 0.
> > +      */
> > +     copylen = header->desc_offset + size_desc - pos;
> > +     copylen = min(copylen, remain);
> > +     if (copylen > 0) {
> > +             src = (void *)desc + pos - header->desc_offset;
> > +             if (copy_to_user(dest, src, copylen))
> > +                     return -EFAULT;
> > +             remain -= copylen;
> > +             pos += copylen;
> > +             dest += copylen;
> > +     }
> > +
> > +     /* Copy kvm stats values */
> > +     copylen = header->data_offset + size_stats - pos;
> > +     copylen = min(copylen, remain);
> > +     if (copylen > 0) {
> > +             src = stats + pos - header->data_offset;
> > +             if (copy_to_user(dest, src, copylen))
> > +                     return -EFAULT;
> > +             remain -= copylen;
> > +             pos += copylen;
> > +             dest += copylen;
> > +     }
> > +
> > +     *offset = pos;
> > +     return len;
> > +}
>
Thanks,
Jing

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-21 17:46     ` Jing Zhang
@ 2021-06-21 22:45       ` Paolo Bonzini
  2021-06-21 22:58         ` Jing Zhang
  0 siblings, 1 reply; 16+ messages in thread
From: Paolo Bonzini @ 2021-06-21 22:45 UTC (permalink / raw)
  To: Jing Zhang
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On 21/06/21 19:46, Jing Zhang wrote:
>> const struct kvm_stats_header kvm_vm_stats_header = {
>>          .name_size = KVM_STATS_NAME_SIZE,
>>          .num_desc = num_desc,
> The problem is how we calculate the number of descriptors, which needs the
> size of the descriptor array for each architecture.
> Define another global variable to export the size of descriptor array?

Pass it as an argument?

Paolo


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-21 22:45       ` Paolo Bonzini
@ 2021-06-21 22:58         ` Jing Zhang
  2021-06-21 23:35           ` Paolo Bonzini
  0 siblings, 1 reply; 16+ messages in thread
From: Jing Zhang @ 2021-06-21 22:58 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On Mon, Jun 21, 2021 at 5:45 PM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 21/06/21 19:46, Jing Zhang wrote:
> >> const struct kvm_stats_header kvm_vm_stats_header = {
> >>          .name_size = KVM_STATS_NAME_SIZE,
> >>          .num_desc = num_desc,
> > The problem is how we calculate the number of descriptors, which needs the
> > size of the descriptor array for each architecture.
> > Define another global variable to export the size of descriptor array?
>
> Pass it as an argument?
The num_desc can only be initialized in the same file that defines the
descriptor array.
Looks like we have to have a global variable to save that. The
solution would be similar
to have a statically defined header for each arch.
So, keep the header structure for each arch?
>
> Paolo
>

^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-21 22:58         ` Jing Zhang
@ 2021-06-21 23:35           ` Paolo Bonzini
  2021-06-21 23:38             ` Jing Zhang
  0 siblings, 1 reply; 16+ messages in thread
From: Paolo Bonzini @ 2021-06-21 23:35 UTC (permalink / raw)
  To: Jing Zhang
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On 22/06/21 00:58, Jing Zhang wrote:
>> Pass it as an argument?
> The num_desc can only be initialized in the same file that defines the
> descriptor array.
> Looks like we have to have a global variable to save that. The
> solution would be similar
> to have a statically defined header for each arch.
> So, keep the header structure for each arch?

Oh, sorry.  I missed that there's only one call to kvm_stats_read and 
it's in common code.  The remaining comments are small enough that I can 
apply them myself.  Thanks!

Paolo


^ permalink raw reply	[flat|nested] 16+ messages in thread

* Re: [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data
  2021-06-21 23:35           ` Paolo Bonzini
@ 2021-06-21 23:38             ` Jing Zhang
  0 siblings, 0 replies; 16+ messages in thread
From: Jing Zhang @ 2021-06-21 23:38 UTC (permalink / raw)
  To: Paolo Bonzini
  Cc: KVM, KVMARM, LinuxMIPS, KVMPPC, LinuxS390, Linuxkselftest,
	Marc Zyngier, James Morse, Julien Thierry, Suzuki K Poulose,
	Will Deacon, Huacai Chen, Aleksandar Markovic,
	Thomas Bogendoerfer, Paul Mackerras, Christian Borntraeger,
	Janosch Frank, David Hildenbrand, Cornelia Huck,
	Claudio Imbrenda, Sean Christopherson, Vitaly Kuznetsov,
	Jim Mattson, Peter Shier, Oliver Upton, David Rientjes,
	Emanuele Giuseppe Esposito, David Matlack, Ricardo Koller,
	Krish Sadhukhan, Fuad Tabba, Greg KH

On Mon, Jun 21, 2021 at 6:35 PM Paolo Bonzini <pbonzini@redhat.com> wrote:
>
> On 22/06/21 00:58, Jing Zhang wrote:
> >> Pass it as an argument?
> > The num_desc can only be initialized in the same file that defines the
> > descriptor array.
> > Looks like we have to have a global variable to save that. The
> > solution would be similar
> > to have a statically defined header for each arch.
> > So, keep the header structure for each arch?
>
> Oh, sorry.  I missed that there's only one call to kvm_stats_read and
> it's in common code.  The remaining comments are small enough that I can
> apply them myself.  Thanks!
>
> Paolo
>
Cool! Thanks, Paolo.

Jing

^ permalink raw reply	[flat|nested] 16+ messages in thread

end of thread, other threads:[~2021-06-21 23:39 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-06-18 22:27 [PATCH v12 0/7] KVM statistics data fd-based binary interface Jing Zhang
2021-06-18 22:27 ` [PATCH v12 1/7] KVM: stats: Separate generic stats from architecture specific ones Jing Zhang
2021-06-18 22:27 ` [PATCH v12 2/7] KVM: stats: Add fd-based API to read binary stats data Jing Zhang
2021-06-21 16:54   ` Paolo Bonzini
2021-06-21 17:46     ` Jing Zhang
2021-06-21 22:45       ` Paolo Bonzini
2021-06-21 22:58         ` Jing Zhang
2021-06-21 23:35           ` Paolo Bonzini
2021-06-21 23:38             ` Jing Zhang
2021-06-18 22:27 ` [PATCH v12 3/7] KVM: stats: Support binary stats retrieval for a VM Jing Zhang
2021-06-18 22:27 ` [PATCH v12 4/7] KVM: stats: Support binary stats retrieval for a VCPU Jing Zhang
2021-06-21 16:46   ` Paolo Bonzini
2021-06-21 17:42     ` Jing Zhang
2021-06-18 22:27 ` [PATCH v12 5/7] KVM: stats: Add documentation for binary statistics interface Jing Zhang
2021-06-18 22:27 ` [PATCH v12 6/7] KVM: selftests: Add selftest for KVM statistics data binary interface Jing Zhang
2021-06-18 22:27 ` [PATCH v12 7/7] KVM: stats: Remove code duplication for binary and debugfs stats Jing Zhang

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